Chemical engineering education ( Journal Site )

Material Information

Chemical engineering education
Alternate Title:
Abbreviated Title:
Chem. eng. educ.
Physical Description:
v. : ill. ; 22-28 cm.
American Society for Engineering Education -- Chemical Engineering Division
Chemical Engineering Division, American Society for Engineering Education
Place of Publication:
Storrs, Conn
Publication Date:
annual[ former 1960-1961]


Subjects / Keywords:
Chemical engineering -- Study and teaching -- Periodicals   ( lcsh )
serial   ( sobekcm )
periodical   ( marcgt )


Chemical abstracts
Additional Physical Form:
Also issued online.
Dates or Sequential Designation:
1960-June 1964 ; v. 1, no. 1 (Oct. 1965)-
Numbering Peculiarities:
Publication suspended briefly: issue designated v. 1, no. 4 (June 1966) published Nov. 1967.
General Note:
Title from cover.
General Note:
Place of publication varies: Rochester, N.Y., 1965-1967; Gainesville, Fla., 1968-

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
oclc - 01151209
lccn - 70013732
issn - 0009-2479
lcc - TP165 .C18
ddc - 660/.2/071
System ID:

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Chemical Engineering Education
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Chemical Engineering Education

Volume 32 Number 1 Winter 1998

2 Arvind Varma, of Notre Dame, Anne Kolaczyk

8 Wayne State University

14 Chemical Engineering and the Other Humanities, J.M. Prausnitz
52 An Introductory ChE Course for First-Year Students,
Kenneth A. Solen, John N. Harb
58 Freshman Design Projects in the Environmental Health and Safety Department,
Ronald J. Willey, John M. Price
62 Innovative Ways of Teaching Polymerization Reactor Engineering: Exchanging
Information Between the University and Industry,
Jodo B.P. Soares, Alexander Penlidis, Archie E. Hamielec
84 Just a Communications Course? Or Training for Life after the University,
Guido Bendrich

20 COMET: An Open-Ended, Hands-On Project for ChE Sophomores,
Mark R. Prausnitz
24 Animal Guts as Ideal Reactors: An Open-Ended Project for a Course in Kinetics
and Reactor Design, Eric D. Carlson, Alice P. Gast
36 Helpful Hints for Effective Teaching, Robert H. Davis
68 Practical Hints for Gathering Information, Saidas M. Ranade
82 Combustion Synthesis and Materials Processing: Student Exercises,
Daniel E. Rosner

72 Advice from an Old-Timer, W. Dan Maclean

30 Toward Technical Understanding: Part 3. Advanced Levels, J.M. Haile

40 Experiments Illustrating Phase Partitioning and Transport of Environmental
Contaminants, Susan E. Powers, Stefan J. Grimberg
76 An Undergraduate Experiment on Adsorption, Shamsuzzaman Farooq

46 Ships Passing in the Night, Richard M. Felder

48 Make Summer Internship a Learning Experience, Gary S. Huvard

> 13 Letter to the Editor
> 13,29 Book Reviews

CHEMICAL ENGINEERING EDUCATION (ISSN 0009-2479) is published quarterly by the Chemical Engineering
Division, American Society for Engineering Education, and is edited at the University of Florida. Correspondence
regarding editorial matter, circulation, and changes of address should be sent to CEE, Chemical Engineering Department,
University of Florida, Gainesville, FL 32611-6005. Copyright 1998 by the Chemical Engineering Division, American
Society for Engineering Education. The statements and opinions expressed in this periodical are those of the writers and
not necessarily those of the ChE Division, ASEE, which body assumes no responsibility for them. Defective copies replaced
if notified within 120 days of publication. Write for information on subscription costs and for back copy costs and
availability. POSTMASTER: Send address changes to CEE, Chemical Engineering Department., University of Florida,
Gainesville, FL 32611-6005. Periodicals Postage Paid at Gainesville, Florida.

Winter 1998




of Notre Dame

University of Notre Dame Notre Dame, IN 46556
When Arvind Varma was awarded the University of Notre Dame's College of
Engineering Outstanding Teacher of the Year Award for 1990-91, his
students praised him as "an excellent teacher both in and out of the classroom,"
and said he showed a "great interest in his students" and was "willing to be a friend and a
mentor." They cited his extensive availability, saying it was "a rare and valuable opportunity
to work with a person with such great character and work ethic. He will be the professor whom
we will vividly remember twenty years from now, and his influence will be
matched by few in our lifetime."
The award and the citation that accompanied it were gratifying to Arvind, who
believes that the most important thing a teacher can be is a good model for the
students. "Whether you are in the classroom or doing research, you must always
do things the right way," he says. "A teacher should not just impart information,
but should also teach students how to think, how to live. You need to teach
critical analysis, so that they are able to ask questions, to make decisions on their
own. You can rely on people and other sources for information, but you should
be able to analyze on your own to make decisions." That ability to analyze is
what he hopes he has taught his students.
Carmo J. Pereira, a former student who is now a Principal Consult-
ant at DuPont Engineering, believes he learned that ability as Varma's
student. "When I first met Professor Varma, he had just arrived at
Notre Dame after two years in industry. I am a practicing reaction
engineer today in large part due to him. His love for reaction engineer-
ing, his great attention to detail, and his dedication to the profession

* Ann Kolaczyk is Publications Editor in the College of Engineering at the
University ofNotre Dame. This article was written with assistance from the
faculty of the Department of Chemical Engineering.
@ Copyright ChE Division ofASEE 1998

A Asa
in the late



4 As a
student in
the late 1960s,
4 As an
student in the

Chemical Engineering Education

[Arvind] says,

"A teacher should not just impart

information, but should also teach students how to

think, how to live. You need to teach critical analysis, so that

they are able to ask questions, to make decisions on their own.

are truly contagious! I have been greatly influenced by Pro-
fessor Varma's desire to excel, and I have attempted to
follow his example."
Another former student, Bala Subramaniam (now a chaired
professor of chemical and petroleum engineering at the Uni-
versity of Kansas in Lawrence) says, "Professor Varma's
research accomplishments are well known and recognized.
What is probably not as well known is that Professor Varma
is also a gifted teacher with exemplary dedication and excel-
lence in educating his students." He adds, "His lectures are
intellectually stimulating, characterized by careful prepara-
tion and energetic delivery. Professor Varma brought to his
class the latest research developments from his program as
well as others. This allows students to gain a better apprecia-
tion of creativity, which in turn inspires them to be creative.
He is very accessible to his students, and whenever interact-
ing with them either in or outside class, he creates an atmo-
sphere that promotes the students' desire to learn and to
excel. Personally, these experiences have helped shape my
teaching philosophy and methods to a great extent."
Arvind was born in Ferozabad, U.P., India, the fourth of
seven children. He had always been a good student and, due
to double promotions, was only 15 years old when he gradu-
ated from high school in 1962. This made choosing a college
difficult because most of the schools in India had age restric-
tions and required incoming freshmen to be at least 17 or 18
years old. The Indian Institutes of Technology were just
starting then and were already prestigious, but they too had
age restrictions.
Arvind had done well in chemistry and mathematics in
high school and was looking at chemical engineering on the
advice of his father, who was a civil engineer working in
government service. When Arvind learned that Panjab Uni-
versity in Chandigarh (one of the schools without an age
restriction) had recently started a chemical engineering pro-
gram with American collaboration, he applied there and was
accepted. It was a unique situation in that the engineering
college affiliated with the school had the other engineering
disciplines on its own campus, but the new chemical engi-
neering department was autonomous and was housed on the
main university campus.
The chairman of the department was Professor B. Ghosh.
He was young, outstanding, and bright. Recently returned
Winter 1998

from Carnegie Tech (now Carnegie-Mellon), he was a
thoughtful teacher, and through him, Arvind was exposed to
a more American style of teaching. Professor Ghosh's classes
were more open and discussion-based, and he didn't insist
on such a strict student/teacher division. It was at this time
that teaching as a profession began to appeal to Arvind.
"The idea of standing up in front of class, explaining
things, talking about what you knew, was very appealing to
me," Arvind says. "I decided during my freshman year to be
a college teacher."
When he finished his undergraduate work, Arvind was
still only 19 years old and was anxious to come to North
America for his graduate work. His parents weren't too keen
on his leaving the country, but he was ready for new chal-
lenges. He applied to a few places in Canada and eventually
chose the University of New Brunswick, where he would
have the chance to work with Frank Steward in combustion
of solid fuels.
At the University of New Brunswick he was exposed to
even more of the Western style of teaching, further convinc-
ing him that he wanted to be an educator. But in his second
year of graduate school, Frank Steward took a UNESCO
appointment, and Arvind decided to change schools to pur-
sue his doctorate. The University of Minnesota was rated
very highly then, as it is now, and he was accepted and
awarded an assistantship there.
During the late 1960s and 1970s, the University of Minne-
sota was an exciting place to be. A great deal of research was
being done in the area of analysis of chemical engineering
systems, particularly mathematical analysis. This effort was
led by Professor Neal Amundson, who was department head
and also Arvind's thesis advisor. Amundson had gathered
together a top-notch faculty, many of whom had degrees in
the sciences or math rather than in chemical engineering. At
this same time, the Mining and Metallurgical Engineering
Department was closing down and materials science was
brought into chemical engineering. This mixture produced
an emphasis on the fundamental scientific aspects of chemi-
cal engineering-the engineering science approach-in which
there is an application of surface chemistry, biology, math-
ematics, and physics to chemical engineering problems. This
mixture of disciplines is more common now, especially in
research groups, but it was very unusual at that time.

At the University of Minnesota, Arvind was influenced
greatly by both Professor Neal Amundson and Professor
Rutherford Aris. Besides being an innovative leader,
Amundson was a brilliant teacher and researcher. He taught
a two-hour course on math-
ematical methods in chemical
engineering twice a week and
did all his complex computa-
tions on the chalkboard without
any notes. Aris was a great
scholar and writer, very fluent
with words and widely pub-
lished. He was a soft-spoken,
kind gentleman. Where
Amundson was Arvind's model
of an innovator and teacher, Aris
was his model of a scholar.
In 1971, Arvind married his
wife Karen, then a senior ma-
joring in biology at the Univer- Arvind with two people
sity of Minnesota. A few days development-Neal A
after getting married, they spent Aris-at Aris' retire
six weeks in India, meeting his
family and seeing the country. Arvind received his PhD in
1972. His thesis on "Analysis of Tubular Reactor Multiple
Steady States and Their Stability" generated a number of
articles. After he was awarded his doctorate, Arvind stayed
on at the University of Minnesota as a temporary assis-
tant professor for one year, doing limited teaching while
working on research. During this period he got to know
Professors Amundson and Aris even better, as well as a
number of other faculty members.
Arvind firmly believed that to be a good teacher, one
needed industrial experience (as Amundson and Aris had),
so when he was ready to leave the University of Minnesota
he interviewed both in academia and in industry. After con-
sidering offers from a number of sources, he went to work as
a senior research engineer for Linde Research of Union
Carbide in Tarrytown, New York, where he did research in
gas separations.
The research at Union Carbide was very different from
that which Arvind had done for this thesis, but that was part
of its appeal since it meant his experience would become
even broader. He was hired as a part of the Process Research
Group, a newly formed unit that was looking into novel
methods of gas separation processes. Some of the projects
that he worked on in their initial conceptual stages were a
new process for breathing oxygen on aircraft, a new type of
cryogenic insulation using thin evacuated glass microspheres,
a zeolite slurry-based continuous gas separation process, and
a parametric pumping system for an air separation process
for producing oxygen for medical purposes. A number of
these projects subsequently became commercial successes.


During this period, Karen and Arvind also became proud
parents of their first child, Anita, born in 1974. Karen had
worked as a laboratory assistant in microbiology since her
graduation two years earlier, but now gave up her career to
become a full-time mother.
In 1975, after two years at
Union Carbide, Arvind received
an offer from the University of
Notre Dame. The chemical en-
gineering department there was
well known due to the work in
catalytic reaction engineering
done by James Carberry and
Ernest Thiele (who was no
longer at Notre Dame but who
had added greatly to the stature
of the department) as well as
the work in thermodynamics and
phase equilibria being done by
o shaped his academic James Kohn and Kraemer Luks.
idson and Rutherford Also, the department's chair-
atfestivities in 1996 man, Julius Banchero, was a
well-known educator who was
supportive of young faculty. Arvind decided to make the
change to academia and was further convinced that the deci-
sion was a good one when Roger Schmitz came from the
University of Illinois in 1979 to take over as department
chair upon Banchero's retirement. Arvind quickly progressed
through the ranks, becoming a full professor in 1980, the
same year that his younger daughter, Sophia, was born.
In 1982, Arvind became department chair himself when
Roger Schmitz went on to become engineering dean. Al-
though Arvind was young for the position, he had definite
ideas he was eager to implement and, under his leader-
ship, the department grew. During his tenure, Mark
McCready (the current department chair), David Leighton,
and Hsueh-Chia Chang (who served as chair after Arvind)
all joined the faculty.
When he was chair, Arvind chose to teach the "Introduc-
tion to Chemical Engineering" course himself because he
thought it was important for the chair to be visible to the new
students in the department. He also brought team teaching to
the undergraduate labs, with part of the faculty teaching the
fall semester lab for seniors and another part teaching the
spring lab for juniors. This had the dual effect of making it
more interesting for the faculty to teach and encouraging
camaraderie as they worked together. It was also good for
students to have contact with a number of faculty members.
The senior design course is also team taught, so every mem-
ber of the faculty instructs in one of these three courses
every year. All three courses have written and oral reports
due at the end of the semester. By implementing his ideas,
Arvind helped to create an atmosphere of high standards for
Chemical Engineering Education

teaching and research.
Mark McCready, chair of the department, notes another
aspect of Arvind's leadership. "While Arvind is well known
for his mentoring of graduate students and his efforts to
enhance these activities campus wide, he has also mentored
a number of current faculty at Notre Dame. He provided a
great deal of guidance to me during my first few years here.
He helped with proposal and paper writing, encouraged my
participation in departmental committees, and made sure
that my views were heard. His efforts greatly enhanced my
development as a junior faculty member."
In order to devote full time to teaching and research,
Arvind decided to leave the department chair position in
1988. Within a few months of this decision, he was named
the first occupant of the Arthur J. Schmitt endowed chair
professorship, a position he still holds.
All of Arvind's research involves undergraduate, gradu-
ate, and post-doctoral students, true to his vision of an edu-
cator. When he was awarded the 1997 Burs Graduate School
Award from the University of Notre Dame this past May, the
citation noted, in part, that he is "a quintessential professor
who excels in all phases of academic life and for whom there
is no boundary between teaching and research."
In his twenty-three years at Notre Dame, twenty-seven
students have completed their doctoral dissertations under
his direction, and several more are currently in progress.
Every dissertation has resulted in coauthored publications in
leading journals and typically in one or more paper presenta-
tions at technical meetings. One of his students, Jean-Pascal
Lebrat received the 1993 Graduate School Award in Engi-
neering in recognition of the quality of his dissertation re-
search. Furthermore, largely through Arvind's efforts in coun-
seling and mentoring, his former students have been very
successful professionally in both industry and academia. Of
his former PhD and post-doctoral students, eighteen are in
academic positions at institutions around the world.
"As a mentor, Professor Varma led and taught by ex-
ample. His enthusiasm for his research program was infec-
tious and evident during the weekly research group meet-
ings," Bala Subramaniam says.
Arvind's early research involved various topics in chemi-
cal and catalytic reaction engineering, including diffusion-
reaction in catalyst pellets, reactor modeling and optimiza-
tion, gas-liquid reactors, and three-way catalysis for auto-
motive exhausts. Beginning in the early 1980s, his focus was
mainly in two areas. One area was the optimal distribution of
catalyst in pellets, in which the problem addressed is "How
should a fixed amount of catalyst be distributed in a pellet to
optimize some specified performance index?" This problem
is common to all reactions that use supported catalysts. In
systematic and innovative theoretical and experimental work,
Arvind and his students have shown that the optimal distri-
Winter 1998

bution is a Dirac-delta function, i.e., the catalyst should be
deposited at a specific radial position within the pellet. He
has also developed experimental methods for preparing such
catalysts. This work has direct implications for rational cata-
lyst design and manufacture.
The other area of Arvind's research during this period was
parametric sensitivity and runaway in chemical reactors. In
certain regions of operating conditions, chemical reactors
exhibit parametric sensitivity whereby small changes in in-
put parameters lead to large changes in output variables.
This behavior is common to all exothermic reaction sys-
tems. Determining these regions is of substantial interest
because such behavior leads to deleterious reactor perfor-
mance. By original and penetrating analysis, confirmed by
experiments, Arvind and his research group have provided
rigorous and easily applicable criteria for identifying the
regions of parametric sensitivity and runaway for a variety
of reacting systems.
For the last six to eight years, Arvind's research has been
in the area of materials, specifically the combustion synthe-
sis of materials. This is a large research program for mecha-
nistic studies of combustion synthesis: What is the mecha-
nism by which advanced materials such as ceramics, inter-
metallics, and composites are synthesized by the novel tech-
nique called combustion synthesis? How does the reaction
occur? How is the product material formed? How can the
microstructure of the material be controlled as it is being
synthesized? Because the microstructure affects the proper-
ties of the material, by understanding the mechanism of the
reaction and how the microstructure is formed, Arvind hopes
to gain an understanding of the control over what the proper-
ties of the material are going to be. His funding for this
research is from NSF and NASA.
In the NASA program, Arvind is looking at effects of
gravity on combustion synthesis of materials. Both the NSF
and NASA programs have produced some unique results
and new research techniques. One such technique, produc-
ing promising results, is the high-speed microvideo record-
ing of the combustion wave front.
"We are able to expand the wave front through magnifica-
tion, using a long focus microscope attached to a high-speed
video camera," Arvind says. "We can increase the spatial
resolution up to 800 times and can record up to 10,000
frames per second."
Arvind and his students can watch just how the reaction is
occurring and can see many of the details of combustion
wave propagation, leading to a better understanding of how
the wave front propagates in heterogeneous reaction mix-
tures that are used for synthesizing advanced materials. They
have the only facility in the world for doing this and are at
the forefront of developing new techniques for understand-
ing how such reactions occur. Using this novel technique,
Arvind and his research group have identified new modes of

propagation that have never been witnessed before-they
call it a scintillating reaction wave. In recent work, they have
shown that in many instances, the reaction initiates ahead of
the wave front and sparks appear. They are the first precur-
sor of the main reaction that occurs a few milliseconds later.
Another direction of Arvind's current research is inor-
ganic membranes. With funding from the National Science
Foundation and from industry (primarily Union Carbide), he
is studying various types of inorganic membranes-both
metal composite membranes in which a thin (a few microns
thick), dense, metal film is deposited on a porous support, as
well as ceramic membranes with controlled pore size and
catalytic activity distributions. He and his students have
developed some novel techniques, such as the use of osmosis
in conjunction with electroless plating. Using this idea, they
have synthesized high-flux thin metal composite membranes
for both high temperature reaction and separation processes.
In his current research, Arvind is applying the principles
of chemical engineering and novel experimental techniques.
His approach of combining theory and experiments, and of
determining the influence of processing variables on the
resulting microstructure and the reaction mechanism and
extent, is having a strong impact on the materials synthesis
field. He is frequently the only, or one of only a few, chemi-
cal engineers invited to speak at conferences related to the
reaction synthesis of advanced materials. Examples include
the TMS Annual Meeting in 1991 and all four International
Symposia on Self-Propagating High Temperature Synthesis
held in the former USSR (1991), Honolulu (1993), China
(1995), and Spain (1997). His plenary lecture on the "Com-
bustion Synthesis of Advanced Materials" at the 1992 Inter-
national Symposium of Chemical Reaction Engineering has
received considerable acclaim and attention as a landmark
summary of research in this area. His forthcoming mono-
graph will update this work and has been praised already as
"the seminal review on combustion synthesis."
Arvind has published extensively in collaboration with
Massimo Morbidelli, now a chaired professor at ETH in
Zurich, Switzerland. Massimo came to Notre Dame in 1979
on a fellowship from Italy. He stayed only six months, but
wrote four papers while he was here and made a lasting
impression on Arvind, who felt that he had great potential
and encouraged him to get his advanced degree.
His influence made a difference to Morbidelli. "I decided
to come back for my PhD," Massimo recalls, "But since I
was a researcher at Politecnico de Milano, I could not do it on
a full-time basis. It was Dr. Varma who arranged (with the
help of the department chairman at that time, Dr. Roger Schmitz)
a semi-non-resident PhD program for me at Notre Dame."
Since then, Massimo and Arvind have written some forty
articles and two books together, making their collaboration
one of the longer standing ones in academia. Their textbook

Mathematical Methods in Chemical Engineering (Oxford
University Press) was published earlier this year, and Para-
metric Sensitivity in Chemical Systems (Cambridge Univer-
sity Press), written jointly with research associate Hua Wu,
was completed this past August and will be published early
next year as part of the Cambridge Series in Chemical Engi-
neering, of which Arvind is the founding editor.
"I have continued my collaboration with Dr. Varma for
almost twenty years now," Massimo says, "And I find it
always more exciting, although we have now evolved in
different research areas. But even recently, when after long
hours together, one in front of the other at the same table,
reviewing our math book when we finished it, I felt the same
sense of accomplishment as when we finished our first paper
in 1979. I really felt I did something to my best, without
saving energies. This was in fact the program that Dr. Varma
stated many years ago when starting the 'book adventure.
He'd told me, '. and at the end we will sit together, read
each page of the book, and leave there each word only if we
like it.' And it has been done. This is really a great teaching
for how to proceed in science, and I have seen this teaching
penetrating all my students who later came to work for
longer or shorter periods of time with Dr. Varma from Italy:
Alberto Servida, Roberto Baratti, Giacomo Cao, Hua Wu,
Marco Apostolo, and others.
"Professor Varma has made significant contributions to
reaction engineering," Carmo Pereira says. "His work on
optimizing catalyst intraparticle profiles and on high tem-
perature synthesis is seminal, and he has received many
honors for his work, including AIChE's prestigious
Wilhelm Award."
Arvind has also found time to serve the University of
Notre Dame as well as many professional organizations. In
1992, he was awarded a Special Presidential Award by the
University for his "indefatigable energy in research, writing,
and all activities that engage his sharp mind and for serving
simultaneously on a large number of university, college, and
departmental committees." He was a member of the
University's Executive Committee of the Academic Council
for three years, served on the Academic and Faculty Affairs
Committee of the Board of Trustees for three years, and was
chairman of the Task Force on Research Systems, as well as
other committees. He is a founding director of the Catalysis
and Reaction Engineering Division of AIChE, serving a
three-year term; a current member of the AIChE Awards
Committee, serving a five-year term; and has organized and
chaired numerous technical sessions at national and interna-
tional conferences.
"Professor Varma's well-balanced contributions in teach-
ing, research, and service are truly remarkable and make him
the consummate professional and excellent role model that
he is," Bala Subramaniam says. "The fact that several of his
students have gone on to assume successful careers in aca-
Chemical Engineering Education

Arvind and Karen, along with his research group
and their terrier Frankie, at a recent
get-together at their home. >

A family photograph in traditional Indian dress on
the occasion of older daughter Anita's marriage to
Ken (also a chemical engineer) in May of 1997.
On the left is younger daughter Sophia,
currently a high school senior. V

demia and in major companies is a testament to his excellent
training and positive influence on his students."
Roger Schmitz, Keating-Crawford Professor of Chemical
Engineering at Notre Dame, has worked with Arvind for
eighteen years and says, "I find it difficult to identify Arvind's
strongest points because he excels in virtually every respect
in his professional and personal life. Few individuals can
match the combination of traits-dedication to academic
work, motivation to excel, adherence to high standards of
quality, selflessness in service to the university and the
profession, boundless energy and capacity for work-
that make him a valuable member of our faculty and of
our profession.
Massimo Morbidelli finds it hard to pick just one out-
standing attribute from the many things that he has learned
from Arvind. "The one that I am not sure I have learned, but
one that I certainly admire, is his honesty in science. By this
I mean not only of a moral but also of an intellectual nature.
In particular, stating and writing a concept only after he has
tried by all means to clarify and to penetrate it. I do not recall
a single time when he said, 'Well, it doesn't matter....' He
always wanted to go as deep as possible in all aspects of a
problem and in all details, which was not always easy for
grad students. Another aspect was his profound knowledge
of the literature and his capability of always giving appropri-
Winter 1998

ate credit to all other researchers."
"Above everything else, Professor Varma is an outstand-
ing individual who treats his students with courtesy and
fairness," Subramaniam adds. "Among the many memories
that I cherish from my graduate students days at Notre Dame
are the cookouts and get-togethers at his house. Professor
Varma and his wife, Karen, are extremely gracious hosts and
treated students to a variety of culinary dishes, including, of
course, spicy Indian food! The friendships and associations
forged there have been long-lasting. At the AIChE annual
meetings, Professor Varma makes it a point to organize a
dinner-outing with his former students. These outings have
become a pleasant forum for developing new friendships as
well as reminiscing about old times."
Arvind's commitment to his students extends beyond just
the schooling years. He has truly lived his belief of being a
model for them all.
In spite of the intense agenda of work and professional
activities to which he holds himself, Arvind has managed to
balance his time and interests between professional and fam-
ily obligations. He is quick to express pride in the accom-
plishments of Karen and his daughters, and he considers his
family to be the most important element in his life. Anita is a
1996 Notre Dame graduate in political science. She worked
for one year as a volunteer in the Americorps Vista project
and is currently a first-year law student in Washington, DC.
Earlier this year, she married Ken Motolenich, a Notre Dame
chemical engineering graduate with a master's degree in
environmental engineering from MIT. Their wedding in-
cluded both church and traditional Hindu ceremonies.
Sophia is currently a senior in high school, busy with
college applications, and has strong interests in drama
and musical theatre. Anticipating more free time in the
future, Karen has been preparing for the last several
years for a teacher's certificate in high school science
and expects to start her teaching career next fall. She is
also an accomplished opera singer. O

r department

Wayne State University

he Detroit metropolitan area is
one of the largest in the United
States. Businesses of every size
and kind, including the research and
production facilities-and world head-
quarters-for the "Big Three" U.S. au-
tomobile companies and many of the
high-tech companies that supply them,
are within a short drive of one another.
The excitement of these business and
research opportunities, combined with
the natural attractions of the Great Lake
State, bring nonstop traffic to the nearby
airport as people from around the na-
tion and around the world stream into
southeastern Michigan.
Amid this flurry of activity is Wayne
State University and its Department of
Chemical Engineering and Materials
Science. The department, chaired by
Esin Gulari, has 200 undergraduate stu-
dents, 120 graduate students, and 15
full-time faculty members. Students make full use o
research and employment possibilities presented by a
metropolitan setting and the facilities offered at a n
urban research university-all while learning in ,
and intimate departmental classes more reminiscent
private institution.
Wayne State University has the advantage of being i
middle of it all, literally and figuratively. Its location i
heart of metropolitan Detroit gives both faculty mer
and students the chance to explore great variety in the a
cultural and business communities. Metropolitan Detro
a worldwide reputation as a dominant manufacturing
and it is also gaining recognition as a center for techno
cal innovation. Through various co-op programs an
search collaborations between hundreds of these comp
and Wayne State, students have the freedom to incorp
on-the-job training into their overall education.

Wayne State's College of Engineering Building.

Most of Wayne State's 31,000 students commute to WSU
from the city and its suburbs, but thousands also come from
other states and countries. The campus has a richly diverse
faculty and student body, bringing different and unique per-
spectives to the classroom.
In addition, the metropolitan Detroit area has all of the
cultural attractions expected in an urban environment (most
within easy walking distance of the WSU campus) along
with the benefits of various recreational areas, many situated
on one of the state's 11,000 lakes. Sports are also prominent
in Michigan. Detroit's professional hockey, football, base-
ball, and basketball teams draw some of the nation's most
enthusiastic audiences.
Beyond its prime location, Wayne State University has
earned a reputation for its excellent educational, research,
and community-service programs. For example, Wayne State
is ranked as a Carnegie I Research University, placing it
among the top 88 universities nationwide to hold the presti-
gious designation. Conferred by the Carnegie Foundation

Copyright ChE Division ofASEE 1998
Chemical Engineering Education

Chemical Engineering Faculty Members: Left to right, Professors Putatunda,
Matthew, Kummler, Ng, Salley, Gulari, Kannan, Rothe, Mao, Shreve, Huang,
McMicking, and Manke.

for the Advancement of Teaching, this title is reserved for universities that meet
highly selective criteria for emphasizing research in addition to undergraduate and
graduate education.
Wayne State University is in the middle of it all, and the Department of Chemical
Engineering and Materials Science has taken its place as one of the university's
premier departments.
Students and faculty members alike find the Wayne State University Department of
Chemical Engineering and Materials Science to be an ideal size-small enough to
engender a sense of community, yet large enough to provide varied curricular and
research opportunities.
The sense of community is most clearly evident among the faculty members, who often
meet in groups to take casual lunches together, or who spend time in one another's offices
discussing progress in the lab or in the classroom. This atmosphere has also given rise to a
number of stimulating research collaborations among faculty members.
The department itself is a collaboration of sorts. In 1993, chemical engineering and
materials science, two separate but complementary disciplines, extended the good reper-
toire they had already developed and merged. Opportunities arose for cross-listed courses
and multidisciplinary laboratories.
For students, the dual-disciplined department also opens doors for them to have two or
more faculty mentors. In addition, students can learn from classmates and faculty mem-
bers in the other discipline and begin to see their field through others' eyes. Departmental
graduates find this kind of insight particularly useful in the workplace.
The curriculum in the department is wide in scope. The undergraduate program includes
courses that promote an understanding of physical, biological, and chemical operations
and processes. Graduate students can choose from a breadth of electives toward the MS
and PhD in chemical engineering, the MS and PhD in materials science and engineering,
Winter 1998

The department

... has 200



120 graduate

students, and

15 full-time

faculty members.

Students make

full use of the

research and



presented by a

large metropolitan

setting and the

facilities offered

at a major


all while

learning in

small and intimate



reminiscent of a

private institution.

and the MS in hazardous waste management. Specialized
training is also available, including graduate certificates
in polymer engineering, environmental auditing, and haz-
ardous waste control.
Outside of the classroom, students make use of modern
laboratory facilities throughout the Engineering Building,
computer workstations in the
Engineering Building and
around the campus, and a
complete university research
library. The newly opened un-
dergraduate library provides
ample study areas and ex-
tensive computer equipment
for student use.

Going well against the
grain, WSU's Department of
Chemical Engineering and
Materials Science brings to-
Professor Esin Gulari
gether the lower tuition rates Vi r Khn eri
of a public university, the
well-equipped laboratories of
a major research institution, and the small undergraduate
class sizes of a private college. This combination presents an
excellent environment for its students.
Class sizes are generally in the range of 20 to 25 students.
In this more intimate setting, students feel comfortable meet-
ing one-on-one with their professors and getting to know
their classmates. Students commonly create informal groups
to work out complex study problems or to prepare for tests,
both very effective learning tools.
Research is also a meaningful aspect of the undergraduate
educational experience within the department. Undergradu-
ate students can elect courses that involve research programs
or can take part in one of the many active projects of the
faculty members by accepting student research assistant-
ships. Either way, participating students can augment their
course work (and their resumes) both by working closely
with professors who are conducting related research and by
sharing a laboratory with highly trained graduate students
and with other like-minded undergraduate students.
While not a requirement, at least half of the undergraduate
students take part in the department's well-developed Coop-
erative Education Program. The unique relationship between
WSU and local industry helps to create the diverse opportu-
nities presented through the program. Participating students
alternate full-time study terms with full-time work assign-
ments in nearby companies. The location of the university
makes it easy for the students to commute from the work-
place to campus, and the department's accommodating course

g a

schedule has day and evening courses to meet the needs of
students in the program.
Another unique educational venture in the department is
the undergraduate seminar series that brings in scientists
from industry and academic institutions along with now-
working alumni. During each of the three semesters of semi-
nars the undergraduate students
are required to attend, each stu-
dent prepares a memo for the
department chair about his or
her educational progress and
thoughts about the overall de-
partmental program. The exer-
cise not only allows the stu-
dents to evaluate their goals,
but it also helps the chair to
prepare for the department's


Research tAssistant The graduate program at
t polymer phases. Wayne State's Department of
Chemical Engineering and Ma-
terials Science is actually two
programs: one designed for doctoral students pursuing full-
time thesis research and another for master's students pursu-
ing part-time course work.
The opportunity for graduate thesis research is abundant.
Students, who come to Wayne State from the United States
and all over the world, choose a research advisor from an
internationally recognized faculty of active scholars. Re-
search topics available are particularly diverse and span
many of the "hot" new areas of chemical engineering, in-
cluding supercritical processing, interfacial phenomena, ad-
vanced materials processing, and bioengineering.
Strong federal, industrial, and internal support has resulted
in the graduate facilities at Wayne State being second to
none. For example, the department possesses several state-
of-the-art instruments, including atomic force microscopes,
an integrated optical biosensor, a rheo-optical FTIR spec-
trometer, various shear and extensional flow rheometers,
and an excimer-laser-based imaging system. Additionally,
connections with other research institutes on campus and
with local industries provide access to unique chemical and
material characterization facilities. Competitive stipends typi-
cally support the students.
Another unique feature of the Wayne State graduate pro-
gram is the course-work master's degree program. Students,
who typically are working engineers from the local area, are
able to complete their degrees in a reasonable time due to
flexible course offerings and the university's convenient
location. The department designs many of the courses in
Chemical Engineering Education

collaboration with industry to ensure that the students are
best trained to deal with the contemporary issues of the
discipline. As evidence of the program's success, Wayne
State is currently the nation's number-one conveyor of
master's degrees in chemical engineering.

Three graduate certificate programs round out the
department's curriculum: polymer engineering, environmen-
tal auditing, and hazardous waste control.
The Graduate Certificate Program in Polymer Engineering
provides specialized education for working engineers and
scientists. The program includes core courses and electives
(such as composite materials, polymer theology, and poly-
A mer kinetics) that are developed with input from profes-
The signals in industry. Students can complete the program in
Under- as little as one year.
graduate Designed with working professionals in mind, the Hazard-
Library ous Waste Control and Environmental Auditing programs
on have a combination of core courses and more specialized
campus. electives. The Graduate Certificate Program in Hazardous
Waste Control teaches state-of-the-art methods for he man-
agement, control, and disposal of a broad range of hazardous
substances, wastes, and materials. Students also gain practi-
cal knowledge in meeting government guidelines for waste
A management. The Graduate Certificate Program in Environ-
Salley Yurgelivic and mental Auditing covers the management, assessment, and
Suzanne Dakin, Research auditing of facilities and property, hazard identification,
Assistants. exposure, analysis and risk characterization, regulatory
noncompliance analysis, sources of liability, and alterna-
tives for corrective action.

Professor Paul Van Research conducted in the WSU Department of Chemical
Tassel with Research Engineering and Materials Science falls into three expansive
areas; materials processing and synthesis; pollution preven-
tion and control; and bioengineering. Many of the
department's faculty members have interests that combine
more than one area (see Table 1, next page).
Dr. Joseph Smolinski The research of Esin Gulari and Charles Manke recently
and Research Assistant gained public attention when they received the highly re-
Zeynep Ergungor garded Henry Ford Technology Award. They became the
first non-Ford Motor Company employees to earn that
distinction. The award recognized their work in reducing
misting of metal-working fluids in Ford's manufacturing
plants. The two professors worked closely with all three
of the U.S. automotive companies, even using company
research laboratories and manufacturing plants to refine
and verify their results.
Both Howard Matthew and Guang-Zhao Mao hold Na-
tional Science Foundation Faculty Early Career Develop-
ment Program (CAREER) Awards. This prestigious award
recognizes faculty members who embody the excitement of
Winter 1998 11


Faculty: WSU's Department of
Chemical Engineering and Materials Science
(Additional information through the CHE and MSE option on
the web page at

John Benci (PhD, University of Pennsylvania, 1989)
Deformation and fracture of materials
High-temperature mechanical properties of alloys, intermetallic
compounds, and ceramics
Esin Gulari (PhD, California Institute of Technology, 1973)
Thermodynamics and transport properties of polymer solutions and
Processing of polymers with supercritical fluids
Light-scattering-based particle and drop-sizing techniques
Yinlun Huang (PhD, Kansas State Universtiy, 1992)
Pollution prevention and waste minimization
Process design and synthesis
Rangaramanujam Kannan (PhD, California Institute of Technology, 1994)
*Dynamics of polymeric systems and interfaces
Rheo-optical spectroscopy and scattering techniques
Ralph Kummler (PhD, Johns Hopkins University (1966)
Modeling of combined sewer overflows and sediments
Chemical kinetics
Computer simulations
Charles Manke (PhD, University of California-Berkeley, 1983)
Polymer processing and rheology
Molecular dynamics and kinetic theory of polymeric liquids
Guang-Zhao Mao (PhD, University of Minnesota, 1994)
Opto-electronic properties of thin films and crystals
Self-assembly of polymers and surfactants
Colloidal stability of waterborne paints
Real-time imaging of surface phenomena at the molecular level
Howard Matthew (PhD, Wayne State University, 1992)
Tissue engineering and biomaterials
Artificial organ substitutes
James McMicking (PhD, Ohio State University, 1961)
Correlation of thermodynamic data
Simon Ng (PhD, University of Michigan, 1985)
Heterogeneous catalysis
Polymer kinetics
Spectroscopic and thermal analysis of material surfaces
Susil Putatunda (PhD, Indian Institute of Technology, Bombay, 1983)
Effects of microstructure on fatigue
Fracture toughness
Creep in metals and alloys
Erhard Rothe (PhD, University of Michigan, 1959)
Applications of high-powered UV lasers
Machining of electronic chips
Diagnostics of internal combustion
Steven Salley (PhD, Detroit University, 1976)
Biochemical/medical engineering
Design of artificial organs
Immobilized enzyme reactors
Gina Shreve (PhD, University of Michigan 1991)
Environmental and biochemical applications
Microbially mediated biotransformations
Paul Van Tassel (PhD, University of Minnesota, 1993)
Shape-selective catalysis
Protein adsorption and bioseparations

research and learning.

Matthew's research involves tissue engineering and
biomaterials and is working toward developing tissue- and
organ-replacement systems. In one of his projects, he is
investigating the use of polymer composites to fabricate
small-diameter vascular grafts. The results are promising.
Mao is working on surface templates made of molecules
of mixed functional groups, She uses these molecular
templates to induce and control the growth of dye crystals
with tunable colors.

Among other things, Susil Putatunda is a cast iron
expert. His research centers on several areas, including the
development of high-carbon/high-silicon austempered steel,
the fatigue and fracture behavior of austempered ductile
cast iron, and the development of a fatigue-damage model
for polymer-based composites.

Another of the department's many active research groups,
led by Yinlun Huang, is studying intelligent process sys-
tems engineering and is developing a process synthesis
methodology based on artificial intelligence and fuzzy
logic. This work may lead to cost-effective, highly con-
trollable and environmentally benign process systems. In
addition, the research group hopes to meld optimal pro-
duction with pollution prevention in electroplating plants.

With its staff of full-time faculty members, the depart-
ment encompasses a diversity of research interests. While
the faculty members take cues from local industry, they
are very often much more than industry problem solvers;
they are research innovators. They develop the new tech-
nologies that entice industry to come to them.


Faculty members new to WSU's Department of Chemi-
cal Engineering and Materials Science are welcomed with
substantial start-up funding and institutional support.
They also find a firm advocate in the departmental
chair. Once on board, faculty members continue to
receive substantial internal support, including summer
and graduate student support.

The department's faculty team comprises fifteen full-
time members, each of whom holds a national reputation
in his or her specialty, and four adjunct professors who are
affiliated with the graduate program. The faculty members
have received many awards from prestigious engineering
organizations and other institutions in the profession.

The faculty of the Wayne State Department of Chemical
Engineering and Materials Science has many research
options and educational possibilities open to them and
their students. Being part of a major research university
located in the heart of a metropolitan area, they are able to
explore them all. O

Chemical Engineering Education

letter to the editor

Dear Editor:
In their recent article titled "An Experiment to Characterize a
Consolidating Packed Bed" (CEE, 31(3), p. 192, 1997), Gerrard,
Hackborn, and Glass misinterpret the Kozeny equation for low gas
flow through packed beds and consequently arrive at an incorrect
The Kozeny equation as written by these authors is
Ap= 5a2(1- e)2 hv /3 (1)
(Nomenclature and numbering of equations follow those of the
article criticized, with the addition that numbers assigned to cor-
rected equations have the letter "a" appended to them.) In this form
of the equation, the term a signifies the specific surface of the
particles in the packed bed, i.e., particle surface area/particle vol-
ume, and is independent of the bed consolidation (assuming rigid
particles). Therefore, in the authors' terminology,
a = ao (3a)
The specific surface of the packed bed, particle surface area/bed
volume, is given by the product a(l E). Unfortunately, the authors
incorrectly assume that a alone signifies the specific surface of the
bed, and hence they write
a =aoho /h (3)
which is incorrect for a as used in Eq. (1).
If instead of Eq. (3), one correctly substitutes Eq. (3a) and the
authors' Eq. (2),
(1- )h (2)

into Eq. (1), the result is
5 a2h(l- e)2lvh2
Ap h-(l-ojh43


Ap = kvh2 /(h- G)3

k= 5aoho(1- )2is

G=(l-eo)ho (7)
Rearranging Eq. (5a) gives

(hv/Ap) = k h-k G (8a)
Thus it is (h2 /Ap) and not (v/Ap) 3, that should be plotted
against h in order to linearize Eq. (5a). That approximate
linearlization was actually obtained by plotting (v/ Ap) /3 instead
of (h2/Ap)1 against h can be attributed to the fact that the
maximum decrease in h2/3 for the experiments performed was
only 1-(0.41/0.61)2/3 = 23%.
The authors should note that if they were to substitute their Eq.
a = 6(1- )/Dp (9)
into Eq. (1), the right-hand side of the latter equation would then
contain (1- e)4 in the numerator, which is clearly incorrect. The
error arises from the misinterpretation of a, which is not the packed
Winter 1998

bed specific surface given by Eq. (9), but the particle specific
surface given by
a = EnD/(nt/6)D3 = 6/Dp (9a)
(Alternately, if we define a as the authors have done, then the
(1- E)2 term in Eq. (1) would disappear.)
Professor Norman Epstein
Department of Chemical Engineering
The University of British Columbia

Dear Professor Epstein:
Thank you for pointing out the correction, which makes the fit
even better.
Professor Mark Gerrard

Book review

Batch Distillation
Simulation, Optimal Design and Control
by Urmila M. Diwekar
Published by Taylor & Francis, 1101 Vermont Ave., N.W., Suite 200,
Washington, DC 20005; 211 pages including index; $59.95 (1995)

Reviewed by
Phillip C. Wankat
Purdue University

Batch processes, and batch distillation in particular, are
understudied in universities. The typical undergraduate sepa-
rations textbook devotes a short chapter to batch distilla-
tion, and typical coverage in courses (CEER, 28, p 15,
1994) is from one to three class periods. The average gradu-
ate student does no additional study of batch distillation.
Yet, batch distillation is an increasingly important separa-
tion method in industry, and there is significant interest in
batch distillation research.
Batch Distillation, which is "primarily designed to serve
as a textbook for a graduate course," is very timely. The
companion software MultiBatchDS (education edition from
CACHE Corp.) was not available and is not reviewed here.
A review of the book and the software from a consultant's
viewpoint was recently published (Chem. Engr. Progr., p.
77, June 1997).
If the software is available, this would be a good text for a
graduate-level course. There are 38 homework problems in
the book, which is probably sufficient for the first time the
course is offered. With the exception that packed columns
are not covered, the coverage is broad and most topics of
interest are included.
Chapters 1 and 2 introduce batch distillation and analyze
binary systems. These two chapters are a good resource for
professors and undergraduate students, but some professo-
rial guidance will be needed. For example. Eq. (1.6) and
Continued on page 81.

p -- curriculum



University of California Berkeley, CA 94720

How is engineering related to other intellectual or
professional disciplines? What is the role of chemi-
cal engineering in a modern university, and how
does it fit into the spectrum of knowledge? And, finally,
what can possible answers to these questions tell us concern-
ing our educational philosophy and curriculum for training
the engineers of the future?
These are difficult multidimensional questions with many
aspects. I will discuss here only one aspect, one that is
essential but has not received much attention: the need to
remember that chemical engineering is not an isolated sub-
ject; that it is not limited to applied science, but rather is a
significant part of daily life, related to health, to human
relationships, to politics and sociology and law, to the way
we think and feel about ourselves as individuals and as
members of society, to our aspirations, our hopes, and our
fears. In other words, I want to emphasize the old but too-
often forgotten concept that chemical engineering is not
apart from, but indeed a part of, what (broadly speaking)
we call the humanities.
Toward introducing that concept, Figure 1 shows a fa-

John M. Prausnitz, Professor of Chemical Engi-
neering at the University of California, Berkeley,
has devoted most of his professional career to
phase equilibria as required for process design.
His undergraduate education was at Cornell Uni-
versity, and he received his PhD from Princeton,
which also gave him an honorary Doctor of Sci-
ence degree two years ago. Author or coauthor
of more than 500 technical publications, he is the
senior author of the widely used text Molecular
Thermodynamics of Fluid-Phase Equilibria.

* Adapted and abbreviated from a lecture delivered at Notre
Dame University, The University of Missouri-Columbia, and the
University of Michigan (1996-97).

mous painting by Titian. The painting, about 400 years old, is
in the Borghese Palace in Rome and is titled Sacred and
Profane Love. Early in this century, a copy of the painting
was on the wall of the seminar room of the Institute for
Mathematics at the University of G6ttingen in Germany.
From the middle of the nineteenth century until 1933, when
the Nazis started to destroy the German universities, Gottingen
was the world's leading center of mathematics, attracting the
best minds of the day. In the seminar room, underneath the
painting, was not the original title but a new one, Pure and
Applied Mathematics.
We do not know who retitled Titian's painting, but it was
not only for amusement. The institute at Gittingen was far
ahead of its time; not only was the mathematics done there
new, vigorous, and bold, but (what was, and too often is still,
unusual) the Institute also did outstanding work in both pure
and applied mathematics. It was far ahead of other mathemat-
ics departments and gave serious attention to numerical meth-
ods for solving difficult differential and integral equations.
The painting and its new title were intended to stimulate
discussion, starting with the obvious question: there are two
female figures-which one represents pure mathematics and
which one represents applied mathematics? The question can
be argued either way. The woman without clothes could be
identified with carnality, with the physical as opposed to the
spiritual side of life, and therefore represents applied science,
while the clothed, serious, brooding woman represents as-
cetic values, divorced from earthly concerns, and thereby
represents pure science. On the other hand, we could argue
that the absence of clothing and the upward ecstatic glance
toward heaven represents purity, while clothing (notice that
the clothes are coarse and drab) represents earthly values and
that the clothed woman's dour, downcast look represents the

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

... chemical engineering is not an isolated subject;.. .it is not limited to applied science, but rather
is a significant part of daily life, related to health, to human relationships, to politics and
sociology and law, to the way we think and feel about ourselves as individuals
and as members of society, to our aspirations, our hopes, and our fears.

applied sciences that
must deal with daily
Titian's painting
shows that there is a
unity in opposites, an
old idea in philoso-
phy: truth and ultimate
reality are revealed to
us in a variety of
faces. In today's
world, we talk about
unity in diversity, we
read books about the Figure 1. Sacred and Profane Lc
Sciences Institute of the Univ
increasingly similar Pure and Appl
roles of male and fe-
male, and we profess
the virtues of blending Eastern and Western cultures. Sacred
and Profane Love (or Pure and Applied Mathematics) illus-
trates the fuzziness, the growing disappearance of borders
between intellectual categories. It shows what is increas-
ingly recognized in universities today-that, while uni-
versity departments may be necessary for efficient ad-
ministration, intellectual concerns now overflow depart-
mental division. Intellectual concepts are increasingly
delocalized as the interests of faculty in one department
overlap those in another.
My claim, that chemical engineering is one of the humani-
ties, goes beyond the by-now clear evidence that contempo-
rary chemical engineering is increasingly related to a variety
of other physical and biological sciences. What is only slowly
becoming apparent is that chemical engineering is also closely
related to the social and humanistic "sciences," where "sci-
ences" is now in the original sense of "scientia"-that is, not
necessarily natural science, but more generally, knowledge
in all of its varieties. This close relationship follows from
both practical and intellectual trends in contemporary soci-
ety, as I shall now try to explain.
The practical trend is so fundamental that we are tempted
to forget it: chemical engineers exist because society wants
chemical products that will satisfy human needs. Chemical
engineering is driven by society's wish for a better life,
where better is not only materialistic, but also deeply hu-
man-as for example, in medicine and pharmacy for health,
in cosmetics for beauty, and in agricultural chemicals for
feeding a hungry world.


I can best illustrate
the practical and also
deeply human basis
of chemical engi-
neering by recalling
a revealing anecdote
from a late col-
league, Professor
Irving Fatt, in
Berkeley's optom-
etry department. He
asked his class,
"Who is respon-
by Titian. In the Mathematical sible for the multi-
y of GBttingen it was retitled million dollar con-
Mathematics. tact lens industry?"
As usual, initially
there was silence, followed by some students shyly men-
tioning names of prominent polymer scientists. "Wrong,"
replied Fatt, "The father-more correctly, the mother-
of the contact lens industry was a poet, Dorothy Parker,
author of the immortal lines, 'Men seldom make
passes...At girls who wear glasses."'
Chemical engineers are driven into ever-new areas by the
needs, often deeply humane needs, of a society that wants to
improve its quality of life. Chemical engineers work not
only to make girls more attractive, but also, for example, to
make acid-free paper for preserving literary and historic
documents, to make new drug-delivery systems for chronic
illnesses such as diabetes, to make special paints and glues
for restoring old paintings and archeological artifacts, to
make new wound dressings for severe burns, to make
water-absorbing gels for diapers and for providing mois-
ture to the roots of desert trees that yield not only fruit
for food, but also shade from the brutal sun. If the goal of
chemical engineers is to satisfy human needs, chemical
engineers must have some understanding of human na-
ture, of psychology and international relations, of social
organizations, and of the clash of cultures.
Chemical engineers do not live or work in a vacuum. They
must understand labor laws, health insurance, safety, pollu-
tion abatement, and local customs and cultural values-in
other words, the concerns of social scientists from econom-
ics to sociology. But beyond that, a successful chemical
engineer must also understand how his product can either
satisfy or offend his constituency; he must have some un-

Winter 1998

derstanding of the ever-so-complex human
soul, and that inevitably leads him to his-
tory, to psychology and to art-in short, to
the humanities.
Both practical and intellectual trends in con-
temporary society make chemical engineer-
ing one of the humanities. The intellectual
trend is not as evident as is the practical one,
but it is clear to anyone who is familiar with
what literature, art, and philosophy have em-
phasized for at least two generations: the dis-
solution of boundaries, the inter-relatedness
of objects, phenomena, and observers. Noth-
ing stands alone. Any one thing is without
end, related to many other things. Literary
critics tell us that to understand a text, we
must probe not only into the author's history
and his state of mind when he wrote his text,
not only must we consider the customs and
prevailing values that existed when the text
was written, but we must also probe into the
reader's history and his values and his state
of mind when he reads the text. Thus, every
interpretation depends on numerous factors,
including the color of the book cover and the
type of paper used by the printer. In the limit,
this critique leads to the infamous movement
"Deconstruction" where ultimately nothing
objective remains. The only remaining ulti-
mate reality is inter-relations.
The dissolution of boundaries is strikingly
evident in art. Figure 2 shows Escher's Night
and Day. Notice how the white birds flying
to the right change, not abruptly but continu-
ously, to black birds flying to the left.
The dissolution of boundaries extends not
only in space, but also in time. Figure 3 shows
a famous painting by Marcel Duchamp titled
Nude DescendingStairs (An unsympathetic
critic called this painting "Explosion in a Tile
Factory.") We cannot localize the young
woman; her fuzziness is not only spatial, but
also temporal; she is simultaneously at the
top of the stairs and at the bottom.
A related idea is indicated in a remarkably
simple modern sculpture by my former gradu-
ate student, Dr. Bryan Rogers, who is now
chair of the Art Department at Carnegie
Mellon University. Bryan is probably the only
person in the world who has a joint PhD in
chemical engineering and in art. Figure 4
shows a set of clocks as found in any interna-
tional airport. But the usual designations, e.g.,

Figure 2.
Night and Day,
by Escher

Figure 3.
Descending Slairs,
by Duchamp

Figure 4.
by Rogers



Chemical Engineering Education

New York, London, Tokyo, Moscow,
etc., have all been replaced by Berke-
ley. We see here the idea of inter-relat- [We ml
edness. No place is isolated; what hap- studei
pens anywhere in the world, happens technology
also in Berkeley. human n
Twenthieth-century philosophers like person
Heidegger, and especially his German dis- cole
ciple Georg Gadamer, and to some extent how appli
his American admirer Richard Rorty, have a response
emphasized the importance of context and aspiration
contingency. The significance and effec- often is
tiveness of any object lies not in itself, but conseque
in how it interacts with its environment, also a st
This fundamental idea has greatly influ- re
pure s
enced recent and current work in history, and how t
literature, economics-in just about every
social science and humanities department
women wa
in every major university. women w
drive the
In literature, history, anthropology, so- ro
ciology, law, business administration, etc., depart
emphasis is increasingly placed on inter-
relationships, on how one subject is re-
lated to another-in other words, on con- Like every
text. Historians of art are not only looking scholarly
at what artists were doing at the time when engine
a particular painting was created; they are philologist,
also looking at the social relations that economists
artists had with each other and their pa- or theol
trons, at the political climate of the time, strive tow
at the literature of the day, at religious underst
practices and conventions, and at the ourselves c
mechanisms artists used to publicize and more n
market their work. Researchers in busi-
ness administration are no longer prima-
rily concerned with the internals of a cor-
poration, but instead, with how the corporation relates to the
community, with health and safety matters, with how corpo-
rations interact with other corporations, with government,
and with social groups representing a variety of religions
and ethnic traditions. Mathematical economists are inter-
ested not only in cash flow, taxes, and interest rates, but also
in so-called externalities, including psychological factors,
tastes, fads, fashions, perceptions, and the persistence and
decay of myths and folklore.
No objects or subjects exist by themselves, but always in
relation to other objects or subjects. Chemical engineering,
by itself, has no value. The value and legitimacy of chemical
engineering arise only when it stands in relation to some-
thing else, toward satisfying some human need, toward
answering a question of deep human concern. Chemical
engineering is an applied science in detail, but it is a
humanity in intent.
Winter 1998

nts I
is r
ed s
e to
s an
he c
nt c
s, ch
s, p1

For chemical engineering education, the
essential role of context should not be del-
show egated to courses in humanities. To be truly
low effective, they can easily be integrated into
elated to the present chemical engineering curricu-
s, both lum. It takes only a little time to show stu-
and dents how chemical sciences relate to the
re; world around us. Toward that end, the main
science is requirement is an open-minded attitude by
human instructors, a willingness to depart from that
d how it confined area where they are expert and feel
Totally secure and to devote a few minutes
just a
to related areas where they are not expert
uof but but where the relevance of their subject lies
lus to, and where they, as role models, can show
nce; humanity and openness to the world rather
concerns than the confinement of a narrow spe-
n and cialty. All too often the image that fac-
md need ulty present is such that only the instruc-
idemic tors' expertise is visible, while their di-
or all verse talents, interests, passions, and
its on weaknesses-in short, their humanity-
remains hidden. No wonder that so many
else at a students think of faculty as a species sepa-
on rate from the rest of humankind!
sor The regrettable bifurcating mind of many
emists or faculty was aptly described in a short story
ysicians by the Italian writer Ignazio Silone. In this
story, the wife of a professor talks about
ns, we him and gives the concise description,
a better "Oh, he knows everything. But that's all
!ing of he knows."
toward a
to d a When we present the principles of refrig-
e life. eration, we usually take a few minutes to
discuss the desirable properties of refriger-
ants, including freons. At that time, it is a
simple matter to talk briefly about how some freons attack
the ozone layer that protects the earth from excessive ultra-
violet radiation and to indicate the need for synthesizing
new compounds that can serve as environmentally ac-
ceptable refrigerants.
To illustrate the principles of heat transfer, we need not
confine attention to the time-worn double-pipe heat ex-
changer. Along with the usual equations for conduction,
convection, and radiation, we could also talk about solar
energy, cooling requirements for supercomputers, heat ef-
fects in reentry of space vehicles, cryosurgery, and such
home-related topics as microwave ovens, fire-resistant paja-
mas for infants, or design of an effective fireplace.
When we talk about flowing fluids, let's mention check
valves, rupture discs, human failures, and the tragedies at
Bhopal in India and Chernobyl in the Ukraine. When we
discuss condensers, let's mention fog at airports. When

we derive colligative properties of solutions, let's talk about
salt for removing snow on our streets and then about
subsequent corrosion of automobiles. When we discuss
evaporation, let's mention desalting of sea water and the
drought in Ethiopia.
When we encounter the free en-
ergy of formation of ammonia, let's
also say something about fertiliz-
ers, about starvation in Somalia,
and perhaps a few words about the
latest farm bill passed by Congress.
Further, let's recall for our students
that ammonia is used for making
nitric acid, that nitrates are used
for making explosives, and that if
Fritz Haber had not invented his
synthetic-ammonia process early
in this century, Germany would
have run out of ammunition in
1915 and would have been un-
able to continue World War I af-
ter the first year.
I mention these examples not
only to stress the relevance of
chemical engineering, but also to
suggest that, when taught with gen-
erosity, chemical sciences can serve
as an integrating factor for under-
standing our living world as de-
scribed in newspapers, television,
and history books. Fig
To prepare students properly for I and My Vil
meeting the expanded expectations
of society, faculty can no longer restrict their undergraduate
courses to narrow specialization with the comfortable thought
that the student's "other" educational needs will be supplied
on the other side of the campus. The responsibility for good
education cannot be so easily compartmentalized. There is a
crucial difference between the words integrated and sepa-
rate but equal, as the U.S. Supreme Court decided about
forty-five years ago.
If we believe-and I suspect that we all do believe-that
engineering is ultimately not merely a technical but also,
essentially, a human enterprise, then we are obligated to
communicate that belief to our students in a consistent way.
We cannot meet that obligation by merely requiring our
students to attend an occasional course in history or anthro-
pology or whatever. If we are to be consistent in our
purpose, then it is our task, in our own courses, to show
the intimate continuity between applied science and ulti-
mate human concerns.
Pressures from government and its funding agencies are


already providing incentives to encourage teamwork in re-
search, better cooperation with industry, team teaching, in-
terdisciplinary courses, and lowering of departmental barri-
ers-in short, toward integrating engineering education and
research with those broad areas that
engineering serves. Funding agen-
cies now prefer research proposals
that are problem-oriented, to be
conducted not by separate investi-
gators but by a team of scholars
from several disciplines. At the
same time, students and parents are
demanding that more attention be
given to courses that emphasize
"why" instead of "how," that
stress overall purpose rather than
details of method, and, as a per-
ceptive undergraduate at the Uni-
versity fo Rochester said, "to
courses that give fewer scales and
more music."
As it prepares for the next cen-
tury, every chemical engineering
department faces two challenges.
The first one is well known and
relatively simple: to keep up with
impressive new developments in
science and to make them relevant
for practice. Surely that is one of
the traditional goals of engineer-
Sing. It is likely that essentially
all chemical engineering depart-
e, by Chagall ments will meet this first chal-
lenge with success.
The second, and more difficult, challenge is to humanize
the curriculum, not through new courses but by introducing
into existing technical courses the human dimension; to show
students how technology is related to human needs, both
personal and collective; how applied science is a response to
human aspirations and how it often is not just a consequence
of, but also a stimulus to, pure science; and how the concerns
of what men and women want and need drive the academic
programs for all departments on campus. Like everyone
else at a scholarly institution, engineers or philologists,
chemists or economists, physicians or theologians, we strive
toward a better understanding of ourselves and toward a
more noble life. In our relations with students and faculty in
other departments, let us not be separated by our differences
but joined by our common purpose.
I plead for teaching this commonality of purpose not only
because it is fashionable to reverse the alarming trend of the
university to a multiversity. My plea is motivated by two
equally important goals.

Chemical Engineering Education

First, if we humanize our cur-
riculum, we produce better engi-
neers, we raise the prestige of en-
gineering, and we help to combat
the threatening anti-science and
anti-technology movements that
are growing in our alienated popu-
lation. Engineers must increas-
ingly communicate, to listen with
empathy to those who do not un-
derstand or who are frightened
by new technology, and to speak
to them effectively, leading them
toward confidence and trust.
Good skills in English are not
enough. The engineer must also
have some understanding of his
audience; in other words, he
needs to understand the human
dimensions of his work. In the
world now emerging, an Ameri-
can engineer must know how to


t I n



Ln.1 + V.-, = L. + Vn


Figure 6. Free-body diagram for plate n in a
distillation column.

communicate, to listen and to
speak, with a peasant in India, a rabbi in Jerusalem, or a
lawyer in Washington.
Second, a chemical engineering department is not a trade
school. A worthy chemical engineering department is not
content to limit its educational efforts toward producing
robots for industrial employment; it strives to produce
thoughtful, sensitive, and independent-minded graduates
who are not only competent engineers but also well-
educated individuals, prepared for fulfilling lives both
inside and outside their profession. To achieve this edu-
cational goal, engineering faculties must integrate and
interrelate what we do in engineering with the greater
world that engineering aims to serve.
Toward explaining my conviction that engineering is an
integral part of our spiritual as well as our physical exist-
ence, I have shown examples from several artists. Finally, I
would like to show one more: a well-known painting by
Marc Chagall, painted about seventy-five years ago when
Chagall was a young man remembering his childhood in
rural Russia. In a sense, it is an autobiography. It is called I
and My Village (Figure 5), and it indicates the influences
that made Chagall the particular individual that he was at
that time. It shows a set of memories that are separate, yet
integrated to form a harmonious continuum.
Contrast this painting with the essential image we use to
teach applied mechanics-the free-body diagram. In a free-
body diagram, we isolate the essentials of our focus of study,
we neglect the surroundings, and we ignore the context.
In teaching chemical engineering, we also use free-body
diagrams. For example, as shown in Figure 6, in teaching
Winter 1998

distillation we look at one plate in
the distillation column and then write
mass balances for all flows that en-
ter or leave that plate. In this exer-
cise we forget not only the rest of
the distillation column but also the
entire chemical plant and the com-
munity that it serves.
I am not opposed to free-body dia-
grams, nor do I suggest that we re-
frain from using them in instruction.
Free-body diagrams constitute a
pedagogical tool that has been, and
continues to be, valuable for effec-
tive education. But free-body dia-
grams convey an attitude, a philo-
sophical viewpoint that is seriously
incomplete. We should not abandon
free-body diagrams, but we should
not restrict engineering education to
the attitude that they imply. I plead
for a shift of balance where we rely
not only on the isolated specifics but

also, as suggested by Chagall's painting, give attention to
the larger view, toward awakening engineering students to
see both the leaves on the trees and the forest, the mountains
and the cities, and the human beings that live in them.
To illustrate this shift of balance, to help our students
broaden their professional horizons and to attain more mean-
ingful lives, it may be useful to recall a well-known (possi-
bly true) story concerning the great physicist Niels Bohr.
Bohr, a distinguished professor of physics at the Univer-
sity of Copenhagen, liked, on occasion, to retreat to a modest
cabin in a nearby forest where he could read and think
without interruption. But an enterprising journalist discov-
ered this cabin, and wanting to interview Bohr, knocked on
the door. Bohr opened the door and the journalist entered.
When he did so, he noticed an old horseshoe nailed to the
door frame. Surprised, he said to Bohr, "You are a great
scientist. Surely you are not superstitious. Surely you do not
believe that a horseshoe can bring good luck." Bohr an-
swered without hesitation, "Of course I do not believe that.
But I have been told that a horseshoe can bring good luck
even if you don't believe it."
This charming story tells us once again that, even for a
great scientist, life has a strong non-rational component and
that we are all human beings subject to the hopes and fears
that characterize the human condition. Let us reflect this
duality when we teach our students science and technology.
Let us not rely on others to do what we owe to the young
men and women entrusted to our care. Let us show by our
example and in our classrooms, that engineering, in particu-
lar chemical engineering, is also one of the humanities. O

" classroom


An Open-Ended, Hands-On Project

for ChE Sophomores

Georgia Institute of Technology Atlanta, GA 30332-0100

"Georgia Tech was the site of intense competition Monday. but this time it was not Olympic
athletes who sought gold. Instead, eleven determined teams made up of chemical engineering
majors met in quadrant tr o of SAC's main gym to embark on a battle of wits.... Kamikaze
team member Heather Ledbetter explained howa her team's COMET operated: "Our COMET
stores elastic potential energy by displacing a spring. This potential energy is then converted
to work, acting on our projectile-an egg.... The peeled egg worked the best. "*

Sophomore chemical engineers at Georgia Tech re-
cently built Controlled-Operation Mechanical Energy
Transducers (COMETs) as part of a project to intro-
duce them to a number of important engineering concepts
that are often not addressed until later in the curriculum, if at
all. In the COMET competition, student teams designed,
built, and used simple, self-powered devices that indepen-
dently traveled to a designated location.
While electrical and mechanical engineering students fre-
quently participate in design competitions involving stu-
dent-built machines,11 chemical engineering students' hands-
on experience is usually limited to prefabricated laboratory
experiments during the junior or senior year. To introduce
activities other than pencil-and-paper homework assignments
earlier in the curriculum, development of hands-on design
projects appropriate for beginning chemical engineers has
recently received increased attention.[2'31 Motivated by this
concern, I developed and offered the COMET competition

Mark Prausnitz is Assistant Professor of Chemi-
cal Engineering at Georgia Tech. He was edu-
cated at Stanford University (BS, '88) and MIT
(PhD, '94). He currently teaches mass and en-
ergy balances to chemical engineering sopho-
mores, recently spent a year teaching biomedical
engineering in developing countries with ORBIS
International, and has taught public speaking for
more than ten years. He conducts research on
novel mechanisms for improved drug delivery by
controlling tissue permeability using electric fields,
ultrasound, and microfabricated devices.

* Excerpt from a final COMET report written by a team of


-35' 5'
Figure 1. Schematic of the COMET competition arena
located on an indoor basketball court. COMETs traveled
by land and/or air from a launching area, around or over a
large barrier, and to as close to a target location as pos-
sible. The COMETs were designed and built by teams of
sophomore chemical engineers.

in two consecutive sophomore-level classes on energy bal-
ances.[4] It was designed to achieve the following goals:
Teamwork Students formed teams of two to four mem-
bers who worked together on all aspects of the projects.
Open-Ended Problem Because there were few rules in
the competition, many possible designs could accom-
plish the assignment.
Design Given only a spending limit and a final goal,
students had to design, build, test, and use their COMET.

Copyright ChE Division ofASEE 1998
Chemical Engineering Education

Hands-On Experimentation Because a successful
COMET design depended largely on empirical physical
testing, students needed to get their hands dirty.
Technical Writing Each group prepared a final report
that described and analyzed the design of their COMET,
including written text, figures, and calculations.
Estimation Based on Limited Data Quantitative esti-
mates of kinetic and potential energies were required in
the final report. Students designed and performed addi-
tional experiments to calculate rough estimates of those


The COMET project had few rules, thereby giving stu-
dents the opportunity for creative
design. In groups of two to four
students, each team designed and A
built a COMET that could be
launched from a designated lo-
cation and, without human inter-
vention after launching, would
come to a stop as close as pos-
sible to a target location approxi-
mately forty feet away (Figure
1). To make the assignment more
challenging, a large object was
placed five feet in front of the
target so that a straight path to
the target would be blocked. The C
COMET had to cost less than
$20, measure less than one foot
in all dimensions, have no elec-
trical, chemical, or human power
sources, and be safe. The
COMET could have a separate
launching unit of any size, but
the launching unit had to remain
behind the starting line.

The assignment was given to
the students two to three weeks
before the competition. Immedi-
ately before the assignment was
given, we held an in-class brain-
storming session to help students
think broadly about the project.
We identified possible paths an
object could follow between two
points separated by a barrier and
considered ways in which an ob-
ject could be powered to follow
some of those paths.
One week before the competi-
Winter 1998

tion, a preliminary design of the proposed COMET and its
expected course was collected to ensure that each group had
started work on the project. I provided feedback on these
preliminary designs, commenting on approaches that seemed
overly complex, unlikely to work, or unsafe. Students also
received sample energy balance calculations to guide them
in preparing their reports, as described below. Optional prac-
tice sessions were held before the competition so that teams
could test their COMETs in the competition arena.

The competition consisted of three rounds. During each
round, each team in turn launched its COMET toward the
target (see Figure 2). The referees (i.e., class TAs) measured
the shortest distance between the target and the COMET.

Figure 2. COMETs being
launched at the competition.
(A) The "Tomato" team shot a
rice-filled balloon from a rubber
band-powered cannon.
(B) The "Quadrangular" team
COMET drove to the side of
the barrier and then made a 90'
turn by triggering a second
set of wheels.
(C) The "Slingers" launched a
putty-based COMET from
a slingshot.
(D) The "Spartans" vehicle
followed an arced path around
the barrier and was powered
in part by a rat trap.

After the third round, the teams were ranked by aggregate
score from all rounds of play. Members of the winning team
each received a small trophy.

The ability of the COMETs to reach their
target ranged from reproducibly having no
net movement to reproducibly landing and
stopping within inches of the target. Most
designs were based on potential energy stored
in the form of a spring or rubber band that
was used to catapult an object through the air.
Others used the potential energy of gravity to
move the COMET either on the ground,
through the air, or a combination of both.
Designs ranged from store-purchased pro-
jectiles modified for the competition to home-
made vehicles, some with complex and clever
mechanisms to control the COMET's direc-
tion and speed. While the complex designs
were fun to see, they were generally unreli-
able and yielded only average performance.
The winning designs in both of the COMET
competitions were either a rocket or an arrow
launched from the ground at a predetermined
angle with a reproducibly applied force and
having a mechanism to prevent rolling or
bouncing once the COMET hit the ground.

Although the competition was the highlight
of the COMET project, grades were deter-
mined from each team's final report. The re-
port was due two days after the competition
and consisted of four parts:

1. A schematic diagram and description of the
2. A sketch and description of the intended course
the COMET would follow
3. Receipts for items used to build the COMET
4. Quantitative energy-balance calculations for each
phase of the COMET's travel
Grading was based half on clear, concise, and neat presen-
tation and half on energy balance calculations. Quality of
COMET design and construction and the COMET's ability
to reach the target did not influence grades as long as each
team had made a reasonable effort to do well.
The final reports were generally clear and well written,
and they provided reasonable analysis of the energy bal-
ances associated with the COMET's travel. The sketches of
the COMET design and its intended course were mostly
simple, hand-drawn diagrams (see Figure 3) supported by
one or two paragraphs of descriptive text. The receipts all

totaled under $20, as required in the assignment; some
amounted to just a few dollars.

... Control
Operation Mec
... part of a pr
number of imf
engineering co
that are oftej
addressed unt
in the curricu
if at all. In
COMET compi
student tea
designed, build
used simp.
self-powered d
that indepenc
traveled to
designated loc

to share group responsibilities. They also approached this
open-ended design project with an open-minded attitude, as
demonstrated by the many different types of COMETs built,
most of which worked well. Students spent a lot of time
building and testing their COMETs, which indicated they
enjoyed the opportunity for hands-on learning. The final
reports contained adequate technical writing and data analy-
sis, topics that are addressed more thoroughly in later classes.
To assess student opinion of the project, a brief, anony-
mous survey[5'61 was given a week after the assignment. It
revealed that students generally found the COMET project
to be educational, enjoyable, and worth repeating. Figure 4
shows student responses to the three specific questions asked.
Students also provided written comments, which are sum-
marized below.
The average scores shown in Figure 4 indicate generally
favorable responses by the students, but not enthusiastic
endorsement of the project. This observation should be tem-
pered in two ways. First, a large standard deviation is associ-
ated with each average, largely due to a few students who
Chemical Engineering Education

Students performed energy balance calculations for each
phase of the COMET's travel. A representa-
tive example follows, taken from the "Ber-
led- noulli Bunch" group's analysis of a COMET
hanical that was shot into the air from a rubber-band
sling shot, landed on the ground, and finally
bounced and rolled to a stop. First, these stu-
ers dents estimated the elastic potential energy of
) the rubber band by shooting an object of known
oject to weight straight up into the air. They measured
e the maximum height of the object and, assum-
] to a ing no friction with the air, set the elastic
ortant potential energy lost by the rubber band equal
to the gravitational potential energy gained by
ncepts the object. They determined this energy to be
n not 1.4 J. They then calculated the COMET's ve-
il later locity to be 11 m/s upon leaving the rubber-
ilum, band launcher by setting the COMET's ki-
the netic energy equal to the potential energy lost
petition, by the rubber band. Using energy balances
applied when the COMET reached its maxi-
mns mum height, first hit the ground, and finally
t, and stopped, they determined at each point the
le, COMET's kinetic and potential energy, as well
devices as its position and velocity.
From the instructor's perspective, the
COMET project accomplished the six goals
for which it was designed. Students responded
well to the teamwork environment and seemed

Figure 3. A sample student sketch of the intended
course the COMET would follow to the target (above)
and a schematic diagram of the COMET launching
unit (below) from the "COMET Busters" team final

1 2 3 4 5



use again? ]

Figure 4. Student assessment of the COMET project.
Based on anonymous responses from 28 students (solid
bar) and 34 students (grey bar) in two different classes,
averages and standard deviations are shown for re-
sponses to the following: Rate your learning from the
COMET project (1 "waste of time" to 5 "very valu-
able"); Rate your enjoyment of the COMET project (1
"dull" to 5 "lots of fun"); Give your recommendation
on using the COMET project again (1 "absolutely not"
to 5 "absolutely yes"). Overall, students found the
COMET project to be educational, enjoyable, and worth
repeating (see text).
Winter 1998

covnt ouMTze


7 as
i. 25 ft


- 1- -.n 1.. -

were unhappy with the project and rated it with a 1 or 2. The
vast majority of students gave ratings of 3 and higher on all
three questions. If the averages were recalculated without
the two or three dissatisfied students in each class, all three
questions would have average values above 4. Second, the
scores from the first class were consistently higher than
scores from the second class. Based on student comments,
this difference is largely due to greater time pressure: the
second class received only two weeks to work on the project,
while the first class received three weeks.
Some representative student comments are provided be-
low, followed by a discussion of what these comments say
about the successes and shortcomings of the COMET project.

Enjoyable Project
"This is the only project I have had at Tech that was enjoy-
able. I didn't even feel like I was doing a projectfor a grade."
"Fun project, but still learned a lot."
Many students enjoyed the project. They were surprised to
find that something educational could also be fun. Making
the connection between academic values (i.e., learning) and
personal values (i.e., fun) may be the most important lesson
of the project. Student-perceived relevance of course mate-
rial is known to be important for effective learning.'171

Hands-On Learning
"It was nice to do something in ChE away from paper and
"Home Depot is very fond of Georgia Tech students."
A number of students commented on the hands-on nature
of the project and appreciated it as a refreshing change from
conventional problem sets. The opportunity to exercise
"right-brain" thinking through an active process that yields
concrete results appeals to students with learning styles
not easily accommodated in conventional "left-brain"
classroom lectures.191

Weak Connection with Course Material
"I don't think I really learned anything from the project that
pertained to the course."
"I'd suggest allowing chemical energy sources. After all, this
is a Chem E class."
Some students were concerned that the project was not
closely related to the rest of the course material. I partially
share this concern. While the quantitative energy balance
calculations required in the final report relate directly to
material presented in lectures, the design, construction, and
testing of COMETs are not as closely linked to the rest of the
course. Nevertheless, I believe it is important to expose
engineering students to concepts like teamwork, open-ended
design problems, and hands-on experimentation, and I think
the COMET competition provided an exciting framework
Continued on page 45.

l Oclassroom


An Open-Ended Project

for a Course in Kinetics and Reactor Design

Stanford University Stanford, CA 94305-5025

Educational researchers have identified a need to ex-
pand the typical teaching approach found in most
engineering courses beyond the lecture and problem-
set format."' Strict adherence to this traditional teaching
method has several shortcomings. First, students possess a
variety of learning styles.[2] Educational researchers have
attempted to correlate learning styles with traits such as
Meyers-Briggs Type Indicators,'[3'4 gender,'[5 and regions
where the students grew up.161 By implementing only one
teaching method, educators can lose some of their audience
and place some students at a disadvantage. Second, tradi-
tional teaching methods often do not promote the creativity
desired by most employers and researchers. Third, tradi-
tional methods of teaching do not necessarily encourage
students to develop the self-reliance essential in an industrial
job or in graduate research. In the "real world," problems do
not come out of a book, numbered and self-contained, nor do
they proceed directly from the previous day's lecture. Ulti-
mately, graduates need to be able to define their own prob-
lems and to determine what information is needed to solve
them. Finally, engineering problems sets do not emphasize
the importance of communication.
In this paper, we present an open-ended project tailored
for a senior kinetics and reactor design course. The project is
based on work by Penry and Jumars in which basic reactor
design equations are used to model the digestive system of
several animals.17] We will begin by describing the assign-
ment, will follow with the results, and will close with some
overall conclusions about the success of such a project.

We asked the students to model the digestive system of an
animal of choice as one or more ideal reactors, applying
principles from the course. There are three aspects of the
project, each with its own goal: a literature search, the devel-

opment of a model, and the communication of the model to
an audience. While the project is intended to be open-ended,
students in general do not respond well to nebulous assign-
mentst18 so we gave them our concrete expectations at the
very beginning, including specific goals to attain for each
aspect of the project.
We asked each student to choose his or her own individual
animal, thus ensuring that each model would be unique.
Individual choice also allowed the students to apply the
project to an animal they found personally interesting.
The first phase of the project focused on searching the
literature. To build a theoretical model of their animal's
digestive system, students had to acquire information about
the diet (reactant feed), the digestive process, gut size (reac-
tor volumes), throughputs, and any enzymatic and bacterio-
logical kinetic rate data from the literature. Not surprisingly,
there is an abundance on literature information of some
animals, but very limited information on others. We recog-
nized that some students would find this disparity frustrat-

Eric Carlson is a chemical engineering PhD
candidate at Stanford University, studying the
optical-rheology of elastomeric polypropylene
with Prof. Gerald G. Fuller. He earned his MS
from Stanford University and his BS from North
Carolina State University, where he was intro-
duced to the joys of cooperative learning. On
the few occasions he escapes from the lab, he
enjoys mountain biking, rollerblading, volleyball,
and poor attempts at golf.

Alice Gast is Professor of Chemical Engineer-
ing at Stanford University. She obtained her BS
from the University of Southern California and
her PhD from Princeton University. Her research
interests in complex fluids combine statistical
mechanical models of suspensions and solu-
tions with neutron, X-ray, and light scattering
experiments. Among other activities, she enjoys
regular trips to the San Francisco Zoo and
Monterey Aquarium.

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

In this paper, we present an open-ended project tailored for a senior kinetics and
reactor design course. The project is based on work by Penry and Jumars
in which basic reactor design equations are used to model
the digestive system of several animals.

Digestive Schemes

Animals display a variety of digestive schemes to handle available
food sources. Single reactor schemes can model simple animals with
minimal energy requirements, like
starfish. Larger animals with higher
energy requirements offer a larger S
variety of digestive schemes. Simple
Carnivores, frugivorous primates, and Small Intestine
omnivorous humans all possess a
simple stomach and small intestine to
break down high-energy food.

Some animals rely on more readily available, lower-energy foods such

Complex, Multi-
Chambered Stomach

To Small Intestine

ForePut Fermenter

as grasses and leaves. These animals
generally need the assistance of
microbes to break down food to
provide energy. Foregut fermenters
are animals in which microbial
fermentation of ingested material
precedes catalytic digestion (e.g., cows,
sheep, goats, deer, hippos, kangaroos,
whales, and manatees). Microbial
fermentation takes place in a well-
mixed rumen or complex stomach, after

which the food passes to a long, tube-like intestine where catalytic
digestion occurs.

In hindgut fermenters (e.g., horses,
rhinos, koalas, rabbits, and
elephants), microbial fermentation
takes place in the cecum following
catalytic digestion.

Small Intestine

Hindm ut Fermenter

ing, but we hoped they would tolerate it and rise to the
challenge once we explained the relevance of open-ended
literature searches to their education. On a mundane level,
students learned how to perform on-line searches and to
effectively use the WWW, how to find and explore appropri-
ate libraries, and what type of information is found in texts
as opposed to journal articles. At a higher level, students
learned how to select relevant facts from a large, perhaps
overwhelming, body of information. We asked that the stu-
dents turn in a concise summary of the relevant aspects of at
least three references.
Winter 1998

The next phase of the project was model development. We
asked the students to sketch the ideal reactor series em-
ployed and to present the equations used to predict conver-
sions and residence times. This portion of the project al-
lowed students to apply course knowledge to a new problem
that they devised for themselves. Based on their literature
search, they had to decide what reactor or reactor series was
appropriate, where there was essentially continuous flow,
whether mixing was ideal, and what reactions were impor-
tant. If experimental data were available in the literature,
model predictions were to be compared with experimental
values of conversions and residence times. Generally, ki-
netic and conversion data are not available for most animal
species, so students were asked to fill in the gaps with
appropriate assumptions by extrapolating data from other
related species. In cases where such extrapolation was not
feasible, students were asked to describe in detail how one
might experimentally gather kinetic data on the digestive
system to compare with their model.
Along with the model, students were asked to provide a
critique, discussing the strengths and weaknesses of their
analysis, and to describe how well it would serve to predict
reality. The critique forced the students to think about the
equations and to understand the assumptions that go into
them at a high enough level to be able to explain it to others.
The last aspect of the project was the development of
communication skills. In addition to the short summaries of
the literature articles, students had to prepare a written report
describing the model of their animal's digestive system,
including an introduction motivating the application of
the model to their animal. A small class size also allowed
the students to make oral presentations of their report.
The emphasis of the oral and written reports was on
organizing a coherent presentation of the model, its moti-
vation, and its critique.

As stated in the introduction, this project is based on Penry
and Jumars' work using basic reactor design equations to
model the digestive system of a variety of animals and to
identify the digestive operating systems that optimize the
utilization of nutrients and the production rate of energy.171
Their reactor design models and basic kinetic rate expres-
sions can be found in most undergraduate kinetics and reac-
tor design textbooks, 9-21 making the development ideal for

use in the classroom. The authors discuss modeling the guts
of marine deposit feeders, mammalian hindgut fermenters,
and mammalian foregut fermenters (see Table 1).
In their analysis, the authors assume that digestive reac-
tions are homogeneous, kinetically controlled enzyme pro-
cesses in which food component A binds reversibly to en-
zyme E and dissociates irreversibly into products) P and
free enzyme:

A+E EA -P+E (1)
They further assume that all digestive reactions fall into two
main categories. Digestive reactions catalyzed by an animal's
own enzymes are described by the Michaelis-Menton kinet-
ics and follow the rate expression

VmaxCA (2)

CA concentration of A
Vmax (kCE)
KM (k++k,)/k,
Digestive reactions that rely on microbial fermentation are
autocatalytic. Microbes M are produced as food component
A is broken down. This can be described by

A+M -> MA P+M+M (3)
Such reactions have an additional dependence on the con-
centration of microbes, CM:

SVmaxCACM (4)
Reactor design texts[9121 derive design equations for the
three ideal reactors used in the gut analysis of Penry and
Jumars: batch reactors, plug flow reactors (PFRs), and con-
tinuously stirred tank reactors (CSTRs). The time in a batch
reactor or space time (r = V / V) in a continuous flow reactor
required for digestion to achieve a particular conversion, X,
can be found using the familiar design equations





V dX
t==CAO N -
v =CAo -rA

V CAO(Xout -Xin)
v (-rA)out


reaction rate
initial number of moles of reactant A
feed concentration of A
reactor volume
volumetric flow rate of the feed

Figure 1 shows the graphical design equation for finding
the space time of an animal gut performing a catalytic diges-
tion process following Michaelis-Menton kinetics. To mini-
mize the space time, Michaelis-Menton catalytic digestion is
optimized by a PFR design. Figure 2 shows a plot of recipro-
cal reaction rate versus conversion for an autocatalytic mi-
crobial fermentation process. Autocatalytic reactions are op-
timized by a CSTR operating at the point of maximum
reaction rate, followed by a PFR.
Penry and Jumars suggest general designs for deposit feed-
ers, mammalian hindgut fermenters, and mammalian foregut
fermenters. Depending on the specific animal being mod-
eled, reactor design models may need modifications to ac-
count for various factors-such as variable flow rate, vari-
able gut volume, non-ideal mixing, recycling by means of
coprophagy (reingestion of feces), and caecotrophy
(reingestion of partially separated feces, as in rabbits)-and
residence time distributions. Modifications to the reaction
kinetics may account for different forms of enzyme kinetics,
mass-transport limitations, heterogeneous catalysis, and non-
isothermal conditions. Ultimately, fundamental reactor de-


Conversion, X

Figure 1. Graphical design
equation for a
plug flow reactor (PFR).

tn j TPFR


Conversion, X

Figure 2. Graphical design
equation for a continuously
stirred tank reactor (CSTR).

Chemical Engineering Education

sign equations can form a biologically meaningful, math-
ematical framework for the description of animal digestion.

Using the tools of kinetics and reactor design and the ideas
presented in the work of Penry and Jumars, the class was
able to develop models about the digestive behavior of ani-
mals across the animal kingdom. Some animals had seem-
ingly simple digestive systems, while others had more com-
plex guts. Table 2 lists typical animals that students mod-
eled. A few of the animals were modeled with single ideal
reactors (vampire bat, sea anemone, starfish) and offered
simple systems like the deposit feeders in the article by
Penry and Jumars. Many of the animals required a series of
reactors. A student model of the hippo gut (foregut fer-
menter; CSTR-PFR) is presented below. Several students

V',=0.46m- \-=0.15m3

S L=47m
Figure 3. The familiar hippopotamus and a student
model of the hippopotamus gut
(foregut fermenter; CSTR-PFR).

Catalytic Digestion

Autocatalytic M

Distal Colon/Rectum

Negligible Digestion

Figure 4. Student model of the koala gut (hindgut
fermenter; CSTR-PFR-Separator-CSTR-PFR).
Winter 1998

extended their model to account for digestive behavior dis-
tinctive to their animal, using either additional reactors or
modification of the underlying assumptions. Two prime ex-
amples are also presented below: a koala bear (hindgut fer-
menter; CSTR-PFR-Separator-CSTR-PFR) and a manatee
(hindgut fermenter; CSTR-PFR-CSTR-PFR).

Hippopotamus Hippos are foregut fermenters that
spend about five hours a day eating about 40 kg of short
grasses. The student modeled hippo digestion with a CSTR
and a PFR in series with information about the volume of the
stomach, the length of the intestines, and the feeding rate
from the literature.1131 The model is shown in Figure 3.
The volume of the intestine was calculated based on data
of the distribution of digesta between the stomach and the
intestines. Reactor volumes and throughputs allowed for the
estimation of fairly reasonable residence times: CCSTR = 3.5
days, TPFR = 1.1 days. The student suggested tracer studies to
check the accuracy of these estimates. Detailed kinetic data
were not available to calculate the actual conversions. The
student discussed how one might get the kinetic information
experimentally, either by monitoring hippos in the field,
examining hippo excrement, or by extrapolating from a
known body of data on animals with similar digestive
systems (e.g., cows). Researchers could then use the de-
sign equations and compare calculated conversions with
those found experimentally. Because the nightly feeding
of hippos only lasts about five hours, a more rigorous
model would account for the unsteady nature of the di-
gestion process.

Koala Koalas are hindgut fermenters with a unique diet.
Exceptionally picky eaters, koalas focus entirely on a select,
low-quality food source-eucalyptus leaves from only about
5 of over 100 available species. Koalas have evolved
highly specific guts to digest this food source, and reac-
tor design analysis can give insight into the importance
of nature's design.
The contents of eucalyptus cells are highly diges-
tive, according to the literature."1 The student as-
sumed that all digestion of the cell contents occurred
in the stomach and small intestine by means of cata-
lytic digestion. Microbial breakdown of the eucalyp-
tus cell wall occurs only in the cecum and the colon.
Koalas are not born with these helpful microbes, but
rather gain them from ingesting adult fecal matter
shortly after being weaned.*
The model of koala digestion is shown in Figure 4.

On a field trip to the San Francisco Zoo, the class
learned of the availability of hippo excrement; hippos
leave the water to distribute their feces rather widely to
mark their territory.
** On the same field trip to the San Francisco Zoo, we
learned of weaning and eating habits of young koalas.

v=40 kg/day, p=306 kg/m3

Literature provided the student with tracer and dissection
studies of koalas that reveal two main residence times in the
koalas' guts. The mean residence time for particulate matter
was about 100 hours, while that for the solute phase was
about 210 hours. The student decided to employ a separation
process within his model to account for these two residence
times. Because koala eating is spread fairly continuously
throughout the day between periods of sleep, the student
modeled koala digestion as a continuous process.
Using this model and literature values for throughput rate
and gut volumes, the student was able to match the experi-
mental residence times for both the coarse particles and
soluble fine particles. Unfortunately, the student was unable
to find kinetic data for these reactions; he pointed out that
kinetic data would allow one to study the digestion of koalas
with mathematical models and reduce the need for slaughter/
dissection studies.

Manatee Another
modification of Penry and
Jumars' hindgut fermenter
was presented by a student
who modeled the guts of S c
Stomach Small Intestine
manatees. A scheme of V=93L V=68L
four reactors was chosen r=42hrs T=3lhrs
to model its digestive be-
havior. The student de- Catalytic Digestion
cided that Penry and
Jumars' model of a hind- Figure 5. Student mod
gut fermenter PFR-CSTR fermenter; CS
series was a poor choice
in the case of the manatee for two main reasons: first,
manatees are known to achieve large conversions, and
large conversions that operate beyond the maximum au-
tocatalytic reaction rate are inefficient in a CSTR, and
second, the long curvaceous nature of the colon, coupled
with the viscous nature of the digesta found in the mana-
tee makes perfect mixing unlikely.
Like horses and elephants, manatees use the cecum and
colon as primary fermentation sites, whereas the stomach
and the small intestine are used for catalytic digestion.
Because both the colon and the small intestine are long and
narrow, they were both modeled as PFRs. The open cavities
of the stomach and the cecum are more amenable to CSTR
design. Thus, a CSTR-PFR-CSTR-PFR series was chosen
to model the manatee gut, as shown in Figure 5.
Equations of forms (2) and (3) were used to model the
catalytic digestion and the autocatalytic fermentation reac-
tions, respectively. CSTR and PFR behavior were modeled
using Equations (5) and (6). The student was unable to find
kinetic data specific to manatees, but she was able to find the
typical range of rate parameters VMAX and K, found in
hindgut fermenters for fermentation and catalytic digestion

el of

processes. The only unknown variable is CM, the concentra-
tion of microbes. For the purposes of calculating general
trends, the student assumed that the microbe concentration
was directly related to the concentration of food, CA. Now,
by examining each reactor in sequence, one can calculate the
output CA and conversion.
Even with her broad kinetic generalizations, the student
found that the theoretical overall conversion fell between
60% and 80%, comparing extremely well to the literature,
which cites 45% to 70% for manatees (and about 84% for
dugongs, another species of sea cow).
As weaknesses of her model, the student cited several
factors, including the lack of true kinetic data, the assump-
tions of constant volume digesta, and complete mixing in the
CSTR compartments. This model allows one to conceptual-
ize the conversion of food, however, and illustrates the effi-
ciency of nature in de-
signing its own reactors.

-'c _____ ^c
ecum Colon Students (and instruc-
V=IL V=185L t
--0.5hrs T=84hrs tors) responded we to
this open-ended project.
Autocatalytic Microbial Fermentation It was enjoyable for ev-
eryone and it added a
unique dimension to the
the manatee gut (hindgut class. As a teaching tool,
the project was a suc-
cess on several levels. While the subjective nature of
evaluating student performance* makes it difficult to give
direct, quantitative comparisons with more traditional prob-
lem assignments, there were several indicators by which we
were able to judge this project's success.
Foremost, it was obvious that students learned from this
exercise. The project allowed students to apply kinetics and
reactor design concepts and to extend their knowledge of
course material to a unique reactor system. Based on their
own knowledge, they had to decide for themselves what
model assumptions were appropriate. The project saw the
development of several fairly comprehensive models built to
account for complex reactive and flow behavior. The in-
class presentations allowed students to present to and teach
each other about the applicability of ideal reactor models.
Not only was the project instructive, but it was also enjoy-
able to the students. Overall, student response was highly

* Students were told from the beginning that the project would
count for a non-trivial part of their grade. Evaluation would be
based on proper use of course material, exhaustiveness of the
literature search, completeness of the model based on available
information and creativity, rigorousness of the critique, and
quality of oral and written presentations.
Chemical Engineering Education


favorable. When asked their opinion of the course after-
wards, students responded that they "enjoyed the project"
and that it was "fun"-phrases rarely used to describe a
typical homework set.
We did receive a few less positive responses at the begin-
ning of the project. While some students liked the flexible
nature of the project, a few students worried about what was
meant by "the project's success being up to them." Several
students were initially turned-off by the idea of an open-
ended literature search. We dealt with complaints about
trying to chase down details that may or may not exist in a
large body of literature in a case-by-case manner. Ulti-
mately, the students developed searching strategies and
were able to organize the information. The open-
endedness of the project made creativity possible, which
the students all seemed to enjoy.
An additional success indicator was increased office hour
attendance. Students who previously had not shown exces-
sive interest in course material began arriving early and
asking questions. Several became quite stimulated by the
topic and would engage each other in discussion about their
models. These discussions provided an effective cooperative
learning environment in which students relied on each other
to learn and to teach the subject matter.11
Finally, students were both more creative in their problem
solving and more expressive in the discussions of their mod-
els. This project was a success as a teaching tool because its
open-endedness and active learning emphasis appealed to a
wide variety of learning styles. The open-ended project was
complimentary to more traditional problem sets in that it
allowed students to extend their knowledge beyond what
had been directly presented in the classroom.

Reactor design models can be successfully employed to
model the guts of a variety of animals, and the use of such
models on unique animal systems provides a stimulating
learning experience for both the students and the instructor.
We would encourage any one teaching a reactor design class
to use this or a similar type of project to engage the students
and help seize their interest.


We would like to thank the students of ChE 130 from the
winter quarters of 1996 and 1997 for their participation,
enthusiasm, and creativity. In particular, we would like to
thank Sao Wei Lee for his model of the hippo gut, Dhruv
Gupta for his model of the koala gut, and Lani Miyoshi for
her model of the sea cow gut. APG would also like to thank
Deborah Penry for giving her the initial idea for this project
at the 1st Annual Symposium on German-American Fron-
tiers of Science.

Winter 1998

1. Rosati, P.A., and R.M. Felder, "Engineering Student Re-
sponse to an Index of Learning Styles," Proceedings-1995
Frontiers in Education Conference, IEEE, New York, NY, p.
2. Felder, R.M., and L.K. Silverman, Eng. Ed., 78(7), 674
3. Myers, I.B., and McCaulley, Manual: A Guide to the Devel-
opment and Use of the Myers-Briggs Type Indicator, Con-
sulting Psychologists Press, Palo Alto, CA (1985)
4. Rodman, S.M., R.K. Dean, and P.A. Rosati, "Learning Style
Among Engineering Students: Self Report vs. Classification
of MBTI," Proceedings-1995 Frontiers in Education Confer-
ence, IEEE, New York, NY, 48 (1985)
5. Felder, R.M., K.D. Forrest, L. Baker-Ward, E.J. Dietz, and
P.H. Mohr, J. Engr. Ed., 82(1), 15 (1993)
6. Felder, R.M., P.H. Mohr, E.J. Dietz, and L. Baker-Ward, J.
Engr. Ed., 83(3), 209 (1994)
7. Penry, D.L., and P.A. Jumars, American Naturalist, 129, 69
8. Felder, Richard M., "Meet Your Students: 6. Tony and
Frank," Chem. Engr. Ed., 29(4), 244 (1995)
9. Levenspiel, O., Chemical Reaction Engineering, 2nd ed.,
Wiley, New York, NY (1972)
10. Fogler, F.S., Elements of Chemical Reaction Engineering,
2nd ed., Prentice Hall, New Jersey (1992)
11. Smith, J.M., Chemical Engineering Kinetics, 3rd ed.,
McGraw-Hill, New York, NY (1981)
12. Hill, Jr., C.G., An Introduction to Chemical Engineering
Kinetics and Reactor Design, Wiley, New York, NY (1977)
13. Clemens, E.T., and G.M.O. Malloy, J. of Zoology, 198, 141
14. Cork, S.J., I.D. Hume, and T.J. Dawson, J. Comp. Physiol.,
153,181 (1983) 0

book review

by C. Pozrikidis
Published by Oxford University Press, 198 Madison
Avenue, New York NY 10016; $75.00 (1996)

Reviewed by
Michael D. Graham
University of Wisconsin-Madison

Introduction to Theoretical and Computational Fluid Dy-
namics is an ambitious text, attempting and largely succeed-
ing to encyclopedically cover the theoretical fundamentals
of incompressible, nonturbulent Newtonian fluid mechanics.
In addition, the book gives a flavor of the numerical methods
by which fluid dynamics problems are often solved. The
Continued on page 75.




Part 3. Advanced Levels

Clemson University Clemson, SC 29634-0909

he papers in this series* stalk the question of what we
mean by an understanding of technical material. We
have asserted that to understand has multiple mean-
ings, and we organized those meanings into a hierarchy of
seven levels: (1) Making conversation; (2) Identifying ele-
ments; (3) Recognizing patterns; (4) Solving problems; (5)
Posing problems; (6) Making connections; (7) Creating ex-
tensions. In the second paper of this series, we discussed
understanding at Levels 1 through 4, which we refer to as
elementary understandings. To progress beyond problem
solving at Level 4, we must realize that solving a problem is
not the same as knowing how to solve it. This realization
marks the beginning of the transition to the more advanced
levels addressed in this paper. The discussions here rely on
the descriptions of brain structure and function that were
summarized in the first paper of the series.

Level 4 (Solving Problems)
Level 5 (Posing Problems)
Motivation: Solving a problem is not the same as knowing
how to solve the problem.
Reformulation: The initial solution procedure is refined
by rehearsal and the problem plus its solution are explored
by exercising variations on a theme.

We practice problem solving not to obtain an answer, but
to learn how to solve problems. That is, implementing a
procedure to obtain an answer occupies a lower level of

* Part 1, "Brain Structure and Function" was published in the
summer 1997 issue of CEE (Vol. 31, No. 3) and Part 2, "Elemen-
tary Levels," appeared in the fall 1997 issue (Vol. 31. No. 4).

understanding than does devising the procedure. To develop
skills for solving problems, we must confront new problems,
solve them, and then solve them again and again. Repetition
allows us to shift our attention from obtaining an answer to
learning a procedure. Repetition also promotes creation of
long-term memories, which we need for reusing a procedure
in the future. The connections between repetition and memory
will be discussed first, then we will make connections be-
tween repetition and problem solving.
Posing Problems to Create Memories
Creating memories serves as one hedge against future
needs. In particular, long-term memories (certain long-last-
ing neural networks and combinations of networks) enable
us to reuse problem-solving strategies that we have found
successful in the past. At the subconscious level, we don't
know how the brain selects what ideas are to be remem-
bered. That is, in spite of popular wisdom, the brain does not
lay down a memory for every mental state nor for every
sensory experience; on the contrary, most pass through short-
term memory and are lost. But we do know that we can
consciously select what ideas are to be remembered and
we can consciously create those desired memories; the
operative mechanism is repetition-repeatedly thinking
about the ideas.
Repetition causes the cortex to repeatedly fire the same
pattern of neurons; such repeated activations appear to
strengthen synaptic junctions and perhaps develop new junc-
tions. Thus, by repeated use, a track through a wilderness
becomes a path, then a walk, and finally a highway. More-
over, besides strengthening connections, repetition also seems
to refine the neural network that reproduces the desired

J.M. Haile, a professor of chemical engineering at Clemson University, is
the author of Molecular Simulation, published by John Wiley & Sons in
Copyright ChE Division ofASEE 1998
Chemical Engineering Education

firing patters-it makes the network more efficient. When
the mind contrives a pattern for a new idea, it seems to arise
"on the fly"-the new thought is hastily thrown up as a
permutation of an existing pattern. If a new idea seems
interesting or important, and therefore worth remembering,
then repeatedly thinking about it may create
a new network that is largely separated from
the parent network but connected to other 1
networks that represent related ideas.
Perhaps a helpful metaphor here would be real
scaffolding. A new, hastily constructed, net- SOlving
work is a fragile thing, momentarily stabi-
lized by a scaffolding of neural connections is not tf
that allow us to examine the new idea. If the
idea is judged worthy, then we use repetition knowil
to strengthen important synaptic junctions in
the network and remove the scaffolding. Of- solve
ten, the scaffolding is produced by studying
the intermediate details that appear in any realizal
logical development, such as those that con-
nect a conclusion to a hypothesis, those that the be
relate an effect to a cause, and those that the fra
connect an answer to a problem statement.
Without intermediate details, scaffolding is the
sparse or nonexistent, and student under-
standing remain poorly developed. Rep- advand
etitions make such connections at first
plausible, then acceptable, and finally ob- address
vious-these correspond to stages in re-
moving the scaffolding. p(
Repetition also serves to distinguish pro-
cedural memories from episodic memories.
Procedural memories are created by conscious practice, while
episodic memories are apparently created from a single ex-
perience. How might episodic memories be formed? Deep in
the brain, forming part of the limbic system, is the hippo-
campus-a pair of structures whose shapes each resemble
that of a sea horse. If a hippocampus is damaged or removed,
we lose the ability to form new long-term memories; old
memories remain, but new ones do not form. Thus, the
hippocampus plays some crucial role in forming long-
term memories. Further, it communicates with the cortex
through two bundles of axons, one apparently for input
and another for output. This suggests that the hippocam-
pus may act, in effect, as a buffer between short-term and
long-term memories.111
Perhaps when many networks in the cortex are busy-
attacking a hard problem-the cortex is too preoccupied to
continue the structural changes that produce long-term memo-
ries. Perhaps, instead, networks in the hippocampus are acti-
vated, loading the buffer. Later, when networks become
available in the cortex (perhaps during rest, or sleep), the
hippocampus "replays" important patterns in the cortex,
Winter 1998

thereby creating long-term memories in the cortex.121 If such
a scenario is true, then all memories are formed by repeti-
tion; the difference between procedural and episodic memo-
ries is merely that procedural memories are created by con-
scious repetition, while episodic memories are created be-
low consciousness via repetitions instigated
Sby the hippocampus.

we must

ize that

a problem

ie same as

ng how to

it. This

tion marks

ginning of

msition to


ced levels

sed in this


Thus, part of our activity during rehearsal is to probe and
verify the logic of the algorithm; such activity conforms to
Poincar6's statement that in a chain of logic, the order of the
elements is more important than the elements themselves.*
Another part of rehearsal is the search for a better algorithm.
That is, problems are interesting and instructive to the extent
that they can be solved in more than one way. Problems can
themselves be viewed as patterns with their multiple mean-
ings reflected in the various ways by which they can be
solved. By repeatedly posing the same problem to ourselves,
we create opportunities for finding alternative solution pro-
cedures and therefore for finding additional meanings.
A powerful motivation for rehearsal occurs when we in-
tend to present the solution to others-perhaps as a lecture or
as a written document. Such presentations are most effective
when the chain of logic is economical, with every element
moving the development in an obvious way toward the goal.
Such presentations are developed by rehearsing, wherein we
systematically try to reformulate a logical development into
*See Level 3 in Paper 2, Chem. Eng. Ed., 31(4), 1997).

Posing Problems by Repetition
We invest time and effort in learning so as
to realize future benefits; this implies that
we intend to remember what we learn. Prob-
lem posing is the level of understanding at
which we use repetition for learning how to
solve problems and for creating memories of
the solution procedure. We identify two kinds
of repetition: rehearsal, in which we repeat-
edly pose and solve the same problem, and
variational, in which we pose and solve
new problems that are closely related to
the original problem.
Rehearsal* Having solved a problem, we
rehearse the procedure to learn how we solved
it. Since we know that the procedure leads to
the solution, our minds during rehearsal are
free to consider (1) why each step is impor-
tant and how it contributes to the solution,
(2) whether alternative steps may be more
economical, and (3) whether the steps and
intermediate results can be connected to other
things we know, thereby attaching additional
meanings to the procedure, the solution, and
the problem.


a sequence that is not only economical but also rich in
meaning. Minsky'13 has emphasized that reformulation is the
central act of creativity. For example, in spite of the common
attitude that rehearsal is merely mechanical repetition, the
rehearsal involved in preparing lectures and writing text-
books provides opportunities for high levels of creativity
and originality.31'
Variational Besides repeatedly posing the same prob-
lem, we should also pose and solve other problems that we
create by systematically changing the original problem. Thus,
we enhance problem-solving skills by posing variations on a
theme. This activity is analogous to a practice technique
used by musicians. Consider the passage from Chopin's
third Prelude (Opus 28) for piano, shown in Figure 1. This
one measure is scored as a phrase-a musical pattern of
sixteen notes. The third Prelude is marked vivace, which
means a lively allegro, and corresponds to a speed of about a
measure per second. In fact, a measure per second would be
a little slow; five measures in four seconds would be more
nearly correct. Thus, each of the sixteen notes should be
sounded at a uniform interval of about 5/100 of a second.
How is such skill developed? Not simply by repeatedly
playing the measure as written, but rather by practicing
rhythmic variations, such as are also shown in Figure 1.
Each variation shifts the emphasis to a different note, hence
a different finger; additional variations would be used to
shift the emphasis among different groups of notes. The
figure shows only three variations, but in practice, the musi-
cian routinely works through 40 or 50 variations of the same
phrase. And those are just the rhythmic variations; one also
works through variations in tempo and in dynamics (loud-
ness). It may seem paradoxical that to achieve what the
composer has written, one practices something other than
what is written, but such practice proves to be an effi-
cient way to attain absolute control over the material; to
embed a metaphor within a metaphor, a chain is made
stronger by systematically and repeatedly strengthening
one link at a time.
Likewise, we can improve our grasp of and control over
technical material by posing variations on the theme inher-
ent in any problem. Say the original problem requires us to
obtain the volume V occupied by one mole of nitrogen at P =
2 bar and T = 500C. Having obtained the answer, we can
systematically vary that problem to create somewhat differ-
ent, but related, problems to solve. For example: (1) What
would V be if T were 1000C instead of 500C? (2) What
would V be if P were 3 bar at 500C instead of 2 bar? (3)
What would V be if we had 5 moles instead of one at 50'C, 2
bar? (4) Can we generalize what we've learned from these
four calculations? (5) What if we knew N, V, T and needed
to find P? (6) What if we knew N, V, P and needed T? (7) If
the gas were a binary mixture of nitrogen and oxygen, what
would change in all these calculations? (8) What if the gas


Variation A

Variation B
> > 4 >

Variation C

i i

Figure 1. Three rhythmic variations on the first measure of
Chopin's Prelude for piano, Opus 28, No. 3. On each staff,
horizontal lines and spaces between them represent keys
on the keyboard; notes indicate keys to be struck. On each
of the four staffs, the same keys are to be struck; thus, each
staff contains the same pattern of notes. But the variations
differ from the original and from one another in that they
require keys to be struck with different amounts of force
and held for different amounts of time. In an analogous
manner, engineering students can exercise their under-
standing of technical material by repeatedly using the
same pattern of information, but emphasizing different
aspects of the pattern; that is, they can pose and solve
several variations on a problem originally assigned by
their instructor.

were a twenty-component mixture? (9) Presumably, we have
used the ideal-gas law in these calculations, so by what
criteria do we decide that the ideal-gas law no longer ap-
plies? (10) When the ideal-gas law doesn't apply, what
should we use instead?
Note that the original problem has led us to devise ten
variations-effectively, ten new problems. This process is
most effective if students are merely shown the strategy and
they create their own variations. Hopefully, they eventually
create problems that they don't know how to solve, then they
initiate a dialog with the instructor. This process is system-
atic and can be applied to any problem; in fact, rather
than solving 100 different problems, students seem to
Chemical Engineering Education

gain more by solving ten problems plus ten variations of
each. More on variational problem posing can be found
in a book by Brown and Walter.'41
Earlier we noted that reformulation is a central aspect of
creativity; this observation can now be pushed farther by
noting that devising variations on a theme is itself a reformu-
lation. Hence, as Hofstadter has discussed,l'] variations on a
theme is the crux of creativity. Any new object, process, or
idea is created by modifying, to a greater or lesser extent,
existing objects, processes, and ideas. (There is, after all,
nothing new under the sun.) This aspect of creativity un-
doubtedly reflects the way minds work-not by spontane-
ously creating a completely new neural net, but rather by
continually modifying existing assemblies of neurons.
But the lesson here is that in practicing variational rep-
etition on solved problems students practice creating new
things. And even though their first attempts are mundane
and uninteresting, the habit, once acquired, can eventu-
ally serve them well.

Level 5 (Posing Problems)
Level 6 (Making Connections)
Motivation: Having learned to solve a problem, we should
then ask whether that knowledge can be applied to other
problems within the same domain and to analogous prob-
lems in other domains.
Reformulation: Pattern, problem context, and solution are
generalized to other domains.

The understandings gained at Level 5 can require substan-
tial effort and labor because they often require us to make
substantial modifications to dendritic trees and neural net-
works. So once such modifications are made, we try to
increase their usefulness by connecting them to other net-
works that represent other patterns and problem contexts.
That is, we try to project our newly acquired understandings
into other domains of knowledge. Sometimes ideas for cross-
domain connections can be evoked by posing a simple heu-
ristic: Having solved the immediate problem, can we now
solve a similar problem or an analogous problem? But more
often, we must employ cross-domain devices to help us find
ideas that transcend domains. Cross-domain devices are re-
lations, patterns, or procedures that are invariant under
changes of context; thus, they can be extracted from one
context and inserted into another. Such devices provide pow-
erful ways to increase understandings, and therefore it is
probably not surprising that relatively few of them are known.
We are always seeking to add new cross-domain devices to
our repertoire, for every such device gives us another way to
Winter 1998

learn. Five common cross-domain devices follow.
(1) Our most powerful cross-domain device is mathemat-
ics. This statement often surprises students, for they tend to
view mathematics as a tool for computation. But the real
value of mathematics is that its rules for reasoning are inde-
pendent of context: mathematics is powerful because it is
abstract. As a simple example, consider the exponential
growth law
where a may be positive or negative. This one equation
applies to certain processes in a number of very different and
unrelated contexts. For example, it describes the decay of
radioactive isotopes, the variation of density with altitude in
a stagnant isothermal atmosphere, the growth of a popula-
tion in a limitless environment, the cooling of a warm body
in cooler surroundings, and the growth of capital in an inter-
est-bearing investment.
(2) A second device for extending ideas across domains is
provided by scaling laws. These devices exploit the extent to
which certain behaviors are universal-independent of con-
text-when variables describing phenomena are scaled ap-
propriately. Thus, we have the many dimensionless groups
that correlate fluid flow and heat transfer in transport phe-
nomena, we have corresponding states ideas for correlating
thermodynamic properties, and we have scaling laws for
describing the behavior of materials near critical points.
More generally, we now have numerous disparate phe-
nomena, referred to collectively as fractals, that are invariant
under changes of scale. For example, the Brownian motion,
first described by Robert Brown in 1828, originally referred
to a microscopic scale; when viewed through a microscope,
a minute particle displays random movements caused by
collisions with molecules of the surrounding medium. But
such movements are also observed on macroscopic scales in
colloidal suspensions and on galactic scales in the motion of
stars in open clusters, such as the Pleiades.
(3) Another effective way to cross domains is by using an
analogy: the presumption that if two things have certain
similarities, then they also have other similarities. Analogies
can be structural or functional, and it is wise to keep clear
which you intend in a particular case; the common pitfall is
to assume that structural similarities imply functional simi-
larities. Examples of fruitful analogies include those among
the linear transport laws of Newton, Fick, Fourier, and
Ohm. In thermodynamics, certain phase diagrams for
vapor-liquid equilibria are structurally analogous to dia-
grams for liquid-solid equilibria. And in process control,
artificial neural networks bear certain functional analo-
gies to biological neural networks.
(4) Still another device is the metaphor, which we use to
describe an unfamiliar thing in terms of some more familiar
thing. Unlike an analogy, a metaphor typically attempts to

relate two things that have neither structural nor functional
similarities. Minsky has emphasized that we typically use
spatial forms and concrete objects as metaphors for abstract
ideas and concepts.J31 For example, we talk about an idea
being solid, firm, fluid, or off-the-wall. More generally, we
have family trees, the tree of life, the tree of knowledge,
dendritic trees, and logic trees; we have roots of a family, the
root of an idea, the root of the matter, the root of a prob-
lem, and the root of all evil; we have bridges between
domains of knowledge, the bridge of time, a bridge over
troubled water, and a bridge (no less) to the 21st century.
One of the most compelling metaphors of recent years
has been that of the desktop for manipulating operating
systems on personal computers.
(5) The last cross-domain devices we mention here are
various graphing templates for representing relations. The
most common is a simple x-y plot, which shows how an
effect is correlated with its cause. To have something less
familiar, we show in Figure 2 examples of an interaction
square,[31 which shows how two causes either reinforce or
compete in contributing to a single effect. In the first and
third quadrants of the square, the two causes act together to
either amplify (quadrant I) or suppress (quadrant III) the
effect. The interesting behavior occurs in the second and
fourth quadrants, in which the two causes compete. If we
have a mathematical relation for how the two causes contrib-
ute to the effect, then we can usually solve for the locus
along which the two causes exactly compensate for one
another. This locus transverses the second and fourth quad-
rants. A particular example appears in the bottom of Figure
2, which shows how temperature and flow rate contribute to
a particular value of the Reynolds number for fluid flow.
In the discussion of Level 3 (Paper 2 of this series), we
observed that organizing knowledge into patterns provides a
mechanism for improving the efficiency of education. Un-
derstanding at Level 6 provides a similar opportunity for
efficiency. At this level our intention is to find existing
neural structures created in one context and apply them to
problems in other contexts. When this can be done, we avoid
much of the laborious effort required at Level 5 in making
major structural changes to old networks.
Level 6 (Making Connections)
Level 7 (Creating Extensions)
Motivation: Having learned to recognize and solve analo-
gous problems in various domains, we should ask what
problems can still not be solved, but which might be solved
if we could extend, modify, or reformulate what we have
Reformulation: Generalizations are modified to attack other



At Level 6, our understanding is sufficient for us to realize
that a certain pattern, problem, or procedure, devised in one
context, can be useful when transplanted in toto to another
context. At Level 7 we realize that a complete transplant will
not be useful, but if the pattern, problem, or procedure is
modified, then the transplant will bear fruit. In some situa-
tions, the necessary modification can be generated by merely
devising a variation on a theme, but more likely, we need a
reformulation that is more elaborate than a simple variation.


Cause B



-- amplify

suppress 4 Cause A

-50 -25 0
T(C) T,

Figure 2. (Top) Generic template for an interaction square
that shows how two causes, A and B, contribute to one
effect. (Bottom) A particular example, showing how tem-
perature and flow rate combine to maintain the Reynolds
number at 104 for water flowing through a 2.54-cm pipe. If
the water temperature increases from the nominal condi-
tions of To = 500C at uo = 0.72 f/s, pushing the operating
point into the shaded region, then the desired Re can be
regained by adjusting a supply value to decrease the flow.
Inversely, if the temperature decreases from T,.

Chemical Engineering Education

25 50


That is, we are seeking a homomorphic projection across
domains-a projection that identifies the essential features
and that suppresses the inessential details.
An example is Maxwell's development of his theory for
electromagnetic fields, which grew out of an analogy with
vortices created in rotating incompressible fluids, as de-
scribed by Helmholtz and Thomson. Here is Maxwell re-
viewing some of Thomson's papers on electrostatics and
.. illustrations of magnetic force are not put forward as
explanations of magnetic force .... They belong more properly
to that remarkable extension of the science of hydrokinetics...
(The first italics is Maxwell's; the second is mine.)
Creating extensions is a first step in the more general topic
of pattern posing and as such it links the study of established
patterns to the research involved in creating new patterns. A
principal strategy for posing new patterns is to shift, remove,
or otherwise violate boundaries. By boundaries, we mean
the assumptions and preconceptions that are inherent in any
established pattern, concept, or procedure. Even experimen-
tal work involves assumptions; that is, we design an experi-
mental protocol involving certain pieces of equipment under
the preconceptions that certain phenomena will be observed
and not others. But bounds serve as barriers that limit our
thinking. So when a problem does not yield to attacks using
established patterns and procedures, then we should test the
bounds-examine our assumptions and preconceptions. As
Root-Bernstein has noted,[17 in such situations it's not the
problem that causes our lack of comprehension; rather, the
impasse arises from assumptions that we take for granted.
Bounds are a product of negative thinking. Up to now, this
paper has focused on positive thinking-on identifying ways
to promote firing of useful patterns of neurons. But the brain
has both inhibitory and excitatory synapses, so not only can
we learn productive ways to think, but we can also learn to
avoid unproductive ways to think. By imposing bounds on
positive thinking,13' negative thinking helps us be more ef-
fective because it helps us avoid wasting time on unproduc-
tive and counterproductive trains of thought. But we don't
want the bounds produced by negative thinking to be too
rigid because creative extensions can sometimes be found by
shifting those bounds or by recognizing that some bounds
have been misinterpreted or are inappropriate. Achieving
a balance between positive and negative learning requires
a delicate hand on the part of the instructor, for overem-
phasis on negative thinking can easily suppress creative
impulses in students.
Lastly, note that violating bounds-juxtapositioning the
incongruous-is a principal attribute of intellectual humor.
Indulgence in intellectual humor exercises the mind in vio-
lating bounds and produces combinations of thoughts that
might otherwise remain unconnected. It is a conceit of mine

that such exercise preserves some flexibility in neural net-
works, and it might-just might-represent some lowly prac-
tice at creating extensions.

In this series of papers, we have presented a strategy for
studying technical material; the strategy is organized into a
hierarchy of seven levels. We enter the hierarchy at Level 1
when our attention is drawn to a topic and we begin to pose
questions about it. We leave the hierarchy, as it applies to a
particular topic, at Level 7 when we begin to consider how
the topic's objects and concepts can be modified so that
they can be applied to other topics. Note that problem
solving, at Level 4, occupies the central level in the
hierarchy, but problem solving is neither the goal nor
terminal point of the hierarchy.
An overriding theme of these papers has been that any-
thing interesting or useful has multiple meanings, and under-
standings of those meanings arise out of connections: con-
nections among objects and concepts to form meaningful
patterns, connections between patterns and a problem con-
text, connections among different problems and their con-
texts, and connections among different domains of knowl-
edge. The hierarchy of understanding provides a scheme for
systematically making connections. The hierarchy can be
used by instructors to help organize how material is pre-
sented to students and to help assess student understanding.
Similarly, it can be used by students to help organize their
study of a topic, to assess their comprehension, and to iden-
tify what should be done to move to the next level.
We have devoted considerable effort in trying to find
meanings for the word understanding. Perhaps some addi-
tional insight can be gained by inverting the issue and identi-
fying things that are not understanding:
1) Verbal fluency is not understanding-people can en-
gage in conversations about a topic without being able
to answer questions about the topic or to explain the
topic to others;
2) Experience is not understanding-people routinely use
automobiles and computers without understanding how
such things work;
3) Solving a problem is not understanding-people can
solve a problem without realizing how they solved it
and without being able to explain their procedure;
4) Making predictions is not understanding-before 500
B.C., the ancient Babylonians had correlated sufficient
observations so that they could predict lunar eclipses,181
but they could not explain the geometry that causes an
5) Accumulated knowledge is not understanding-the
Nobel laureate Albert Szent-Gyorgyi once remarked
Continued on page 39.

Winter 1998

r M classroom



University of Colorado Boulder, CO 80309-0424

A few years ago, when I was new as Chair of Chemi-
cal Engineering at the University of Colorado, my
colleagues and I felt the need to take action to
improve our teaching. The idea was born, in part, out of a
sense of frustration in trying to communicate effectively
with students in the face of increased enrollments in our
courses at the time.
As a starting point, we held a brainstorming workshop
attended by (nearly) all faculty. We next formed small groups,
each with the same task of making a list of effective teaching
attributes. Each group then presented its findings, which
were discussed and organized into four categories:
Course Organization and Preparation
Classroom Communication
Rapport with Students
Assignments, Examination, and Grading
In preparation for our workshop, I prepared a handout of
hints for effective teaching that I later revised with the in-
sights gained from the workshop. Since it is easy to lose
focus of our primary responsibility as educators and to fail to
set aside ample time for helping our students learn, I make it
a habit to review these hints several times a year. I have also
given this handout to our all of our faculty.
What follows is the most recent version of the handout,
with annotations in italics added for this article. The reader
should understand that it is not a systematic or complete

Robert H. Davis is the Patten Professor and
Chair of Chemical Engineering at the Univer-
sity of Colorado. He received a BS degree
from the University of California at Davis, and
his MS and PhD degrees from Stanford Uni-
versity. His research and teaching interests
are in fluid mechanics, membrane separations,
and biotechnology.

scholarly work on teaching, but rather one that has evolved
from my experiences and those of my colleagues. In this
sense, it has a similar flavor to several other recent
articles"l-3J on personal perspectives, and many of the conclu-
sions are ones of common sense and experience. I encourage
the reader to also consult more thorough studies and discus-
sions of teaching methods and learning styles.'14-6


A Ask to teach courses related to your expertise. Your
knowledge of the material and your enthusiasm, both
ingredients of effective teaching,"71 will be highest in
such courses.
A Outline the entire course in advance. A logical presen-
tation of the material will be most effective if you decide
up front what the course learning goals are, what topics
are to be covered, and how much time should be spent
on each topic, and then prepare a detailed (two to four
pages) numbered outline that is used throughout the
A Prepare well-organized notes for each class period. It is
easy to get into (and hard to get out of) the pattern of
preparing for a class the night before (or even the same
day). While this approach works for some of my
colleagues, I am more relaxed if Iprepare a week or
more in advance.
L Set aside at least thirty minutes right before each class
period to review the materials and to focus your
L Read and assimilate several sources in addition to the
assigned text. Your course should have your personal
touch and should be prepared in a style and sequence
that makes sense to you, rather than just following a
text. I recommend that you go through several books,
journals, popular press, and notes from other faculty to

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

In preparation for our workshop, I prepared a handout of hints for effective teaching
that I later revised with the insights gained from the workshop.... I make it
a habit to review these hints several times a year.

select your materials.
[ On the first day of class, give the students a course
syllabus that includes the course goals, an outline,
reading assignments, homework expectations, exam
schedule, and grading policies.
[ On the first day of class, and periodically throughout
the term, discuss the relevance of the course material to
practical applications and to the rest of the curriculum.
If we want students to learn, then we must provide
motivation on why the material is important.17' Even
better, ask them to brainstorm on real-life applications
and tie-ins with other courses, either in small groups or
in an open-class discussion.
[ Provide and discuss review sheets prior to each exam.
These help the students see the big picture of what they
(should) have learned and how it ties together.
L Your course outline, notes, and materials should be
reviewed and updated each time you teach the course.


[ Put an outline on the board and provide a preview at the
beginning of each class period, whether giving a lecture
or using another style; use a brief review of the previ-
ous class period as a transition.
L Summarize the key points, with the help of students, at
the end of each class period.
A Come to class well prepared and undistracted, so that
you are less likely to stumble over derivations or
solutions. If you do make a mistake, admit your error. If
you get stuck, promise the students that you will find the
answer for next time; do not bluff "'
A Do not read your notes to the students. Simply reading
lecture notes or from a book is a sure way of turning off
the students' learning processes.1'8 While some gifted
faculty can deliver an entertaining and factual lecture
with no written materials, I am most comfortable with a
middle-of-the-road approach where I bring about five
pages of handwritten notes to a 50-minute class
period-about half of them represent material that I put
on the board for the students and the rest is highlighted
prompts to me on questions, illustrations, stories, etc.
A Write neatly on the board or overheads, use visuals, and
give students sufficient time to take notes. Board use

shouldfollow an orderly and logical progression, the
physical layout of which should be visualized in
advance, and include numbered headings consistent
with the course and class outlines. Visuals (pictures,
drawings, graphs, charts, etc.) are excellent learning
tools.1J7 When using overheads, it is especially impor-
tant to give students time to write down what is neces-
sary-or to provide them with copies of the overheads. I
like a mix of writing on the board for the main part of
the lecture, interspersed with breaks where I pass out a
one-page handout of an example or derivation that I
then go through quickly using an overhead.
[ Ask questions in order to maintain the students' focus
and assess their understanding of the material. Well-
formulated questions should stimulate the students'
thought processes.101 Give the students plenty of time to
answer the questions, and provide prompts or hints, if
necessary. I sometimes call on students by name; this
must be done with courtesy and respect, as some
students prefer to remain in the background. A student
must never be embarrassed or ridiculed for not
knowing the answer.
i Use examples in class that students can relate to. In a
heat-transfer course, discuss why the same temperature
"feels different" in dry air, humid air, water, and wind.
In a fluids course, calculate how much the shower
temperature will go up when the toilet is flushed, and
suggest an alternative plumbing design that minimizes
this effect.
A Start and end the class period on time, and gently but
firmly maintain order.


[ Learn each student's name. While this is more difficult
with larger classes, suggestions include asking each
student to write a short biographical sketch on the first
day of class, taking photographs, handing back
homework individually just before the start of class,
greeting students by name, and asking students their
names when you don't know them.
( Schedule at least two office hours or optional-help
sessions per week at times available to the students.
One should be the day before an examination is held or
homework is due, and the others) earlier in the cycle.

Winter 1998

Most important, be present for your office hours and
inform the students and reschedule those times for
which there are unavoidable conflicts.
A Be willing to see students outside scheduled office
hours and help sessions. One of the most difficult issues
we face is how to make availability to students a high
priority when there are so many other demands on
faculty time. When students drop by, my intention
(though I often fall short) is to set other things aside
and listen and help. If meeting their needs will take
longer than I can spend at that time, then I set up an
appointment. To make the necessary uninterrupted time
for writing and other tasks, I come in early; others may
prefer to stay late or spend part of the day working at
[ Be attentive and sympathetic to students; do not say
anything that might make a student feel put down,
either in public or in private. The most common student
complaints that I receive as Department Chair is that
they have not been treated with respect by faculty.
While insensitive words or actions are often unin-
tended, we must never lose sight of our calling to serve
and encourage our students.
[ Take at least one class period, or parts of two or more,
to dispense with the course material and discuss a
subject such as professional ethics or your own experi-
[ Solicit and respond to mid-course feedback by a group
interview or evaluation questionnaire. Using class
representatives or peer evaluation can also yield useful
feedback while there is still time to make changes.13'"
A Provide food. At help sessions, during special occa-
sions in class, or for an end-of-term party.
A Understand that relationships with students do not end
with the course. If you show students that you care, then
they will naturally ask you to write recommendations
and provide career advice. 2' Some will come to you
with personal problems (know when to seek help from
campus professionals). Some will stay in touch for
years. These are some of the responsibilities and
rewards of our profession.


[ Inform the students of the course grading scale or
method at the start of the course. The second most
common complaint that I receive from students involves
grades-that they were not informed by the instructor
that a certain exam would make up half of their grade,
that they were not told what performance was required
to get a "B" in the course, or that a friend received a

higher grade with the same or lower scores.
" Make sure that the exam problems correspond to the
course objectives and learning goals, which should be
the major topics of the class periods and homework
assignments. Students learn more when they are
actively involved,"' and one of the best activities is
homework on carefully selected problems.
" In each assignment and examination, include a mix of
simple, medium, and difficult problems. Since students
learn and demonstrate knowledge in different ways, it
helps to include a variety of exercises.[71
A Develop solutions for all homework and exam ques-
tions before they are handed out, and work the prob-
lems yourself. Not only does this serve as a check that
the problems are reasonable, but it also gives you the
necessary preparation for answering questions.
A Grade as thoroughly as time allows, providing com-
ments and partial credit. Careful grading is needed for
fairness and consistency, and it provides important
feedback to the students. This requires time; if neces-
sary, use this article to help convince your department
to invest adequate resources in graduate and under-
graduate course assistants.
L Return graded homework, exams, and reports promptly.
Students want feedback.171 More important, prompt
grading shows students that they are a high priority.
These hints for effective teaching can be summarized in
one word: time. It takes time to prepare a course well; it
takes time to know students. If we care deeply about stu-
dents and their learning, then teaching will be a high priority
among our other responsibilities and we will take the time to
do it well.

1. Bird, R.B., "Seven Rules for Teaching," Chem. Eng. Ed.,
27(3), 164 (1993)
2. Turian, R.M., "The Quest for Excellence in Teaching," Chem.
Eng. Ed., 27(4), 182 (1993)
3. Bowman, C.N., "Teaching in the First Few Years," Chem.
Eng. Ed., 28(4), 280 (1994)
4. Wankat, P.C., and F.S. Oreovicz, Teaching Engineering,
McGraw-Hill, New York, NY (1993)
5. McKeachie, W.J., Teaching Tips:A Guidebook for the Begin-
ning College Teacher, 8th ed., D.C. Heath & Co., Lexington,
KY (1986)
6. Kolb, D.A., Learning Style Inventory, McBer and Co., Bos-
ton, MA (1985)
7. Wankat, P.C., "What Works: A Quick Guide to Learning
Principles," Chem. Eng. Ed., 27(2), 120 (1994)
8. Wankat, P.C., "Synergism Between Research and Teaching
in Separations," Chem. Eng. Ed., 30(4), 202 (1997)
9. Felder, R.M., "Things I Wish They Had Told Me," Chem.
Eng. Ed., 27(2), 108 (1994)
10. Felder, R.M., "Any Questions?" Chem. Eng. Ed., 27(3), 174
11. Brent, R., and R.M. Felder, "It Takes One to Know One,"
Chem. Eng. Ed., 30(1), 32 (1997) 0

Chemical Engineering Education

Toward Technical Understanding
Continued from page 35.

that during his study of muscular action he came to
realize that the more he learned, the less he understood,
and so he became fearful of finally learning everything,
but understanding nothing.[10
The discussions here raise many questions that would
seem to serve as starting points for further, more detailed
investigations. Here is a list of some of the more obvious
1. If the pattern can indeed serve as the fundamental unit of
understanding, then what are those patterns that distinguish
one topic from another? For example, what patterns distin-
guish transport from thermodynamics and thermodynamics
from reaction kinetics? Then, by extension, what patterns
distinguish chemical engineering from chemistry and from
other engineering disciplines?
2. Repetition is necessary to solidify certain kinds of under-
standings, and therefore some amount of redundancy needs
to be incorporated into a curriculum. But efficiency in edu-
cation can be attained by appealing to patterns and other
devices that cross subject domains. To what extent can a
curriculum be made more effective by organizing it around
patterns rather than topics?
3. What are appropriate cues that will activate, in student
brains, proper patterns and homomorphic projections needed
to address particular problem situations? Are there mini-
mum numbers of cues that are sufficient?
4. Can we contrive a complete list of devices for making
connections across subject domains? Is there a minimum
number of such devices that a student should be able to use?
What are the most effective ways for students to develop
facility with cross-domain devices?
5. Can we devise systematic procedures for identifying and
testing default assumptions and probing tacitly assumed
6. Are there ways to gauge the importance and impact of
negative thinking relative to positive thinking?
7. What indicators can we devise for determining when stu-
dents successfully make a transition from one level of un-
derstanding to another?
8. Presumably, we do not expect all students to achieve the
same levels of understanding. What levels are appropriate
for BS students? For MS students? For PhD students?
9. Traditional descriptions of brain function use time to iden-
tify two kinds of memories: short-term (you look up a
phone number and remember it only long enough to dial it)
and long-term (you still remember your name). But recent
evidence suggests a third: intermediate-term memory, in
which a buffer (perhaps the hippocampus) is loaded while
structural changes are made in the brain to lay down the
corresponding long-term memory. Thus, students who cram
before a test often do not retain the crammed information
because they are only loading a buffer, not creating long-
Winter 1998

term memories. This suggests that simple linear progres-
sion through material over a semester may not be as effec-
tive as some cyclic procedure in which important patterns
are revisited at intervals. Revisiting amounts to repetition,
which stimulates creation and solidification of long-term
memories and pares away superfluous scaffolding. If this
conjecture were confirmed, what kinds of cyclic presenta-
tions should be used? What are the optimum times between
re-exposure to the same patterns?
10. Finally, note that throughout these papers we have empha-
sized what rather than how. So, how do we help students
progress through a hierarchy of understanding?

Understanding never ends.

Many of the ideas presented in this series were tested and
clarified by continually referring to Marvin Minsky's book,'31
The Society of Mind; without that book, these papers would
have taken a very different form. Over the years of my
struggle to understand understanding, I have learned much
from discussions with my colleagues R.W. Rice
(Clemson) and J.P. O'Connell (Virginia); my thanks for
their forbearance.

1. Rolls, E.T., and A. Treves, "Neural Networks in the Brain
Involved in Memory and Recall," Progress in Brain Res.,
2. Calvin, W.H., The Cerebral Code, MIT Press, Cambridge,
MA (1996)
3. Minsky, M., The Society of Mind, Simon and Schuster, New
York, NY (1986)
4. Brown, S.I., and M.I. Walter, The Art of Problem Posing,
Erlbaum, Hillsdale, NJ (1983)
5. Hofstadter, D.R., "Variations of a Theme as the Crux of
Creativity," in Metamagical Themas, Basic Books, Inc., New
York, NY (1985)
6. Maxwell, J.C., "Review of Reprint of Papers on Electrostat-
ics and Magnetism by Sir W. Thomson," in The Scientific
Papers of James Clerk Maxwell, Vol 2., W.D. Niven, ed.,
Cambridge University Press, Cambridge (1890); reprinted
by Dover Publications, New York, NY, p. 301(1965)
7. Root-Bernstein, R.S., Discovering, Harvard University Press,
Cambridge, MA, p. 296 (1989)
8. Neugebauer, O., The Exact Sciences in Antiquity, reprint of
2nd ed., Harper & Brothers, New York, NY (1962); 1st ed.,
Princeton University Press (1952); 2nd ed., Brown Univer-
sity Press (1957)
9. Toulmin, S., Foresight and Understanding, Indiana Univer-
sity Press, Bloomington, IN (1961); cited in D.A. Crosby and
R.G. Williams, "Creative Problem-Solving in Physics, Phi-
losophy, and Painting: Three Case Studies," in Creativity
and the Imagination, M. Amsler, ed., University of Dela-
ware Press, Newark, DE (1987)
10. Szent-Gyorgyi, A., "In Search of Simplicity and Generaliza-
tions (50 Years Poaching in Science)," in Current Aspects of
Biochemical Energetics, N.O. Kaplan and E.P. Kennedy,
eds., Academic Press, New York, NY (1966) O

Me laboratory





Clarkson University Potsdam, NY 13699-5710

Historically, chemical engineers have been primarily
concerned with maximizing the efficiency of indi-
vidual processes while designing chemical produc-
tion facilities. Current regulatory pressures to minimize risks
associated with the production of chemicals, however, re-
quire chemical engineers to understand the fate of these
chemicals in the environment. The fundamental mass trans-
fer processes controlling the migration of contaminants in
environmental systems are similar to those in chemical engi-
neering processes. There are distinct differences, though,
that have implications in how individual processes are ana-
lyzed. For example, contaminant concentration in the envi-
ronment is generally very low (on the order of parts per
million (ppm)), and the number of compounds present in a
given environmental system is very large and unknown com-
pared with typically well-controlled chemical engineering
processes. The complexity of these systems needs to be
simplified in order to describe mass transfer process envi-

Susan E. Powers received her BS and MS
degrees in chemical engineering and environ-
mental engineering, respectively, from Clarkson
University. In 1992, following the completion of
her PhD in environmental engineering from the
University of Michigan, she returned to Clarkson,
where she is presently Assistant Professor in
the Department of Civil and Environmental En-

Stefan J. Grimberg received a Diplom Engi-
neering (TU) degree in chemical engineering
from the Munich Technical University, and his
MS and PhD degrees in environmental engi-
neering from the University of North Carolina,
Chapel Hill. He presently holds the position of
Assistant Professor in Clarkson's Department
of Civil and Environmental Engineering.

ronmental systems.
At Clarkson University, the fate of hazardous organic
pollutants in the environment is covered in the class "Haz-
ardous Waste Management Engineering." Senior-level stu-
dents from the departments of civil and environmental engi-
neering, chemical engineering, and industrial hygiene typi-
cally enroll in this class. Fundamental processes governing
the environmental fate and transport of organic contami-
nants are covered during introductory lectures and are used
throughout the semester to support more advanced material
related to human exposure levels, risk assessment, and de-
sign of treatment strategies. Throughout the semester, the
relationships between chemical behavior and molecular struc-
ture (i.e., size and polarity) are emphasized.
After this class was taught for two years, it became appar-
ent that students had difficulty grasping the concepts of
partitioning of solutes between phases. Thus, the experi-
ments described here were developed to help students under-
stand the partitioning and transport of organic compounds in
environmental systems. Constraints of class length (50 min-
utes), size (30-40 students per section), and budget, how-
ever, limited the scope of possible experiments. A creative
solution of using nontoxic, colored solutes, allowing strik-
ingly visual detection as the solutes partitioned between
phases, effectively illustrated the concepts of phase par-
titioning and enabled all students to be active partici-
pants in both the qualitative and quantitative components
of this laboratory.

A significant fraction of groundwater contamination in the
United States is the result of spills and disposal of organic
liquids in the ground. The organic phases, referred to as non-

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

aqueous phase liquids (NAPLs), are typically consid-
ered to be immisciblee" with water, although their
solubilities are high enough to contaminate groundwa-
ter at levels higher than drinking-water quality stan-
dards."I Figure 1 illustrates the partitioning and trans-
port processes affecting a NAPL such as gasoline.
Since gasoline is less dense than water, it accumu-
lates at the water table. Subsequent partitioning of
contaminants into both the groundwater and soil
gases will occur.
The equilibrium dissolution of solute from a NAPL
and subsequent sorption of the aqueous-phase solute
to sand are considered in this laboratory. Because of
the low concentrations involved in these processes, it
is assumed that the density and molecular weight of
the phases, and activity coefficients of each species in
the aqueous phase, remain essentially constant. For
many NAPLs, it is reasonable to also assume that the
organic phase is an ideal solution and, thus, that activ-
ity coefficients in this phase are close to one. With
these simplifications, phase equilibria governing the
partitioning of solutes between these environmental
compartments is often approximated with linear rela-
tionships describing the concentrations of a species
between phases 21

NAPL-water systems: C = CX (1)
Soil-water systems: q = KdC (2)

C concentration (mg/L) of a compound in the aqueous phase
C* solubility of the pure liquid chemical in water (mg/L)
X mole fraction of this compound in the NAPL
q concentration sorbed on the soil (mg/kg)
K soil-water distribution coefficient (L/kg)

Equation (1) is Raoult's Law for liquid-liquid equilibria
and has been shown to be fairly accurate for even com-
plex NAPL mixtures comprised of chemicals with low
solubilities.1 J
Both C* and Kd are partition coefficients describing the
linear equilibrium relationship between phase concentrations.
Their values are highly dependent on the molecular structure
of the compound.131 Nonpolar organic are hydrophobic, ex-
hibiting trends of generally decreasing solubilities and in-
creasing soil-water distribution coefficients with increasing
molecular weight. The presence of polar functional groups,
especially those with O, N, or S atoms, decreases the aque-
ous-phase activity coefficient, thereby greatly increasing the
aqueous-phase solubility and decreasing the soil-water dis-
tribution coefficient of organic compounds.
Following the partitioning of organic compounds from the
NAPL to the aqueous phase, the contaminant molecules are
transported with flowing groundwater, potentially polluting
Winter 1998

Fundamental processes governing the
environmental fate and transport of organic
contaminants are covered during introductory lectures
and are used throughout the semester to support more
advanced material related to human exposure levels,
risk assessment, and design of treatment strategies.

Figure 1. Processes affecting the fate of a NAPL such as gasoline
in the subsurface.

downgradient sources of drinking water. Convection (also
called advection by environmental engineers) and dispersion
are the predominant transport mechanisms, although the sorp-
tion of solutes to soil effectively retards the transport rate.
Assuming equilibrium between solid and the liquid phases,
the standard transport equation with a linear sorption term
added can be written in one dimension as

ac '2C C pb da
dr= D x d
at ax n at

ac D, "2C ux aC
at R Ox2 R ax

D, hydrodynamic dispersion coefficient in the longitudinal
ux average linear interstitial velocity of the aqueous phase
R retardation coefficient (R = I + pbKd / n)
n porosity of the porous medium
Pb bulk density of the porous medium
The retardation coefficient can also be described as the ratio
of the mean velocity of water (ux) to the mean velocity of
the solute (uo,)

R = (4)

A solute with a low retardation coefficient (R~-) will be
relatively mobile within an aquifer system, potentially
resulting in higher human exposure levels than a solute
that sorbs strongly.

A laboratory experiment was developed to reinforce the
concepts of phase partitioning and its relationship to mo-
lecular structure and the mobility of a solute in a groundwa-
ter system. Three NAPLs with different colors and hydro-
phobicities were mixed with water, and then the contami-
nated water infiltrated through sand to observe the parti-
tioning of the colored solutes. This experiment was in-
cluded in the hazardous waste management class during
the fall semester of 1995.
An assessment of the effectiveness of this laboratory indi-
cated that the students perceived an increase in their compre-
hension of these concepts. Results of their homework as-
signments, however, showed that they still struggled with
quantitative homework problems. Thus, an additional ex-
periment was designed for the 1996 class that involved a
more quantitative measure of retardation coefficients as con-
taminated water samples were pumped through a soil col-
umn and the velocity of the contaminant was measured
relative to the velocity of water.
Materials Adding dye to nontoxic organic phases
created three NAPLs with different colors and a range of
partitioning behaviors. Table 1 describes the composition of
the "red," "blue," and "green" NAPLs. The polarity (or
hydrophobicity) of these dyes is the property critical to their
partitioning behavior and the success of the experiment. The
overall polarity of a molecule depends on contributions of
polar atoms (O, S, N, Cl) and nonpolar atoms (C, H). Quali-
tatively, oil-red-o is more hydrophobic than methylene blue
because a greater fraction of the oil-red-o molecule is com-
prised of carbon (see Table 1). Similarly, green food color is

more polar than methylene blue since the number of polar
atoms in green food color is higher than in methylene blue
(Table 1). In order for the observed partitioning of the color
to be representative of the overall bulk NAPL partitioning,
the polarity of the dye has to mimic the polarity of the
NAPL. The polarity of the bulk organic liquids used in-
creased from mineral oil to ethanol. Thus the polarity of the
selected colors represent the polarity of the NAPL.
Other materials included tap water as the aqueous phase
and clean quartz sand, suitable for a child's sandbox, for
the soil.

Laboratory 1
A Qualitative Understanding of the Partitioning of
Solutes Between NAPL-Water and Water-Sand Systems

The first laboratory allows a qualitative assessment of the

Figure 2. Photograph illustrating the
partitioning of red, blue, and green solutes
(left to right) from a NAPL to water.

Composition of Colored NAPLs

NAPL Bulk Organic Phase Solute'" Chemical Formula Characteristics

red mineral oil oil-red-o2' C6H24 N40 very hydrophobic
blue 5% (by vol.) octanol in mineral oil methylene blue'31 C,,H,,NSCI slightly hydrophobic
green ethanol green food color4' C6H 007C12 NaS 2151 hydrophilic
C16HONNa2S 261

Only a small amount of dye required for each to provide vivid color
2 Available through Fisher Scientific (biotechnology reagent)
3 Dissolved in octanol prior to mixing with mineral oil
4 Mixture of FD&C Yellow 5 and FD&C Blue 1; available through McCormick & Co. Inc., Maryland
5 FD&C Yellow 5 (5)
6 FD&C Blue 1 (5)

Chemical Engineering Education

partitioning behavior of the red, blue, and green solutes as
well as the bulk organic phases. Teams of 3-4 students each
were provided with bottles containing each of the three
NAPLs, three 40-mL screw-cap vials about 75% full of
water, two filtering crucibles about 50% full of dry sand, two
50-mL beakers, and several disposable capillary pipettes.
In the first phase of the experiment, students observed the
range of possible partitioning behaviors between the NAPLs
and aqueous phase. The steps simply involved adding ap-

Questions Posed to Increase Conceptual Understanding

Questions for NAPL-water partitioning
Classify the solubility (soluble, partially soluble, insoluble) of
three colored solutes and the bulk organic phases
Discuss the implications of these differences on the fate of
NAPLs in the subsurface
What differences in the chemical structures would you expect
based on the observed solubilities?

Questionsfor aqueous phase-soil partitioning
Rank the solutes in order of increasing potential for sorption;
explain your answer
Discuss the implications of these differences on the mobility
of these solutes in the environment
What differences in the chemical structures would you expect
based on the observed sorption behavior?
Summary questions
Are the observations and conclusions drawn from the
solubility experiment consistent with the results of the
sorption experiment? Explain.
Describe the overall fate of each of the three NAPLs
following a spill to the environment

syringe pump with
100-mL syringes

Figure 3. Schematic of experimental system for column
retardation experiment.
Winter 1998

proximately 1 mL of NAPL to each of the three water vials,
gently shaking them to equilibrate, and then observing the
distribution of color and the bulk organic fluid between
phases. Results range from no observable partitioning of the
hydrophobic red solute in mineral oil to the complete disso-
lution of the very polar green solute in ethanol (see Figure
2). The blue solute illustrates the concept of having a
partially soluble solute in an essentially insoluble bulk
organic phase. In this case, much of the blue color trans-
ferred to the aqueous phase, although most of the volume
of NAPL remained as a separate immiscible phase. This
case is most representative of environmentally signifi-
cant NAPLs such as gasoline.
The second phase of the first laboratory provided a greater
understanding of the partitioning of solutes between aque-
ous and soil phases. As described above, the mixing of
NAPLs and water generated blue and green contaminated
water. Each of these aqueous phases was then poured through
sand in the filtering crucibles that were held over 50-mL
beakers. The very polar green solute was not retarded, as
evidenced by the lack of change in color of either the sand or
water. With the less polar blue solute, however, the sand
turned blue and the effluent became clear, illustrating that
slightly soluble solutes can be strongly sorbed, greatly de-
creasing contaminant concentrations in the aqueous phase.
In order to help students increase their understanding of
partitioning behavior, we posed several questions to pro-
mote their ability to connect experimental observations to
fundamental concepts (see Table 2). These questions fo-
cused primarily on the relationship between chemical struc-
ture and mobility of chemicals in the environment.

The second laboratory was developed to quantify the ex-
tent of solute sorption. The equipment required for this labo-
ratory (see Figure 3) was more extensive and, thus, the
laboratory was conducted as a demonstration, with students
taking turns making the measurements over time. Colored
aqueous phases for this experiment were prepared by the
direct addition of dyes into the aqueous phase (0.05 g/L
methylene blue for the "blue" aqueous phase and 10 mL/L
green food color for the "green" aqueous phase).
Two Plexiglas columns (3.8-cm diameter by 25-cm long)
were carefully packed with a uniform sand (30-40 mesh; d5s
= 0.5 mm) to provide a relatively homogeneous sand to help
minimize solute dispersion within the column. Several pore
volumes of degassed water were then pumped through each
column to displace and dissolve all of the air. At t=0, pump-
ing of the blue and green aqueous phases through the col-

umns at rates typical of groundwater flow (Q=0.1 mL/min)
was initiated.
Using colored solutes allowed visual assessment of the
migration of these solutes. The interface between clean and
colored water was marked on each column over time and the
average distance traveled by the colored water was recorded.
Assuming that convection is the predominant transport
mechanism, the position of the sharp front marked by the
colored water was used to estimate the interstitial solute
velocity. Thus, the retardation coefficient (Eq. 4) was calcu-
lated as

R =QA (5)
Q volumetric flow rate of water
A column cross-sectional area
L distance traveled by the colored water in time t
n porosity, included to convert to an interstitial aqueous
phase velocity

Equation (5) can be rearranged to calculate the retardation
coefficient by linear regression of the L-versus-t data.
Figure 4 illustrates differences in the travel time of the
solutes through the soil columns. As expected from the
qualitative experiment described above, the greater distance
traveled by the very-polar green solute indicates that it is
much more mobile than the less-polar blue solute. The ob-
served variability in the position of the front around the
column perimeter at any point in time (Figure 4) is attributed
to column-scale heterogeneities in soil permeability that af-
fect local rates of convection. To accommodate for this
variability, the experimental analysis was completed using
the average of four measured travel distances at each time.
These average travel distances with error bars representing
one standard deviation are included in Figure 5.
Linear regression of the data was used to estimate the
retardation coefficients for each solute. Regression coeffi-
cients greater than 0.99 were obtained in both cases. The low
retardation of the green solute (R= 1.40.1) confirms the fact
that this solute would be highly mobile in an aquifer system,
while the higher retardation coefficient for the blue solute
(R=4.4+0.2) provides quantitative evidence of the greater
extent of sorption of this solute. With both visual and quanti-
tative interpretation of this experiment, students grasped the
impact of sorption and the connection between this partition-
ing process and the potential for exposure to contaminants
through drinking water downgradient of a pollution source.

Students completing these experiments observed the wide
variability in the behavior of organic pollutants in the envi-
ronment. They concluded that the mobile green solute and
the bulk organic liquid that comprised this NAPL were hy-

Figure 4. Photograph of the column retardation experi-
ment after twelve hours. The polar green solute clearly
travels at a higher velocity than the blue.

0 500 1000 1500 2000
Time [min]
Figure 5. Calculation of retardation coefficients from mea-
sured average distance of solute travel as a function of
time. Solid lines represent the linear regressions and error
bars illustrate one standard deviation of the four indi-
vidual measurements of distance at each time.
Chemical Engineering Education

drophilic and very mobile in the environment. The solute
and bulk organic liquid that comprised the red NAPL, on the
other hand, were very hydrophobic and relatively immobile
in an aquifer system.
From a pedagogical standpoint, providing students with an
active learning experience and very visual observation of
these phenomena effectively improved their overall under-
standing of the fate and transport of organic contaminants in
an environmental system. In terms of Bloom's hierarchy of
learning,'4' the first laboratory increased the students' com-
prehension, while the second laboratory addressed the appli-
cation of these ideas in engineering calculations. Both com-
prehension and application are critical steps for the students
to achieve prior to advancing to the more challenging tasks
of analysis and synthesis. Thus, by completing these labora-
tories early in the semester, students were better prepared for
tackling more complex issues associated with formulating
engineering decisions with respect to the potential for envi-
ronmental contamination.

Support from a National Science Foundation CAREER grant
(BES-9501567) was used in developing these laboratories.

1. Cohen, R.M., J.W. Mercer, and J. Matthews, DNAPL Site
Evaluation, C.L. Smoley, Boca Raton, FL (1993)
2. Thibodeaux, L.J., Environmental Chemodynamics: Move-
ment of Chemicals in Air, Water, and Soil, 2nd ed., John
Wiley and Sons, New York, NY (1996)
3. Verschueren, K., Handbook of Environmental Data on Or-
ganic Chemicals, 2nd ed., Van Nostrand Reinhold, New
York, NY (1983)
4. Wankat, P.C., and F.S. Oreovicz, Teaching Engineering,
McGraw-Hill, New York, NY (1993)
5. Colour Index, 3rd ed., The Society of Dyers and Colourists,
Bradford, England (1971) O

COMET Project
Continued from page 23.
for introducing these topics.
As the instructor, I should have made more clear to the
students the connections between the project and the course
material. I also should have explained why the project is of
value to a beginning engineer. Clearly stated instructional
objectives are known to facilitate student learning.'"" The
project might have been more closely linked to the main
course content if, for example, it had permitted chemical
energy sources and involved more energy balance calcula-
tions in the COMET design. But this would have been diffi-
cult since the project had to be safe and relatively short and
simple for sophomore students. The COMET project is there-
fore a compromise that achieves the primary goal of intro-
Winter 1998

during ideas not found in traditional pencil-and-paper
projects, but does so in a non-chemical engineering-specific
Logistical Improvements
"I think this project would have been better at the beginning
of the quarter."
"Give the groups an extra week or so to think about the
"Make the project worth more than 5%."
A number of students would have preferred different lo-
gistical arrangements for the project. Because it involved a
lot of work, students wanted the project assigned earlier in
the quarter when it would not conflict with midterms, wanted
more time to work on the project, and wanted it to be worth a
larger fraction of their grade. All of these changes can be
easily made and will be implemented next time.

The COMET project provided a relatively simple assign-
ment that introduced sophomore chemical engineers to a
number of important engineering concepts that are often not
addressed until later in the curriculum: teamwork, open-
ended problems, design, hands-on experimentation, techni-
cal writing, and estimation based on limited data. Most stu-
dents enjoyed the project and recommended its use in future

Thanks to Melissa Bradley, Richard Felder, and David
McGill for helpful discussions and to Dayton Funk for pho-
tography. This work was supported in part by a CAREER
Young Investigator Award from the National Science Foun-
dation (BES-9624832).

1. West, W., W. Flowers, and D. Gilmore, "Hands-On Design
in Engineering Education: Learning by Doing What?" Eng.
Ed., 80, 560 (1990)
2. McConica, C., "Freshman Design Course for Chemical Engi-
neers," Chem. Eng. Ed., 30, 76 (1996)
3. Davies, W.A., "Design Competition for Second-Year Stu-
dents," Chem. Eng. Ed., 30, 102 (1996)
4. Felder, R.M., and R.W. Rousseau, Elementary Principles of
Chemical Processes, 2nd ed., John Wiley & Sons, New York,
NY (1986)
5. Angelo, T.P., and K.P. Cross, Classroom Assessment Tech-
niques: A Handbook for College Teachers, 2nd ed., Jossey-
Bass, San Francisco, CA (1993)
6. Bell, J.T., "Anonymous Quizzes," Chem. Eng. Ed., 31, 56
7. Schmeck, R.R., ed., Learning Strategies and Learning Styles,
Plenum Press, New York, NY (1988)
8. Felder, R., "Meet Your Students: 3. Michelle, Rob, and Art,"
Chem. Eng. Ed., 24, 130 (1990)
9. Felder, R., "Matters of Style," ASEE Prism, 6, 18 (1996)
10. Mager, R.F., Preparing Instructional Objectives, 2nd ed.,
Lake Management and Training, Belmont, CA (1984) J

Random Thoughts...


North Carolina State University Raleigh, NC 27695-7905

Ever get a sneaking suspicion that our students may not be
totally focused on the intellectual delights of thermodynam-
ics and transport phenomena while we're lecturing? It some-
times happens that other things are on their minds, especially
when we're enthusiastically filling the board with letters,
numbers, and squiggles that have no apparent connection to
anything they know or care about. For example,

Professor Cheever:
". .. and next we'll examine laminar flow of a
newtonian fluid in a circular pipe and derive Equa-
tion 4.5-35 in your text. We first draw this differen-
tial element and now we itemize the stresses
acting on it, starting with .."

Student A (SA): "Hey Jerry, how's the rest of your
schedule look?"
SB: "Not bad-I've got a couple of humanities courses so I
shouldn't be overworked."
SA: "Unless you get old Ferguson .. last spring she gave
us five books to read in the first week, including Moby
Dick. It's about a fish."
SC: "What did he say that arrow pointing up is?"

Richard M. Felder is Hoechst Celanese Pro-
fessor of Chemical Engineering at North Caro-
lina State University. He received his BChE from
City College of CUNY and his PhD from
Princeton. He has presented courses on chemi-
cal engineering principles, reactor design, pro-
cess optimization, and effective teaching to vari-
ous American and foreign industries and institu-
tions. He is coauthor of the text Elementary
Principles of Chemical Processes (Wiley, 1986).

@ Copyright ChE Division ofASEE 1998

SD: "Who knows? ... Ijust wonder how I'm going to make
it to December if I'm this lost now."
SC: "You and everybody else ... except maybe old Arthur
here ... Hey Art-you getting this?"
SE: "No, but I've seen his old tests-you don't need to
understand anything, you just need to plug into
SD: "Cool!"

Professor Cheever:
"... and as we know from calculus, the limit of this
expression as delta r approaches zero is what? ...
anyone remember? ... no? ... well, it's the partial
derivative, and so we can replace..."

SF: "What say, Chief-coming to the Delta Chi mixer
SG: "No can do-I got a physics test tomorrow and if I
don't get my grades up I can kiss my scholarship
SF: "Aw, come on, Sir Isaac-you know that stuff A couple
of brews and you'll be relaxed and ready to hit that
test like a sledgehammer."
SG: "That's what you said before the chemistry final last
spring and if I remember right you relaxed your butt
into a D.
SF: "Yeah, but that final was..."
SH: "So how'd it go last night?"
SI: "Don't ask ... that geek Rachel set me up with is
majoring in soil science or something and he spent the
whole night talking about fertilizer. Let me tell you a

Chemical Engineering Education

few things about phosphorus that you probably
never. ..

Professor Cheever:
"Now at this point we introduce the stress tensor, a
convenient and concise representation of the nor-
mal and shear stresses in the..."

SJ: "Yo, Sally-hand me some of them chips there."
SK: ". Problem 3 on the thermo homework?"
SL: "Yeah, it's a killer, but it's cute-you have to figure
out the equilibrium partial pressure of nitrous oxide to
know if the dental hygienist poisoned the bank presi-
SK: "Right, Ifigured that much out, but at that pressure
you can't just plug into Raoult's law and I don't how
how you.. ."
SJ: "Yo, Gene, can I have a hit of your Dr. Pepper?"
SM: "What time you got-I think this has been going on for
about four hours but I'm not sure."
SA: "Twenty minutes to go and counting."

SA: "Ten minutes.
SN: "Shh-don't wake Brenda ... she's the only one
getting anything useful out of this class."
SO: "It's my grandmother this time-I'll probably have to
go home for the weekend again and just hope I can
find some time to look over the..."
SJ: "Yo, Bruce, hand me a couple of them Cheez Doodles,
would ya?"
SQ: "Hear about Monica, Sheila's roommate?"
SR: "No, what about her?"
SQ: "She's been acting weird lately, just lying in her room
staring at the ceiling for hours."
SR: "Sounds bad."
SQ: "Gets worse-someone found her passed out next to
an empty pill bottle yesterday. Sheila saw her at the
hospital today and thinks she'll be all right but she still
looks kind of green."
SR: "Bummer! That's like what happened to Rudy last
year, only instead of popping pills he ..."

SA: "One minute."
ST: ". ok, now here in Problem 4 what I think we need to
do is..."
SU: ". so the horse says to the chicken ..."
SJ: "Yo, Angie, lemme have a couple of those M&M's-I
like the orange ones."
SV: ". .. and at least we got to do something in those class
exercises Furze was always giving in mechanics-you
make me sit for an hour without doing anything and
i'm ."
SG: ". no, we're going down to the beach Friday right
after class-tell Jack and Ella we'll meet Monday
afternoon in the lounge and finish that report, and then
we can ...
SE: ". but that correlation only works at low concentra-
tions. Maybe if we..."
SW (laughing): "That's a good one ... did you hear the
one about the rabbi, the priest, and the chemical
engineering professor who were on a ..."
SX: ". .. and he's really mad and told Mom that he's not
going to pay my tuition any more so I may have to find
a job, and I don't think I can stay in school and work
enough hours to ..."
SY: "Hey, Cindy-how about asking him if we're respon-
sible for this stuff on the exam. I love the faces they
make when you ask them that."
SA: ". .. and there's the buzzer, and I'm out of here."
SZ: "Yo, Vinnie, bring your book to the Keg tonight-I got
afew questions about Eq. 4.5-237. "
SJ: "Hey, no problem-that one's my favorite. Come on-
let's grab a burger and fries across the street before
we go to the..."

Professor Cheever:
". and now if you substitute this expression for
the friction term you end with Equation 4.5-35.
Everybody understand? Good, see you Friday."

SA: "And the point of all that is?"
SZ: "Beats me." C

All of the Random Thoughts columns are now available on the World Wide Web at and at

Winter 1998


5j9 learning in industry

This column provides examples of cases in which students have gained knowledge, insight, and
experience in the practice of chemical engineering while in an industrial setting. Summer interns and
co-op assignments typify such experiences; however, reports of more unusual cases are also wel-
come. Description of analytical tools used and the skills developed during the project should be
emphasized. These examples should stimulate innovative approaches to bring real world tools and
experiences back to campus for integration into the curriculum. Please submit manuscripts to
Professor W. J. Koros, Chemical Engineering Department, University of Texas, Austin, Texas 78712.



12218 Prince Philip Lane Chesterfield, Virginia 23838

any engineering undergraduates have the oppor-
tunity to work on one or more summer internships
before they graduate. In principle, the students are
paid to spend the summer learning how engineering projects
are carried out in the real world.
Time out for a reality check. Without significant planning
by faculty, the chances of an undergraduate summer intern
actually learning something useful are not very good. Unlike
graduate students, who usually receive projects consistent
with their research expertise, undergraduates are often sim-
ply parceled out to various plants or R&D facilities. Rarely
are faculty members involved in site or project choices; no
one really knows what the students will end up doing, and
there is rarely any follow-up to find out if they learned
anything of substance.
Let's review how this process often works. Sometime
around March or April, someone on the faculty starts phon-

Gary S. Huvard earned a BS in Chemistry from
Campbell College (1974) and a PhD in Chemi-
cal Engineering from North Carolina State Uni-
versity (1978). He spent eight years with the
Corporate Research Group at BFGoodrich
(Brecksville, Ohio) and three years with du Pont's
Tyvek Technical organization (Richmond, Vir-
ginia) before establishing a private practice in
1989. Since that time, he has worked with more
than 20 different companies on projects span-
ning the breadth of ChE practice.

ing industrial contacts-usually research directors or plant
managers-with questions like "How many kids can you
take this year?" "Can't you squeeze just one more slot out of
the budget?" The director comes up with a number and the
faculty advisor jots it down and continues to make calls until
the available slots match the number of students wanting
internships that summer.
On the industry side, a hand-off then takes place. The
logistics of getting the students in, getting non-disclosure
agreements signed, arranging something with Accounting
and so forth is passed to the Human Resources Depart-
ment. Around the first or second week of May, the HRD
calls the director (or whoever) to inform him or her that
everything is set and that 2 (or 4 or whatever) students
will be arriving on June 5.
Now the real planning starts. The director immediately
begins scanning a list of technical persons, identifying likely
candidates to supervise a summer intern. The scientists cho-
sen are requested to submit, by Friday at the latest, a descrip-
tion of The Project.
On Wednesday afternoon, the about-to-be intern supervi-
sors earnestly look for a gas chromatograph and a discarded
286. Being experienced industrial scientists, they are well
aware that any engineering student can be safely and harm-
lessly occupied for at least three months so long as The
Project entails one of two activities:

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

Project #1, Description
Optimum functionality of our proprietary
XLR34 Recombinant Distillation Process
requires a complete understanding of the
quaternary splits of all components
throughout the column internals. The
summer intern will be used, as suggested
by our Total Quality Management Life
Cycle Engineering guidelines, as a
resource to speed up the analysis of tray-
to-tray hydrodynamics in the XLR34
downcomers. The data will be used to
build a simulation (see The Project #2) of
downcomer flow stability needed for
optimum economic ROI.
I'm going to have the kid stand in front of
that old GC for three months injecting
samples and recording peak areas. Aside
from stabbing himself with the needle, there
is virtually no way the student can get hurt
and I'll never have to deal with the safety
people or do any of their paperwork. Plus,
he'll have an enormous pile of numbers to
plot and try to make sense of which will
keep him out of my hair for three months
and give him at least six overheads to present
in the project review in August.

Project #2 Description
The Economic Viability Indices for our
proprietary XLR34 Recombinant Distilla-
tion Process are very dependent on
downcomer hydrodynamic functionality. In
order to maximize the R&D Investment
Index, as suggested by our Total Quality
Management Life Cycle Engineering
guidelines, it is critical that fluid dynamic
computations be carried out to model the
flow striations previously described in our
Project Monthly dated 2/9. A suitable
computer system has been procured for use
by the summer intern. Our goal will be to
develop a proprietary computer simulation
to describe these striations. Infuture
communications, this program will be
code-named Program XLRC to minimize
the potential that in-kind competitors
recognize our activities.
We found an old 286 that nobody was

using and set it up in the corner of the
high bay. Since any program has to be
written in QuickBasic to run on this
thing, it should take at least three months
to get ain driiI, working. Aside from eye
strain, there is virtually no way the
student can get hurt and I'll never have
to deal with the safety people or do any
of their paperwork. Plus, there will be an
enormous pile of code to write and try to
debug, which will keep this person out of
my hair for three months and give him or
her at least 6 overheads to present in The
Project Review in August. Best of all, by
September 10, nobody on earth will
remember what XLRC means, and I
can bury the whole business and get on
with my life.

The Research Director, having received the
project descriptions in a timely manner, passes
them on to the faculty advisor. The advisor is
quite pleased. These students will really learn
something this summer! (Not!)
We have just described two very successful
summer internships. I have personally witnessed
dozens of them. From the standpoint of the
Research Director and the company, the stu-
dents came in, worked on something presum-
ably useful to the company, and left without
having been physically altered. Too bad no one
thinks to ask the intern whether he or she actu-
ally learned anything useful.
To be fair, we should point out that many
companies make an admirable effort to identify
appropriate intern projects. In these companies,
project ideas are solicited and reviewed by staff
engineers (possibly a special committee) prior
to intern assignments. Rarely, however, do pro-
fessors take part in these reviews. While many
companies conduct on-campus interviews for
summer interns, the results may be undesirable
since the professors, again, are left out of the
planning process.
Unfortunately, few practicing engineers are
able to assess whether a given project is appro-
priate for an undergraduate chemical engineer-
ing student. To test this, just ask a few indus-
trial colleagues to submit problems for the
sophomore mass and energy balance course.
Don't be surprised if many of the problems are
far too difficult for students at this level. We

planning by
faculty, the
of an
useful are
not very
good. Rarely

are faculty
involved in
site or project
no one
really knows
what the
students will
end up
doing, and
there is
rarely any
to find out
if they

anything of

Winter 1998

easily forget how hard those problems once seemed.

Setting up meaningful summer internships for your stu-
dents is possible. But, it takes commitment by the entire
department and continue ing effort. If you really want your
students to learn something useful, try following the route
outlined below.

Establish Contacts with Engineers,
NOT with Managers
It must be very tempting, given everything else you have
to do, to simply place that once-a-year call to the R&D
Director. Unfortunately, many R&D Directors I have known
don't have a clue on how to define a good internship prob-
lem. But if you make the effort to befriend the engineers who
actually do the technical work, you can make dramatic
progress toward the goal of finding truly excellent summer
intern problems. The hard part is finding the right engineers.
In addition to using whatever contacts you already have
(alumni are excellent contacts), try scanning the programs
from recent AIChE meetings for industrial participants
who either wrote or co-wrote papers. Chances are good
that a phone call and short pitch to these contacts will
unearth a number of people interested in working with
someone from the university.
Generally, engineers will not have the authority to grant
internship funding. If their company is not in the habit of
hiring summer interns, you may need to help the engineer
outline for management the economics of sponsoring one or
two interns. To do this, e-mail or fax the engineer a single
page showing the approximate cost for having a student on-
site for three months. It should include student salary, travel
reimbursement, and housing if appropriate.

0 Sell the Program
Once you have a commitment from the engineer, get the
name and telephone number of the appropriate manager and
place a call to that person. Be prepared to wait one to three
months (or more) for management approval; virtually noth-
ing is done in industry without having one or two meetings.
Expect the manager to say something like, "Let me get
together with Bob and some of the other engineers to discuss
this first, and I'll get back to you later." Always get a firm
date and time when the manager will "get back to you." If
they don't contact you within a reasonable amount of time,
and often they won't, get back to them. A certain amount of
nagging can be productive.
Managers like to perceive benefits, tangible and intan-
gible, for any and all money they spend. And, you are asking
them to spend money on something they haven't been con-
vinced they need or want. To this end, have a list of potential

benefits handy. Mention such things as
Increased productivity without a fixed cost on the
balance sheet.
Students are well trained and might bring in new
ideas and techniques.
Students often accept positions after graduation with
their internship sponsors. This can help hold down
recruiting costs.
Publications that result from internships reflect well
on the sponsoring company and its management.
The sponsoring engineer will have better access to the
university and any technical or recruiting help the
faculty might provide in the future.
If it sounds like I'm telling you to "sell" internships, I've
made my point. That is precisely what you are doing and
exactly how you should approach the activity. It need not be
a hard sell; the best sponsors, long-term, will be those who
buy enthusiastically after a soft pitch. All you want is a
commitment and a letter from that manager supporting the
internships. Once you have this commitment in writing,
whether obtained through the engineer or by directly ap-
proaching management, you are in a position to start defin-
ing the problems.

Defining the Internship Problems
You will always know far more than your engineer-spon-
sor about the capabilities of the students and the types of
problems that would be suitable for them. But, the engineer-
sponsor knows far more about his or her process than you
know and, therefore, presumably knows what the problems
are. So, in this phase, you should have two goals:
1) Learn about the process so you can help define
appropriate problems.
2) Teach the engineer-sponsor what he or she needs
to know to suggest appropriate problems.

The first goal above should be a short-term activity. If
possible, visit the plant or R&D center to learn about the
process yourself; do not assume that the engineer-sponsor
fully understands the process. Chances are there are many
aspects of the process that are not considered "problems"
simply because they aren't presently troublesome. I have
never encountered a process that couldn't be improved in
dozens of ways if someone simply paid some attention to the
aspects that weren't "problems." Many such improvements
could result from a three-month internship study. Since the
cost of the internship is relatively low and the return on such
improvements is usually rapid and measurable, it is easy for
the company to justify the work. But, someone has to clearly
point out potential improvements or they will continue to go

Chemical Engineering Education

The second goal (training engineers to define good in-
ternship projects) is a long-term investment in your pro-
gram. After expending considerable time and energy to de-
velop sponsors, you would like to retain them for many
years and, as quickly as possible, reach a point where the
engineer-sponsors can suggest suitable problems without
your assistance.
Good internship problems have certain distinguishing at-

LI The problem can be approached by a junior or senior
chemical engineering student and solved (or good progress
can be made) using skills that students at that level can be
expected to have or to easily acquire. The analysis or design
of a single unit operation is usually appropriate. As an ex-
ample, suppose a plant has a rotary dryer that uses preheated
air for drying, but there is no recycle of the exhaust. How
much money could be saved by recycling some of the hot
exhaust air? Would the product quality be the same if the
dryer is operated at a higher humidity? Would productivity
suffer? How much capital investment would be required?
Should this change be made? Even though the dryer perfor-
mance is currently "acceptable," the operation might be
wasting a substantial amount of energy. An analysis of this
dryer would make a great three-month intern problem. The
solution requires mass and energy balances, understanding
relative humidity and psychrometric charts, basic equipment
cost estimation, and basic economic-return calculations. Some
experimentation might also be needed, but chances are, old
company reports will have drying curves for the product at
different conditions of temperature and humidity. The stu-
dent will then also get some practice in doing an internal
literature search.

E[ The problem can be completed (or really good progress
can be made) during the time allotted to the internship.
Don't minimize the importance of this attribute. Students
quickly become demoralized if they begin a project and then
discover they cannot possibly complete it. They find it em-
barrassing and often discouraging to have to give the cus-
tomary end-of-internship talk to the technical staff on a half-
completed project. For example, an analysis of the entire
heat exchanger network in a large plant cannot be carried out
by anyone in three months, but an intern could analyze the
performance of one small network of heat exchangers (three
or four) in that time.

E The sponsor should have already obtained any needed
data that cannot be collected in the first month of the study.
For example, the analysis of a batch polymerization reactor
might sound like a good project, but chances are that the
sponsor does not have the necessary kinetic data for the
analysis. (If the data existed, someone would have already
done the reactor analysis.) If you assign this problem with-

out reviewing the available data, you may doom the student
to a miserable summer. The intern may spend the entire
summer waiting for analytical equipment to be delivered or,
worse, spend the summer trying to get an ancient GC work-
ing that never will.

E The project should test and stretch the student's engi-
neering skills. Does the project require mass and energy
balances to be written and solved? Is statistical analysis of
data required? Does the project require the student to learn
some new chemistry? Are periodic written progress reports
required? Is a literature search needed? Beware of project
ideas that begin with "We could sure use some help getting
the data we need on Project GruntWork...."-it is a sure bet
that your student will spend three months standing in front of
some infernal apparatus testing one sample after another.
The intern learns NOTHING from this type of activity. If a
company just wants some data taken, it should hire a temp.
You can do better for your students.

El The intern should be safe while working on the project.
Most engineer-sponsors will go to heroic lengths to guaran-
tee the safety of their interns. Nevertheless, you should, if at
all possible, look over the sponsor's shoulder on this issue.
Ideally, your program teaches industrial safety as an integral
part of the chemical engineering curriculum and your stu-
dents are capable of auditing their own work environments.
Give your students practice before turning them out by as-
signing safety audits as part of your unit operations and
design courses.

Complete the Cycle
Defining appropriate projects will be far more time-con-
suming than arranging internships. Clearly, one or two fac-
ulty members cannot do all the work. One good way to
spread the work load is to get the students involved. Once
given a set of guidelines like the ones above, there is no
reason that small teams of students (three or four to a team)
can't work with engineer-sponsors to draft lists of potential
projects. If possible, involve yourself in the review process.
By observing the ability of your students to assess the project
ideas, you will quickly find out whether they have learned
the material you've been teaching.
In this way, you can help each class identify new projects
and problems for the classes to follow. In addition to learn-
ing to identify those "hidden" process improvements de-
scribed above, your students will be learning teamwork,
proposal preparation, communication skills, salesmanship,
and, hopefully, a bit about obligations to future generations.


The author would like to thank Prof. R.M. Felder for his
helpful revisions and editorial contributions. 1

Winter 1998

r curriculum



Brigham Young University Provo, UT 84602

Freshman students who have an interest in chemical
engineering have several important needs that we feel
should be addressed. First, many of them are still
undecided about their major and need help making that
decision. Second, these students need to receive instruction
that provides a broad, integrated perspective to serve as a
foundation for subsequent classes. Finally, first-year stu-
dents need to experience support and encouragement from
faculty and other students.
In spite of these needs, chemical engineering departments
traditionally have done relatively little for these students,
often relegating them to a generic computing class or to a
generic freshman engineering class. For example, for many
years at BYU, the only "chemical engineering" courses taken
by first-year students were a course in FORTRAN program-
ming and a 0.5 credit freshman seminar. But we have re-
cently changed our curriculum to better meet the needs of
these students; among those changes has been the development
of a new introductory course-the subject of this paper.

We began development of a course for first-year students
with several distinct goals in mind (summarized in Table 1),
with the most important of those goals being
1. To provide knowledge about the chemical engineering
field to help students select their major.
2. To provide an integrativefoundationforfuture courses.
We wanted to provide sufficient information about the
discipline to enable students to make an educated decision
regarding their choice of a major. To meet this goal, we felt
it was important for the students to experience chemical
engineering reasoning, calculations, decisions, and applica-
tions. These experiences should include an introduction to
some of the fundamental principles and equations (e.g., Fick's
Law, Fourier's Law, etc.). To increase learning and interest,
we also wanted to help students understand the impact of
chemical processing on their own lives and to understand the
connection between chemical engineering and their "every-

day" experiences. We felt that it was important for the stu-
dents to evaluate and draw conclusions from numerical re-
sults as would be typically done by a chemical engineer.
Further, we wanted to expose students to "design" problems
that were open-ended and had multiple solutions.
Finally, we wanted the material to challenge the students
in order to stimulate their interest and to provide them with a
sense of the curriculum's rigor. This last goal was motivated
in part by our prior experiences with survey courses that
failed because they did not offer much intellectually to the
students entering our department; students felt that such
courses were neither challenging nor informative and were
essentially a waste of their time.
We wanted this course to play a significant role as part of
our undergraduate curriculum by providing a foundation and
perspective for subsequent classes. It has been our observa-
tion that sophomores, juniors, and even seniors sometimes
view each course in their program as an isolated entity,
unrelated to the other subjects they have studied. Instead of
building on past learning, they often seem to start over with
each new subject. Hence, they frequently fail to see the
discipline as a whole until very late in their program (if at
all). Therefore, a key objective of our course was to provide

Ken Solen is Professor and Department Chair of
Chemical Engineering at Brigham Young Univer-
sity. He received his BS in Chemical Engineering
(1968) from the University of California at Berke-
ley and his MS in Physiology (1972) and his PhD
in Chemical Engineering (1974) from the Univer-
sity of Wisconsin. He conducts research in bio-
medical engineering and artificial organs.

John Harb is Associate Professor of Chemical
Engineering at Brigham Young University. He re-
ceived his BS (1983) from Brigham Young Uni-
versity and his MS (1985) and PhD (1988) from
the University of Illinois, Urbana, all in chemical
engineering. His research interests include elec-
trochemical engineering and mathematical mod-
eling of complex physical systems.
Copyright ChE Division ofASEE 1998
Chemical Engineering Education

an integrated overview, offering a broad perspective and
serving as a framework upon which subsequent courses could
be built. That objective included helping the student under-
stand where subsequent chemical engineering courses fit
within the larger perspective as well as how knowledge
obtained from other disciplines (e.g., chemistry, math, phys-
ics, economics, etc.) is essential. In a figurative sense, the
introductory course would create a "skeleton" by broad shal-
low coverage of the discipline, and later courses would add
the "meat" to that skeleton.
Additional goals were related to the social needs of the
students. It is our opinion that first-year students should have
close interaction with the faculty. While some interaction is
facilitated by faculty-student socials, required meetings with
advisors, etc., our course provides many more faculty-stu-
dent contact hours than any other method. Of equal impor-
tance to faculty-student interactions are interactions between
the students themselves. One of our goals for the introductory
course was to help develop a "community of chemical engi-
neers" through the use of learning teams and group activities.

of the potential advantages that it would offer our students,
provided that the course was designed to minimize the re-
source requirements associated with it. Consequently, the
course was designed as a two-credit-hour one-semester course
without a laboratory (even though we recognized the value
of a laboratory experience for our beginning students). Two
credits were made available for the course as part of a
general restructuring of the curriculum, and the necessary
resources were allotted for development of the course.

The goals listed in Table 1 had a significant impact on the
course's structure during its development. In particular, our
desire to provide an integrated overview required that the
individual course topics be connected together in a logical
fashion. This integration was accomplished by structuring
the course around an engineering design problem that could
be solved by designing a simple chemical process. The en-
tire semester and all the material presented in the course
were dedicated to the design of that process.

There were several concerns that in-
fluenced development of the course and
led us to minimize the credit hours and
faculty resources associated with it. It
was clear that a new course could not
simply be added to a curriculum that
was already overflowing, especially at a
time when we were being encouraged to
decrease the number of credit hours in
order to help students graduate more
quickly. Thus, inserting this course meant
reducing the credit hours of more ad-
vanced courses, and some faculty ques-
tioned the value of such a trade. Also,
since a large number of beginning stu-
dents do not continue in the discipline
after their first year, there was concern
that an introductory course would dedi-
cate resources to teaching
students who would not
graduate in chemical engi- Ce
neering. Further, the course Prob
we envisioned would need Chemical
to be developed from processes
scratch since a suitable text Ino
was not available, thus add- p"
ing to the required re-
After some discussion,
the department decided to
support the course because Figure 1.
Winter 1998

Goals for an Introductory Course in ChE
1. To provide information about the chemical en-
gineering field and thus enable students to knowl-
edgeably select their major.
2. To provide an integrated overview of chemical
engineering as a foundation for subsequent
3. To teach significant chemical engineering prin-
ciples, including
Fundamental concepts and quantitative rela-
Connections to the students' past experiences
Typical chemical engineering calculations and
Open-ended, multi-solution design problems.
4. To promote interaction between first-year stu-
dents and the chemical engineering faculty.
5. To help develop a "community of chemical en-

Matenal Mateals
Balance Flud Reacton
Mechanic Engineern Energy
Units./ Balance
Process Spreadsheets. Mass Hea Proc
vanrablhe e Graphing Caont


Schematic of the topics covered, where the
ch bar represents the time spent on the topi

The problem-oriented scenario begins
the first day of class when the students
are asked to imagine that they "are
chemical engineers working for the ABC
Chemical Company." The student engi-
neer receives a memo from his/her su-
pervisor reporting that the contractor
who has been disposing of the hydro-
chloric acid by-product from "our"
manufacturing process is going out of
business. The memo goes on to ask the
student to take responsibility for solving
this problem, and the remainder of the
course is directed toward leading the
student to that solution. This design prob-
lem provides the framework for integra-
tion of material presented throughout the
The general topics presented in the
course are shown in Figure 1, with the
approximate amount of time
dedicated to each topic in-
dicated by the length of the
segment to which the topic
title is attached. This two-
Eonormics credit course is designed to
s be taught in fourteen weeks,
the length of a semester at
BYU. Written material de-
veloped for each of the top-
.SES v cs has recently been com-
bined into a textbook,1" with
length of each topic forming a sepa-

rate chapter. The table of contents of the textbook, shown in
Table 2, reflects the detail and sequence of topics treated in
the course.
The topics are introduced on a "just-in-time" basis as the
solution to the design problem is developed throughout the
semester. For example, after discussing strategies for gener-
ating and evaluating possible solutions, the decision is made
to design a chemical process in which sodium hydroxide is
used to neutralize the HCI. Material balances are then taught
in order to determine how much NaOH is needed. Spread-
sheets are also introduced as an engineering tool. The stu-
dents are then taught simple fluid mechanics to provide the
basis for delivery of the NaOH and HCI from the storage
facilities to the point of reaction. This approach continues as
issues are considered regarding mixing the acid and base
(mass transfer is taught), the volume of reactor needed (reac-
tion engineering is introduced), and cooling the final product
to an acceptable temperature for disposal (energy balances
and heat transfer are studied). The final step is an evaluation
of the profitability of the proposed process (economics are
By the end of the semester, students have developed skills
in several of the subdisciplines that make up chemical engi-
neering and have applied them toward the solution of an
engineering design problem. These skills represent a useful
subset of those that they will learn in subsequent chemical
engineering courses. In order to illustrate the level at which
the material is presented, Tables 3 and 4 provide examples
of problems used in the course along with the appropriate
solutions as presented in the textbook.
Process flow diagrams are used throughout the course to
help the students visualize how the different aspects of the
course and design problem are connected. Students are in-
troduced to these diagrams and required to use them very
early in the semester (Chapter 2). Then, as each new topic is
introduced and used to design an additional component of
the "process," the process flow diagram and stream table are
updated to reflect the new addition and its relationship to the
previous components of the process.
In contrast to the acid-neutralization design problem, the
solution for which is developed for the students throughout
the semester, the course also features a second design prob-
lem, or case study, to be solved independently by student
teams. The case study, described in the last chapter of the
book, involves the isomerization of meta-xylene to ortho-
xylene and requires the use of material and energy balances,
the sizing of a pump, reactor, and some heat exchangers, the
preparation of a process flow diagram, and the completion of
an elementary economic analysis. It is introduced near the
end of the semester and provides the students with an oppor-
tunity to work together, to learn from each other, and to
apply nearly all of the concepts and principles they have
learned throughout the semester. Although new material is

presented in class during the time that students are working
on the case-study assignment, the last few topics (particu-
larly engineering materials and process control) are treated
qualitatively and briefly, with minimal homework assign-
ments, to give the students time to focus on the case study.
Students are periodically required to inform their "supervi-
sor" in writing concerning the progress made to date on the
case study, and a final design report is also required from
each team. The xylene-isomerization case study is the only

Table of Contents
1. The Assignment
2. What is Chemical Engineering?
What is Chemical Engineering?
What is a Chemical Process?
The Impact of Chemical Processing and Chemical Engineering
3. Solving Engineering Problems (What Shall We Do?)
Strategies for Solving Problems
The Use of Teams in Solving Problems
4. Describing Physical Quantities
Some Important Process Variables
5. Steady-State Material Balances (How Much Base Do We Need?)
Conservation of Total Mass
Material Balances for Multiple Species
6. Spreadsheets (Calculating the Cost of the Base)
The Calculation Scheme
Setting Up a Spreadsheet
7. Fluid Flow (Bringing the Base to the Acid)
How Do Fluids Flow?
Pumps and Turbines: Examples of Fluid Flow Devices
8. Mass Transfer (Mixing the Acid and Base)
Molecular Diffusion
Mass Convection
Mass Transfer Through Boundaries
Multi-Step Mass Transfer
9. Reaction Engineering (How Fast Will the Reaction Go?)
Describing Reaction Rates
Designing the Reactor
10. Heat Transfer (Cooling Down the Product)
Energy Balances for Steady-State Open Systems
Some Applications of the Steady-State Energy Balance
Heat Exchange Devices
11. Materials (From What Shall We Build the Equipment?)
Metals and Corrosion
Strength of Materials
12. Controlling the Process
Strategies of Process Control
How Do Computers Talk to Equipment
13. Economics (Is It All Worth It?)
Economics of the Acid-Neutralization Problem
14. Case Study (Integrating It All Together)
The Problem
Using Engineering Teams for this Case Study

Chemical Engineering Education

case study currently included in the textbook. Thus, it has
been reused from year to year, in spite of the risk that
students may copy reports from previous semesters. We
have not found this to be a problem so far, probably because
of the honor code at BYU, but we do recognize the value of
developing additional case studies for future use.

In order to teach first-year students with varying back-
grounds, the course was designed with few prerequisites.

Example Used in Course
Species A in liquid solution (concentration=0.74 M) enters a CSTR at
18.3 L/s, where it is consumed by the irreversible reaction
where rreaction,A = krCA (kr = 0.015/s and cA is in units of gmol/L)
What reactor volume is needed so that the concentration of species A
leaving the reactor equals 0.09 M? The density can be assumed to be
SOLUTION (Note that the steps correspond to the instructions in
Tables 5.1 and 5.2.)
Drawing a diagram for this problem:
",n=18.3L/s c,, =0.74M-"i I rA- C
'L" Arreaction,A = (0.015/s) cA
volume=V -o, = ? CA ot= 0.09 M

As outlined in Table 5.2, we want to construct a mole balance on A.
For this case (for a single input and single output stream), the mole
balance becomes + rformatlon,A -= A,out rconsumption,A
Species A is being consumed, but no species A is being formed, so
rformationA = 0. This, along with substituting more convenient forms
for the molar flow rates, gives
CAin + in = CAout outt +rconsumption.A (a)
The value of the outgoing volumetric flow rate is not specifically
given, so we need a total mass balance, which for a single input and
single output stream, is
min = mount
which, in more convenient terms, is
PinVin = Pout Vout
Since the density is constant, this reduces to
Vin = Vout =V (b)
We can now calculate rconsumptionA using Eqs. (a) and (b). Equation
(a) becomes

rconsumption.A = CA;,n in -cAo,,, out = (CA, -CAout
( gmol gmol )( L) gmol
= 0.74- 0.09 18.3-- = 11.9
I L L )A s s
Up to now, everything we've done is a repeat of the material balances
we learned in Chapter 5. The new step is to equate the rconsumption,A
term to the given rate expression times the reactor volume, where CA
(in the reactor) = CAout

rconsumptionA krcAou )V

V rconsumptionA 11.9gmol/s 8,800L
c ,, =8,800L
krCA1 0.015 09gmol
rAut 09 L

Specifically, we did not assume any previous exposure to
calculus. We also assumed only a minimal knowledge of
chemistry, such as provided by even a mediocre high-school
chemistry class. Finally, while the course requires minimal
computer word-processing experience, it does not require
prior exposure to computer spreadsheets.
There are several other aspects of the day-to-day operation
of the course that may be of interest to the reader. For
example, the course includes frequent use of group activi-
ties, which serve to hold student interest, increase learning
effectiveness, and help first-year students form friendships
with one another. In-class quizzes are also used to motivate
students to keep up with their learning (a particular problem
for many first-year students who developed the habit of last-
minute cramming in high school). Classroom demonstra-
tions and examples from everyday life are used to illustrate
the chemical engineering principles being discussed. Small
pieces of equipment, such as pumps and heat exchangers,
are partially disassembled and passed around during class
for students to examine; photographs of larger equipment
items are also used.

Outside the classroom, we assign reading questions to be
answered for each new reading assignment before the mate-

Example Used in Course

A heavy oil stream must be heated to a higher temperature, so the
decision is made to use a heat exchanger with saturated steam being
condensed to saturated water as the heating source on the other side of
the exchanger. The characteristics of the oil are
Oil mass flow rate: 960 Ibm/min
Oil mean heat capacity: 0.74 Btu/lbmF
Oil inlet temperature: 350F
Desired oil outlet temperature: 110F
The saturated steam has the following properties:
Steam temperature: 280F
Heat of vaporization (@280"F): 925 Btu/lb,
What steam flow rate is needed for this exchanger?

Saturated steam, Saturated water,
280F, rt,,,am 280F, rh,,,s
Oil, 110F, 960 lbm/min Oil, 350F, 960 Ib,/min

For this problem, the oil is the cold stream and the steam/water is the
hot stream. For the oil side, Eq. 10.24b gives

Qduty [nm (Tout -Tinoi)]

= 960- m 0.74 Btu (11035F) 53,280B
I min lbm F) mm
For the steam/water side, as indicated in Table 10.2, for condensation
AHphase change = -A vaporization
so Eq. (10.24c) gives

-Qduty -53,280Btu/min Ib
msteatm -57.6-
-AHvap -925Btu/lb, min

Winter 1998

rial is discussed in class, and we assign homework problems
for the material after it has been discussed in class. Other
course features include the case study, which has already
been described, two mid-term examinations, and a final exam.
Grading is performed according to predefined criteria in
order to encourage cooperation between students.
As mentioned previously, this introductory experience is
completed in a two-credit-hour one-semester course. Thus,
the resources expended are relatively minimal, while our
experience indicates that the benefit derived is significant.

We have now taught the course for four years, and student
response has been very positive. At the end of every semes-
ter, all courses in our department are subjected to a student
evaluation questionnaire, which includes numerical scores
to specific questions and the opportunity for students to
make unrestricted comments. The numerical scores for the
introductory course have consistently corresponded to an
overall rating of "excellent" and are among the highest in the
department. We also send a questionnaire to all students who
change their major from chemical engineering to another
discipline. The comments from both of these types of ques-
tionnaires, along with feedback during informal conversa-
tions, indicate that students feel they have a much better
understanding of and appreciation for chemical engineer-
ing after having taken the course. Some comments from
those surveys are:
* "The course gave me a good idea of what to expect in my
"The course is much more applicable to a business or
real-life situation than any course I have taken. "
"The course was EXTREMELY helpful in my decision to
stay with ChemE as my major. "
"The course has given me a good idea of what Chemical
Engineering is about. "
"I really enjoy this course. If it were up to my chemistry
class, I would drop out of ChemE. But this course shows
the light at the end of the tunnel. "
"Good prep (sic)for my major, applies concepts and
possible real life situations, but not too far over our
heads. "
"ChE 170 [was a] good class-I just knew after that one
that I didn't belong. "
"I enjoyed ChE 170, but I wouldn't like to do it for a
In some cases, that knowledge has resulted in students chang-
ing majors to something other than chemical engineering.
That decision is judged to be positive if made with adequate
knowledge and experience.
The course appears to have slightly increased the overall
retention of students in the chemical engineering program,
but that is difficult to verify at this time. The difficulty arises
because approximately 80% of the first-year students in our

program leave the university after the first semester or after
the first year to serve a two-year mission for the Church of
Jesus Christ of Latter-Day Saints. Some of those students
take our introductory course before leaving, while others
take it after returning. Those students who took the first-year
course in the last three years and then began serving their
missions have not yet returned for a full year of school, so
we are not able to determine if they will continue in the
Where there are complete data, we have examined reten-
tion as defined by the percentage of first-year students who
eventually, but not simultaneously, took the subsequent course
in our program (our sophomore course in material and en-
ergy balances). During the five years before implementation
of our course, freshmen took FORTRAN programming as
the first-year course, and 40% eventually took the sopho-
more class. During the last four years, the new course has
been offered in both the first semester (enrollments ranging
from 86 to 105) and the second semester (enrollments rang-
ing from 47 to 76). For students who took the introductory
course during the first of those years, the retention was
higher, at 46%. We will continue to compile retention data
as they become available. We feel, however, that changes in
overall retention are less important than, and may not be a
good indicator for, the increased ability of first-year students
to intelligently decide if chemical engineering is a good field
for them (one of our main goals).
In addition to providing an overview of chemical engi-
neering, students felt that the introductory course helped
prepare them for future courses, particularly the course on
material and energy balances normally taken by sophomores.
This opinion was consistent with that of the course instructor
for the sophomore course, who observed that the students
who had taken the introductory course were better prepared
than previous students. The instructor also noted that the
students had a significantly broader knowledge of the disci-
pline. For example, when he mentioned to the students in the
class that phase equilibrium would be important in separa-
tion processes such as distillation, they recognized the pro-
cesses to which he was referring and appreciated the signifi-
cance of his statement.
Although a quantitative evaluation is difficult, other anec-
dotal information provides positive feedback about the course.
For example, two students who had recently completed the
introductory course requested help from one of the authors
to explore an issue in process control for use in a paper for a
technical writing class. Specifically, they wanted to explore
differences between feedback and feedforward control strat-
egies. The students were in the first semester of their third
year, a full year before they were scheduled to take our
senior-level process control class. Prior to the time we began
teaching the introductory course, students at the same point
in their education had little, if any, concept of process con-
Chemical Engineering Education

trol. Yet, these students had learned 70
enough in the introductory course to de- 60
fine a question and pursue the topic fur-
ther on their own. Incidentally, they were 50
supplied with a process simulation pro- % of 40
gram (PICLESi21) and were able to use Students 30
the program to address the issues of in-
terest. 20
It has also been our perception that 10
the course has served to help build rela- 0
tionships between students. They appear 0-2
to be working in groups and helping
each other much more than they did pre- Figure 2. Number
viously. This interaction is facilitated outside of cl
by the group work required as part of
the class. Also, grading is structured so that students do not
perceive that they are hurting their own grade by helping
their classmates. Interaction between the faculty member
teaching the course and the students has also been very
positive. In many cases this has resulted in continued
interaction and discussions, exchange of e-mail, sharing
of wedding announcements, etc., long after the final exam
is taken.
In order to provide the desired integrated overview, it was
necessary to cover a broad variety of chemical engineering
concepts. We were concerned that in doing this we might
overwhelm the students with too much material. Like most
schools, our target for work outside of class (reading and
homework problems) is two hours outside class per one hour
inside. For a two-credit class (two hours per week in class),
this translates to four hours per week outside of class. A
recent polling of all our students concerning the time they
spend in class work outside of class indicated that the
workload for the introductory course was on target at an
average of approximately 3-4 hours a week. We conclude
from this that the students have not been overwhelmed by
the material presented in class.
Finally, the written material for the course has evolved
considerably over the past four years, but has now stabilized
to a large extent. As mentioned previously, we have recently
published a textbook'1 for the course that is available for
others who may be interested.
We end this section by noting that the course described in
this paper has an appeal that extends to other situations
where beginning students need to know about chemical en-
gineering. For example, some colleges have a common fresh-
man engineering course, and the chemical engineering de-
partments do not see the students until the sophomore year.
In those cases, the course described here could be given to
first-semester sophomores prior to the traditional course on
material and energy balances. It could also be used in two-
year colleges from which students may transfer into our
Winter 1998

2-4 4-6 6-8 >8
of hours per week spent
ass on this course.

A new introductory course has been
developed for first-year students inter-
ested in chemical engineering. This two-
credit-hour one-semester course is de-
signed to provide a broad overview of
the chemical engineering discipline and
a foundation for other courses in the
curriculum. Other objectives for the
course include the introduction of fun-
damental principles related to chemical
engineering, connection of material
to the students' experiences and fu-
ture coursework, introduction of de-

sign concepts, and development of
student/faculty and student/student relationships. Student
feedback, although qualitative, indicates that the course
has been largely successful in accomplishing these ob-
The laying of a broad introductory foundation at the be-
ginning of a long academic program was of particular inter-
est and importance. Consequently, the course was designed
to establish the framework for the rest of the curriculum. Our
intention was to facilitate learning by providing an overview
and establishing connections so that in-depth material from
upper-division courses could readily be integrated into an ex-
isting framework, rather than waiting until a senior capstone
course to attempt to tie things together. The approach also
facilitates learning through repetition by providing a first-year
exposure prior to the more-in-depth upper-division exposure.
We are providing this information so that other schools
may consider this approach for adoption into their programs.
Universities with no freshman engineering course may con-
sider adding a course like the one described here. Schools
with an existing general freshman engineering course might
consider replacing it with this course for students who are
seriously considering chemical engineering as a major.
Where this is not possible, this course might be offered
to sophomores in chemical engineering. In addition, two-
year colleges might use this course to prepare their stu-
dents for transferring to four-year chemical engineering
We are anxious to receive impressions and suggestions
from others who have seen our course or book, or who have
experience with similar attempts to prepare first-year stu-
dents for this discipline.

1. Solen, K.A., and J.N. Harb, Introduction to Chemical Pro-
cess Fundamentals and Design, McGraw-Hill, New York,
NY (1997)
2. Cooper, D.J., PICLES (Process Identification and Control
Loop Explorer System), Version 4.1, Department of Chemi-
cal Engineering, University of Connecticut (1995) O

[efi curriculum


In the Environmental Health and Safety Department

Northeastern University Boston, MA 02115

Freshmen usually come to us without an engineering
background. They are accustomed to working alone
on small, well-structured problems, do not under-
stand the laws of thermodynamics, and have little concep-
tion about conservation of momentum, energy, and mass.
Consequently, we have been reluctant to give open-ended
design problems to them in spite of the fact that the fun of
engineering is working on real problems and finding solu-
tions to them. It seems too big of a risk.
While incorporating engineering health and safety issues
into the engineering curriculum is desirable and has been
addressed by ABET,"m meeting this major challenge is diffi-
cult given the many other ABET requirements. Past papers
that address possible approaches include the work of Gute,
et al.,121 Bethea,13' and Rossignol, et al.141 Our approach intro-
duces students to open-ended problems early in the curricu-
lum. We find that their creative abilities provide fresh solu-
tions to mundane problems.

Northeastern University has a five-year cooperative edu-
cation program in engineering. The freshman year has three

Ronald Willey holds BSc and PhD degrees in
chemical engineering from the University of New
Hampshire and the University of Massachusetts
(Amherst), respectively. He has six years of in-
dustrial experience in the paper industry and
has been at Northeastern University since 1983.
His teaching responsibilities include the Unit Op-
erations laboratory.

John M. Price is Director of Environmental Health
and Safety at Northeastern University. After re-
ceiving a BS and MS in chemical engineering
from Northeastern, he earned an MS in environ-
mental sciences from Harvard University. He has
fifteen years experience implementing and man-
aging occupational and environmental safety pro-
grams at academic research institutions.

While incorporating engineering health and safety
issues... is desirable and has been addressed by
ABET,11 meeting this major challenge is difficult... Our
approach introduces students to open-ended problems
early in the curriculum.... their creative abilities
provide fresh solutions to mundane problems.

quarters, and upperclassmen take two quarters of classes and
of cooperative education during each of the next four years.
The result is eleven quarters of classroom training and seven
or eight quarters of industrial experience.
To allow freshmen the opportunity to meet College of
Engineering (COE) faculty early in their academic career,
COE faculty take an active role with freshman engineering
students. Engineering courses offered in the freshman year
*C-programming during the fall
*Problem solving using spreadsheets and MathCad in the winter
*Engineering design in the spring
The engineering design course is divided into ten sections,
with about thirty students in each section. The sections meet
for 65 minutes three times a week. Our quarter system al-
lows for just under eleven weeks of classroom meetings
each quarter. Sections are divided by intended major and
assigned to faculty from the appropriate departments. This
paper is devoted to declared chemical engineering majors.
Engineering design uses a textbook developed by
Northeastern's Gerald Voland, Engineering by Design.15 He
breaks down the design process into key stages that include
1) Needs determination
2) Design goals and specifications
3) Abstraction
4) Evaluation of alternative designs
5) Ergonomic analysis
In general, engineering design students are assigned a minor

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

Major Design Projects, Spring 1996

# Department
1. Mail Services
2. Mail Services

3. Physical Plant

4. Physical Plant
5. Environment Health

6. Environment Health

7. Environment Health

8. Environment Health

9. Environment Health

Location Contact Project Description
Basement J. Devine Workstation lighting evaluation
Basement, Columbus PI. J. Devine Noise level survey for letter-stamping
Mail room, Columbus PI. J. Devine Employee fall protection from loading

Various laboratories

Various dark rooms

Various computer labs

Various laboratories

Various laboratories

10. Chemical Engineering 8 Mugar

B. Mitcheson Loading-dock assessment
S. Brehio Quality control check on safety show-
ers and eye-wash station survey
S. Brehio Evaluation of silver recovery options
for environmental compliance
J. Price Ergonomic evaluation of computer
S. Brehio Opportunities for waste minimization
in the generation of HPLC solvent
S. Brehio Strategies, facility requirements, and
costs for a central organic solvent bulk-
ing facility
A. Bina Design of flow measurement experi-

Proposal Outline for Student Project Design Submittal

GE1103 Spring 1996
Minor Design Project Due April 23, 1996
"If there isn't a need why bother?" R.J. Willey 4/5/96
Excellent designs begin with a proper needs assessment and the correct statement of the problems to be
solved. An excellent example of posing the proper questions before solving the problem at hand is space
craft reentry. Your group is to prepare a 5-page proposal (double spaced and 12-point Courier font) and a
5-minute presentation about your major design project. This work will be due on April 23, 1996. Mr.
Jack Price will review and assign grades on your oral presentations (25% of the total minor design project
grade). Each group must go to the front of the classroom. After a brief introduction from each group
member, one of your group members should serve as a spokesperson. That person should briefly define
the need, the problem to be solved, and the methods to be used.
Proposal Outline
Using a numbered list, state your objectives. Be as precise as possible.
Who will be served by your solution/design? Where will your solution/design be used? What is the
past history related to the problem? Are there any important references related to the problem that you are
working on? Existing solutions and prior work on the problem should be described.
Focus on what techniques you will use to help you solve the "problems" and succeed with a successful
design. Use Prof. Voland's and class notes to obtain methods on how to proceed.
Proposed Schedule Include a proposed schedule that is similar to the schedule shown in Figure 2.6,
page 88. Use weeks as the time period and adjust phases to match your problem/design.
Person Loading Chart Include a person loading (Gantt) chart like the one shown in Figure 2.7. Use
hours as the time period and adjust the task list to match your problem/design requirement.
Autocad Drawing Include a schematic or layout drawing for the project that you are working on.
Expected Results
Begin with the end in mind. What are the "deliverables"? Who will benefit?
Costs What will be the costs involved? "Personpower" can be estimated at a direct cost of $45.00/hr.
Other costs will involve materials and supplies to bring about the solution/design (not the cost of the final
recommended design).

and a major design project, each to
be completed using the methods pre-
sented in Voland's text. In the
chemical engineering section, these
minor and major projects address
the same problem. Our minor de-
sign project (see Table 1) consists
of a needs assessment and proposed
approach to one of the major design
projects listed in Table 2. The ma-
jor design project is execution of
the actual work proposed.
Students are divided into groups
of three at the second class meet-
ing, providing a total of ten teams.
Each team selects a project from
Table 2-no duplication is allowed.
Each team's interests are matched
to a project.
Each project assigned to a team
has a University administrator who
serves as the "client." The student
teams serve as consulting engineer-
ing services. Additionally, our Of-
fice of Environmental Health and
Safety (OEHS) serves as a mentor
and an interface between the clients
and the consultants.
As Table 2 shows, design projects
vary from noise surveys in the Uni-
versity mail room to the optimiza-
tion of hazardous waste disposal.
The projects introduce students to
survey instruments, to data evalua-
tion, to regulatory compliance is-
sues, and involve interaction with a
variety of people. Students begin
learning engineering principles (e.g.,
velocity measurements involving
Bernoulli's equation), team skills,
communication skills (written and
oral), and economics. With a little
investment and some oversight by
the OEHS, the University benefits
from the students' project recom-
mendations (discussed in more de-
tail below).
The minor and major assignments,
the proposal, and the design solu-
tion comprise 55% of the course
grade. The remaining portion is
based on two examinations (30%)
and daily homework assignments

Winter 1998

(15%). AutoCad is also presented in this class
(about one third of the lectures), and students are
encouraged to make drawings of their major
assignment using it.

As with any open-ended term project, students
tend to put off work until the last minute, with
the usual disastrous results. To avoid this out-
come, students are required to submit a weekly
log book and are given small assignments that
push them 1) to get their groups together, 2) to
begin meeting with their contacts, 3) to obtain
background information, and 4) to work towards
a solution. The logbook system also serves to
identify early such problems as an inability to
connect with the University contact or the exist-
ence of a nonparticipating member.

For the instructor, the project process is simi-
lar to managing a small consulting firm made up
of all "rookie" teams. The students generally
find their contacts during the first week and will
begin the literature checks, but then their meth-
ods diverge. One year, two seniors were inten-
tionally recruited to work with two freshman
team members. With the advantage of the se-
niors' co-op and military experience, the teams
attacked their project with vigor. Both design so-
lutions-the redesign of a loading-dock area and
the creation of a safety check list (see Table 3)-
are now being implemented by the University.

Eight of the ten groups functioned well. Their
final designs were quite good. They succeeded,
in part, because they were self-selecting and
they shared a general interest in working on a
real problem.

On the other hand, one of the eight all-fresh-
man teams was not successful. No previous en-
gineering work experience or effective leader-
ship existed within the group. One student made
his initial contact with the client regarding the
design of a flow measurement system for two
centrifugal pumps. He quickly assessed the situ-
ation, claimed the solution was easy, and stated
that he should be done after just a few hours of
work. He never included the other team mem-
bers in the plans or their execution and they, in
turn, never tried to participate, expecting this
student to carry them through.

Other all-freshman teams turned in good-to-
excellent reports. One team worked the mail
room workstation lighting problem. As part of
their presentation, they built a 3-D model of the
room. The model ceiling had holes cut out at the




Loading Dock Safety Checklist
Generated by Students Who Worked on Project #3

General Area
no Are loading positions for trucks marked with lines?
no Are dock guards in operable condition?
no Are loading areas free of potholes?
no Are floors cleaned daily?
no Are trash containers emptied daily?
no Are trailer wheel chocks provided for each truck?
no Are trailer wheel chocks chained to the building?
no Are proper warning signs clearly visible for general safety issues?
no Is ventilation adequate?
no Is lighting adequate?
no Does the dock have a roof?
no Does roof of dock have a drainage system (i.e., gutters)?
no Is dock within height accordance of all trucks that will use the dock?
no Are proper signs posted instructing drivers to turn off their engines?
no Are first-aid kits readily available?
no Are emergency telephones easily accessible?
no Are fire extinguishers/sprinkler systems in working order and accessible?
no Is noise level of dock in accordance with federal regulations?
no Is dock equipped with handrail?
no Is dock marked with vivid paint to display hazardous areas?
no Are emergency exits provided, marked, and kept clear?
no Are foot rails in place at the edge of the dock?
no Are mirrors provided for "blind spots"?
no Are storage areas of equipment, pallets, machinery marked and kept clean?
no Are areas for drivers provided during loading and unloading?
no Are pedestrian walkways clearly identified?
no Are incline of ramps used for hand loading/unloading not too steep?

Training and Personnel
no Is safety and health training provided to dock personnel?
no Are employees tested or evaluated on their knowledge of safety procedures?
no Are refresher courses in safety and hazard prevention provided to workers?
no Are dock personnel trained in the use of bridge plates or dock levelers?
no Are dock personnel trained in the proper care of heavy packages?
no Are visitors given protective wear and area away from dock to congregate?
no Are dock personnel familiar with using a manual and motorized equipment?
Are dock personnel provided with safety equipment (if applicable)
no Hard hats
no Weight belts
no Gloves
no Eye protection
no Ear protection
no Footwear
no Are dock workers trained to secure loads for transport?

The above checklist is based on a ranking system of I to 3 points per question. A (3) is deemed
critical, a (2) is deemed important, while a (1) is deemed optional. To find your total possible
score, add the possible points column, disregarding those questions that are non-applicable. For
each question answered "yes," give yourself the point amount given to that question. For each
question answered "no," add no points. Add all your scored points. This will give you your total
raw score. Now review your total raw score and make sure it complies with the following:
All the questions given a rank of(3) are answered "yes."
At least 80% of the questions given a rank of(2) are answered "yes."
Questions with a ranking of(l) are left to the discretion of the proper management.
If these compliances have been met, then your dock is in accordance with the safety measures we
require. If this is not so, then adjustments and modifications must be made until the requirements
are met.

Chemical Engineering Education

existing lighting-fixture locations, and
using a simple flashlight shining from
above, the students were able to dem-
onstrate the inefficiencies of the light-
ing grid. They then demonstrated how
the placement of two additional light-
ing fixtures over the proper work area
could correct the lighting. By ex-
changing the top of the 3-D model
with the properly modified ceiling
and shining the light through it, they
were able to present their solution
efficiently and observably.
Since students have generally been
conditioned to work individually prior
to entering college, one of our big-
gest challenges was getting them to
work together. While team work is a
novelty in the academic environment,
when these students take on their first
industrial co-op assignment, team
work is often the expected mode of
operation. An important feature of
our approach is to develop team-
working skills. Figure 1. Student
Another related challenge was the model made
division of work. While eight of the related to saj
ten student teams handled the divi-
sion of work quite well, in one team there was one student
overly concerned about the "grade" and another more con-
cerned about what he was "really learning." These two never
reached a consensus about what the professor wanted and
ended up giving individual solutions. Meanwhile, the group's
third member watched in bewilderment while the other two
argued constantly during team meetings.
Another poorly functioning group had a clear cultural
divergence that led to little or no team effort. This group was
not self-selecting, having been formed of late registrants
who came to class for the first time on the second day. The
members were from different countries and did not know
each other previously. This team did not work well to-
gether primarily because one team member worked on
the problem by himself and didn't include the other two
members who, in this case, were satisfied that someone
else was going to do the work.
We required two group reports and two presentations dur-
ing the quarter. The first report was the proposal for the
"client's approval" and was due about midway into the quar-
ter. The corresponding presentations were limited to five
minutes per group and were given on the day the propos-
als were due. The second, formal report described the
final design solution intended to meet the client's needs.
The second presentations were twenty minutes each and
Winter 1998


consisted of a summary of the design
Several models, iconic (resembling the
situation but not having the functionality)
and analogic (not resembling the situation
S but having the functionality) were made
by the groups as the projects progressed.
-; Figure 1 shows one example of student
S creativity. The model shower pictured was
made to help explain design requirements
for American With Disabilities ACT com-
pliance concerns.
Another group built a scale model of a
process to recover silver generated in the
University's photo labs. This model was
constructed so that each major functional
component could be removed. The stu-
dents used the model during their presen-
tation to help the class understand the func-
tionality of their proposed silver-recovery
system. The presentation was extremely
rewarding for the class and the instructor.

ling an iconic Open-ended, real problems are challeng-
'roject #5 ing to make work in the classroom. There
showers. is no instructor's solution manual avail-

able and each project is demanding, re-
quiring constant attention by the instructor. Project paths
can change as the quarter progresses. Common difficult
situations center around a contact not responding or a
group member not participating. Sometimes, design prob-
lems are too vague.
We encourage others to contact their Environmental Health
and Safety departments to discuss a similar approach at their
University. Not only will their students learn to alleviate
persistent campus hazards, their school just might gain some
inexpensive physical improvements.

1. ABET, Criteria for Accrediting Programs in Engineering in
the United States, Engineering Accreditation Commission,
Accreditation Board for Engineering and Technology, Inc.,
New York, NY (Sections IV.C.2 and IV.C.3) (1994)
2. Gute, D.M., A.M. Rossignol, N.B. Hanes, and J.T. Talty,
"Factors Affecting the Performance of Occupational Health
and Safety Topics in Engineering Courses," J. Eng. Ed., p.
163, July (1993)
3. Bethea, R.M., "Engineers Encourage Universities to Em-
phasize Safety in Curriculum," Occ. Health & Safety, p. 22,
June (1992)
4. Rossignol, A.M., and N.B. Hanes, "Introducing Occupational
Safety and Health Material into Engineering Courses," Eng.
Ed., p. 430, April (1990)
5. Voland, G.M., Engineering by Design, Addison Wesley Publ.
Co., Reading, MA (1998) 0

lff curriculum




Exchanging Information Between the University and Industry

University of Waterloo Waterloo, Ontario, Canada N2L 3G1

he polymer industry is one of the most important and
fastest growing segments of the chemical industry
today, and this growth has created a high demand for
professionals with adequate knowledge to attend to its very
special needs. Besides the classical core subjects of the
chemical engineering curriculum, knowledge of several ad-
ditional topics is required for the student who intends to
apply for a position in the polymer manufacturing industry.
The technology for polymer manufacture is in a constant
state of change, and any undergraduate or graduate program
that relies only on established approaches in polymer chem-
istry and physics will quickly find itself out of date. In this
article we will describe how our interaction with several
polymer manufacturing companies through industrial short
courses and research projects has led to the development of a
dynamic and up-to-date undergraduate and graduate curricu-
lum in polymer science and engineering technology.
The technology for polymer production is a very dynamic
field due to the high demand for polymeric materials with
entirely novel or improved properties. New discoveries and
applications in polymerization catalysts and initiators, in
polymer reaction engineering, polymer characterization, and
polymer processing frequently redefine the boundaries of

Jodo B. P. Shares received his BEng (1983) from Federal University of
Bahia, Brazil, his MSc (1985) from State University of Campinas, Brazil,
and his PhD (1994) from McMaster University, all in chemical engineer-
ing. His main research interests are in the fields of metallocene and
Ziegler-Natta polymerization.
Alexander Penlidis received his Dipl. Eng. (1980) from the University of
Thessaloniki, Greece, and his PhD (1986) from McMaster University, both
in chemical engineering. His interests lie in the areas of polymer reactor
modeling, design, optimization, and computer control.
Archie E. Hamielec joined the chemical engineering department at
McMaster University in 1963, took early retirement in 1993, and is cur-
rently a Professor Emeritus. He is actively engaged in consulting for the
polymer manufacturing industry.

* McMaster University, Hamilton, Ontario, Canada L8S 4L7

knowledge in polymer science and technology. As a result,
several of the leading technologies for polymer manufacture
are constantly being modified to meet new market demands.
Although it is stimulating for those involved in the field,
this dynamic pace nonetheless creates a significant concern
for instructors teaching polymer-related courses in academia
since it requires that both undergraduate and graduate courses
be regularly updated to reflect these new developments.
Keeping up to date with the scientific literature alone, even

Partial List of Scientific Journals
in Polymer Science and Engineering

Journal Name (Periodicity) Publisher
European Polymer Journal (Monthly) Pergamon Press
International Polymer Science and Tech. (Monthly) RAPRA
Journal of Applied Polymer Science (Quarterly) John Wiley & Sons
Journal of Macromolecular Science (Monthly) Marcel Dekker
Journal of Polymer Engineering (Quarterly) Freund Pub. House
J. of Polymer Sci.: Poly. Chem. (Month/Semi-Month) Wiley & Sons
J. of Polymer Sci.: Poly. Phy.(Month/Semi-Month) Wiley & Sons
Macromolecules (Bi-Weekly) American Chem. Soc.
Macromolecular Reports (8 per Year) Marcel Dekker
Macromolecular Symposium (Irregular) Hiithig & Wepf Verlag
Polymer (Bi-Weekly) Elsevier
Polymer Bulletin (Bi-Monthly) Springer
Polymer Engineering and Science (Semi-Monthly) Soc. of Poly. Eng.
Polymer International (Monthly) John Wiley & Sons
Polymer Journal (Monthly) Soc. of Poly. Sci., Japan
Polymer Reaction Engineering Journal (Quarterly) Marcel Dekker
Progress in Polymer Science (Bi-Monthly) Pergamon Press
Trends in Polymer Science (Monthly) Elsevier

Copyright ChE Division ofASEE 1998
Chemical Engineering Education

in a relatively narrow branch of polymer science and
engineering, can be a time-consuming task due to the
numerous scientific journals available in the field, some
of which are listed in Table 1.
The polymer science and engineering theme illus-
trates remarkably well the old saying that in order to
teach a subject well, one must be actively involved in
research in that subject. That is the only way one can
stay current with all the new developments and main-
tain a sense of coherence and relevance in the face of
the immense body of information available to academ-
ics nowadays.
An additional and equally important point to remem-
ber when designing an academic course, especially at
the undergraduate level, is that equal importance must
be given to both scientific-relevant topics and those
that are of immediate concern to industry, since most
students will be seeking industrial jobs after gradua-
tion. Results from recent surveys on employment in the
United States and Europe indicate that as many as 70%
of chemical engineering graduates will have worked with
a polymer-related industry at some point in their profes-
sional career. Unfortunately, the importance of polymer
courses for chemical engineers at the undergraduate level
is still overlooked in several academic institutions.
In this article, we will describe our instructional ef-
forts in polymer science and technology at three dis-
tinct levels: industrial-intensive short courses, academic
courses, and final-undergraduate-year design and re-
search projects. We will show how these activities
complement each other, leading to university courses
with a high content of industrially relevant material
and to industrial courses that bring recent academic
advances in polymer science and engineering to in-
dustrial applications.

We offer three courses annually in Canada, the United
States, and Europe. Although the details of these courses
might vary according to the type of audience they are
intended for, they combine a very strong component in
fundamental understanding of polymerization reaction
engineering with recent advances in several aspects of
polymerization processes. In addition to the regular
lecturers, invited speakers (mainly from industry,
but also from academia) are regularly asked to give
two- to four-hour lectures. It has been our experi-
ence that the material covered by the invited speak-
ers is highly relevant to our industrial short courses
and can be successfully used to complement the
content of our university courses.
Table 2 shows the syllabus of a recent industrial
intensive short course in polymerization chemistry and
Winter 1998

)v Sessions
1 Chain-Growth
Mechanisms and

Syllabus of Industrial Short Course

* Linear, branched, and crosslinked chains via free-radical
* Linear and branched chains via ionic mechanisms
(Ziegler-Natta and Metallocenes)
* Stockmayer's bivariate distribution-instantaneous property

Advanced Identification of multiple active site types (GPC,
Polymerization TREF, NMR)
Kinetics Identification of active site performance
Long chain branching
Ziegler-Natta and metallocene catalysis
2 Emulsion, Styrenics, PVC
Dispersion, and Batch, semi-batch, and continuous operation
Suspension Thermodynamics and surface chemistry
Processes Particle nucleation and growth
Ionic and steric stabilization
Particle size distribution and molecular weight distrib.
Polyolefinic Molecular, theological, and solid-state properties (LDPE,
Processes HDPE, LLDPE, PP, impact copolymers)
Effect of short and long chain branching and molecular
weight distributions
Effects of main process variables on productivity and
polymer properties
Models of polyolefin production processes and plant data
3 Principles of Batch, semi-batch, and continuous operation
Polymer Reactor Dynamic modeling of reactor systems
Modeling and Population balance equations for particle size and molecular
Kinetic Data weight
Collection Screening and factorial designs for data collection
Sequential and non-linear design of experiments
Evolutionary operation
Model discrimination issues
4 Modem Special Bulk, solution, and emulsion terpolymerizations
Topics Reactivity ratio estimation
Monte Carlo methodology and applications
Reactivity ratio estimation
Optimal sensor selection
Reactive processing
Principles of temperature rising elution fractionation (TREF)
Measurement of long chain branching (GPC/VISC/LALLS)
Chemical modification of polymers
Crystallization Analysis Fractionation (CRYSTAF)
Rubber Definitions of rubbers and elastomers
Manufacturing Synthesis and production of rubbers
Processes and Recent developments in EP(D)M and poly- a -olefins:
Product metallocene catalysis/gas phase process/single site vs.
Characterization multi-site catalysts
Molecular structure and physical properties
Compounding, vulcanization, and applications
5 Monitoring, Overview of current control practices
Dynamics, and Sensors for monitoring reactor behavior
Control of Energy balance and rate control
Polymerization Control of product properties
Reactors Model use to combine on-line and off-line data
Kalman filtering and inferential control
Software sensors and multivariable statistics
Optimal reactor grade changes
Advanced linear and nonlinear control

reaction engineering, with emphasis on
metallocene catalysts, emulsion, and suspension
polymerization processes. As can be seen, the
first three sessions concentrate on fundamentals
and mathematical modeling of coordination and
free-radical polymerization. This forms the basis
for understanding of the more applied topics cov-
ered in subsequent sessions.

Properties of polyolefin resins and rubbers, es-
pecially structure-property relationships, are
given special attention. Recent advances on re-
actor monitoring, dynamics, and control, as well
as kinetic data collection and analysis, are also
covered in depth.

A session on modern special topics is generally
offered to cover new technologies and research
topics in polymer science and engineering. Mod-
em polymer characterization techniques are gen-
erally covered in the last session, although they
are discussed at every available opportunity dur-
ing the previous sessions, including applications
of on-line sensors.

As mentioned before, invited speakers make an
important contribution to this instructional effort.
Table 3 lists the names, topics, and affiliations of
some of the invited speakers who have partici-
pated in our courses in the past five years.

In-house short courses are also offered to meet
the needs of specific companies. These in-house
courses may range from one to five days. They
can be as general as the course described in Table
2 or focused on the technologies of the specific
company. Possibilities also include combinations
of special topics: for example, a two-day update
on the use of statistical methods and the design of
experiments for polymerization processes. Table
4 shows the syllabus of such a course on polymer
reaction engineering of polyolefinic processes re-
cently given in the United States. This particular
course concentrated on the manufacture of
polyolefins, with special emphasis on new tech-
nologies for metallocene catalysts.

It has been our experience that these courses are
mutually beneficial for the industrial participants
and for the lecturers. On one hand, the industrial
participants have an opportunity to update their
knowledge of modern advances in a broad area of
polymer science and technology, and over the
years we have been glad to note that several in-
dustrial participants have initiated research col-
laborations with the instructors after taking the
courses and that some of the topics introduced

Partial List of Invited Speakers, Their Topics, and Affiliations

Dr. T.A. Duever

Design of experiments for
polymerization data collection

Dr. G.N. Foster Characterization and physical
properties of polyolefins

Dr. E. Kontos
Dir., Elastomers


Chem. Eng. Department
University of Waterloo

Union Carbide
Bound Brook, NJ

Rubber manufacturing processes Uniroyal Chem. Co.
and product characterization Naugatuck, CT

K. Malone Organic peroxides for free- Elf Atochem.
radical polymerization Buffalo, NY

Dr. B. Monrabal

Dr. G.L. Rempel

Dr. C. Tzoganakis


Crystallization analysis
fractionation (CRYSTAF)
Metallocene catalysis and cata-
lytic modification of polymers
Polymer processing and reactive

Polymer Character., S.A.
Patera, Spain
Chem. Eng. Department
University of Waterloo
Chem. Eng. Department
University of Waterloo

Syllabus: In-House Short Course for
Polyolefin Production and Characterization

Soluble vs. heterogeneous catalysts
Polymerization mechanisms: homo- vs. copolymerization/linear
vs. branched chain formation
Control of stereoregularity, molecular weight, short and long
chain branching
Effect of polymer microstucture on mechanical and theological

Polymerization Gas phase/slurry bulk monomer and diluent/solution
Processes Fluidized bed vs. stirred bed gas-phase reactors
Loop reactors vs. stirred-bed slurry reactors
Processes for manufacture of high-impact copolymers
Vis-breaking processes

Basic Mathematical
Modeling of

Catalytic Site Type

Reactor Dynamics

* Mass balances: batch, semi-batch, and continuous operation of
CSTRs and CSTR trains
* Energy balance
* Polymerization kinetics
* Population balances
* Instantaneous properties methods vs. method of moments
* Multiplicity of active sites
* Heat and mass transfer limitations
* Particle size distribution

* Deconvolution of GPC curves using Flory's most probable
* Deconvolution of TREF curves using Stockmayer's distribution
* GPC/LC-transform-a new approach to site identification
* Overview of current control practices
* Sensors for monitoring reactor behavior
* Energy balance and rate control
* Control of product properties
* Model use to combine on-line and off-line data
* Kalman filtering and inferential control
* Software sensors and multivariable statistics
* Optimal reactor grade changes
* Advanced linear and nonlinear control

Chemical Engineering Education

The technology for polymer manufacture is in a constant state of change, and any
undergraduate or graduate program that relies only on established approaches in polymer chemistry
and physics will quickly find itself out of date. In this article we will describe how our interaction with
several polymer manufacturing companies ... has led to the development of a dynamic and up-to-date
undergraduate and graduate curriculum in polymer science and engineering technology.

Syllabus for Polymer Reaction Engineering Course

Week Topics
1 Overall course objectives Basic concepts and definitions in polymer science
2 Definition of molecular weight averages and distributions Method of moments *
Analytical techniques for measuring molecular weights
3 Step growth polymerization Condensation vs. addition polymers Statistical
treatment of step-growth polymerization Equal reactivity assumption (ERA) *
Irreversible growth with ERA Carothers equation Flory-Shultz distribution *
Determination of kinetic constants
4 Stoichiometry of linear systems Generalized Carothers equation Deterministic
treatment of step-growth polymerization Modeling step-growth polymerization
without ERA Effect of monofunctional agents Reversibility and interchange
5 Free-radical homo- and copolymerization Initiation, propagation, and termination
Basic hypotheses Commercial initiators Initiation rate Isothermal operation *
Initiator efficiency Propagation characteristics
6 Chain conformations Tacticity Termination characteristics Choice and amount
of initiator Inhibition and retardation Impurities Development of equations for
polymerization production rate Homopolymerization in batch reactors Dead-end
7 Derivation of the instantaneous copolymer composition (ICC) equation Plots of
the ICC equation Reactivity ratios Introduction to composition control methods *
Meyer-Lowry equation Cumulative copolymer composition Depropagation *
Molecular weight (MW) development for linear homopolymers
Mid-Term Exam
8 MW development: averages and distributions Practical hints on MW control and
temperature programming Energy balances Temperature and controller design *
Modes of termination Reactions with chain transfer agent Chain transfer to
monomer MW development: branched homopolymers
9 Transfer to polymer Terminal double-bond and internal double-bond reactions *
Backbiting Industrial examples Method of moments for branched systems MW
development for linear and branched copolymers Effect on glass transition
temperature Bimolecular termination kinetics
10 Emulsion polymerization: contrast with other polymerization methods Nucleation
and growth Thermodynamics Free-radical concentration Emulsion polymeriza-
tion kinetics: homo- and copolymerization
11 Latex particles size Polymer molecular weight Effects of pH and ionic strength *
Impurities Coagulation Multiple phase latex particles Introduction to
mathematical and computer modeling
12 Ionic (anionic and cationic) and coordination (Ziegler-Natta and metallocene)
polymerizations Brief overview Mechanisms Polymer properties
13 Review Sample problems and general discussion on the design of large polymer-
ization reactors
Final Exam

Winter 1998

during the courses have found practical appli-
cations in industry. On the other hand, the in-
structors benefit greatly from these interactions
since the contacts permit them to stay "in tune"
with the current needs of industry and with
recent advances of a practical nature that very
often are not disclosed in the scientific litera-
ture. This is not only a good way of influencing
the direction of some of our applied research,
but also an excellent way of covering current
trends of the polymer industry in our university
courses. Our students enjoy, and benefit tre-
mendously from, a knowledge of these current
industrial trends.

Table 5 presents the syllabus of the introduc-
tory polymer course given in the Chemical En-
gineering Department at the University of Wa-
terloo. It is offered annually (6 hours per week)
as a technical elective course for senior un-
dergraduate students and as an introductory
course for graduate students who are pursu-
ing MASc and PhD degrees in polymer sci-
ence and engineering.
This course covers the main areas of polymer
reaction engineering for step-growth and chain-
growth polymerization. Special emphasis is put
on understanding fundamental polymerization
principles, using both experimental polymer-
ization data and mathematical modeling tech-
niques. The statistical nature of polymerization
is examined in detail together with the concepts
of molecular weight and chemical composition
distribution in polymers. Polymer characteriza-
tion techniques are introduced as tools to corre-
late polymer chain structure to polymerization
mechanisms and processes. Several modern po-
lymerization processes (free-radical emulsion,
suspension, and solution, as well as Ziegler-
Natta and metallocene-catalyzed processes) are
presented to illustrate the fundamental concepts
covered in the initial part of the course. The
experience gained by our interaction with in-
dustry via collaborative research projects and
short courses helps us identify the most relevant

polymerization processes for this section of the course. In
this way, it has been possible to design a course with a strong
industry-oriented component while at the same time main-
taining a high level of scientific and academic content.
The course components consist of bi-weekly assignments,
a mid-term exam, and a final exam. Graduate students are
also required to work on a project, results from which are
presented orally at the end of the course. Table 6 shows a
selective list of required and supplementary references for
the course. In addition to these references, several technical
articles describing the state-of-the-art in polymerization re-
action engineering are given to the students as recommended
reading throughout the course.
In order to familiarize students with the vast amount of
literature available in polymer science and engineering, on-
line literature searches are also conducted during the course
in collaboration with our library personnel. Computer simu-
lation case studies in polymerization reaction engineering
are also done using WATPOLY, a user-friendly package
developed at Waterloo for the dynamic simulation of solu-
tion, emulsion, and suspension polymerization reactors. In
this way, several complex aspects of
these polymerization systems can be
examined by the students without
the need of tedious and time-con-
suming calculations. Allcock and Lampe Co
Additionally, the course is comple- Bicerano Prediction ofa
mented with a tour to the polymer- Billingham Molar Mas
ization pilot plant facilities of the de- Billmeyer Textbook of
apartment and with site visits to poly- Brandrup and Immergut
Brandrup and Immergut
mer manufacturing and processing
Several authors Compr
companies in the region.
Dotson, Galvan, Laurenc
Samples of polymer reaction engi- Elias Macromolecules,
Elas Macromolecules,
neering-related problems (tests or as-
Flory Principles of Poll
signments) that have arisen from our ry Priiles o
industrial interactions are presented Grulkey Polymer Proce
in Table 7. Some of these problems Gupta and Kumar Reac
are open-ended and may have mul- *Ham Vinyl Polymerizat
tiple solutions. They are an extremely Hiemenz Polymer Cheti
powerful vehicle in giving the stu- McCrum, Buckley, Buck
dents a flavor of "real-world poly- Moad and Solomon Tlu
mer production" problems. Odian p Principles ofPol

SENIOR-YEAR Peebles Molecular Wei
DESIGN/RESEARCH Rabek Experimental Mi
PROJECTS Rempp and Merrill Pol'
Rodriguez Principles of
All fourth-year undergraduate stu-
dents have to complete either an in- *Rosen Fundamental Pr
dividual research or design project or Rudin The Elements of
a group process design project in di- Saunders Organic Polym
rect collaboration with one faculty Sperling Introduction tc
member. Several Canadian and van Krevelen Propertie
American companies sponsor these

projects. Our interaction with polymer manufacturing com-
panies has been beneficial in defining polymer-related re-
search and design projects. Some of these projects are de-
scribed in Table 8.

University-industry interaction via industrial short courses
and collaborative research projects can bring several advan-
tages to both academic and industrial participants. As a
result of our own experience with short courses, we have
been able to design academic courses with a high content
of industrially relevant material. Instead of jeopardizing
the academic and fundamental content of these under-
graduate and graduate courses, this approach has actually
stimulated the students to better understand the mecha-
nistic and fundamental aspects of polymerization pro-
cesses that have prominent application in both academia
and industry.
On the other hand, industrial short courses that bring re-
cent fundamental scientific advances to industrial applica-
tions have helped clarify or show different solution alterna-

Textbook and Supplementary Reading

ntemporary Polymer Chemistry, 2nd ed. Prentice Hall (1990)
Polymer Properties Marcel Dekker (1993)
s Measurements in Polymer Science Kogan Page Ltd. (1977)
Polymer Science Interscience (1984)
* Polymer Handbook John Wiley & Sons (1975)
rehensive Polymer Science, 7 volumes Pergamon Press (1988)
e, and Tirrell Polymerization Process Modeling VCH Publishers (1996)
2 volumes Plenum Press (1984)
vmer Chemistry Cornell University Press (1953)
ss Engineering Prentice Hall (1994)
tion Engineering of Step Growth Polymerization Plenum Press (1987)
ion Marcel Dekker (1967)
nistry: The Basic Concepts Marcel Dekker (1984)
nall Principles of Polymer Engineering Oxford University Press (1988)
e Chemistry of Free Radical Polymerization Pergamon Press (1995)
Yymerization, 3rd ed. McGraw-Hill (1991)
ght Distribution in Polymers Interscience (1971)
methods in Polymer Chemistry John Wiley & Sons (1980)
rmner Synthesis Huthig/Wepf Verlag (1986)
Polymer Science McGraw-Hill (1970)
inciples of Polymeric Materials John Wiley & Sons (1993)
Polymer Science and Engineering Academic Press (1982)
mer Chemistry Chapman and Hall (1988)
Physical Polymer Science, 2nd ed. John Wiley & Sons (1992)
s of Polymers Elsevier (1990)

Chemical Engineering Education

Polymer Reaction Engineering Problems
Assignments and Exams

PROBLEM 1: Given the following data, calculate (at 0 and 50% conversion): (a) the instantaneous number average chain length of the polymer,
and (b) the average lifetime of a growing chain. Neglect chain transfer and assume that termination is by disproportionation only.
DATA: k= 900 L/mol.s: k2 /kt = 2.314 L/mol.s: k= 3 x 0s': = 0.017 mol/L: M,,= 1.5 mol/L: pM = 0.91 g/cm

PROBLEM 2: MMA is being polymerized in solution in a batch reactor using AIBN as initiator. The solvent is ethyl acetate and the contents are
maintained at 60C. The reactor is initially charged with 75% by volume MMA, 25% by volume ethyl acetate, and enough initiator to achieve
10=0.05 mol/L. Compute and plot (a) rate of polymerization, (b) heat of polymerization. and (c) number average molecular weight as a function
of polymerization time.
DATA: Kp= 170 L/mol.s; k,,= 1.85 x 106 L/mol.s; k,= 7.5 x 106 s'; k,/k,= 0.00014; pM = 0.91 g/cm'; p, = 0.85 g/cm1; f= 0.5

PROBLEM 3: Redo Problem 2 using the following gel-effect functionality for the termination rate constant: k =k, for x < 0.36; k =
0.1296(k/x') for x > 0.36.

PROBLEM 4: Find the reactor volume, total flow rates, and average residence time to produce 10.000 ton/year of styrene-acrylonitrile bulk
copolymer containing 28% (mole) acrylonitrile (365 days/year, 24 hours/day). If you need to make assumptions, state them clearly and justify
them. Assume that the total conversion in 60%.
DATA: r,= 0.41; r,= 0.04; k,,= 176 L/mol.s: k,_= 2500 L/mol.s; k= 5 x 10' L/mol.s: p, = 0.903 g/cm: p, = 0.811 g/cm'; R,= 107
mol/L.s; M, = 104 g/mol; M,= 53 g/mol. (l=styrene, 2=acrylonitrile)

PROBLEM 5: Consider a CSTR free-radical polymerization operating at steady state. Using the following data, map out the possibilities for
steady-state conversion versus residence time. How would you achieve 75% conversion? For results uniformity, consider a reactor operation of
365 days/year and 24 hours/day.
DATA: I = 1,,= 0.017 mol/L; M,,= 1.5 mol/L; k,,= 3.5 x 10' L/mol.s; kd= 3 x 10 s '; kp = 900 L/mol.s; f = 1
k=kforx<0.2 and k= (kJ0.512)(1-x) for x >0.2
kp= kp, for x 0.85 and k = (k1/0.0225)(l-x) for x > 0.85

PROBLEM 6: An isothermal polymerization is carried out at 100'C with a dual initiator system. After three hours of polymerization, the
monomer conversion is 60% in a 40,000-liter batch reactor. (a) Calculate the total radical concentration at 60% conversion of monomer (k,=10'
L/mol.s); (b) How long does it take to grow a polymer chain of molecular weight equal to 105 at 60% conversion? (c) Find the instantaneous
heat generation rate at 60% conversion. Compare this with the value at zero conversion: (d) Calculate instantaneous M and M at 0% and 60%
conversion; (e) The growth in M at high concentrations gives too broad a MWD. The solution is to use a chain transfer agent (CTA). Find the
amount of CTA required to keep M, almost constant over the conversion interval 0-60% given that k,= 100 L/mol.s. Compare M values at 0%
conversion for cases with and without CTA.

DATA: I0= 2 x 10 mol/L; I,,,= 5 x 10' mol/L; MW= 100 g/mol: (-AHp) = 17 kcal/mol; ktd(= 107 L/mol.s: k l= 10 s ; k,,= 10s-';
M,= 10 mol/L; k, =0: kp= 101 L/mol.

TABLE 8 tives to several problems encountered in industry. The ques-
SL 8e tions raised during these short courses have resulted several
Some Senior-Year Design/Research Projects
times in new research projects at both the undergraduate and
Dynamic simulation of ethylene-propylene impact copolymers in a the graduate level. In the process of attempting to tackle
series of CSTRs these industrially related problems, novel fundamental knowl-
Copolymerization kinetics of methyl methacrylate/vinyl acetate edge is generated, pushing the boundaries of our knowledge
Terpolymerization kinetics of methyl methacrylate/vinyl acetate/ in polymer science and engineering even further.
butyl acrylate NOTE
Investigation of kinetics of a -methyl styrene/methyl methacrylate at
elevated temperatures As a point of information for the academic readers of this
Investigation of butyl acrylate homopolymerization at high article, we are planning a series of short courses to assist
conversions chemical engineering academics who are teaching, or wish
Modeling of suspension polyvinyl chloride reactors to teach, polymer-related courses at the undergraduate level.
Educational uses of a general polymerization simulator package We welcome all communications from interested academics
Injection molding of medical plastics who would like to either attend these short courses or to give
Gel content in polyethylene/polypropylene sheets lectures on undergraduate courses in the polymer area that
they have successfully given. 7
Winter 1998 67

I classroom



Consultant Houston, TX 77079-2995

Engineers working in process plants are problem-
solvers. They play a very important role in process-
plant troubleshooting. For example, consider the
following situation:
The quality of a product from a certain unit has been de-
grading for some time and for some "unknown" reason.
You are a plant support engineer and you have been called
upon to help. Your job is to identify the root cause, to
quantify the business benefits of solving the problem, and
then to suggest ways to eliminate the factors causing the
What is problem-solving, and how does it begin? The verb
"solve" comes from the root solvere, which means "to loosen,
release, or set free." The word "problem" comes from the
roots pro, meaning "forward," and ballein, meaning to "throw
or drive." So, problem-solving is a process of proposing and
considering questions in a way that throws or drives us
forward toward greater freedom.[
In their entertaining book, The Universal Traveler, Don
Koberg and Jim Bagnall define the seven stages of creative
problem solving as "acceptance, analysis, definition, ide-
ation, idea-selection, implementation, and evaluation."121
Clearly, being aware of a problem's existence is the first
step. Gathering information about the situation is the next
step. One can learn about the situation through literature and
document searches, by direct observation, and by gathering
information from people closest to the problem. This skill of
gathering data from others is a critical success factor for all
practicing engineers. Whereas gathering information from
literature and the Internet is emphasized in most engineering
courses, to the best of my knowledge, training in how to
gather information from others is not offered.
The main objective of this article is to share some practical
ideas on improving the speed and effectiveness of the pro-
cess of gathering information from others. It is based on my
experience in designing and conducting opportunity and sup-
port needs assessment surveys for process modeling in pro-

cess plants. Although the article will focus on techniques for
more organized information gathering (such as surveys and
on-site visits), the principles illustrated are equally appli-
cable to informal information exchanges. This domain of
designing and conducting surveys has been developed ex-
tensively by social scientists. I will begin first by defining
the prerequisites for effective information exchange and
then I will provide specific guidelines on how to pose the
right questions. The article will also include a brief dis-
cussion on how one might be able to use this information
in a classroom setting.

Early in my career, I learned that communication consists
of a message, a sender, a receiver, a medium, a context,
feedback, and noise.[3,4] For gathering information, the mes-
sage is the "questions," and the medium may be a printed
survey or a face-to-face interview (i.e., spoken words). I
have discovered five key prerequisites necessary for cre-
ating the right context, capturing the feedback, and mini-
mizing noise.
Trust This is the first prerequisite. Thanks to authors
such as Peter Senge[51 and Stephen Covey,16' discussions on
trust and trusting are becoming more acceptable, even among
hard-core engineers. Trust is the foundation of all effective
communication. The survey recipients must clearly under-
stand the purpose of the information exchange. They must
know "why" the information is being requested and "how"

Saidas M. Ranade PhD, PE, was the Principal
Consultant for Aspen Technology, Inc.'s Model-
ing Success Program. Some of the tools he
has developed and applied to ensure that cus-
tomers get the best value from AspenTech's
modeling technologies and services include
modeling opportunity assessments, modeling
needs assessment, a template for documenting
successes, and a method for cataloging pro-
cess models. He can be reached at

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

their information will be used.17'81 It is the
interviewer's obligation to pursue the truth The ma
and truly believe in doing everything to ben- of this
efit the interviewees. Of course, trust can- to sht
not be mandated, and there are no shortcuts practice
to building trust. Vendors of software and improving
associated services have the challenging task effective
of overcoming a history of "lack of trust" process
created by their industry-for example, cus- inform
tomers do not believe in software release others..
dates. Also, in dealing with process manu- the ar
facturing plants, the issue of confidentiality focus on
of information is very important and must for mor
be explicitly addressed prior to any useful informati
information-gathering session. (such
Credibility and Respect The second and on-
prerequisite to effective information-gath- the princip
ering is the interviewer's credibility in the are equal
domain of the specific inquiry. People are to ii
more open to answering your questions if infoi
you have already established a track record, excJ
either with the site or the process or the
field of inquiry (i.e., if they respect you). There are pros and
cons to this phenomenon. You may be very talented and may
have a novel approach to solving problems; but you may not
be effective simply because you are new. Also, due to this
emphasis on "credibility," it is very tempting to use the
jargon of the business superficially to establish credibil-
ity, but experience has shown me that instead of attempt-
ing to appear knowledgeable, it is better to admit that
you are new to the field.
Effective Listening This is the third prerequisite. Hon-
est and open exchange of ideas is possible only when you
have a genuine interest in the views and opinions of the
interviewees. One of the best definitions of effective listen-
ing comes from Dr. Stephen Covey. He equates effective
listening to faithful translation. The main requirement to
having a dialogue and not just a discussion is to be com-
pletely open to the outcome. This is at the heart of any true
discovery process. The word "dialogue" comes from two
Greek roots: dia, meaning "through," and logos, meaning
"the word." It carries a sense of "meaning flowing through."
The word "discussion," on the other hand, stems from the
Latin discutere, which means "to smash to pieces." Addi-
tional useful information on the topics of "Inquiry" and "The
Art and Practice of Conversation" is presented in Ref. 5.
Proper Timing and Setting This is the fourth prerequi-
site. One of the biggest challenges for engineers and opera-
tors in process plants is to make time available for surveys
and audits. Hence, the surveys must be aesthetically de-
signed and the participants should be given ample time to
complete them. In a face-to-face information-gathering ses-
sion, the room in which interviews are conducted should be

in ol
ire s
al id
of ga
e org
on g
is su
ly a

Winter 1998

comfortable and open, with several
jective whiteboards and easels. During a scheduled
cle is plant turnaround, a plant is typically shut
some down for several weeks. This period is used
eas on to make major modifications to the process
speed and and to install new plant equipment. Many of
s of the these new items have to be ordered six to
withering nine months in advance, and it takes about
n from three to six months to develop detailed speci-
lthough fications for major items. So the best time to
will conduct opportunity assessments is about
hniques nine to fifteen months prior to a scheduled
:anized turnaround. In this manner, the recommended
gathering revamp-type projects can be implemented
rrveys during the turnaround period.
visits), Gratitude This is the fifth prerequisite.
illustrated It helps immensely if your demeanor con-
pplicable veys a genuine sense of gratitude toward
nal those from whom you collect information.
tion In today's atmosphere, it seems that
:es. everyone's agenda is full all the time, so
even if you do not find some of the responses
to be useful, it always makes sense to thank the interviewees
or survey participants for their time. It is also important to
publicly acknowledge any contribution made by others to
the success of your projects.

After having satisfied the above prerequisites, one may
still not be effective in conducting surveys and on-site inter-
views. This is where the "science" of asking questions comes
into play. The following quotes and events signify the im-
portance of questions and questioning:
D "You can tell whether a man is clever by his answers. You
can tell whether a man is wise by his questions."
Naguib Mahfouz
Winner, Nobel Prize for literature, 1988[11
When Richard Feynman was a child, his Mother asked the
future Nobel Prize winner the same question every evening
at the dinner table: "What did you ask at school today,
Richard?" (Feynman won the Nobel Prize for physics in
1965.) 1
> Hammurabi of Babylon changed the course of history by
changing the representation when dealing with the prob-
lem of an inadequate water supply. Instead of asking how
to get the people to the water, he asked how to get the
water to the people. This led to the invention of canals."101

Creation of the proper context is necessary for both printed
surveys and on-site interviews. In a printed survey, the con-
tent and the order of the questions must be carefully se-
lected. In a face-to-face interview, in addition to the choice
of words and their sequence, proper tone of your voice plays
a very important role.

I will begin with a brief discussion of different types of
questions. Then I will provide guidelines on wording of
questions and maintaining a flow for the on-site interviews.
Types of Questions
In his book Just So Stories (1902), Rudyard Kipling (who
won a Nobel Prize for literature in 1907) had this to say
about types of questions: "I keep six honest serving men.
They taught me all I know. Their names are What and Why
and When and How and Where and Who." The "how"-type
question is the most open-ended. The "why"-type question
may put the interviewee on the defensive. At some point in
time, the questions beginning with "why" are essential to
finding the cause of the problem; initially they may not be
very effective, however.
Yet another method of classification also results in six
types of questions. They are questions pertaining to experi-
ence/behavior, opinions/values, knowledge, feeling, sensory,
and background (or demographics)."91 For each type of ques-
tion, one can ask about the present, the past, or the future.
Questions pertaining to experience or behavior or actions
are easy to answer and should be used first. Sensory- and
background-type questions are mundane and should be dealt
with toward the end of the on-site interview. Questions
pertaining to participants' opinions/values and knowledge
are very important for identifying symptoms and causes of
problems, but they require proper context-building prior to
their use. It is important to gauge the level of an individual's
knowledge about a given situation without making it seem
that you are testing him. Engineers, in general, tend to shy
away from "feelings"-type questions and, hence, they should
be kept to a minimum.
For the time-frame, it is always appropriate to start from
the present and then move to the past and then to the future.

Basics First, ask truly open-ended questions. "How
satisfied are you with the performance of this heat ex-
changer?" may seem like an open-ended question, but it is
not. Second, it is important to ask a "singular" question (i.e.,
refer to only one idea per question). A good question should
be relatively short, clear, and unambiguous. Do not run a
string of questions together. If you want to ask a string of
related questions, then ask one at a time and get a response
before proceeding.1"" The question, "How often do you mea-
sure the pressure drop across this exchanger, how good are
the measurements, and do you know the cause of the
sudden increase in the pressure drop?" should be split up
into three separate questions.
The third basic rule is to use the terminology and language
of the interviewee or survey-recipient. Be careful of acro-
nyms such as QIT, BIP, PIP, etc., because they may have
different meanings at different plants. If you do choose to

use acronyms, it is always beneficial to define them.
A Few No-No's In the beginning, avoid questions that
result in "yes" or "no" responses. The whole idea is to get
the participants to "open up." Also, avoid "why" questions
in the beginning. From our childhood, we have been condi-
tioned to associate some type of blame with the word "why."
("Why" did you break this vase?) The objective of gather-
ing information from others is accomplished when you
make them feel comfortable about the situation and encour-
age them to have a dialogue with you.
Proven Techniques Presupposition-type questions are
good. For example, "What is your most important idea
regarding the cause of fouling?" This question presupposes
that the interviewee is capable of having several good ideas
about the cause of the problem. Questions pertaining to
tough topics or questions that seem too direct can be soft-
ened considerably either by role playing (i.e., putting your-
self in a new role in the question) or by simulation (i.e.,
putting the interviewee in a new role in the question). Rather
than asking, "What do you do in the plant in the morn-
ing?" ask, "If I were your colleague accompanying you
in the plant, what would I observe?" And, instead of
asking a unit engineer, "What are the goals of the entire
plant?" try, "If you were the plant manager, what would
be your top priorities?"
Keeping the Flow It is very important to keep the on-
site interviews flowing smoothly. This depends on several
factors. Establishing rapport with the individual and main-
taining neutrality toward the information they provide are
very important steps for keeping the flow. It always helps to
make transitions smooth rather than abrupt by making spe-
cific announcements before the transitions. Prefatory state-
ments such as, "The next question may seem a bit vague,"
are very useful to ensure that the interviewee is not under
undue pressure to look for a precise answer. Elaboration,
clarification, and contrast-type probes are very useful in
getting some individuals to talk. Of course, thanking the
interviewee for providing a response to a tough question is
also effective in keeping the flow of the process. In general,
it is very hard to get engineers to converse openly with you,
but occasionally you will come across individuals who try
to monopolize the conversation and will not stop talking.
In such cases, it is important to emphasize, in a conver-
sational tone of voice, that everyone's time is important.
The flow of the process can be easily disrupted by long-
winded or irrelevant comments.

One easy way to make students aware of the issues in-
volved in gathering information from others is to ask stu-
dents to read this article and spend about an hour discussing
the topic in the classroom. As an additional homework
assignment, you may ask students to watch the 1996 Twen-
Chemical Engineering Education

tieth Century-Fox movie, Courage Under Fire, which clearly
demonstrates that the same event (or a problem) can be
perceived very differently by different people. Since the
right psychology and information may not exist readily in
most chemical engineering classrooms, the only way to di-
rectly practice the techniques prescribed in this article is by
simulating a few real-life situations in a classroom setting
and requesting students to play specific roles. One such
approach, which requires a fair bit of preparatory work, is
described in the Apppendix.

Engineers and managers are problem solvers. An impor-
tant step in identifying and defining problems involves gath-
ering data. Since every situation is unique, it always helps to
gather information about a situation from the people who are
closest to it. The techniques for gathering information
from others are very important for process-plant trouble-
shooting and are not emphasized enough in formal chemi-
cal engineering education.
The main point is that one will be able to easily acquire
useful information from others by ensuring that the prerequi-
sites such as trust, respect, effective listening, proper timing,
and gratitude are met and following the guidelines for cor-
rect wording, sequence, and tone of the questions. Practic-
ing the techniques without the prerequisites is possible,
but only results in manipulation and deception and should
be avoided at all costs.

The opinions expressed or implied are those of the author
and do not represent the views of AspenTech.

1. Gelb, M.T., Thinking for a Change, Harmony Books, New
York, NY, 96 (1995)
2. Koberg, D., and J. Bagnall, The Universal Traveler, Crisp
Publications, Inc., Los Altos, CA, 41 (1991)
3. Wurman, R.S., Follow the Yellow Brick Road, Bantam Books,
New York, NY, 17 (1992)
4. Salsbury, G.B., A Resource Manual For Effective Presenta-
tions, Salsbury Communications, Inc., Manhattan Beach,
CA (1985)
5. Senge, P.M., et. al., The Fifth Discipline Fieldbook, Cur-
rency-Doubleday, New York, NY (1994)
6. Covey, S.R., Principle-Centered Leadership, Fireside, New
York, NY (1992)
7. Salant, P., and D.A. Dillman, How to Conduct Your Own
Survey, John Wiley & Sons, Inc., New York, NY (1994)
8. Sudman, S., and N.M. Bradburn, Asking Questions: A Prac-
tical Quide to Questionnaire Design, Josey-Bass, Inc., San
Francisco, CA (1982)
9. Patton, M.Q., Qualitative Evaluation and Research Meth-
ods, 2nd ed., Sage Publications, Newbury Park, CA (1990)
10. Rubenstein, M.F., and I.R. Firstenberg, "Tools for Think-
ing," in Developing Critical Thinking and Problem-Solving
Abilities, Ed., Stice, J.E., Josey-Bass, Inc., San Francisco,
CA (1987)

Winter 1998

11. Wankat, P.C., and F.S. Oreovicz, Teaching Engineering,
McGraw-Hill, Inc., New York, NY, 101 (1993)
12. Lieberman, N.P., Troubleshooting Process Operations, 3rd
ed., PennWell Books, Tulsa, OK (1991)
13. Saletan, D., Creative Troubleshooting in the Chemical Pro-
cess Industries, Chapman & Hall, New York, NY (1994)

An Experiment for Testing the Ideas
in a Classroom Setting

Preparation At the beginning of the experiment,
divide the students into groups of five. Provide each
group with a handout or script describing a specific
situation. Examples of such situations include safety
incidents, environmental excursions, product quality
problems, etc. You may use the published case studies
from books, such as those by Lieberman,"121 Saletan,1'31
etc., to create the specific scenarios. On each team,
assign one of the following roles to each student
Plant Engineer
Tech-Support Engineer from a Central Group
Plant Manager
Assignment To identify, define, and solve problems
faced by all the other teams.
Rules Give students about four weeks to complete
the assignment. Request that the students
Not reveal the actual script or handout to
anyone outside of their team
Play the assigned roles as faithfully as possible
Only answer the questions being asked while
remembering the mindset of the role they are
Document their strategy for gathering the
required information
Document their feelings, thoughts, and any
other reactions to the mode of inquiry used by
each of the other teams.
Criteria for Grading
Number of problems identified
Number of problems solved
Nature of the means used to obtain information
Impact on the feelings of others during the pro-
cess of gathering information
Quality of the document describing the strategy
used to acquire information
Quality of the document describing the feelings
and thoughts during the inquiry by other teams.

looking back


Pinnacle Technology, Inc. e Lawrence, KS 66044

Process engineers, such as myself, who are approach-
ing retirement or are at an age where "you can see it
from here," probably received their undergraduate
training in the 1950s. As we consider the prospect of
retirement, or edge into it through part-time work or
consulting jobs, it is interesting to consider how we dif-
fer from today's graduate.
There is little question that today's graduate is better
equipped with the "tools of the trade" and better prepared to
be immediately useful. But it can be argued that my genera-
tion spent an apprenticeship doing hand calculations that
were more productive. For example, hours, if not days, were
spent checking a heat exchanger design by hand, giving us a
better feel for the variables involved than doing computer
iterations would. But time soon evens everything out.
So, what can my generation pass on to new process engi-
neers? Perhaps some rules-of-thumb that have been useful,
or some guidelines for good practice, or some judgmental
discernments that we have learned through unfortunate ex-
periences. What follows are some of the rules and guidelines
that have proven useful to me over the years.

The stream efficiency, or annual on-stream operating time,
is a key factor in successfully operating any chemical plant.
Plants are designed to run on gallons per minute, or pounds
per day, or barrels per stream day. But cash is generated and
investors are rewarded from tons per annum, or pounds per
year, or barrels per calendar day.
A key number to remember is 8760-the number of hours
in a year. In a perfect world that is error and maintenance
free, a plant would produce in a year 8760 times what it
could produce in an hour. But allowing for a two-week
annual maintenance shutdown and an unscheduled outage of
one day a month, the operating hours in a year are actually
8136, for a stream efficiency of 93%.
In actual practice, a promise of more than 8000 operating
hours in a year (or a stream efficiency of 91%) is highly
suspect. Oil refineries that are well run and well maintained

show that stream efficiencies in the 90s are difficult to achieve.
The refining industry as a whole probably operates with a
stream efficiency in the mid-to-high 80s.
Projected high stream efficiencies often stem from mas-
saging the numbers to improve a project's economics, and
"name plate" capacities are probably derived from a 72-hour
test run, or whatever was contractually agreed upon at the
beginning. Remember, though, that the real test run is the
8000-hour test. One should use 8000 operating hours per
year as the goal, even when giving appropriate consider-
ation to feed outages, power interruptions, changing prod-
uct grades, etc.

There are many excellent guides to preparing economic
projections for a new project. For the most part, these
guides focus on developing the "bottom line," i.e., net
profit, cash flow, payback, etc. That is what owners and
investors want to see.
Much useful information, however, can be obtained from
an analysis of the "top line," i.e., the total sales generated.
One should look at sales generated per dollar invested in
much the same way as stock analysts look at a company's
sales-per-share. How many times per year the sales "turn
over" the capital invested can lead to a good appreciation of
a project's risks and rewards.
Assume annual sales per invested dollar are substantially
greater than one; unless the project is the proverbial license

Dan Maclean graduated from the University
of Toronto with a BASc in chemical engineer-
ing in 1954, and received his MASc in chemi-
cal engineering from Birmingham University
(United Kingdom) in 1959. He worked for
Celanese Corporation and for several oil refin-
eries during his career, and since 1984 has
had a wide range of consulting assignments,
usually in the area of alternative fuels such as
alcohol/gasoline blends and pyrolysis oils.

Copyright ChE Division ofASEE 1998

Chemical Engineering Education

to print money, the margin per sales dollar is going to be
thin. Examine the margin carefully. How firm is it? A small
reduction in the margin could eliminate any profit. Is the
operation a value-added one, such as refining crude oil where
the margin is protected by a direct link between raw material
and product prices? If a large volume of raw materials and
products is involved, has sufficient attention been paid to
materials-handling factors? Concentrate on the cost factors
involved in the project.

Without question, the most common mistake made in speci-
fying heat exchangers is made by the conservative engineer
anxious to supply adequate equipment who specifies too
much area! By a unit that is too big, fluid velocities are
reduced to less that 3 feet/second, transfer coefficients fall,
and deposits build up in stagnant zones. Performance is poor
and even, in some cases, inadequate.
Three feet/second is the absolute minimum velocity,
shell or tube side, that should be considered. Providing
the head required is a small price to pay for good heat
exchanger operation.
A rapid way to estimate the number of tubes in a shell and
tube exchanger is with the formula
N = C(L/P)2
N = number of tubes
P = tube spacing, inches
L = "outer tube limit," inches
C = constant, 0.75 for square pitch, 0.86 for triangular pitch
The "outer tube limit" is 5/8 in. less than the shell diameter
for fixed tube sheet or U-tube construction, and 1 1/2 in. less
for floating head construction.
Assume 20-inch nominal shell diameter (19.2-inch inside
16-ft tube length, fixed tube sheet, 3/4-inch tubes
on I-inch square pitch
N = 0.75 (18.575/1)2 = 259 tubes
Area = (259)(16)(0.196) = 812 sq. ft.
or assume As above, but with 1-inch tubes on 1 1/4-inch
triangular pitch
N = 0.86 (18.575/1.25)2 = 190 tubes
Area = (190)(16)(0.262) = 796 sq. ft.
This formula neglects tubes lost due to multipass construc-
tion, impingement plates, etc.

The old adage, "All pump problems are suction prob-
lems," still applies. Design for low velocities in suction
lines: 0.5 to 1 foot/second for boiling liquids, and 1 to 3 feet/
second for non-boiling liquids.
Vortex breakers are often omitted or ignored. Cross or flat

There is little question that
today's graduate is better equipped
with the "tools of the trade" and better
prepared to be immediately useful. But it
can be argued that my generation spent an
apprenticeship doing hand calculations
that were more productive.

plate baffles, with a width of 2 to 4 times the nozzle
diameter and a height of one-half the nozzle diameter are
effective vortex breakers.

A company I once worked for operated some acetylation
kettles in which sheets of cellulose (wood pulp) were acety-
lated with acetic anhydride. The kettles were jacketed with a
recirculating brine to remove the heat of reaction. Brine
circulation was controlled manually to prevent rising tem-
peratures from degrading the cellulose and falling tempera-
tures from reducing the reaction rate.
Varying temperatures, humidities, and time in storage of
the cellulose resulted in varying moisture levels in the cellu-
lose. This resulted in varying reaction temperatures and the
recurring question-were we over- or under-controlling?
Were we looking at random noise when the temperature
wandered, or had reaction conditions actually changed?
Routinely, we plotted kettle temperatures to see to what
extent we were diverging from set point. Next, we initiated a
new plot for every five minutes, showing the cumulative
extent to which temperature diverged from the set point. If
the temperature was cycling randomly around the set point,
this second curve would make an exaggerated cycle but
would return to zero (see Figure 1).
If, however, reaction conditions had changed and a new
equilibrium temperature had been established, the second
plot would rapidly indicate this by going outside any bound-



Figure 1

Winter 1998



Figure 2

ary limits (see Figure 2). Boundary limits can be readily set
after some operating experience.

The same kind of plot can be useful in any situation where
you want to establish if a status quo situation or an existing
trend line had been breached. They can be used alongside
moving average plots in financial quotations.

Another plot I have found useful is the probability paper,
both normal and logarithmic. A probability paper is most
suited to record a series of events distributed around a mean
where one wants to design for a certain fraction of the
occurrence of the events. These events could be temperature


Daily Truck Loadings

#of Day number
Trucks "M"
60 1
40 2
85 3
30 4
67 5
46 6
60 7
42 8
90 9
51 10
53 11
62 12
34 13
73 14
80 15
50 16
38 17
28 18
40 19
45 20(N)

53.7 Avg.

Daily Truck Loading
in Ascending Order

# of Trucks
Loaded, [M/(N+1)]
in order
28 0.048
30 0.095
34 0.143
38 0.190
40 0.238
40 0.286
42 0.333
45 0.381
46 0.429
50 0.476
51 0.524
53 0.571
60 0.619
60 0.667
62 0.714
67 0.762
73 0.810
80 0.857
85 0.905
90 0.952

Figure 3

or wind levels, ship arrivals, river flows, etc. As an example,
consider daily truck loadings at a terminal. The number of
trucks per day is tabulated by day "M" in Table 1. Next,
arrange them in ascending order and divide "M" by (N+1),
where N is the total number of days, and plot "M"/(N+1) vs
the number of trucks/day, or probability paper. The data
aligns reasonably well (see Figure 3).

To satisfy the loading demanded four days out of five, or
80% of the time, inventory would be required to fill 70
trucks. If it was desired to satisfy the loading demanded nine
days out of ten, inventory would be required to fill 85 trucks.


The guideline "1 pound per 100 feet" pressure drop can
serve to size lines in a wide variety of situations. The tables
in "Cameron Hydraulic Data," based on the Williams and
Hazen formula, form a conservative standard. Two points
worth mentioning here are:

1) In long, large-diameter lines, hold the velocity down to a
walking pace of 4-5 miles per hour, or 6-7 feet per second.

2) 1 1/2-in. sch. 40 pipe is the smallest size that will span 15-
to-20-foot pipe racks without intermediate support. Opera-
tors often climb on piping to take readings, etc., so 1 1/2-in.
pipe is the smallest pipe size that should be used for routine

These are some of the guidelines and rules-of-thumb that
have been of value to me during my career. Perhaps this
article will prompt other "senior" process engineers to share
some of the experience they have gained during their ca-
reers. We seniors owe a lot to a profession that has rewarded
us well, both personally and professionally. O

Chemical Engineering Education


99.9 -
99.5 .
98 -
S 80
7 60 -4
40 -

1 0


0 20 40 60 0O 00

BOOK REVIEW: Introduction to Theoretical and Computational Fluid Dynamics
Continued from page 29.

emphasis of the book is strictly on fundamentals, particu-
larly the general mathematical description of fluid motions
and the presentation of solutions for important fundamental
flow problems. The exposition is relatively abstract; little
reference is made to applications, to experiments, or to ob-
servations of natural phenomena. In general, solutions to
posed problems are obtained or outlined through exact ana-
lytical and numerical methods, primarily via singularity ap-
proaches or finite difference methods. This book contains a
vast amount of detailed information, from the differential
geometry of general surfaces in flow fields to the similarity
solutions for Stokes flow near covers to the subtleties of the
stability problem for inviscid shear flow.
The book begins with two excellent chapters on the kine-
matics of flows; of particular note are explicit general for-
mulas for surface mean curvature and a collection of veloc-
ity fields determined by various vorticity distributions. The
next chapter introduces stress and the equation of motion;
nice features include a concise exposition of constitutive
equations and a good discussion of vorticity transport; vor-
ticity is a theme that receives a great deal of emphasis
throughout the book. A brief chapter on hydrostatics fol-
lows, including many examples of the computation of static
free surface shapes. Curiously, mean curvature is defined
again, with no reference to Chapter 1.
Chapter 5 presents many of the classical exact solutions
for viscous incompressible flow, including unidirectional
flows, Jeffery-Hamel flow, stagnation point flows, and flows
due to point sources.
Flow at low Reynolds numbers is the topic of Chapter 6.
The primary emphasis is on singularity solutions of Stokes'
equation, including a sketch of boundary-integral equation
methods. A fairly detailed exposition of local solutions near
covers is also given. Transient flow effects and the first
effects of inertia are touched upon.
Chapters 7 and 8 describe irrotational flow and boundary
layer theory, respectively. For irrotational flow, the basic
results on force and torque exerted on a body in steady or
time-dependent irrotational flow are described. Several
pages are devoted to the use of conformal mapping for
solving the Laplace equation. The chapter on boundary
layers provides good coverage of the classical material.
As in other places though, the author is sometimes overly
terse here.
Chapter 9 is a very nice chapter on hydrodynamic stabil-
ity, containing the basic results for shear flow, free surface,
capillary, and centrifugal instabilities, though perhaps too
brief regarding centrifugal instability. Noteworthy is the dis-
cussion of the concepts of absolute and convective instabil-

ity and their relationship. It would have been nice, however,
to see some generic results about nonlinearity, such as a
brief discussion of supercritical and subcritical bifurcation.
Chapters 10 and 11 focus on the solution of inviscid flow
problems. Chapter 10 outlines the boundary integral equa-
tion approach to the solution of potential flow problems,
while Chapter 11 describes vortex motion in inviscid fluids,
with the goal of providing the framework for numerical
solution of vortex dynamics problems. Chapters 12 and 13
provide a whirlwind tour of finite-difference approaches to
solving convection-diffusion and incompressible flow prob-
lems. One attractive feature of this section is the presentation
of the modified differential equations associated with some
of the approaches, showing, for example, that the instability
of the FTCS scheme for a hyperbolic equation is traceable to
an effective negative numerical diffusivity. Finally, two con-
venient appendices contain basic results in vector calculus
and basic numerical methods.
There is clearly a great deal of material covered here, and
covered well. Nevertheless, the breadth and depth of cover-
age has its cost. The text occasionally becomes an extended
list of formulas, solutions, or methods. This is fantastic as a
reference; I have used it repeatedly myself and referred parts
of it to several graduate students. It is not always ideal for
teaching purpose though, as the means by which solutions
are obtained is often given little motivation. Details of solu-
tion procedures are often not provided, and sometimes op-
portunities to impart physical insight are bypassed in favor
of a terse, elegant, mathematical statement or argument.
The level of mathematical sophistication assumed is at
least that of a first-year grad student in chemical engineer-
ing, preferably one who has already taken an applied math
class covering linear algebra and elementary partial differen-
tial equations. Because of the mathematical level of this
book, the abstract point of view, and the sole emphasis on
fundamentals, it is not appropriate as an undergraduate
text for chemical engineering students. Nevertheless, it
is probably a text that any serious student of fluid dy-
namics would like to own, and it would provide a good
text for either an introductory or advanced graduate course
in fluids, depending on the topics chosen. The lecturer
will need to fill in many of the motivations and solution
details, but this is not a large price to pay for a text that
outlines theoretical fluid dynamics as thoroughly as this
one does.
In my opinion, this is a very important contribution to the
textbook literature in fluid dynamics-a book I am happy to
own and one that I would highly recommend to anyone
working in theoretical fluid dynamics. O

Winter 1998

e= laboratory



National University of Singapore Singapore 119260

Adsorption separation has become a major unit op-
eration in the chemical process industry. Under-
graduate chemical engineering students at the
National University of Singapore receive about six hours of
lectures on adsorption fundamentals and applications as part
of the course Separation Processes II, offered in the third
year of their study.
We have long felt there is a need for a suitable laboratory
experiment that reinforces the basic design concepts. Since
reliable equilibrium and mass transfer data are central to the
design of an adsorption separation process, we have recently
introduced an experiment in our third-year laboratory in
which the students determine these parameters from break-
through measurements in an adsorption column. During
analysis of the breakthrough data, the students also develop
a basic understanding of adsorption process dynamics.

The experimental apparatus for breakthrough measure-
ments, schematically shown in Figure 1, consists of a col-
umn packed with the adsorbent under study and a host of
pressure and flow controllers that control the operating pres-
sure and concentration of the adsorbate in the feed, respec-
tively. Further details on the experimental apparatus and the
adsorbent used are given in Table 1. The adsorbate is nor-
mally mixed with an inert carrier. The effluent stream is
analyzed using a suitable detector to monitor the break-

degrees in chemical engineering from BUET
(Bangladesh) and his PhD from the University of
New Brunswick (Canada). A faculty member in the
Chemical Engineering Department at the National
University of Singapore since 1991, his research
interest is in the area of adsorption gas separation.
He is a coauthor of the book Pressure Swing Ad-
sorption (VCH, 1994).

@ Copyright ChE Division ofASEE 1998

- Bypass line
Pressure gauge
4 On-off valve
1 Mass flow controller




Jacketed Adsorption column
Oxygen analyzer
Back pressure regulator
Chart recorder

Figure 1. Schematic diagram of the breakthrough
apparatus. Further details are given in Table 1.

through of the adsorbate. The desorption response is mea-
sured by withdrawing the flow of adsorbate from the feed
after the column has been saturated.

A typical breakthrough response from a clean bed to a step
change in adsorbate concentration in the feed is shown in
Figure 2, where c is the concentration at any time, t, and co is
the constant feed concentration. When the adsorbate concen-
tration in the effluent equals that in the feed, it indicates that
the bed has been saturated. Material balance over a saturated
bed gives

mean residence time, t, = (shaded area in Figure 2)

c L 1- +r I e- qo
= 1- 1 dt= -1+
Co Vo E Co
L length of packed bed
Vo interstitial feed velocity
Chemical Engineering Education

e bed voidage
qo equilibrium adsorbed amount corresponding to feed con-
centration, c.

A typical favorable equilibrium isotherm is shown in Figure
3. Henry's constant will be measured in this study, which
requires that the experiments are conducted in the linear
(low concentration) range of the isotherm. Ratio of Henry's
constants of two adsorbable components is the primary mea-
sure of their separability.

It is important to note that here Henry's constant is dimen-
sionless, since it has been expressed as concentration ratios.
Henry's constant follows the Arrhenius Law of temperature
dependence. The following equation is applicable for di-
mensionless Henry's constant:

K= Ke RT

Ko pre-exponential factor
Rg gas constant in heat units
T temperatures in absolute units

A semilogarithmic plot of K vs. 1/T should give a straight
line with -AUo /Rg as the slope and Ko as the intercept. The
change of internal energy due to adsorption, AUo, is related

c/co dC/C

0 t t

Adsorption column
Feed Effluent
v, cm/s c moles/cc
Co moles/cc

Figure 2. A typical breakthrough response for a step
change in feed concentration.

Adsorbed q,
q (moles/cc) slope=q

Fluid phase concentration, c (moles/cc)

Lt qo= Dimensionless
Co 0 co Henry's constant, K

Figure 3. Favorable adsorption isotherm.

Winter 1998

Details of the Experimental Apparatus Shown in Figure 1.

Item Manufacturer Model/Part No. Range/Size
Mass Flow Controllers
Helium line Brooks 5850E (Controller) 0-10 l/m
0151E (display)
Oxygen line J & W 200-2002 built-in span adjustment from 1 cc/m to 1000 cc/m

Jacketed Adsorption Column (stainless steel) Fabricated in the Pressure tested at 200 psi
Length: 40 cm workshop
Inner tube: 1 1/2 inch; schedule 40
Outer tube: 2 1/2 inch; schedule: 40

Temperature Regulated Water Circulation Poly Science 9101 10-950C; 7 or 15 1/m

Oxygen Analyzer SERVOMEX 572 Output: 0-1 V for 0-100% oxygen

Chart Recorder Rikadenki R-61A 100 mV full-scale setting was used

Pressure Gauge WIKA 0-100 psi

On-Off Valves Whitey SS-41S2 1/8 inch

Stainless steel tube 1/8 inch
Male connector Swagelok SS-200-1-2 1/8 inch
Union Swagelok SS-200-6 1/8 inch
Union elbow Swagelok SS-200-9 1/8 inch

Adsorbent Carbon molecular sieve: Shirasigi MSG 3A from coconut shell. Provided by a local
pharmaceutical company from the supply for their PSA nitrogen unit.

to the limiting heat of adsorption, AUo = AH + RgT. For cal-
culating AH, from AUo, the average temperature of the
experimental range is used.
On the other hand, if the Henry's constant is expressed in
terms of adsorbate pressure (we denote it by K'=K/R'T,
where R' is the gas constant in pressure units), then its
temperature dependence may be directly related to the heat
of adsorption
K'= K' e R T

The desorption breakthrough is obtained when a saturated
bed is purged with inert. In the linear (and very low concen-
tration) range of the isotherm, the adsorption and desorption
profiles obtained at the same velocity are symmetric.
The system of equations that describe the dynamic re-
sponse of an adsorption column is given in Table 2. Analyti-
cal solution to the set of equations is given by Lapidus and
Amundson"1 in the form of complicated infinite integral. In
this study, numerical solution by the method of orthogonal
collocation is used. (The collocation form of the model
equations may be obtained from the author upon request.)
The input parameters for the model are
Column length, L -> given (40 cm)
Bed voidage, e -4 given (0.35)
Column radius, R -> given (2.05 cm)
Adsorbent particle radius, Rp -- given (0.1 cm)
Interstitial feed velocity, vo = uo / -> uo is calculated
from the flow rate measured during experiment
Equilibrium constant, K obtained from the break-
through curve
Peclet number, Pe determined from available

Mass transfer parameter, k -- to be determined by
matching the experimental breakthrough curve

Pe =
where DL = 0.7 Dm + voRp
The molecular diffusivity of the adsorbate in the carrier is
Dm(cm2/s) and may be calculated from Chapman-Enskog's
equation.[2] All known commercial adsorbents offer external
film, macropore, and micropore resistances to the transport
of the adsorbate molecules from the bulk phase to the inte-
rior adsorption sites. A linear driving force (LDF) rate model
is used here to represent the transport across these resis-
tances, k is the overall LDF rate constant. The LDF model
approximates a distributed resistance to be confined in an
equivalent thin zone. The individual resistances linearly add
up to give the overall LDF resistance, 1/k:

1 RpK
k 3 kf

+ p
15 De

15 D
15 D,

macropore micropore
resistance resistance

The LDF model may be viewed as a lumped parameter
model with the luxury of relating the overall constant to the
more fundamental parameters that characterize the constitu-
tive transport processes. The film mass transfer coefficient,
kf, may be calculated from the following correlation pro-
posed by Wakao and Funazkri:131
Sh = 2.0 + 1.1 Re-6 Sc1/3
Sh Sherwood number = 2 kfRp/Dm
Re Reynold's number = (2 Rp)puo 1/
Sc Schmidt number = g / pD,

Model Assumptions and Equations
(In the following equations, Y is the mole fraction of the adsorbable component in the gas phase;
z is the axial distance; t is the time; P is the total system pressure; and 4 is the total adsorbed amount. Other symbols are defined in the text.)

Item Assumptions Equation

a&y Dy ay I -E RgTO aq=
Fluid phase component material balance Isothermal -DL + v + + --E = 0
D z2 + z 3t E P at
The flow pattern is described by the axial
Continuity condition dispersed plug flow P # f(z) # f(t)

Flow boundary conditions The frictional pressure drop is negligible D Y = y 0
Flow boundary conditions D Lc p^- =-V'0 Y -Y =0
Ideal gas law holds az z=o z + Z =L
The mass transfer rates are represented by q ,_
Mass transfer between fluid and particle linear driving force rate expressions t = k q)

Equilibrium isotherm Linear isotherm = Kc = KcY

'8 Chemical Engineering Education

p, p density and viscosity, respectively.
The above correlation is particularly recommended as it was
able to reconcile experimental data from a large number of

De =

where 1/Dp = 1/Dm + I/DK
The Knudson diffusivity, DK (cm2/s), becomes important
when collision of the diffusing species with the pore walls
becomes significant in comparison to the intermolecular col-
lision. Poiseuille flow and surface diffusion are two other
parallel contributions to transport in the macropores.
Poiseuille flow is neglected since the pressure range in which
it becomes important will not be encountered in this study.
Surface diffusion occurs through the adsorbed layer on
the macropore walls. This is commonly found to be impor-
tant in homogeneous adsorbents, such as activated carbon,
activated alumina, silica gel, etc. For composite adsorbents,
such as carbon molecular sieve and pelleted zeolites, the
adsorption capacity is mainly in the micropores; the
macropore walls are practically inert and the condition for
surface diffusion to occur does not arise. Therefore, surface
diffusion is also neglected, since we will study the adsorp-
tion and diffusion of oxygen in carbon molecular sieve. Of
course, in the chosen system, both molecular and Knudson
diffusion are much faster than the micropore diffusion and
may be neglected as well. Nevertheless, these terms are
discussed further in view of their wider conceptual impor-
tance as mechanisms of transport in porous media in general.
Knudsen diffusivity is given by

D = 9700 T(

4 pore radius (cm)
T temperature (in absolute units)
M molecular weight of the adsorbate
Ep, r absorbent particle voidage and tortuosity, respectively.

A typical value for / Ep is approximately 10.

Therefore, in the expression for mass transfer parameter,
the micropore diffusional time constant, Dc / r1, is the only
unknown that is determined by matching the model solution
for a breakthrough with the experimental response. Micropore
diffusion is an activated process and follows Arrhenius-type
temperature dependence
D, = DcoeRgT

A semilogarithmic plot of D, vs. 1/T, known in the literature
as the Eyring plot, will give the activation energy, E, from
the slope and the pre-exponential factor, D0o, as the intercept.
For some adsorbents, such as carbon molecular sieve, r,

Winter 1998

cannot be measured explicitly. In such cases, D. / rf is plot-
ted against 1/T, which yields Dco / rf as an intercept.

The study of adsorption and diffusion of oxygen in a
carbon molecular sieve is chosen as the model system here.
Helium is used as the inert carrier. The following set of
instructions is provided to guide the students through the
various steps of the experiment.
The oxygen analyzer response should be checked for 0 and
100% oxygen. The output range is 0-1 V and is linear. The
calibration curve for the mass flow controller used for the
carrier gas is provided. The total mixed flow can be easily
determined by analyzing its oxygen content.
It is suggested that the interstitial feed velocity in the column
and oxygen concentration in the feed are maintained between
5 and 10 cm/s and between 2 and 4%, respectively. The
adsorption column should be bypassed during flow and
concentration adjustments. The system gauge pressure should
not exceed 0.5 bar. The effluent is analyzed using the oxygen
A chart recorder is used to record the analyzer signal. The
chart speed and range setting must ensure sufficient resolu-
tion of the output signal from the oxygen analyzer as a
function of time.
Water (from a temperature-regulated tank) is circulated
through the jacket of the column at the desired temperature.
The measurements should be conducted at three temperatures
in the range of 30 to 500C. The choice of temperatures should
be evenly spaced and at least 45 minutes must be allowed for
the bed to attain thermal equilibrium with the circulating
water. It is also recommended to move from low to high
The bed should be purged with helium until the 0 V baseline
is attained. This ensures a clean bed with respect to oxygen.
Introduction of the oxygen step in the feed and switching the
chart on at the desired speed must occur simultaneously.
It is essential that the breakthrough curves be measured until
It is necessary to record the desorption breakthrough curve for
at least one temperature in order to check linearity of the
isotherm at the chosen concentration level.
Other than the formal desorption run, the bed is regenerated
by purging with helium and increase in temperature. The
adsorption breakthrough measurement is repeated when the
bed has been completely regenerated and has attained the new


The students are required to include the following results
in their report on the experiment:
1. Plot of c/co vs. time for adsorption and (1-c/co) vs. time
for desorption on the same graph in order to check the

2. Ko, AUo, and AHo values from the semilogarithmic
plot of K vs. 1/T.
3. Dco / r2 and E values from the semilogarithmic plot
of D /r,2 vs. 1/T.
Typical plots are shown in Figures 4 through 6. The param-
eter values determined from these plots are also shown in the
respective figures. The equilibrium constant is obtained di-
rectly from the mean residence time calculated by integrat-
ing the breakthrough curves, as discussed earlier. The mass
transfer parameter is obtained by matching the breakthrough
profiles with the model solution. The effect of the mass
transfer coefficient on the model solution is shown in Figure
7. It is clear that the model solution is quite sensitive to the
value of k. The students are reminded that several numerical
techniques are available to determine the best-fit values.
But students carry out all the necessary computations and
calculations in the laboratory and, in view of the limited
laboratory time, they are allowed to use eye estimation to
decide on the best fit.
While using the above method to measure D / r2, it is
extremely important to remember that all the dispersive ef-
fects in an adsorption column (namely, axial dispersion,
external film, and intraparticle diffusional resistances) that
are identified in the mathematical model have similar effects
on the shape of the breakthrough curve. Therefore, these
effects cannot be separated from a single experiment. More-
over, since the resistances are linearly additive, there is
always a risk of misinterpreting the results. Hence, there is
an inherent need to always ensure that the rate parameter
under investigation is indeed the controlling factor of the
process dynamics. Reliable accounting of other effects is
also necessary when they are not completely negligible.
Estimation of external film and macropore resistances are
more reliable than prediction of axial dispersion.
Maldistribution of gas flow and extra-column effects con-
tribute to additional axial dispersion unpredictable by pub-
lished correlations. Agglomeration of small particles may
also result in excessive axial dispersion (see reference 3 for a
comprehensive discussion). All these possibilities were taken
into account while designing the experimental system used
here. In order to ensure proper flow distribution, the column
size was chosen to satisfy the recommended column-to-
particle diameter ratio. Furthermore, 1/8-inch tubes and fit-
ting were used to minimize extra-column mixing effects. In
spite of all these precautions, experimental verification is
recommended to confirm that the associated dispersive ef-
fects are correctly estimated.
Although the available laboratory time is not sufficient to
include such supporting experiments, the students do not
remain ignorant on these matters. In addition to writing a
general discussion on the findings, they are also asked to
suggest an experiment to prove that the present system is
micropore-diffusion controlled and to comment on the effect

o 0.8 -
0.6 A
n 0.4 ] A Adsorption
S0.2 o 0 Desorption

0 50 100 150 200 250 300
Time (s)

Figure 4. Symmetry of the adsorption and desorption
breakthrough curves in the linear range of the equilibrium

AUo = -3.5 kcallmol; AH, = -4.1 kcal/mol


1 I -
0.003 0.0031 0.0032 0.0033 0.0034
1/T (K1)

Figure 5. Temperature dependence of Henry's constant
(oxygen in a carbon molecular sieve) showing that it
follows Arrhenius Law.

E = 4.12 kcallmol
0, 1.00E-02 I___

0.003 0.0031 0.0032 0.0033 0.0034
1/T (K1)

Figure 6. Eyring plot showing temperature dependence of
micropore diffusivity for the diffusion of oxygen in a
carbon molecular sieve.

S- k=0.10 (/s)
O. --k=0.20 (ls)
S0.4 k=0.05 (Is)
0.2. L Expt
0 1
0 50 100 150 200 250 300
Time (s)

Figure 7. Effect of LDF mass transfer coefficient (k) on the
model solution.
Chemical Engineering Education

of macropore size and operating pressure on the macropore
resistance. These questions guide their thoughts to the fol-
lowing important points:
*For a micropore-controlled system, a reduction in the
macroparticle size should not affect the mass transfer kinetics.
Hence, when the k value remains unaffected by a change in the
particle size, it serves as clear proof that the axial dispersion
and macropore resistance are practically negligible. On the
other hand, a variation in values estimated from experimental
runs with different particle size and/or at different velocities
will indicate that the secondary resistances are not negligible
and their contributions have not been properly estimated.
*The importance of Knudsen diffusivity depends on the effective
macropore size and is independent of pressure, whereas mo-
lecular diffusivity is inversely proportional to pressure and may
affect the overall transport rate at a higher pressure.

This laboratory exercise introduces the students to the
calculations of equilibrium and kinetic parameters for an
adsorption separation process. The use of a dynamic model
for the extraction of the mass transfer parameter provides a
useful visualization of the role of this parameter on process
performance. The simulation model can also be effectively
used to illustrate in detail the numerical solution of a system
of coupled partial differential equations. The consistency of
results obtained by different groups is encouraging. Equilib-
rium capacity and mass transfer resistance of the chosen
system are well suited for completing the required number
of runs and necessary computations in one standard labora-
tory session of six hours.

1. Lapidus, L., and N.R. Amundson, J. ofPhy. Chem., 56, 984
2. Sherwood, T.K., R.L. Pigford, and C.R. Wilke, Mass Trans-
fer, McGraw-Hill, New York, NY; Chap. 2
3. Ruthven, D.M., Principles of Adsorption and Adsorption
Processes, Wiley Interscience, New York, NY, Chap. 7 (1984)

BOOK REVIEW: Batch Distillation
Continued from page 13.

Example 1.2 are easily misinterpreted. And there is a tech-
nical mistake in the calculation of the heat to the reboiler in
Eqs. (2.13) and (2.17). The author ignores the energy re-
quired to vaporize the distillate product in the reboiler.
Equation 2.13 should be QR=X(R+I)D.
The graduate-level material starts in Chapter 3, "Column
Dynamics," which derives the unsteady mass and energy
balances. Then error, stability, and a summary of numerical
integration techniques are presented. The need for an inte-
gration technique capable of handling stiff equations is
clearly illustrated in Example 3.1. The chapter is completed
Winter 1998

with sections on start-up and approximate models. There
are some parts that will confuse students. For example, the
numbering of stages in Figure 3.1 does not agree with the
equations, and derivation of Eq. (3.44) requires assump-
tions not mentioned in the text.
The author is clearly an expert on the application of
shortcut (Fenske-Underwood-Gilliland) methods to batch
distillation. Readers are told to "be careful in choosing the
appropriate value for the light key and heavy key for suc-
cessful use of this method," but how to be careful is not
explained. This and other small mysteries will cause confu-
sion. The modified shortcut method developed next re-
quires lumping a number of plates into compartments.
Other than comparison with an exact solution, no guid-
ance is given on how to select the number of plates in
each compartment. The last section on the hierarchy of
models in the simulator will be very helpful to students
using the simulator.
Chapter 5, "Optimization," describes objective functions,
degree of freedom analysis, feasibility, and the general frame-
work of solution methods. This chapter is quite general and
would benefit greatly from numerical examples. Chapter 6
on optimal control problems builds on Chapter 5. This
chapter would also benefit from numerical examples in
addition to the derivation examples.
The last chapter analyzes azeotropic systems and col-
umns with a middle vessel. Since most students will be
unfamiliar with the analysis of steady state azeotropic dis-
tillation, more details on residue curve maps and synthesis
of batch distillation systems would be welcome. The short-
cut method is extended to binary azeotropic systems and
simple ternary systems. Extension to more complicated ter-
nary azeotropic systems would be welcome.
The index appears to be quite well done. An author index
would be appreciated. The reference lists at the end of each
chapter appear to include all the important historical and
recent papers. The nomenclature list is quite complete, and
the tables that summarize the equations after each theoreti-
cal development are helpful. The type is easy to read and
there appear to be few typographical errors. Unfortunately,
the figures are not of professional quality and are difficult to
interpret. Many of the figures have multiple curves that are
not labeled. When two theories are compared on the same
figure, the reader needs to guess which is which. The curves
are not smooth and it is often unclear if the wiggles are real
or due to the plotting routine.
Every chemical engineering department should obtain a
copy for their library's reserve section. Chapters 1 and 2
will be helpful as a reference for undergraduates doing
laboratory or design projects on binary batch distillation.
The remainder of the book will help graduate students and
professors who occasionally encounter multicomponent
batch distillation problems. O




Student Exercises *

Yale University New Haven, CT 06520-8286

The student exercises below are representative of those
developed for the Yale graduate course, "Combustion for
Synthesis and Materials Processing," described in the fall
issue of CEE (page 228). Among other purposes, they demon-
strate that rather simple but quite rational calculations can be
made to estimate approximately how large a combustion reac-
tor must be in order to produce, say, a metric ton of high-
value product every hour. Such preliminary design calcula-
tions are prudent first steps before considering more detailed
follow-on calculations. They also develop a young engineer's
intuition and provide interesting CS/MP examples of the im-
portant role of the ChE core subjects: chemical thermody-
namics, homogeneous/heterogeneous chemical kinetics, trans-
port phenomena, separation processes, and chemical reaction
engineering. All notation is that of the author (Ref 7, loc cit.).
Educators interested in further CS/MP exercises can contact
the author at Yale University or electronically via

Consider the combustor volume required for sulfur spray
combustion at 1.4 atm at the S(1) feed rate of 50 t/d.
a) If efficient S(1) spray combustors can be operated at
volumetric chemical energy release rates, < em >, of
about 2 MW/m3, then what volume should be provided
for a 50 t/d unit?
b) How does this average volumetric chemical energy re-
lease rate compare to that in a small oil burner for home
heating? Or a gas turbine engine combustor (at 3 GW/m3
at 30 atm) when corrected down to 1.4 atm? (cf. Fig. 1,
loc cit.)
c) If the amount of excess air used is that required for the
combustion product mixture to have a temperature near
1400 K, then what will be the mean residence time (ms)
in such a sulfur burner?
d) Estimate the time required to heat up a 100 jtm S(1)
droplet from 415 K to 700 K if the liquid heat capacity is
Copyright ChE Division ofASEE 1997

estimated as 0.28 cal/g-K and the density is 1.8 g/cm3.
e) Estimate the time required to burn a 100 jum S(1) droplet
at approximately 700 K if the latent heat of S(1) vapor-
ization is 0.42 kcal/g and the ambient conditions are
(002,o = 0.232, T, = 350K.
f) What phenomena would lengthen the time required to
completely convert all S(1) droplets beyond your esti-
mates from parts "d" and "e" above?
g) Is the combustor volume provided in part (a) likely to be
adequate in this case? What would be the next steps you
would recommend before "cutting metal"?

a) Does the successful growth of diamond films from gas
mixtures containing CH3(g) and H(g) at 1 atm on 1200 K
surfaces shake your confidence in the value of thermo-
dynamic principles to judge the feasibility of chemical
syntheses, generally? (See reference 1, below.) Does
combustion synthesis of diamond films under these con-
ditions violate the second law of thermodynamics? Dis-
cuss the broader implications of this recent discovery.
b) Approximately 20 pm (volume equivalent) diameter dia-
mond crystallites (grains) are grown from rich C2,H/02
flames impinging on 1200 K solid targets at p=l atm.
How many carats are these? (1 carat = 200 mg). How do
they compare to the 30-mg diamonds synthesized (since
1954) by GE Corporation at p = 30 kbar, T = 2200 K? To
get a physical feel for this pressure, convert to the units:
metric tons (force) / (mm)2.
c) Consider the phase equilibrium C(graphite) <>C(diamond)
in the single element system: carbon, from the viewpoint
of the Gibbs phase rule. How many state variables are
needed to define this system?
d) We know that CH2(g) can be commercially synthesized
from the pyrolysis of methane, CH4(g), via a partial
combustion process at acceptable yields. It is interesting
that diamond film growth is found to be possible via the
Chemical Engineering Education

fuel-rich combustion of either C,H2(g) or CH4(g), but the
maximum attainable growth rates (often expressed in
microns/h) have been found to be larger for acetylene by
factors of nearly 20. Considering the overall economics,
how would you decide on which carbonaceous fuel to
use if your goal is to grow commerically interesting
diamond films?

Consider the preliminary design (sizing) of a 25 t/d acety-
lene synthesis reactor (near-plug-flow, axi-symmetric) to
operate at near-atmospheric pressure. Based on preliminary
laboratory data, it appears that the partial oxidation of pre-
heated methane using oxygen, followed by approximately 1
ms. cracking at about 1800 K (before a water-spray quench
to 350 K) leads to a product stream with about 8 mole pet.
acetylene vapor and, unavoidably, produces solid carbon
soot at the rate of about 50 kg/t C2H,. Preheating both
(unmixed) reagents to about 900 K is considered the highest
safe temperature choice to avoid autoignition upstream of
the burner block/flame-holder. Make a self-consistent pre-
liminary choice of all essential dimensions in the course of
answering the following specific questions.
a) If the overall stoichiometry of the partial combustion of
methane is CH4(g) + (1/2)0,(g) --CO(g) + 2 H,(g), then
estimate the individual Oz(g) and CH4(g) mass flow rates
b) Before turning to the turbulent jet mixing-diffuser sec-
tion, estimate the required dimensions of a stable burner/
flame-holder, including the channel diameters, number
of channels, and open area fraction. Also select the down-
stream "cracking chamber" dimensions. For these pur-
poses use the following tentative estimates: flame speed,
S, (rich CH4/0O) = 28 cm/s at 298 K, 1 atm; d In S,/d fn
T, = 1.86 for methane/air; (L/U),cking section = 1 ms. What
factors should govern the channel (hole) lengths? (cf.
Fig. 4, loc cit.)
c) Is the heat of partial combustion [CH4(g) + (1/2) O,(g)
-CO(g) + 2 H2(g)] sufficient to raise the preheated
mixture of methane and oxygen from 900 K to the crack-
ing temperature of 1800 K without the addition of auxil-
iary oxygen at the burner/flame-holder location? Tenta-
tively, neglect the possibly appreciable heat losses to a
(water-cooled?) burner/flame holder.
d) Estimate the heating value of the solid carbon removed
from this unit if it could be recovered and burned to
e) What factors dictate the quench water-flow-rate require-
ment? What spray velocities and drop sizes should be
used? (cf. Fig. 4, loc cit.)
f) How would your choices of dimensions change if you
Winter 1998

opted for a synthesis reactor operating at 5 atm? For this
purpose, note that the effective order of the methane
oxidation corresponding to previously observed Su(p)-
data for combustion with air is about 1.4.
g) Returning to the turbulent jet mixing-diffuser section, can
you provide a rough estimate (bound?) of the required
length, the transverse dimensions (diameters) for the 1
atm device? For all of the above items, spell out and
defend all further assumptions you introduce.

The surface of one C60 molecule contains 20 hexagons and
12 pentagons. Based on the presumption that the C-C bond
distance in Co is close to that in the graphite crystal (1.42 A)
a) The surface area of one C,6 molecule.
b) The effective diameter of one Co6 molecule.
c) Use the result in part b to estimate the Fick molecular
diffusion coefficient of C,6 with respect to CO,(g) at
2100 K and 100 Torr (via hard-sphere kinetic theory).
d) Compare the specific surface area (m2/g) of C,, to that of
commercial activated carbon as well as flame soot (con-
taining non-porous primary particles of 30 nm diameter).
What conclusions) do you draw from this?
e) Extrapolating from the information provided in the re-
cent review of Howard (1992), suppose that C60 could be
produced in a 100 Torr benzene/O, combustor at a yield
of 0.5 pet. of the fuel carbon. If the burner C/O ratio is
about 0.9, use the present costs of benzene ($/kg) and 02
($/std. m3) to
1) Estimate the fuel cost per kg. of C6o produced and 02
cost per kg of C,, produced.
2) Estimate the pumping cost per kg of C60 produced.
3) Compare the sum of these costs to the actual present
cost per kg. of C,0.
4) Is a combustion process currently used (by Aldrich,
Hoechst AG ...) to produce research quantities of
C60? What intrinsic advantages would a combustion
synthesis process have over rival (electric spark and
laser pulse/graphite feed) methods?
f) Use the reported equilibrium vapor pressure of crystal-
line Co,(s) to estimate the frost point temperature of C,6
in the abovementioned synthesis flame. Is a partial de-
sublimation separation method feasible for harvesting
C60 in this case?

1. Dodge, B.F., "Application of Thermodynamics to Chemical
Reaction Equilibria," Trans. Amer. Inst. Chem. Eng., 34,
529(1938) 0

elff curriculum




Or Training for

Life after the University

University of New Brunswick
Fredericton, New Brunswick, Canada E3B 5A3

oday, many chemical engineering curricula include

courses in strength of materials, electronics, heat and
mass transfer, reactor engineering, plant design, eco-
nomics, communication skills, etc. Competence and techni-
cal expertise alone, however, will not guarantee graduates
(or, as a matter of fact, anyone) a job in today's economy.
We should not only teach our students the necessary tools to
enable them to survive in a work environment but we should
also assist them in their transition from the university to
industry. While there are career placement services on al-
most every university, their success in helping students find
suitable employment after graduation is usually limited.
Having noted these difficulties in the past, I felt a need to
become more actively involved in assisting students to find
employment. Our students are now being given an early
opportunity, as part of a two-credit-hour course in "Commu-
nications and Information Systems,"'" to learn more about
technical report writing, oral presentation skills, computer
applications, and life after the university.
Many publications have been written on the subject of
developing good communication skills.[2'31 This paper dis-
cusses the techniques used to teach students the principles of
critical thinking, communication skills, and up-to-date com-

Guido Bendrich joined the Department of
Chemical Engineering at the University of New
Brunswick after spending some nineteen years
in various industrial settings throughout the
world. He obtained a PhD from McMaster Uni-
versity in 1992. His teaching and research inter-
ests are in industrial plant design, cost estima-
tion, plastics processing, developing communi-
cation skills, and education.

Copyright ChE Division ofASEE 1998

Course Objectives (Short Version)

You will bring your own interests and we shall discuss how they may
be incorporated into the ChE 1014 course. We have an academic
responsibility also to ensure that we aim for certain learning objectives
and, for this course, those objectives are as follows:
1. Development of communication skills through oral and written
2. Familiarization with current information technologies.
Learning Objectives
Learning at this stage of your education means the development of
critical skills. In this course, therefore, you will be
0 articulating facts, concepts, principles, and rules;
'problem solving in real life situations;
'using effective communication skills;
interacting productively in small and large group settings; and
Ioenjoying yourself too!

The Tools
We shall select practical examples to illustrate the principles of critical
thinking, communication skills, and up-to-date computer technologies.
The main part of the course shall be centered around the area of "Job
Hunting." The following steps will not only describe the course
structure in more detail but also present a possible application of the
material studied to a real-life situation.
> Career Assessment the most critical phase in the whole process
We shall discuss the various aspects in the area of Critical
Thinking Skills and how we can make good use of it at home, in
school or in a work environment.
Decision Making all about choices
In order to make educated decisions one must have access to
pertinent information. We shall explore different ways of
obtaining the necessary information, e.g. libraries, databases and
the Internet.
The Resumi--a very effective marketing tool
The development of a great r6sum6 requires of computer
technology. We shall familiarize ourselves with the use of various
computer applications such as word processors, databases, etc.
> The Job Market
You will present in a 10-minute oral presentation some detailed
information on the industry of your interest. We shall explore the
use of overhead transparencies and computer-based presentation
techniques. In addition, you will be given an opportunity to
summarize your findings in the form of a technical report.
I The Cover Letter
The writing of cover letters, i.e., letters of transmittal, is an
important part in an engineer's working life. We shall learn about
the various styles of cover letters.
> The Interview
We shall reinforce our critical thinking skills, learn about active
listening, observe and diagnose verbal and nonverbal messages,
and, most importantly, learn how to handle problem (stress)
situations. Practice interviews will assist in refining these skills.
I The Tale of a Success Story
At this stage, the course is coming to an end. You have not only
learned about various computer applications, literature searches,
oral and written presentations, and critical thinking skills but, more
importantly, you have had an opportunity to apply of these
techniques to different situations in your daily life.

Chemical Engineering Education

Six Thinking Hats (Reference: Edward deBono'61)

Color of Hat Characteristics Questions
White Facts, figures, objective material, ... What information do I need to make a decision?
How can this information be obtained?
Red Feelings, emotions, intuition,.. How do I feel about it?
What does my "inner voice" say about this?
Black Logical negative arguments,.. What are the risks?
What does "Murphy's Law" say about this?
Yellow Possibilities, opportunities, ... What are the advantages?
What is the best-case scenario?
Green Creative new ideas, .. Can I come up with a more innovative approach?
Blue Master control for the thinking process Summarize results
Review of results

Name: Date: / /

Suggested Career-Related Topics to Think About

Topic Results from the Six Thinking Hats
Intellectual challenge
Meaningful work
Opportunity to learn new things
Sense of achievement
Interpersonal relationships
Job Security
Social Status
Opportunity to travel
Personal growth
Future power
Variety of tasks
Exciting, stimulating

1. Study the ten most important value items; do you notice any specific patterns?
2. Develop an "I can do" list by identifying some actions that will integrate your expectations in
educational strategy.

Name Date

Winter 1998

puter technologies based on real-world
applications such as "finding the right
job." The course objectives are out-
lined in Table 1. The following steps
highlight the techniques used to
achieve these goals:

> Critical Thinking Skills

S. R. Covey'14 discusses the four
unique human endowments of imagi-
nation, conscience, independent will,
and self-awareness. Imagination, as
defined by Covey, is "the ability to
envision, to see the potential, to create
with our minds what we cannot see at
the present with our eyes." This abil-
ity does not come naturally, but it can
be learned. The Critical Thinking
Skills segment of this course provides
the students with insight in the deci-
sion-making process. Some of the
techniques discussed in detail are ones
described by Covey,[4] deBono,[61 and
Butler and Hope.?1] These techniques
aid students in discovering more about
In one exercise, based on deBono's
approach, each class participant is
asked to imagine six colored hats. Each
hat represents a role one's mind plays
in the critical thinking process. By
switching from one hat to another as
one thinks about a topic, the learner is
forced to look at the topic from a vari-
ety of perspectives.'5' For the exercise,
the students start with six sheets of
paper-one for each hat. They select a
topic or problem that they would like to
think about or work on. Each partici-
pant decides which of the hats would
be good to start with and then works
his/her way through all six, writing
down notes on the thoughts that come
to them with each hat. Table 2 identi-
fies the six hats, their characteristics
and some of the questions one should
ask with each one.1"' The students may
think of other questions as well.
If the learner has worked a problem
through all six hats and has written
down at least three points for each, he/
she will know that all the major points
in the critical thinking process were
covered. Table 3 presents some sug-

gested career-related headings that may be used to
explore the critical thinking process.
This and similar exercises will not only help the
students learn more about themselves but they can
also aid the students in identifying their long-term
career objectives. A significant increase in self-
awareness can be observed over the course of the

- Computer Applications

In this part of the course various computer applica-
tions, such as word processors, spreadsheets, data-
bases, e-mail and Internet tools, are introduced to the
students. Guidance is provided through the use of
slides, handouts, and extensive hands-on exercises.

Obtaining Information

Information Technology is the buzzword of the 90s,
and in that vein, an in-depth summary called "The
Retrieval of Information" is presented to the students.
Among the topics discussed in class are library and
CD ROM searches, organization of database systems,
and "how to surf" the Internet.
Assignments in this section focus on topics such as
"Retrieve information about injection molding of poly-
meric materials," or "Retrieve the latest information
in the area of pulp bleaching." The search results are
then reported, as discussed below, both orally and in
the form of a written report. The added benefit of
these exercises is that the students are, at the same
time, also broadening their knowledge in the general
area of chemical engineering.

- Technical Writing

In this section of the course, topics such as techni-
cal writing and document layout are introduced to the
students. The assignment topics (technical reports)
are based on information retrieved in the Obtaining
Information section, and in addition, the students are
introduced to different types of r6sum6s.
One approach that has proven to be successful (but
by no means the only appropriate model) can be found
in "The Job Hunting Guide."171 Excerpts of this docu-
ment are shown in Table 4. Guidance is provided in
the r6sum6 development process through slides, hand-
outs, and hands-on exercises. The most important part
of this document is the Objective section. Here the
writer addresses the very important issues of "What
skill do I bring to this position?" and "What can I do
for the Company?" The insight obtained in the sec-
tion on Critical Thinking Skills will guide the partici-
pants in the development of this subsection.

The Resume
A Very Effective Marketing Tool

The next step, after having successfully completed the career-planning phase, is
the development of a r6sume. If developed properly, it can be a highly effective
marketing tool. Its two main purposes are to advertise your availability and to supply
information to the recruiter.
How should a resume be prepared? Perhaps the most important thing to remem-
ber is that the format must capture the recruiter. It should enable the recruiter to
quickly find the key points. Clear headings, off-white paper, and point format are
desirable. Remember that you will have less than ten minutes to prove to the person
that you are an exceptional candidate. Effective use of language, emphasis on
achievements, and quantified experience are thus important aspects of a resume.
There are three basic formats being used today. The most widely used and
accepted format, the chronological style, lists your experiences in reverse chrono-
logical order. This style emphasizes your most recent achievements. The functional
format lists the duties performed by category. With this style, it is harder for the
recruiter to get an instant picture of the candidate. The third type, which is not widely
used, is a hybrid of the chronological and the functional format styles.
What key information should a resume contain? The following eleven categories
should be included:
Personal Data The only data required are your name, address, and phone number.
Your fax number and e-mail address are optional. One would not want to supply
information such as religion, marital status, or citizenship. These are 'knock-out'
factors that may or may not be used against you. You do not want to limit your
chances right from the beginning.
Career Objective There is some debate on whether or not this section should be
included in a r6sum6. Unless the objective is written carefully, do not include it. This
section should show what you can do for the company and NOT what the company
can do for you. A sample objective for a person who has participated in a Co-Op
Professional Experience Program could read: "To provide leadership in industrial
research and development activities, where strength in superior analysis of data,
problem solving, innovation, and excellent communication skills will: design and
develop new technologies, provide opportunity for technology transfer, train and
motivate staff and generate results consistent with organizational initiatives.
Professional Profile This summarizes your professional experience in a few short
sentences. The following could be used as a guideline: "Engineering experience
relating to injection molding, process automation, and the modeling of PET resin
drying processes.
Education List your education in reverse chronological order. Do not include your
high school education if you have a college or university degree.
Work Experience Describe all the relevant work experiences here. Use action
verbs such as directed, developed, implemented, designed, and presented to describe
your accomplishments. Do not forget to include your job titles, times of employ-
ment, and the names of your employers.
Selected Achievements This section should list a maximum of three work/educa-
tion-related accomplishments in more detail.
Professional Development This category should include all professional develop-
ment activities that you have undertaken outside of the standard engineering curricu-
Scholarships List all your scholarships.
Professional Affiliations Are you a member of a profession organization? List it
Languages Indicate the languages you know and your level of competence. If you
are fluent in English and can "get by" in Spanish, you should write "Fluent in
English andfunctional in Spanish."
References "Available upon request." Do not include the names of your (three)
references in your resume. Prepare the list of references on a separate sheet to be
used as a handout during the interview.

Chemical Engineering Education

Oral Presentation Evaluation Form

Opening Statements
Did the speak state her/his name?
Did the presenter state the topic?
Did the presenter state the purpose?
Did the presenter outline the presentation?
Is there a logical flow or a rambling monologue?
Does the presentation target the audience?
Is the presentation informing or merely trying to impress?
Is presenter enthusiastic about the topic?
Is the speaking clear or mumbled?
Is the presentation delivered in a professional manner?
Was eye contact made?
Is the talk too long (past target time)?
Were the gestures distracting?
Is the speaker still or walking nervously?
Is the dress code appropriate?
Is the presentation natural and not read?
Visual Aids
Is the layout of the visuals appropriate?
Do they contain a reasonable amount of information?
Are they referred to rather than read from?
Is the grammar correct?
Are they shown for less than one minute?
Subject Knowledge
Does the presenter master the subject?
Closing Remarks
Is the objective statement repeated?
Is the presentation summarized?
Are proper acknowledgments made?
Were the questions answered concisely?

Discussion and Listening Skills

Or question number from list _
Evaluation of Interviewer Improvement Good Short C
Eye contact
Body language
Oral communication
Self-confidence: "Think on your feet."

Evaluation of Interviewee Improvement Good Short C
Eye contact
Body language
Oral communication
Self-confidence: "Think on your feet."_

More detailed comments from the observer should be submitted on a separate

Name Date

Winter 1998

A significant amount of effort by the students is volun-
tarily directed toward the development of this document.
This high degree of motivation may be attributed to the
fact that they are doing something for their own benefit,
i.e. they can apply these skills during their studies as well
as in their life after university.

Presentation Skills

An emphasis on the development of presentation skills
in universities has significantly increased over the past
decade.12 In our course, each student is given the oppor-
tunity to make a formal presentation to the entire class
twice during the term. In a short, three-minute presenta-
tion, topics such as "The use of NaCI in the pulp and paper
industry" or "Recent developments in the area of power
generation" are presented to the whole class. Also, a ten-
minute presentation summarizes the results obtained in
the "Obtaining Information" section. A detailed discus-
sion on the presenter's performance is scheduled on a one-
to-one basis. The Oral Presentation Evaluation Form (Table
5) serves as an aid in this process.
In addition to these "formal" presentations, the students
participate actively in short exercises throughout the term.
At the beginning of each lecture, one student, selected at
random by the instructor, must summarize the previous
class in about three minutes. This exercise serves two
purposes: everybody comes to class prepared and it
gives the students yet another opportunity to hone their
presentation skills. In addition to the above described
exercises, students enjoy frequently-held "one-minute"
impromptu talks.

Discussion and Listening Skills

The way a person asks and answers ques-
tions impacts significantly on the working en-
vironment. Questioning is a valuable tool and
is critical to the oral communication process.
Many successful approaches have been de-
scribed in the literature.' 901 The students learn
about and practice how to ask, as well as how
comments to answer, two basic types of questions: open-
ended and closed-ended.
As the communication process suggests, for
communication to be congruent, one has to
clearly understand the other's frame of refer-
omments ence. The students gain this understanding by
asking questions that will clarify and confirm
the messages others are sending to them. After
the students were encouraged to engage in dis-
cussions, they observe and diagnose the other's
sheet, verbal and nonverbal messages. Through group
exercises and continuous feedback (see Table
6), one observes significant improvements in

the students' performance.

0 Real Life Situations
Employers emphasize that interpersonal and
communications skills are as important as tech-
nical knowledge. Through group exercises, the
students are given several opportunities to prac-
tice different interviewing situations. Learning
how to ask questions, and learning how to
answer difficult ones, does not come quickly.
Practice makes perfect. The skills and knowl-
edge obtained in this course help the students
to overcome interview anxiety.

The purpose of this course is to help students
hone their communication skills. In addition,
the students will learn more about themselves
and their goals. These techniques, tested and

We should
not only teach
our students
the necessary'
to enable them
to survive in a
work environment
but we should
also assist them
in their
transition from
the university
to industry.

refined over many years, work well in both university and
non-university environments. When the concept was first
being introduced, there were comments from our students
such as:

> "This instructor is crazy. He is trying to teach us
communication skills and at the same time he is
asking us to learn more about ourselves!"

> "1 am just a second year student. I can't use this
concept to go after technical summer jobs!"

After a few students tried the approach, the following com-
ments were made:

> "I got a job using the communication skills and job
hunting techniques that I learned in your class."

> "Thank you for your efforts. My communication skills
improved significantly."

Initially, the students have to learn how to overcome their
fears. Active support by the instructor is the key in this
process. Support begins with the instructor's in-depth under-
standing of the course material and its adaptation to the
specific learning environment.
This course, unlike ordinary lecture courses, requires a
significant amount of student/instructor interaction outside
the scheduled class time. During the course of the term, the
instructor should have several private review meetings with
each student. The focus of these meeting should be on work-
ing together to achieve the goals that were set out in the
course outline. By answering questions, resolving problems,
and emphasizing good communication skills, these meetings
can help foster an understanding and a strong commitment
of the learner to her/his chosen profession. The instructor's
responses during the meetings should be positive and sup-

I portive. This will help ensure that the established

goals are successful and are harmonious with those
of the rest of the class.
By the end of the course, the students have not
only significantly enhanced their communication
skills, which of course is our main objective, but
they should have also gained an enhanced self-
awareness that will help them along their chosen
career path.

A course such as "Communications and Infor-
mation Systems" can be taught through the appli-
cation of real life situations. Although there are
currently many discussions being held about the
university's role in today's society, the author
strongly believes that, if one strikes the proper
balance between the economically driven goals
(i.e., the education of marketable students) and the

more traditional goals of the university (i.e., let's educate
great thinkers), this approach will serve the students well in
the future. "Let us not lose sight of the results we seek to
achieve as we focus of the process of providing relevant
chemical engineering education for the 21st century."[10]

The author would like to thank Brian Lowry for his valu-
able input on the "job hunting" topic while co-teaching the
ChE 1014 course. Special thanks are due to Frank Collins,
Robin Chaplin, Don Woods and all the course/seminar par-
ticipants for their assistance in refining the concepts.

1. Bendrich, G., and B.J. Lowry, "Communications and Infor-
mation Systems Course Material," University of New
Brunswick (1996)
2. Nirdosh, I., "Making Successful Oral Presentations-A
Guide," Chem. Eng. Ed., 31(1), 52, (1997)
3. Lordeon, S.L., C.H. Miles, and M. Keane, Some Assembly
Required-A Complete Guide to Technical Communications,
McGraw-Hill Ryerson Limited, Toronto, Canada (1997)
4. Covey, S.R., The 7 Habits of Highly Effective People, Simon
& Schuster, New York, NY (1989)
5. Butler, G., and T. Hope, Managing Your Mind, Oxford Uni-
versity Press, New York, NY (1996)
6. DeBono, E., Six Thinking Hats, Penguin, New York, NY
7. Bendrich, G., "The Job Hunting Guide," Personal Notes
(1994) and (1997)
8. Newell, J.A., D.K. Ludlow, and S.P.K. Sternberg, "Develop-
ment of Oral and Written Communication Skills," Chem.
Eng. Ed., 31(2), 116, (1997)
9. Kauffman, K.J., "How to Make Questioning Work for You,"
Chem. Eng. Ed., 31(2), 134, (1997)
10. McKeachie, W.J., Teaching Tips, D.C. Heath and Company,
Lexington, KY (1994)
11. Buonopane, R.A., "Engineering Education for the 21st Cen-
tury," Chem. Eng. Ed., 31(2), 166, (1997) 0

Chemical Engineering Education


This guide is offered to aid authors in preparing manuscripts for Chemical Engineering Education (CEE), a quarterly
journal published by the Chemical Engineering Division of the American Society for Engineering Education (ASEE).
CEE publishes papers in the broad field of chemical engineering education. Papers generally describe a course, a
laboratory, a ChE department, a ChE educator, a ChE curriculum, research program, machine computation, special
instructional programs, or give views and opinions on various topics of interest to the profession.

Specific suggestions on preparing papers *
TITLE Use specific and informative titles. They should be as brief as possible, consistent with the need for defining
the subject area covered by the paper.

AUTHORSHIP Be consistent in authorship designation. Use first name, second initial, and surname. Give complete
mailing address of place where work was conducted. If current address is different, include it in a footnote on title page.

ABSTRACT: KEY WORDS Include an abstract of less than seventy-five words and a list (5 or less) of keywords

TEXT We request that manuscripts not exceed twelve double-spaced typewritten pages in length. Longer
manuscripts may be returned to the authors) for revision/shortening before being reviewed. Assume your reader is not
a novice in the field. Include only as much history as is needed to provide background for the particular material covered
in your paper. Sectionalize the article and insert brief appropriate headings.

TABLES Avoid tables and graphs which involve duplication or superfluous data. If you can use a graph, do not
include a table. If the reader needs the table, omit the graph. Substitute a few typical results for lengthy tables when
practical. Avoid computer printouts.

NOMENCLATURE Follow nomenclature style of Chemical Abstracts; avoid trivial names. If trade names are
used, define at point of first use. Trade names should carry an initial capital only, with no accompanying footnote. Use
consistent units of measurement and give dimensions for all terms. Write all equations and formulas clearly, and number
important equations consecutively.

ACKNOWLEDGMENT Include in acknowledgment only such credits as are essential.

LITERATURE CITED References should be numbered and listed on a separate sheet in the order occurring in the

COPY REQUIREMENTS Send two legible copies of the typed (double-spaced) manuscript on standard letter-size
paper. Submit original drawings (or clear prints) of graphs and diagrams on separate sheets of paper, and include clear
glossy prints of any photographs that will be used. Choose graph papers with blue cross-sectional lines; other colors
interfere with good reproduction. Label ordinates and abscissas of graphs along the axes and outside the graph proper.
Figure captions and legends will be set in type and need not be lettered on the drawings. Number all illustrations
consecutively. Supply all captions and legends typed on a separate page. State in cover letter if drawings or photographs
are to be returned. Authors should also include brief biographical sketches and recent photographs with the manuscript.

Send your manuscript to
Chemical Engineering Education, c/o Chemical Engineering Department
University of Florida, Gainesville, FL 32611-6005

Full Text

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