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:

Full Text

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Department of Chemical Engineering
University of Florida
Gainesville, Florida 32611
Editor: Ray Fahien (904) 392-0857
Consulting Editor: Mack Tyner
Managing Editor:
Carole C. Yocum (904) 392-0861
Publications Board and Regional
Advertising Representatives:
Gary Poehlein
Georgia Institute of Technology
Past Chairmen:
Klaus D. Timmerhaus
University of Colorado
Lee C. Eagleton
Pennsylvania State University
Richard Felder
North Carolina State University
Jack R. Hopper
Lamar University
Donald R. Paul
University of Texas
James Fair
University of Texas
J. S. Dranoff
Northwestern University
Frederick H. Shair
California Institute of Technology
Alexis T. Bell
University of California, Berkeley
Angelo J. Perna
New Jersey Institute of Technology
Stuart W. Churchill
University of Pennsylvania
Raymond Baddour
Charles Sleicher
University of Washington
Leslie W. Shemilt
McMaster University
Thomas W. Weber
State University of New York

Chemical Engineering Education

110 University of Pennsylvania,
Douglas A. Lauffenburger, Eduardo D. Glandt

116 Roger A. Schmitz of Notre Dame,
J. Elizabeth Kilcup

124 The Chemical Engineering Curriculum-1985,
George A. Coulman

122 Biochemical Engineering With Extensive
Use of Personal Computers,
H. R. Bungay
128 Using Spreadsheets for Teaching Design,
Eric A. Grulke
136 A Computer Graphics Approach to the Use
of the Integral Method in Kinetics,
J. M. Skaates
138 Degrees of Freedom and Precedence Order
in Engineering Calculations,
Jude T. Sommerfeld
148 The Chemical Engineer in the Chemical
Industry, Jacob Zabicky

132 Distillation With Vapour Compression: An
Undergraduate Experimental Facility,
Colin Pritchard
144 A Laboratory Safety Program at Delaware,
George Whitmyre, Jr., Stanley I. Sandler

121 Membership Forum

127, 135, 150, 152 Book Reviews

147 Books Received

CHEMICAL ENGINEERING EDUCATION is published quarterly by Chemical Engineering Division,
American Society for Engineering Education. The publication is edited at the Chemical Engineering Depart-
ment, University of Florida. Second-class postage is paid at Gainesville, Florida, and at DeLeon Springs,
Florida. Correspondence regarding editorial matter, circulation and changes of address should be addressed
to the Editor at Gainesville, Florida 32611. Advertising rates and information are available from the adver-
tising representatives. Plates and other advertising material may be sent directly to the printer: E. O.
Painter Printing Co., P. O. Box 877, DeLeon Springs, Florida 32028. Subscription rate U.S., Canada, and
Mexico is $20 per year, $15 per year mailed to members ofAIChE and of the ChE Division of ASEE. Bulk
subscription rates to ChE faculty on request. Write for prices on individual back copies. Copyright C 1986
Chemical Engineering Division of American Society for Engineering Education. The statements and opinions
expressed in this perodical are those of the writers and not necessarily those of the ChE Division of the
ASEE which body assumes no responsibility for them. Defective copies replaced if notified within 120 days.
The International Organization for Standardization has assigned the code US ISSN 0009-2479 for the
identification of this periodical.


[ department

The University of Pennsylvania
Philadelphia, PA 19104

BENJAMIN FRANKLIN founded the University of
Pennsylvania in 1740. Initially, most of the Ivy
League schools had a formal or informal association
with a religious denomination, and Penn was to be
known as a Quaker school. The Quaker love for things
practical left a strong imprint on the university. Penn
offered one of the earliest courses in chemistry (from
1769), had one of the first departments of engineering
(founded in 1855), and the second-oldest program in
chemical engineering (actually the oldest in continu-
ous operation, since 1893). Today, two-thirds of the
population on the Penn campus consists of graduate
and professional students, and the numerous profes-
sional schools-engineering, medicine, and the Whar-
ton school of business among them-are a vital and
prestigious part of the university.
The pre-eminence of chemical engineering and
chemistry at Penn is not surprising if one remembers
that, since the late 1700's, Philadelphia has been a



center of the American chemical industry. Indeed, the
American Chemical Society was founded here (in
1876), as were the American Association for the Ad-
vancement of Science (in 1847) and the AIChE itself
(in 1907). Appropriately, the Center for the History
of Chemistry and Chemical Engineering (co-spon-
sored by the ACS and the AIChE) is located on the
Penn campus and run by the university. This unique
collection, with its old textbooks, manuscripts, and
many portraits is a delight for visiting chemical en-
gineers and chemists.
The Penn campus is situated in West Philadelphia,
only one mile from "Center City," as the downtown
area is known in Philly. It is a surprisingly beautiful
urban campus, with modern sculptures poised against
ivy-covered collegiate gothic walls. On campus one can
enjoy tree-lined walks, the pleasant lawn of the Quad,

0 Copyright ChE Division ASEE 1986

Benjamin Franklin, 1706-1790
Founder of the University of Pennsylvania. Printer, engineer, states-
man. Engineering education at Penn derives directly from his "Propos-
als Relating to the Education of Youth in Pennsylvania" (1749):

"As to their Studies, it would be well if they could be taught every
Thing that is useful and every Thing that is ornamental: But Art is
long and their Time is short. It is therefore proposed that they learn
those Things that are likely to be most useful and most ornamental.
Regard being had to the several Professions for which they are in-



Towne Building, home of chemical engineering at renn

and even an unexpected small pond tucked away be-
hind the biological/medical building complex. At the
east end of campus, across the street from Franklin
Field and the Palestra (where Ivy League champion-
ship football and basketball teams perform) is the
Towne Building, in which the Department of Chemical
Engineering is located along with most of the other
engineering departments. When it was dedicated in
1906, it received considerable acclaim. The comment
from Engineering News was, "It is with little doubt
the finest, largest, and best-equipped structure de-
voted to instruction in engineering in the United
States, if not the world." Although this venerable
edifice does not pretend to those claims today, there
yet remains a feeling of class and comfort in its mar-
bled hallways.
It was in 1951 that chemical engineering was made
completely independent of chemistry, and became
what was then known as the School of Chemical En-
gineering. Two men had been primarily responsible
for helping the department grow to that point, aided
by an Army training program and a Manhattan Pro-
ject subcontract during World War II: Norman Hix-
son and Melvin Molstad, who had arrived at Penn in
1938 and 1939, respectively. In 1955 they and their
colleagues were joined by Arthur Humphrey, who
would lead the department as chairman from 1962
until 1972. Art, later Dean of Engineering at Penn for
a decade and now Provost at Lehigh University,
played a most important role in shaping the depart-
ment. Many of the current faculty were hired under
Art's direction, setting the stage for the dramatic rise
in prominence that chemical engineering at Penn has
seen during the past two decades. In addition, Art
was one of the first to foresee that biology would be-
come a significant partner with chemical engineering.
His vision allowed Penn to establish itself as a premier
institution for education and research in biochemical

and biomedical engineering well in advance of today's
rush into biotechnology.

It might be most interesting to look at the faculty
in chronological order of joining the department at
Pennsylvania in order to trace the growth of our pro-
gram through the past 25 years. Mitch Litt is our
elder statesman in terms of service, having come to
Penn in 1961. Mitch, of course, was a pioneer in the
application of chemical engineering principles to
biomedical problems, and is well-known for his re-
search in the area of biorheology. At the present time
he devotes most of his energies to the bioengineering
program, serving as chairman of that department.
Bill Forsman has maintained an active research pro-
gram in both theoretical and experimental polymer
science since arriving in 1964. Among his current in-
terests are light and neutron scattering techniques,
composite materials based on graphite intercalation,
and the rheological behavior of biological polymers. A
constant in Bill's work is the application of graph-
theory concepts to the prediction of polymer struc-
tures and properties. Alan Myers has provided high
quality teaching and research in thermodynamics and
separations processes (especially adsorption) during
his more than twenty years here. In addition to his
major research interests, he has been instrumental in
making the personal computer an integral part of
many of our courses. His consistently excellent teach-
ing has been recognized by a School of Engineering
award. A textbook he co-authored with Warren


The central purpose of our graduate program is to educate students to become independent,
creative researchers . Every facet of our program is geared toward providing the personal interaction
with accomplished scholars that is essential for development of scientific judgment and vision .... we maintain a
low student/faculty ratio, with about sixty graduate students present among our faculty of fifteen.

Penn's biochemical engineering program was estab-
lished well in advance of today's rush into the field.

Seider, Introduction to Chemical Engineering Calcu-
lations, is used in many material and energy balance
courses around the country. Alan has also served a
term as department chairman, as has Dan Perlmut-
ter. Dan came to Penn in 1964 from the Illinois faculty,
bringing a prolific and scholarly research program in
chemical reaction engineering. He has made impor-
tant contributions in the mathematical analysis of
reactor stability, and has been a pioneer in the study
of the effects of pore structure on the kinetics of gas/
solid reactions. Dan has lately turned his attention to
the kinetics of inorganic chemical reactions, especially
with application to the processing of novel materials
such as the 3"-aluminas. He is also the author of two
well-known books, Chemical Process Control and Sta-
bility of Chemical Reactors.
Warren Seider, currently a director of AIChE, ar-
rived in 1967 with an interest in the application of
computers to chemical process modeling and design.
Warren is well known for his early and continuing
involvement in CACHE, and for his role in the diffu-
sion of the FLOWTRAN computer-aided design lan-
guage. He is primarily responsible for the superb un-
dergraduate design courses here, and for the de-
partmental computer facilities. In the past few years,
the emphasis of his work has been in the area of nu-
merical analysis of the dynamics of complex chemical
systems. Warren's mentor, Stuart Churchill, came
to Penn in 1967 after many illustrious years at Michi-
gan. One of our three members of the National
Academy of Engineering, Stuart has served as ad-
visor to a number of individuals presently on chemical
engineering faculties around the world. He maintains

a high level of activity in both research and teaching,
as well as in professional affairs. He is a popular favor-
ite among students for his entertaining and instructive
anecdotes, as well as for his service as advisor to our
very active AIChE undergraduate chapter. His major
current research interests are combustion and natural
convection, continuing his long-standing investigation
of transport and kinetic rate processes. A series of
volumes under the title of The Practical Use of Theory
in Fluid Flow continues to emerge from Stuart's facile
pen, to join his earlier text called Introduction to Rate
Two of the major figures in our highly-respected
biochemical/biomedical program were next to arrive
on the scene. David Graves brought his experimental
wizardry to Penn in 1970, and has since generated a
number of innovative research projects. In addition,
he runs our undergraduate laboratory course and
teaches an unusual graduate course in instrumenta-
tion, featuring microprocessor interfacing. His pri-
mary research interests at this point in time center on
novel biochemical separations processes. Two exciting
current developments include the exploitation of mag-
netically-stabilized fluidized bed technology for con-
tinuous protein separation, and use of affinity
techniques for separation of cell populations. Because
of his experimental creativity, David has been a part
of a number of productive collaborative efforts. Some
of these have been with John Quinn, our second
member of NAE. John's addition to Penn in 1971 from
Illinois was another significant step in the growth of
our program. His research remains focused on the fun-
damental understanding of transport processes, with
special emphasis on membrane and interfacial
phenomena. This has led to the recent development of
a number of novel concepts in John's laboratory, such
as the membrane bioreactor and a non-invasive blood
gas biosensor. At the same time, John is another
member of our faculty who has been recognized as an
outstanding teacher by the Engineering School. We
have also had the benefit of his leadership as depart-
ment chairman during the past five years.
The mid-1970's saw the addition of Liz Dussan and
Eduardo Glandt to our faculty, bringing fresh blood
and new ideas. Liz is a recognized authority in fluid
mechanics and interfacial phenomena, having pro-
duced a number of major results in these areas. She
has played a key role in the development of our


graduate program, serving as its chairman for the
past few years. A specific instance of improvement is
the increased emphasis on applied mathematics she
has brought to our curriculum. More generally, her
scholarship and enthusiasm have been instrumental in
setting its tone and in creating an atmosphere of in-
terest in and concern for each student as an individual.
With Liz on a leave of absence at the present time,
Eduardo now bears the primary leadership of the
graduate program. He also directs a very active re-
search group in thermodynamics and statistical
mechanics. Much of their current work is focused
on statistical modeling of disordered systems.
Heterogeneous media are of such a pervasive occur-
rence in chemical engineering that Eduardo and his
students often find themselves interacting with many
of the other research groups in the department.
Eduardo has also been recognized for his teaching ef-
forts, both by the School of Engineering and through
a university-wide award.
We come next to the three youngest members of
our department. Doug Lauffenburger arrived in
1979, bringing an unusual perspective on the applica-
tion of chemical engineering ideas to biology and
medicine. His investigation of fundamental cell be-
havioral phenomena has become a central aspect of
our unique approach to biotechnology. Fusing the
traditionally disparate fields of biochemical and
biomedical engineering, we term our approach
"molecular/cellular bioengineering" when pressed.
Doug has also been in charge of graduate student re-
cruitment for the past five years with great success,
being that rare individual who truly enjoys this task.
Ray Gorte has been here since 1981, building a strong
research program in catalysis and surface science. The
effects of support/metal interactions on reaction kine-
tics have been the major subject of his careful and
clever experiments, undertaken in the best-equipped
laboratories in the department. Ray has quickly be-
come known as an excellent teacher, and is now chair-
man of our undergraduate program. In this position
he has instituted a number of changes in our cur-
riculum, incorporating more advanced fundamentals
and new fields of application. Lyle Ungar has added
both depth and breadth to the theoretical side of our
department since his arrival in 1984, with a strong
research and teaching program in application of ad-
vanced applied mathematical methods to areas rather
new to chemical engineers. One of these areas is the
processing of materials for the electronics industry,
with understanding of transport phenomena involved
in crystal growth and rapid solidification examples of
major importance. Another is the development of ex-
pert systems for chemical process design and control.

In addition, Lyle's expertise in modern numerical
methods is bringing him into collaborative efforts with
a number of faculty.
Finally, we are extremely pleased to have recently
added two senior faculty to our number. Greg Far-
rington has a primary appointment in the Department
of Materials Science, of which he is currently chair-
man. However, his excellent research and teaching in
the field of electrochemistry is becoming an ever more
important part of our program. Greg is one of the
pioneers in the development and understanding of

Doug Lauffenburger conducts a research program on
molecular and cellular bioengineering.

ionic materials, such as the novel B"-aluminas, and is
actively engaged in studies of ionic transport
phenomena in these materials. Greg is also investigat-
ing analogous effects in zeolitic materials. Mention of
zeolites is one of many ways to lead into a proud intro-
duction of our newest faculty member, Paul Weisz.
Paul, of course, has had an exceptionally distinguished
career in research at Mobil, leading to membership in
the NAE in addition to numerous honors and awards.
He is continuing to pursue his many and varied in-
terests with us, including the application of zeolites
for biochemical reactions and separation processes,
and the investigation of the role of diffusion and reac-
tion in living systems. Having Paul here provides us


with an unparalleled intellectual stimulus that we look
forward to continuing for many years.

The aim of the undergraduate program in chemical
engineering here at Penn is to prepare our students
to be able to develop the technology of the future,
rather than to train them as custodians of the technol-
ogy of today. Thus, the emphasis in our core cur-
riculum is on engineering science; that is, on basic
phenomena in thermodynamics, kinetics, and trans-
port phenomena rather than on chemical process oper-
ations. Since a solid education in science and the lib-
eral arts is also expected at an Ivy League university,
our core requirements must be reduced correspond-
ingly. Of 41 course units necessary for graduation,
only 20 are specifically required; the others must be
drawn from basic sciences and mathematics, and from
humanities and social sciences. As a result, our stu-
dents receive an unusually well-rounded education
which serves them well in business, law, or medical

Computer simulations and other high-level computa-
tional studies are carried out on the department's VAX

schools, which are all popular options. This flexibility
also allows each student to tailor an individualized cur-
riculum to satisfy any particular technical or scientific
interests. A large fraction of our students go on to
graduate school in chemical engineering, perhaps be-
cause of the emphasis on the fundamental engineering
science perspective.

The aim of the undergraduate program in
chemical engineering here at Penn is to prepare
our students to be able to develop the technology of
the future rather than to train them as
custodians of the technology of today.

The required core courses are
Sophomore year-Material and Energy Balances, Ther-
Junior year-Fluid Mechanics, Advanced Physical Chemis-
try, Heat and Mass Transfer, Separations Processes
Senior year-Reactor Analysis, Process Control, Chemical
Engineering Laboratory, Process Design (two semesters)
In addition, there are elective courses in biochem-
ical/biomedical engineering, polymers, and elec-
trochemistry offered by our departmental faculty. The
process design courses deserve special comment be-
cause of the attention to providing individualized de-
sign experiences. We take full advantage of our loca-
tion in the Delaware Valley, with its concentration of
chemical and pharmaceutical industries, and invite
senior design engineers to participate in the design
courses as consultants. Each group of three students
is assigned to a different project, and meets weekly
with a faculty advisor as well as with another indus-
trial consultant. The resulting year-end reports give
evidence of how the perspective of our seniors is en-
riched through these interactions which allow them to
apply their knowledge of engineering fundamentals to
applications of current interest. A number of our best
students also choose to do independent research pro-
jects during their junior and/or senior years, which
usually whets their appetite for graduate research.

The central purpose of our graduate program is to
educate students to become independent, creative re-
searchers in chemical engineering. Every facet of our
program is geared toward providing the personal in-
teraction with accomplished scholars that is essential
for development of scientific judgment and vision. To
begin with, we maintain a low student/faculty ratio,
with about sixty graduate students present among our
faculty of fifteen. This allows small class sizes, as well
as research groups large enough to be viable and pro-
ductive but small enough to let an advisor work with
each student individually. Post-doctoral research as-
sistants are discouraged, for they interfere with direct
involvement of the faculty advisor with the students.
In recent years, our graduate student population
has become almost exclusively comprised of PhD can-
didates; less than 10% of our typical incoming class
Continued on page 156.







2nd Edition
Richard M. Felder and Ronald W.
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Now expanded and improved at its second
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tions to all end-of-chapter problems and case
studies, including case studies from the first
(0-471-87324-1) 650 pages Available
February 1986

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Unique in organization, treatment and content,
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New York, NY 10158

S educator

aoae 4. Schu4i


Notre Dame

University of Notre Dame
Notre Dame, IN 46556

SOMETIMES GOOD GUYS do finish first. That seems
to be the moral of Roger Schmitz's life and career.
A further lesson suggests that success need not al-
ways depend on grand master plans and overweening
ambition. Thirty years ago, when Schmitz surveyed
his future, the prospect of a life devoted to academia
seemed remote at best. Now dean of Notre Dame's
College of Engineering, he modestly attributes his
success to luck. Good fortune may have played its role,
but Schmitz's history is much more a tale of hard work
and dedication, of talent and opportunities exploited
to the fullest, and of a family that has been at the
center of all his aspirations and achievements.
Schmitz hails from Carlyle, Illinois, where he en-
joyed a small-town boyhood in a closely knit family.
In that environment and at that time, he says, it
wasn't common for people to go to college. In fact, he
never intended to go to college himself. After graduat-
ing from high school he took a job as a stock clerk at
a local store. Then he struck out on his own and
opened an ice service. His business career was short-
lived; six months later he was drafted into the army.
In retrospect he considers his induction a stroke of
good fortune, since it was only after he served for
those two years that he considered going to college.
Schmitz found that jobs were hard to come by
when he emerged from the service and, since he was
eligible for the Korean G.I. bill, he enrolled at the

... it was an accident that he went to
school at all, but once he was there he found that
he liked it and did well. Mathematics, physics, and
chemistry were the most appealing subjects, and
engineering was the only major he considered.

Copyright ChE Division ASEE 1986

University of Illinois in the civil engineering program.
The G.I. bill allowed for a frugal life-style: $110 a
month covered room, board, tuition, and a $20 pay-
ment on a car. He married his wife Ruth while an
undergraduate, adding to his financial responsibilities
and prompting him to accelerate his education. He
earned his bachelor's degree in three and a half years.
Upon graduation in 1959 the university awarded him
its highest academic honor by naming him a Bronze
Tablet scholar.
Schmitz reminisces, "I don't think I ever really
looked at things and said an education should be good
for me. If I had had an opportunity to get a job that
looked reasonably good to me, that was well paying,
I probably wouldn't have started college." He main-
tains that it was all a kind of accident that he went to
school at all, but once he was there, he found that he
liked it and did well. Mathematics, physics, and
chemistry were the most appealing subjects, and en-
gineering was the only major he considered pursuing.
After one semester at Illinois he switched to chemical
engineering and now he credits John Bailar, his first


chemistry professor at Illinois, with directing him to-
ward the field. Through that freshman course he dis-
covered his affinity for things chemical as opposed to
things mechanical. "I'm not one who spent a great
deal of time under the hood of a car," he explains.
Schmitz's academic goals were further refined with
the help of John Quinn, then a member of the chemical
engineering faculty at Illinois. Under Quinn's direc-
tion, Schmitz worked on an undergraduate mass
transfer project and later presented the results to an
AIChE meeting. Simultaneously, he discovered the
satisfaction of academic research and the impetus to
pursue it further. He applied to graduate schools and
decided to enroll at the University of Minnesota.
The theme of accidental good fortune arises often
in Schmitz's account of his life and career. Although
working with Neal Amundson at the University of
Minnesota "did more for me than anything else," he
did not apply to Minnesota with Amundson in mind.
Minnesota appealed to Schmitz because it offered a
good fellowship and was located in the Midwest. And
he selected Amundson as an advisor simply because
his work looked interesting. By the time he
graduated, Schmitz explains, "Minnesota was recog-
nized as probably the premier place in the country for
graduate work in chemical engineering, with
Amundson the king of his field."
When he started his graduate studies he and Ruth
had one daughter, Jan, who was born in 1958. (Joy
followed in 1961 and Joni was born in 1963.) With a
one-year old daughter, Schmitz again felt rushed,
thinking, "If I take as long as the usual graduate stu-
dent, my daughter will start school before I get out."
He finished his PhD in three years, graduating in
1962. Schmitz worked as an instructor during his sec-
ond and third years at Minnesota and soon found that
his plans for a career in industry could not compete
with the great pleasure he found in teaching. He de-
cided to pursue an academic career.
Another stroke of unexpected good luck came with
his appointment at the University of Illinois in 1962.
Again, the choice was made without much premedita-
tion. Illinois was his alma mater and in his home state.
His parents and in-laws lived nearby. These factors
persuaded him to accept the appointment and, fortu-
itously, as a result he found himself a member of a
strong department with top-notch colleagues and
facilities, good graduate students, and solid support
for research.
Schmitz prefers to emphasize the ways in which he
benefited from the stimulating environment at Il-
linois. But he certainly contributed a fair share to the
department's reputation. As a graduate student, his
research had consisted largely of theoretical analyses

which predicted a variety of complex steady-state and
dynamic behaviors of chemical reactions and reactors
and which concerned reactor control. Shortly after ar-
riving at Illinois he and his graduate students set up
laboratories to test those theoretical predictions.
Their experiments demonstrated that the ideas that
emerged from mathematical analysis represented real
phenomena and were not merely speculative. The re-
sulting articles, some of which were the first published
on such topics, are now recognized as classics in chem-

Research has not had an undivided
claim on [his] time and energy. He has been
equally committed as a teacher. Schmitz was one of the
first professors at ... Illinois to receive the award
for excellence in undergraduate teaching.

ical reaction engineering. Schmitz was awarded a
Guggenheim Fellowship for 1968-69, which he spent
as a visiting professor at the California Institute of
Technology and with the department of electrical en-
gineering at the University of Southern California.
With doctoral student Ronald B. Root, he was
among the first to demonstrate experimentally the
existence of multiple steady states in flow reactors.
This work provided a link with the theories that had
predicted such phenomena since the early 1950s, no-
tably in the works of van Heerden and Amundson.
The pioneering nature of this work was recognized by
the AIChE in 1970 when Schmitz and Root jointly
shared the Institute's Allan P. Colburn award.
Schmitz has received much recognition throughout his
career, but when asked which has meant the most to
him, Schmitz says without hesitation that it was the
Colburn award, and compares it in importance to
Rookie of the Year. Schmitz went on to publish ex-
perimental results which were among the first to dem-
onstrate the occurrence of self-sustained oscillatory
states in a flow reactor and the feasibility of stabilizing
certain intrinsically unstable states by means of con-
ventional feedback control methods.
Through the years both this subject area and
Schmitz's interests have broadened.Biologists, physi-
cists, chemists, mathematicians, and engineers, he ob-
serves,once worked in parallel with few, if any, points
of contact. But increasingly, similarities in the struc-
ture of the mathematical models they employ and in
the phenomena they observe have provided fruitful
bases for interdisciplinary cross-fertilization. The
chemical reactors in complex oscillatory states that
Schmitz studies are fundamentally similar to heart
muscles in erratic fibrillations, and populations of
predator-prey species in cyclic modes. Schmitz regu-
larly joins the researchers in these and other seem-


Their experiments demonstrated that the ideas that emerged from mathematical analysis
represented real phenomena and were not merely speculative. The resulting articles, some of which were the
first published on such topics, are now recognized as classics in chemical reaction engineering.

Even as Dean, Schmitz continues to direct the studies
of three graduate students and one post-doctoral stu-

ingly disparate fields who gather together at Gordon
Conferences and other international symposia.
Most recently, his research has focused on the in-
trinsic oscillatory nature of certain reaction systems.
His experiments were the first to exhibit very com-
plex periodic patterns and even "chaotic" states in
continuous flow reactors. These observations have at-
tracted the attention of workers in other areas also-
particularly those in biology and chemistry.
Not only is his work with complex oscillations at-
tracting the attention of other disciplines to chemical
reaction engineering, but that portion of it which deals
with solid-catalyzed reactions has promise of provid-
ing new information about catalytic processes. Using
infrared thermography to study local reaction dy-
namics on catalytic surfaces, he has observed surpris-
ingly large spatial temperature variations, particu-
larly when oscillations occur. Arvind Varma, chair-
man of the Notre Dame department of chemical en-
gineering, notes that these large spatial variations in
catalyst activity are not usually accounted for in
theoretical studies, and added, "Roger has been
unique in this area in that he has always been ahead
of the game. This is what marks his research." Jeffrey
Kantor, an associate professor of chemical engineering
at Notre Dame who was recruited by Schmitz, com-
ments, "Characteristic of him are elegant experiments
which, for the first time, verify some theoretical pre-
dictions. That's his trademark. When he does his ex-
periments, he also proves that there are a lot of
phenomena for which there aren't good explanations.

He leads the research as opposed to simply trailing
Research has not had an undivided claim on
Schmitz's time and energy. He has been equally com-
mitted as a teacher. Schmitz was one of the first pro-
fessors at the University of Illinois to receive the uni-
versity's award for excellence in undergraduate teach-
ing. He was also one of the first in chemical engineer-
ing to establish an on-line computerized laboratory de-
signed both for undergraduate instruction in process
dynamics and control and for his own research. In
recognition of this effort, he received the American
Society for Engineering Education's George Westing-
house award in 1977. With regard to the time commit-
ment involved in such an enterprise, Jeffrey Kantor
comments: "Innovative research and innovative teach-
ing are both big time sinks and he's capable of doing
both which is very much a testament to what he can
do. It's a reflection of taking professional risk and
exhibiting professional responsibility." Schmitz recalls
the excitement of working on the earliest stages of
computerization. "We had to fabricate devices because
you couldn't pick everything off the shelf like you do
now. And we had to do quite a bit of assembly-lan-
guage programming. There were no software pack-
ages available for our applications. The project served
a good pedagogical purpose, but most of all I enjoyed
doing it. It has had spin-off benefits, even to this day,
in some of my research."
Schmitz is emphatic about the importance of com-
bining teaching and research. "Some people say that
we lose something in undergraduate teaching by in-
sisting that faculty be involved in research. I can't
appreciate that concern because I've never felt that I
slighted an undergraduate class to teach a graduate
course, or to direct graduate students, or to write a
paper or proposal. Granted, some outstanding re-
searchers are absolutely horrible teachers," he ad-
mits. "But I feel that an active researcher is more
likely to bring excitement and enthusiasm to the class-
room and keep courses up-to-date over the years.
We're much better off, in my opinion, if every faculty
member is both a creator of knowledge at the leading
edge, and a disseminator of that knowledge."
Schmitz joined the Notre Dame faculty in 1979 as
Keating-Crawford Professor of Chemical Engineering
and as chairman of that department. He says that an
important factor in his choice of Notre Dame, and ear-
lier of Illinois, was his feeling of emotional attachment


to the institution. It's important to Schmitz to feel a
certain pride in the university, to believe that he can
contribute to its growth. "I don't think I'd ever care
to go to a place where I didn't feel that way. It would
seem like just a job. Or it would seem that I'm just
interested in myself and what the institution does for
me." Illinois' appeal was obvious, offering both a
familiar locale and the reputation of its fine chemical
engineering department. Nevertheless, Notre Dame
had hovered in the back of his mind since childhood.
He recalls hearing discussions of the Notre Dame foot-
ball team's exploits in front of his family's church on
Sunday mornings. He felt attracted to the university,
happy though he was at Illinois-especially as Notre
Dame's College of Engineering increased its potential
for achievement.
Throughout 1979, his first year at Notre Dame,
Schmitz was also finishing up his eighteenth year at
Illinois. This required a once-a-week, four hundred-
mile commute between South Bend and Champaign-
Urbana. Hardest of all, though, was the resistance of
his family to the move. "The tears and the anguish-
you would have thought I was ending their lives! Now
they all say it was the best thing that ever happened
to us." During this demanding period he was also
selected to give the Wilhelm lectures at Princeton
When asked about how he coped with the stresses
of combining a challenging career with family respon-
sibilities, Schmitz concedes that there are com-
promises in time and that it is all too easy to neglect
one's family. He made it a habit to bring work home
with him but, at the same time, refused to let it super-
cede the needs of his children. He puts up with a lot
of teasing at home about never getting away from his
briefcase, but considers it a fair price to pay. "I've
seen many family problems develop simply because a
person thinks he can't work away from his office or
laboratory. If he goes home at all, he goes home for
dinner and then returns to his office. And everybody's
neglected. I've never appreciated the necessity for
doing that. As every academician knows, it's very
easy to get wrapped up in what you're doing, to over-
emphasize its importance, and to think that the uni-
versity can't get along without you. I've always de-
voted long intense hours to my work, but on the other
hand, I wouldn't be able to concentrate on my work
at all if I didn't feel there was harmony at home."
In 1981, after only two years at Notre Dame,
Schmitz was appointed Mathew H. McCloskey Dean
of the College of Engineering. That same year he re-
ceived the R. H. Wilhelm award from the American
Institute of Chemical Engineers in recognition of his
theoretical and experimental work in the areas of

Three days a week, Schmitz takes a break from his ad-
ministrative duties to play a competitive game of hand-
ball and, South Bend winters permitting, runs two to
four miles every day.

chemical reactor stability and dynamics, and kinetic
oscillations. In 1984 he was elected to the National
Academy of Engineering. Recently appointed special
assistant to the provost for computing, he will serve
as the chief architect of Notre Dame's campus-wide
computer, data processing, and management informa-
tion systems, as he continues to serve as Dean of the
College of Engineering.
Jeffrey Kantor comments that the chemical en-
gineering department is a very good environment for
research right now, and he attributes that to the influ-
ence of Roger Schmitz, first as chairman and later as
dean. "There's a very clearcut statement of what he
wants. He's responsible for effectively leading the col-
lege and making his goals felt." Arvind Varma also
speaks of Schmitz's dedication to improving the re-
search climate at Notre Dame. While everyone recog-
nizes that a good faculty and funds for good facilities


are essential ingredients for continued, developing re-
search activities, Schmitz, Varma says, is capable of
attracting both.
Schmitz discusses the topic of academic leadership
with vigor. "You have to get administrators, I'm con-
vinced, from academicians. They have to be respected
by the academicians whom they are trying to lead.
They have to be able to recognize academic quality
and to articulate goals that make sense-and they
have to make decisions that are consistent with those
goals. Every dean says the same thing, 'We want to
be excellent; we want good teachers and researchers.'
But most of them will never develop outstanding col-
leges. Defining goals is important, but the most dif-
ficult part is knowing what steps to take to achieve
He pauses and shakes his head. "It's not easy to
find satisfaction in the things you do as an adminis-
trator. It's not like making a discovery in research or
publishing a paper you're proud of." Admittedly not
inclined to dwell on the past, Schmitz prefers to act
purposefully in the present and plan for the future. "I
think its important to have a model in mind. I have a
vision for the College of Engineering at Notre Dame-
what I think the College could be, what its potential
is, what it would be like if we got there. Even though
the vision may never become a reality in all respects,
I still like to have a model that guides policy and deci-
sion making." He concludes, "I used to say that every
administrator should be required to do some teaching
and research so that he would better appreciate the
professor's situation. Now I say that every faculty
member should have a turn at being dean."
In addition to filling his administrative roles on
campus, Schmitz currently is supervising three
graduate students and one postdoctoral student. Such
a balancing act requires an unusual degree of organi-
zation and focused concentration, and his efforts in
that regard have not gone unnoticed. Schmitz's cur-
rent group of graduate students report that he charac-
teristically appears at every meeting or discussion
carrying a yellow pad filled with messages to himself.
Throughout the meeting he jots down notes, equa-
tions, and diagrams-then often throws them away.
Feeling that the doodles might be useful, one student
finally summoned up the courage to ask for them, tel-
ling Schmitz that he would use them as wallpaper.
Schmitz's highly organized style of working is tes-
tified to by Mark McCready, who started graduate
school during Schmitz's last year at Illinois and is now
a colleague at Notre Dame. McCready especially re-
calls Schmitz's polished lectures at Illinois. He was
renowned for working out a problem two different
ways at the same time on the chalk board. One ap-

proach would require many steps and the other would
have fewer, but when he had finished, both would
occupy exactly the same amount of board space. No
student could ever duplicate the performance.
Schmitz's students have found that he is an adroit
practitioner of the Socratic method of teaching. Peter
Pawlicki, a current graduate student, comments on
Schmitz's unerring ability to draw more out of him
than he realized he knew through a series of insightful
questions and suggestions. Laughingly, his students
agree that his most characteristic question, the ques-
tion that follows every project, discussion, or achieve-
ment, is "What's next?" Their laughter is slightly rue-
ful because often, even when they don't feel ready to
face the next project, they know he will ask of them
just what he demands of himself-to face forward and
move on.
"He's hard to upset and hard to impress," Pawlicki
contributes. Kathi McDonald, another graduate stu-
dent adds, "One of the best comments you can hope
for from him is, 'That's good.' That is high praise."
Always available to them, despite his arduous
schedule, Schmitz never fails to return a call or pause
for consultation. Most importantly, Schmitz's
graduate students realize that, in studying with him,
they are participating in an important academic tra-
dition. This was underscored for two of the students,
Monica Dutton and Kathi McDonald, when, at a con-
ference, they met Neal Amundson. All three agreed
that the two women were probably his first academic
granddaughters. With reference to that academic
tradition Schmitz feels that he would not have ac-
complished much without the forty-nine graduate stu-
dents with whom he has worked, both at Illinois and
Notre Dame (twenty-nine of whom are PhDs).
Schmitz speaks with enthusiasm about the excite-
ment in his graduate students' laboratory right now.
That air of anticipation may be due, in part, to his
standing promise to treat the group to a Cubs game
at Wrigley Field as soon as their infrared imaging
studies reveal some critical new knowledge about
catalyst behavior. One breakthrough that might send
them all to the game is the observation of interacting
oscillating spots or standing patterns arising from spa-
tial instabilities.
That promised ball game is a key to Schmitz's life-
long second love. Satisfying as his academic career
has been, he reveals that he has always harbored a
secret ambition for an altogether different career. "I
would still like to be a baseball player!" he confesses
with a chuckle. As a boy he was sure that his future
promised major league stardom. But he says now that
he would have been thrilled just to play Class D pro-
fessional ball. The left-hander was a first-baseman, an




University of California
Berkeley, CA 94720

THE PROFESSION OF chemical engineering is in a
period of rapid change, where the graduates of
our universities are entering a much wider variety of
industries than in the past. Employment is on the up-
swing in the areas of microelectronics components,
biotechnology, environmental control, analytical in-
strumentation, pharmaceuticals, food processing, and
various materials-oriented industries, while oppor-
tunities in the traditional chemical and petroleum in-
dustries have lessened. There is little likelihood that
this trend will reverse any time soon.
In addition to these exciting changes, rapid de-
velopments in hardware, software, and networks for
personal computing have created opportunities for in-
structional innovation which are only beginning to be
identified and used.
The changing roles of our graduates and the poten-
tial of personal computers are just two of the reasons
why it is imperative that chemical engineering facul-
ties critically examine and revise their curricula and

pedagogical methods. Educators must communicate
with one another. Good ideas must be spread so that
they can be used elsewhere.
The Chemical Engineering Division of ASEE pro-
vides for this communication and exchange of ideas.
In addition to full programs at all annual ASEE meet-
ings, the division arranges a Summer School for
Chemical Engineering Faculty every five years. The
next one of these, to be held in North Dartmouth,
Massachusetts, in the summer of 1987, specifically em-
phasizes changes warranted in response to the evolv-
ing uses of chemical engineers. It affords a fine oppor-
tunity to get a broad overview of possible new direc-
tions. Finally, the division's journal, Chemical En-
gineering Education, has for years very successfully
relayed new educational concepts and teaching
methods, and is a valuable resource for members.
Surely we cannot expect that every faculty on its
own will conceive and implement the best curricular
changes and developments. The Chemical Engineer-
ing Division of ASEE provides the only major forum
in this area, and for that very reason we should all
support it and add to and partake of what it has to
offer. O

Editor's Note: In an effort to encourage non-member chemical engineering faculty to become
members of ASEE, we invite members to submit short commentaries on their reasons for joining
the organization and the benefits they derive from that membership.

outfielder, and an occasional pitcher, but at present
he is satisfied just to play catch with his son-in-law.
It's not difficult to imagine Schmitz as an athlete.
Lean and self-disciplined, he is recognized as one of
the two or three top handball players on campus. In
addition, he has recently added to his regimen. South
Bend winters permitting, he runs two to four miles
every morning, perhaps inspired by his middle daugh-
ter Joy who is in training to run the marathon.
One last question reveals the heart of Schmitz's
success-both personal and public. When asked what
matters most to him, he muses, then speaks deci-
sively. "There's no question. On the whole, the most
important thing in my world is my family. That's
where my pride and satisfaction are centered. As far
as work is concerned, I like to feel that I'm doing

something interesting and important, that someone's
benefitting from what I do, and that my work is more
than merely a 'job.' Accumulating awards is not one
of my priorities." Laughing, he concludes, "I'll accept
an award or prize anytime anyone wants to give one
to me. But it's not a big thing to me. My happiness
and fulfillment don't depend on it."
To Arvind Varma, Roger Schmitz is "a quality per-
son, a person who believes in high quality in every-
thing he does: research, teaching, administration, in-
teraction with people, handball, everything. I think
the key word for him is 'quality'." One can imagine
Schmitz's reaction to such praise. Not one to invite
eulogies, no doubt he would mask his discomfort with
self-deprecating humor and, turning to the pile of pa-
pers on his desk, would ask, "What's next?" D


j classroom


With Extensive Use of Personal Computers

Rensselaer Polytechnic Institute
Troy, NY 12180

A COURSE IN biochemical engineering funda-
mentals was recently described by the authors of
one of the best textbooks on the subject [1]. At RPI
we take a much different approach to biochemical
engineering and make very heavy use of personal com-
puters (PC's) for homework assignments. In addition
to games and exercises that have been published [2],
we have developed computerized interactive tutorials
and numerous problems that require computer simula-
tion of differential equations.
Despite the practices at most institutions, we think
it is inappropriate to have biochemistry, microbiology,
and genetics taught by engineers. Of course, such
training is absolutely essential, but we feel that the
beauty of a topic is best conveyed by those scientists
who are devoted to it. We require formal training in
sciences for our graduate students. By teaching only
the bare minimum of sciences, we have time to
develop more topics in biotechnology and biochemical
engineering. Remedial material is supplied as supple-
mental readings and commercial packages of audio
cassettes with slides to help students in our first
biochemical engineering course. Sufficient biochemis-
try for comprehending the engineering problems is
taught outside of the regular class periods by interac-
tive tutorials that do not slow down the student who
has already had exposure to this material.
Our course starts with the substrates (raw mater-
ials) that may be chosen for a bioprocess. The future
impact of inexpensive sugars from lignocellulosic
biomass is stressed, and it is logical to digress to dis-
cussion of nutrition, alternate processes for biomass
refining, carbohydrate structures, cellulases, feed-
back inhibition, byproducts from lignin, and
economics. The next section of the course addresses
microbial growth, aseptic techniques, culture preser-
vation and handling, and commercial practices and
problems. By this time, the students are comfortable
with personal computers because of the tutorials and

C Copyright ChE Division ASEE 1986

Henry Bungay has been a professor at three universities, has spent
ten years in industry, and has had appointments with NSF, USERDA,
and New York State ERDA. His research in biochemical engineering
addresses biomass refining, microscale effects of oxygen transfer, and
high-rate continuous culture. He has owned a personal computer for
ten years.

are ready for simulation problems. We use a bare-
bones BASIC program that can be learned in about
fifteen minutes. Adding special features to this pro-
gram is illustrated by many different homework prob-
lems. The success of this program comes from provid-
ing a working example. Students have little difficulty
in taking a program that executes nicely and modify-
ing it for new problems.
Production fermenters are studied in considerable
detail, and novel designs are introduced. The reasons
that biological reactors are different from chemical
reactors are covered, but there is no time devoted to
classical approaches to reactor design. Pilot plant fer-
mentation equipment is studied with emphasis on au-
tomation, control, foam problems, assays, and costs.
Lectures on fermentation rheology and mixing follow
the usual textbooks quite closely, but aeration ad-
vances beyond standard practice because of the pro-
fessor's interest in oxygen microelectrodes and oxy-
gen transfer at the microscopic scale.
A very intensive coverage of continuous culture
makes particularly good use of computer simulation.
The systems of differential equations are modeled,
and basic concepts of effects on yield coefficient,
maintenance, and the like take on real meaning for


the students. Mixed culture processes are also cov-
ered in detail, with simulation homework. This leads
into lectures on dynamics of microbial processes.
On alternate years, the entire class (and the stu-
dents that missed out the previous year) visit Bristol
Laboratories in Syracuse, courtesy of Dr. Richard
Elander, Vice-President for Fermentation Research
and Development. He also lectures in our summer
short course on advanced topics in biochemical en-
gineering. Because of the coverage of practical fer-
mentation processes and equipment, the students re-
mark on how interesting it was to see real examples
of topics they had studied.
We are blessed at RPI with several excellent
courses on purification [3], so the biochemical en-

PC Assignments for Biochemical Engineering

Production fermenters are studied in
detail, and novel designs are introduced. The
reasons that biological reactors are different from
chemical reactors are covered, but there is no time
devoted to classical approaches to reactor design.

Student Term Projects


Enzyme kinetics



Interactive tutorial with graphs and quizes.
Cascade of chemostats for exploration of
feeding and recycle. PC version of game
from book.
Interactive tutorial: theory, Michaelis-
Menten kinetics, and types of inhibition.
Translation of Jermferm game (4) to IBM
Interactive tutorial on nucleic acid structure
and gene splicing.

FERMT game from book

SUGAR tutorial

AMINO tutorial

SIMBAS program from book

Kinetics problems
Exercise using log graphs
Oxygen transfer problem

Partial harvest/refill
Growth problems

Air filtration

Oxygen dynamics
Normal distribution curve

Continuous fermentation

MONOD game

TWOCUL, and improved
predation model
BODE tutorial

LEACH program

MEMBRANE tutorial
ADSORB program


Sterilization problems
ENZYME tutorial

Develop intuition for process de-
Refresher for carbohydrate
Amino acid and protein struc-
Simulation of differential equa-
SIMBAS practice
Improve graphics skills
SIMBAS practice and reinforce
Reinforce lectures
In depth study; improved input/
Practice in scaling computer
Reinforce lectures
Handling statistical distribu-
Practice with steady-state mass
Analysis of chemostat relation
ships (best assignment of all)
Study of microbial interactions

Refresher on process dynamics
Insight into protein precipita-
tion and column chromatog-
Tool for countercurrent extrac-
Supplement lectures
Langmuir and Freundlich
isotherms and breakthrough
Introduce continuous steriliza-
Reinforce lectures
Teach enzyme kinetics

gineering course does not go into detail on the newer,
more advanced technology. Nevertheless, three or
four lectures are needed for conventional practices for
isolation of products.
The remainder of the course is on processes using
immobilized enzymes or immobilized cells. There is
brief mention of tissue culture. The final lectures
cover economics, process development strategy, and
the future of biotechnology.
The course has had some computer teaching games
and simulation exercises since the early 1970's [2], but
many more computer assignments were recently
added. Among the options for a term project are
creating or improving the computer assignments.
About half of the students choose a computer assign-
ment, and the others cast a term paper in the form of
a research proposal to the National Science Founda-
tion. Students do quite well in devising interactive
tutorials but only a very few have created a good com-
puter game for teaching. The regular computer as-
signments are shown in Table 1. SIMBAS is the pro-
gram for handling simultaneous, ordinary differential
equations. All the programs are in the public domain
and are written in BASIC to encourage others to
tailor them to their own needs.
The table does not show the progression in com-
puter skills. The students learn how to make the
graphics more elegant, to add delays, logic, and other
features, and to improve interaction with the com-
puter. Interspersed with problems are games and
exercises from the book [2]. Although this course has
been taught many times, it continues to evolve. A
deep investment of time for computer programming
Continued on page 155.


t) curriculum



Cleveland State University
Cleveland, OH 44115

THE AMERICAN Institute of Chemical Engineers,
Education Projects Committee, has surveyed the
chemical engineering undergraduate curricula since
1957 [1-6]. The most recent survey was initiated in
the summer of 1985. The information provided by the
chemical engineering departments in the United
States was to be based on the curricula in effect as of
the fall term of 1985. The survey is based on responses
from ninety departments resulting from a mailing to
all departments listed with AIChE in the summer of
1985. The questionnaire will be reviewed in an effort
to consolidate questions without loss of valuable data.
It is hoped this will result in a greater response to
future surveys.
The data received were entered into a LOTUS 1-2-
3 worksheet for ease of analysis and review. The ques-


Total Semester Hours




110 -


. 138.2

131.7 131.2 131.0

1957 1961 1968 1972 1976

1981 1985

tionnaire was unchanged from previous surveys in
order to allow for easy comparison with data reported
from those surveys.
A comprehensive historical data summary is not
possible since the computer systems are incompatible.
However, some comparisons can be drawn and trends
The semester hours for the degree appear to be

Cultural Content

George A. Coulman is a professor of chemical engineering at
Cleveland State University. He received his BS in chemical engineering
and his PhD as a Ford Foundation Fellow at Case Institute of Technol-
ogy. His MS was received from the University of Michigan. After seven
years in industry he moved to academia. He started teaching at the
University of Waterloo in Canada, moved to Michigan State University
and then to Cleveland State University. Dr. Coulman teaches courses
in control, computation and optimization as well as introductory chem-
ical engineering.
Copyright ChE Division ASEE 1986

1957 1961 1968 1972 1976 1981 1985
SNo. of hours
I % of curriculum


Very little unanticipated change has occurred. The design component has finally reached
100% of the schools reporting. This is probably a result of the accreditation effort in that area. The
disappearance of analog computation . would be anticipated. Transport theory increased and now
seems stable at 83%. ... An increase can also be noted in equilibrium stage calculations.

Chemistry Content

1957 1961 1968 1972 1976 1981 1985
No. of hours
Fl % of curriculum

stabilized in the low 130's, as shown in Figure 1. It is
interesting to observe from the more detailed informa-
tion on the spreadsheet that the range is from 96 to
144 SH. It is difficult to determine if this is an anomaly
of the individual school's credit system or a true reflec-
tion of the classroom hours of the student. Further
detailed study would be needed to determine the cur-
ricular implications of these numbers. It should be
noted that the vast majority of the schools lie in the
range 125 to 135 SH.
The data in Figure 2 indicate a stabilization in the
cultural content of the curricula after a significant rise
during the early 1960's. The content level is now well
above ABET requirements. The chemistry content,
shown in Figure 3, went through a significant drop in
the same period and his stabilized or is possibly rising
slowly. The present level is 18.7% of the average cur-
In contrast to cultural and chemistry content, it is
interesting to observe the communications require-
ments displayed in Figure 4. After a substantial drop
in the percentage of schools which include communica-
tions in the curriculum, from 98.8% in 1957 to 77% in
1976, a rebound has occurred. In 1985, 93.1% of the
schools included communications in the curriculum.
Several responses commented that this was addressed
in the senior design course. I feel certain this increase
is in response to observations by industrial recruiters
on our campuses and recognition by the faculty who

deal with senior reports.
A summary of chemical engineering subcategories
is shown in Table 1. This includes the three most
recent surveys. Very little unanticipated change has
occurred. The design component has finally reached
100% of the schools reporting. This is probably a re-
sult of the accreditation effort in that area. The disap-
pearance of analog computation from the curricula
would be anticipated. Transport theory increased and
now seems stable at 83% of the reporting schools re-
quiring this subject. An increase can also be noted in
equilibrium stage calculations. A significant increase
occurred in the number of schools requiring process
control. A modest increase in the number of schools
offering chemical engineering electives is gratifying.
The table suggests that the options are disappear-
ing. This is inferred from the decline in schools report-
ing biomedical, polymer, nuclear and environmental
options. However, the options are in fact diversifying.
This is reflected in the increase in the number of
schools providing chemical engineering electives in
the program. Further detailed study of the question-
naire suggests the decrease in options is an anomaly
of the questions. Many of the schools still retain the
specific listed areas but provide several alternatives.
As a result they now show up in chemical engineering
The departments listing electives show diversity
not reflected in the general statistics. An attempt will
be made in the next questionnaire to break out this
data. It can be qualitatively reported that depart-

100% -98.8_97.8
92.8 93.1

80 _79.0_ 77.0




1957 1961 1968 1972 1976 1981 1985



ments with electives include polymers, environmen-
tal, and computer applications. It is apparent from
the comments that many departments are examining
the inclusion of some nontraditional curricular oppor-
tunities such as biochemical, materials, electronic
component processing, etc. Local options exist in
biomedical, paper processing and others on an indi-
vidual basis. This suggests that the departments are
responding to the diversity available to chemical en-
gineers without abandoning the fundamentals.
The ABET-AIChE distribution is a useful measure
of the character of the curriculum. The figures are not
immediately discernible from the survey forms but an
effort was made to be as fair as possible in the distri-

ChE Curriculum; Sub-Categories

% Offering
1976 1981 1985

Analytical Geometry 53
Calculus 89
Differential Eqs. 94
Linear Algebra 36
Advanced Calculus 20
Complex Variables 6
Partial Diff. Eqs. 16
Numerical Analysis 20
Dig'tl Comp/Progrmng. 79
Analog Computations 7
Applied Engrng Math 22
Statics 72
Dynamics 36
Chemical Kinetics 60
Chem. Reactor Des. 73

Transport Theory
Transport Lab
Equilibrium Stage
U.O. Theory
ChE Design
Process Synthesis
Process Control
Process Dynamics
Math. Modeling
Computer App in ChE
Biomedical Eng.
Polymer Processing
Nuclear Eng.
Environmental Eng.
Other ChE Required
ChE Electives

Avg. SCH
when Offered
1976 1981 1985

78 73 2.7 2.6 2.6
37 27 2.4 2.5 2.3

68 84
36 43
47 51
83 78

bution of reported credits. The results are combined
with those of 1981 in Table 2. As was the case in the
1981 report, the average curriculum appears to con-
form very closely to the accreditation requirements.
It is unfair to draw conclusions from this limited
data, but it appears that a tendency to "free" electives
may be surfacing in the "other" category. Another
perspective on the curriculum can be gained from
Table 3. The breakdown is somewhat finer than the
ABET classification and illustrates the range of diver-
sity that can exist. Some of the diversity may be at-
tributable to the data but certainly not the majority.
Only two-thirds to three-fourths of the departments
include mechanics or electrical engineering. Further,
only one-half of the departments explicitly include ma-
terials or economics. The range of requirements is also
striking. The mathematics average of 18.72 semester
hours (including computing, deleted in ABET), with

Distribution of Course Work; 1981 and 1985

Curricular Area
Math. beyond trig.
Basic Sciences
(including adv. chem.)
Eng. Sciences and Design
Humanities/Social Sciences
Other Technical Courses
Free Electives


93 98 99 3.6 4.1 4.3 Communications
33 31 24 2.4 2.4 2.1 Culture
14 16 18 1.5 1.6 1.6 Chemistry
64 70 89 2.3 2.5 2.4 Physics
34 40 42 1.8 1.8 1.5 Economics
14 11 14 2.6 2.1 2.1 Electrical
15 27 23 2.4 2.1 2.4 Engineering
1 0 1 4.0 0 3.0 Materials
5 6 2 1.8 2.3 2.5 Required
2 3 0 4.5 4.5 0 Chem Engr.
5 5 2 4.1 5.2 2.6 Elective
34 36 26 2.3 2.3 2.1 Chem Engr.
49 55 57 7.1 5.3 5.2 TOTAL HOURS


1981 1985
Avg. Avg.
13.6 12.7
24.3 25.4
(11.7) (12.8)
37.3 37.2
16.1 15.0
8.7 5.4

100.0 100.0 100.0
133.4 131.0

Summary of Categories
No. of
Schools Average Maximum Minimum
84 5.53 12.00 0.00




67 2.71 7.00 0.00
46 1.55 7.00 0.00

91 38.07 55.0 18.70

52 5.19 12.00 1.00
91 131.00 144.00 96.30


a range from 12.6 to 35.4, is surprising.
The questionnaire also included noncurricular
questions addressing staffing and foreign enrollment.
The departmental average of faculty was 6.1 profes-
sors, 2.6 associate professors, 2.7 assistant professors
and 1.5 others. Over one-half the departments re-
ported 1.7 average faculty openings, ranging from 1
to 6. The undergraduate body was composed of 9.2%
foreign nationals while the graduate students included
38.7% foreign nationals.
It appears that only minor changes have occurred
in the curriculum since the 1981 survey. However, it
appears from the comments (and considering recent
changes in the AIChE accreditation requirements)
that the survey scheduled for 1989 will show greater
change. A detailed review of the questionnaire will be
made prior to that survey and any suggestions for

book reviews


By Siegmund Brandt and Hans Dieter Dahmen
John Wiley & Sons, Somerset, NJ 08873, $29.95

Reviewed by
Henry A. McGee, Jr.
Virginia Polytechnic Institute and State University

Models from our everyday experiences with balls
and strings and sticks and springs are easily pictured
in one's mind, and these pictures aid a study of classi-
cal mechanics. Wave mechanics has no such ordinary
background of familiar pictures, and our learning is
then wholly abstract and based upon complex equa-
tions. This new book utilizes computer graphics to
provide pictures of wave forms, interference, reflec-
tions, time developments, etc., to aid in the visualiza-
tion that is missing from our everyday experiences. It
is a significant step in the teaching of basic quantum
mechanics. The book is wholly fundamental physics
with no discussions of practical matters. A typical
junior-level course in physical chemistry would be a
minimum prerequisite to reading the Picture Book.
The book is written by physicists, and the graphics
that appear on about every other page aid basic phys-
ical understanding. For basic understanding, this
book is excellent. Fortunately, this book does not have
the kind of overpowering or intimidating character of

change will be gratefully accepted by the author.

1. Thatcher, C. M., "The Chemical Engineering Curriculum"
Chem. Eng. Ed., September, 1962
2. Schmidt, A. X., "What is the Current ChE Curriculum?" J. of
Eng. Ed., October, 1958
3. Balch, C. W., "Undergraduate Curricula in Chemical Engineer-
ing 1969-70," Chem. Eng. Ed., VI, No. 1, 1972
4. Barker, D. H., "Undergraduate Curricula in Chemical En-
gineering 1970-71," Chem. Eng. Ed., 6, No. 1, 1972.
5. Barker, D. H., "Undergraduate Curricula 1976," Chem. Eng.
Ed., 11, No. 2, 1977
6. Barker, D. H., "1981 AIChE-EPC Survey," Chem. Eng. Ed.
16, No. 4, 1982
7. Ekerdt, John, Chemical Engineering Faculties 1985-86, Vol.
34, A publication of the Chemical Engineering Education Pro-
jects Committee of the American Institute of Chemical En-
gineers. 0

most books on quantum mechanics that are wholly
mathematical and abstract.
There is nonetheless little here of direct interest
to the chemical engineer who is involved in research
in applied chemistry. Chemical engineers would be
better served by a study of semi-empirical molecular
orbital schemes that have been so well developed over
the last two decades. With these techniques, one can
calculate heats of formation, structure, vibration fre-
quencies, and the like, from input information that
merely states which atoms are joined to which in the
molecule. These techniques continue to be successfully
used by even organic chemists to pursue practical
matters. Even the rational design of drugs-a sort of
quantum pharmacology-is viable. The semi-empirical
quantum techniques can be well-used without the de-
tailed fundamental understanding that is portrayed in
the Picture Book, even as a mass spectrometer can be
well-used without one having a detailed understand-
ing of the electronic pulsing circuitry that makes it all
possible. To be sure, whether in quantum mechanics
or in mass spectrometry, a conceptual understanding
of underlying detail is important. And, as always, the
more detailed one's understanding, the better.
The title sounds tacky, but the book is well done.
The writing and graphics are clear, and the text fills
only two-thirds of each page, leaving much white
space that makes for pleasant reading. [


I classroom


Michigan State University
East Lansing, MI 48824-1226

THE RAPID INTRODUCTION of microcomputers into
the workplace over the past five years has changed
the standard "toolkit" for the practicing engineer. We
can now expect that our graduating engineers will
have microcomputers available either near or on their
desks. The software on these computers will probably
include a word processor, a graphics package, a
spreadsheet, BASIC, FORTRAN, or PASCAL com-
pilers, and a set of statistical and mathematical sub-
routines. We want our Michigan State students to use
similar facilities and software during their time on
campus. We recognize that some job assignments will
require the use of computer-aided design with
graphics, process design packages, dynamic
simulators and on-line process control and are trying
to provide some exposure to these techniques.
Of the items in the standard toolkit, a spreadsheet
program is particularly well-suited to performing the
repetitive calculations needed to solve many chemical
engineering problems. Students in our department

Eric A. Grulke has BChE, MS, and PhD degrees in chemical 'en-
gineering from the Ohio State University. He worked as a research
engineer for the BFGoodrich Chemical Group from 1975 to 1978. In
1978, he joined the chemical engineering department at Michigan
State University. His research projects are centered around mass trans-
fer and separations, including polymer devolatilization and phase
equilibria, and separations in biochemical processes.

have used spreadsheets for assignments such as nu-
merical integration of absorber design equations and
two-dimensional heat transfer problems. Once the
equations for a problem have been set up in a spread-
sheet format, calculations for new conditions or as-
sumptions can be done rapidly. When the basic prob-
lem has been correctly solved, the student can study
the response of the system to other inputs without
long hours of additional computation. This fast compu-
tation for new conditions allows the instructor to deal
with some problems in greater depth without exces-
sive demands on student time.
We have been experimenting with spreadsheets in
our process design course, where recomputation is a
fact of life. Spreadsheets permit computations using
formulas to be executed in the form of a table
[1,2,3,4,5]. We find that spreadsheets help our stu-
dents solve design problems more efficiently. The or-
ganization of the design problems for a spreadsheet
solution gives the student a methodology for finding
a design answer.

Our college of engineering is now providing a
standard "toolkit" of word processing, graphics,
spreadsheet and scientific language packages on IBM
XT microcomputers. In the Case Center for Computer
Aided Design (Prime computer), we have the CHEM-
SHARE process design package which was recently
installed by Dr. Jayaraman of our department. We
have been working hard to integrate problems using
this hardware and software into our undergraduate
and graduate courses. We would like our under-
graduate students to be able to use all these tools by
the time they reach the process selection and optimi-
zation course in the middle of the senior year.
To accomplish this goal, we have been developing
problems to be done on the microcomputer for a
number of our undergraduate courses. Don Anderson
has written software for energy and material balances
with graphics and has used it in our energy and mater-
ial balances course. Dr. Jayaraman has included a
CHEMSHARE problem in the process optimization
Copyright ChE Division ASEE 1986


methods course. Dennis Miller has used a CHEM-
SHARE problem on multicomponent distillation in
our course on stagewise separations. Daina Briedis
has a two-dimensional heat transfer problem im-
plemented on a spreadsheet in a transport phenomena
class. Students in our two laboratory courses are en-
couraged to use the word processors for writing their
final laboratory reports. In 1984, we introduced
spreadsheeting in our process design course for both
balances and economics. In 1985, Martin Hawley and
Dr. Jayaraman used CHEMSHARE for three of the
five design problems. We plan to include CHEM-
SHARE and microcomputer problems in the trans-
port phenomena and separations sequence taught in
the junior year as well as in the phase and chemical
equilibria course. We hope that the continual use of
these computer tools will prepare out undergraduates
for the new work environment.

Spreadsheets provide an easy way for students to
perform material and energy balances without a pro-
cess design package. They are adequate for perform-
ing the balances needed for moderate size processes
except for problems with many recycle streams. Some
can even handle modest models for equipment perfor-
mance. While a process design package such as
CHEMSHARE may be easier to use, the spreadsheet
does have one advantage. The student is responsible
for all spreadsheet input and knows which ther-
modynamic equations, reactor models, and heat trans-
fer correlations have been used. Spreadsheets relieve
the drudgery of recalculating cash flow tables when
economic assumptions are changed.

There are a number of factors to consider when
choosing a spreadsheet for process design calcula-
tions. The physical location and administration of
microcomputers on your campus may place some con-
straints on the software you select. At Michigan
State, we like to provide students 24-hour access to
the computing facilities. While our microcomputer
labs are almost always open, the rooms are not at-
tended. Therefore, we prefer software which can be
installed on the hard disk (legally) and accessed at any
Microcomputers are clustered in several rooms in
the engineering building at Michigan State. These
sites are run by the Engineering Computer Facility,
which maintains the software, provides aid to the stu-
dents, and retains documentation at its central office.

We would like to provide 24-hour access to software
documentation at each site, but have not found an easy
method for doing so. Documentation is available for
check-out at the engineering library located in the
building. We have also used the microcomputer lab
located in the main library. We have not installed
software at sites remote from the engineering building

S. we like to provide 24-hour access to the
computing facilities. While our microcomputer labs
are almost always open, the rooms are not attended.
Therefore, we prefer software which can be installed
on the hard disk and accessed at any time.

because of the lack of convenient ways to retain
In order for our students to trouble-shoot their
own problems and teach themselves some commands,
the software documentation must be well-written,
well-organized and well-indexed. We provide them
with a "primer" for the spreadsheet which includes
information on starting the program, file transfers,
editing commands, formulas and functions, and exam-
ples of typical screen displays. Tutorials supplied with
the software also help. Our most efficient method for
getting students acquainted with a spreadsheet is an
example problem, which will be discussed in a later
The characteristics of the software are also impor-
tant. A fairly complete set of mathematical functions
is preferred. These should include logarithms, expo-
nentials and trigonometric functions. Logic functions
and conditional expressions, such as maxima, minima
and sums, are also useful. Many of the business
spreadsheets have these functions. Some also have
graphing capabilities, which can assist the students in
preparing reports and presenting homework prob-
lems. We prefer software graphics in which the mater-
ial appearing on the screen is the same as that appear-
ing on the printed page.
It is important to try the software you intend to
purchase on the hardware you intend to buy. You'll
want to be sure that the printer supports the charac-
ter fonts supplied with the spreadsheet and that the
microcomputer has sufficient memory. On IBM-com-
patible hardware, an 8087 math coprocessor chip
speeds program execution and is recommended.
The key elements in our choice of spreadsheet
were not the technical features of how large the pro-
gram was, how formulas and text were entered, or
the details of editing. We were most concerned with
software which could reside permanently on the hard
disk, which had clearly written documentation with a
good index, and which had easy-to-use on-line help.


Supercalc III8 provided the best balance of charac-
teristics at the time we made a choice and has
functioned well in the MSU environment.


I try to do as little teaching of the spreadsheet in
class as possible. Table 1 contains a portion of a cash-
flow table for a methanol process used to illustrate the
use of a spreadsheet. Sections of the table are easy to
show by making overhead transparencies. The for-
mulas entered into the cells can be displayed while the
commands needed to enter them are described. Copies
of these example problem files are kept on the hard
disk so that students can refer to them as they do
their assignment. The example files help the students
learn how to organize and construct a spreadsheet.
They also provide motivation to use the microcomput-
I usually end the example problem discussion by
suggesting some changes in the problem which re-
quire new computations. The advantages of rapid data
changing and recalculation quickly become obvious.


I have used spreadsheets to perform material, en-
thalpy, and entropy balances for modest size proces-
ses (20-40 streams) and for generating equipment
cost, capital investment cost, manufacturing costs,
and cash flow tables. I can solve the base case design
faster using a spreadsheet and can quickly identify
high-cost portions of the process for further analysis.
This gives me more time to consider design alterna-
tives and decide how to help the students think about
the problem.
The spreadsheets provide a convenient format for
discussing problem solutions with graders and teach-
ing assistants. They can sit down at the micro and see
for themselves the effects of changing assumptions or
process conditions. The spreadsheet makes it easy to
check solutions of students who may have used differ-
ent correlations or assumptions. It is particularly
helpful in checking the work of students who had a
design idea which the instructor did not consider!


Table 1 illustrates a cash flow analysis for a
methanol process. In this particular example, the
plant is two years in construction and the desired cash
flow rate of return is 30%. Students are able to follow
example problems such as this and can easily con-
struct similar tables for their design problems. The
items in the data block below the title (rows 6-13) are
all inputs to the cash flow analysis. Changing the en-

Methanol Economics: Selling Price for 30% DCF Rate of

Cash Flow Analysis: Costs in K $

Capacity, M gpy
Depr. Cap, M$
Plant Life
DCF Rate
Tax Rate
Selling Price
Annual Revenue
Manuf. Costs
Working Capital

Cap. Outlay
Working Cap.
Manuf. Costs
Net Profit
Cash Flow
Total Cash Flow
Present Value,
Cash flow


70831 str. line
10 years

.853 $/gallon
85300 K$
31450 K$
2151 K$
Year Start-up
86 87 88


0 0
0 0
85300 85300
31450 31450
7083 7083
38533 38533
23383 23383
23383 23383
30467 30467
-42515 -12049
18028 13867

89 90



Sum of Present Value of
Cash Flow 27
Payout Period 2.32 years

tries in this table will allow recalculation of the spread-
sheet. In this problem, the students were to find the
selling price needed for discounted cash flow rate-of-
return of 30%. This can be done by iterating the sel-
ling price until the sum of the present values of the
cash flow is zero.


Spreadsheets provide a method for structuring
material and energy balances when a process design
package is not available. Students can discover how
to organize their problem and detect balance errors as
the subsections of the design are solved.
Table 2 shows a portion of a spreadsheet for solv-
ing material, enthalpy, and entropy balances for a dis-
tillation column using vapor recompression. The
stream numbers are related to a process flow diagram.
Each column represents the properties for one stream
and includes the flow, the enthalpy and the entropy
of the individual components. The liquid-vapor index
in the third row (L= 1, V=2) is used to include the
latent heat in the enthalpy calculations for vapor
streams. The enthalpies and entropies are calculated
from heat capacity models generated from data


around the expected operating conditions. Rather
than use a complete model for the heat capacity, we
suggest linearizing the data to generate a two con-
stant model applicable in the temperature range of
interest. This reduces computation time without much
loss in accuracy.
We suggest that the students use "built-in" checks
of their energy and material balances. It is easy to set
up the overall balances of material and enthalpy
around specific process sections at cells outside of the
main set of equations on the spreadsheet. This
technique allows the student to find balance errors
quickly and easily. The last two rows of Table 2 show
calculations of compressor work (the difference be-
tween the total enthalpy flow of streams 2 and 3) and
heat of condensation from the compressed vapor avail-
able for boiling bottoms liquid in the reboiler (the dif-
ference between the total enthalpy flow of streams 3
and 4). The enthalpy change across the compressor
will be used to check its efficiency. The enthalpy
change of the condensing stream will be compared to
the enthalpy change of reboiled liquid to ensure that
the energy flows around the reboiler balance.
One common error of students is formulating a
spreadsheet to calculate the material and energy bal-
ances for the complete process with very few manual
data inputs. The students may try to write the com-
plete spreadsheet file without checking interim calcu-
lations. It is usually wiser and more efficient to per-

Section of Material and Energy Balance Table for Vapor
Recompression Process

Stream No.
Stream ID

T, F
P, psia
L= 1,V=2
W, lbmol/hr
EtOH, x
H, Btu/lbmol
S, Btu/lbmol-F
H20, x
H, Btu/lbmol
S, Btullbmol-F
H, Btu/lbmol
S, Btu/lbmol-F
H flw,K Btu/hr
Compressor Work
Reboiler Heat


r Recompression-EtOH Distillation
1 2 3
Column Ovrhd. Cmprsr.
Feed Vapor Outlet






5759 K Btu/hr
62503 K Btu/hr

Fermentor Section of an Equipment Cost Table for a
Novobiocin Process

Fermentor Section

R-1 Fermentor
T-1 Innoculum Tank
A-1 Agitator for T-1
P-1 PumpforT-1
T-2 Acid Tank
P-2 Pump for T-2
T-3 Base Tank
P-3 Pump for T-3
T-4 Make-Up Tank
P-4 Pump for T-4




Fermentor Section Subtotal Cost

Cost, K$


*Peters and Timmerhaus

form many checks on interim calculations as the bal-
ances are being entered, just as a computer program-
mer would check code for errors as it is being written.
For example, I routinely show the energy inputs and
outputs around distillation columns to make sure that
I have not neglected condenser cooling water or re-
boiler steam. It is particularly important to resist the
temptation to make the spreadsheet iterate on proces-
ses with many recycle streams. The spreadsheet is
not a sophisticated equation-solver. Some recycle cal-
culations do not converge uniformly and, unless they
have done the calculations by hand prior to program-
ming, students may waste a lot of time discovering
this. It does not seem convenient to use equipment
design algorithms as a part of the energy and material
balance spreadsheet (such as would be included in a
process design package like CHEMSHARE).


Table 3 is a section of an equipment sizing table
for a Novobiocin process. Each item is process
equipment on an associated process flow diagram. The
number of items and their size are inputs on the
spreadsheet. The cost equation contains exponential
equations fitted to cost curves in Peters and Tim-
merhaus [6]. The cost equation includes the item size,
and number of units as inputs. The sizes of some of
the items are related to others. In this example, the
sizes of the inoculum, acid and base tanks were taken
to be one-tenth the size of the make-up tank. The
make-up tank size is related to the fermentor size.
There are similar relationships between the pump
sizes and the tank capacities. Since most equipment
Continued on page 153.

n laboratory

An Undergraduate Experimental Facility

University of Edinburgh
Edinburgh, Scotland EH9 3JL

FOR SOME PURPOSES it is useful to regard a dis-
tillation column as a heat engine, absorbing heat
at a high temperature in the reboiler, performing
separative work and discarding the heat at a lower
temperature in the condenser.
The ideal separative work required to split a feed
containing mole fraction x of component A and (1 x)
of B into pure components is then

W = RT [x in x + (1-x) An (1-

when the components obey Raoult's law.
for any real distillation, the efficiency

ideal separative work
S heat into reboiler

is very small, commonly a few percent [1]
engine, a distillation column is very ineff
since a substantial amount of the chemical
energy use is in distillation, it is worth
why the efficiency should be so low, and
done to improve it.
One reason for low thermal efficiencie

S-11 dAsrd 92'
so5 90
-- e 'per'vr *e :

FIGURE 1. 'Q' Curve for ethanol-water at 1


In practice

Colin Pritchard is a lecturer in chemical engineering at Edinburgh
University. He received his MA from Cambridge University and his
PhD from IIT, Delhi, India. He teaches heat transfer, distillation,
economics and plant engineering, and his research interests are in the
same areas, including energy storage and novel heat pump design.

to choice of reflux ratio: a reflux ratio is normally
. As a heat selected, or controlled, to obtain a desired purity in
icient. And the column overheads. In many common separations
1 industry's (e.g. acetone-water, ethanol-water) the reflux ratio re-
considering quired in the last stages of rectification is far higher
what can be than that required just above the feed, or for the strip-
ping section. Thus in order to perform a comparatively
s is related small amount of separative work for high-purity over-
heads, a great deal of heat has to be supplied at the
reboiler temperature. If heat could be supplied at the
(usually much lower) temperature at which it is re-
quired for separation, then higher thermodynamic ef-
ficiencies could be achieved.
'Q' curves such as Figure 1 are a graphic, though
little-used, representation of heat flows in distillation.
The construction is described in Flower and Jackson
[2] and utilises the enthalpy-concentration relation-
ships used in construction of the familiar Ponchon-
Savarit diagram. Figure 1 reveals that separation of
ethanol-water close to the azeotrope requires 800 kcal
per kg of distillate, compared to only 215 kcal per kg
required to condense the overhead product-equiva-
lent to a minimum reflux ratio of 800/215 = 3.7. But
5s o at a temperature only 1 degree C higher (75% w/w
ethanol) the required net heat flow has fallen to 500
bara Copyright ChE Division ASEE 1986



500 -

goo -

30 -

[..fct~P F1_ P -1J


FIGURE 2. Schematic diagram of vapour compression
kcal per kg distillate (minimum reflux ratio 2.3). Thus
only a fraction of the heat needs to be transferred
over the full temperature range between reboiler and
distillate: much of the heat required could be transfer-
red over a temperature difference of 1 degree C! This
is a point often overlooked in considering energy sav-
ings in distillation, though it is of major significance
in "difficult" separations such as ethanol rectification
in which most of the separative work is achieved over
a very small temperature range [3].
It is in such systems that overhead vapour com-
pression schemes can produce very large energy sav-
ings: because of the low temperature lift, the com-
pressive work required is very small and this "heat
pumping" system exhibits a high coefficient of perfor-
mance. Overhead vapour recompression is the
simplest means of transferring reject heat to a point
where it can perform useful separative work. It is
applied in a number of industrial separations-princi-
pally those involving close-boiling components such as
propylene-propane [4], and is gaining importance as
energy costs rise.

To demonstrate the principles of vapour compres-
sion distillation, two senior students were given a "de-

S. only a fraction of the heat needs to be
transferred over the full temperature range between
reboiler and distillate: much of the heat required
could be transferred over a temperature difference of
1 degree C! This is a point often overlooked . .

sign and build" project. Since only six months were
available for this, some key equipment had to be
purchased in advance, and this effectively dictated the
scale of the pilot plant which was constructed. At the
heart of the system was the compressor, a Compton
D 416-4 gas compressor with 316 stainless steel gas
contacting parts, delivering 1.2 scfm (equivalent to
1.37 mol min-1 at 30C) at 30 psig. Stringent consider-
ations of laboratory safety effectively restricted our
choice of separation system to refrigerants-a fortu-
itous restriction since refrigerant mixtures are "well-
behaved" on compression and many mixtures obey
Raoult's law over a wide range of temperature, pres-
sure and composition.

In Edinburgh where laboratory temperatures in
the six winter months average 60F, the choice of re-
frigerants was unequivocal: Refrigerant 11 (CClF)
boiling at 77F (25C) and Refrigerant 113 (CC12F-
CC1F2) at 119F (480C). In labs where the ambient
temperature does not fall below 780F, a mixture of
R112 (freezing point 78F, boiling point 1980F) with
R113 could be used. However the low boiling mixture
has the advantage that heat losses from the system
are minimised: the rectification system in particular
operates close to ambient temperature and does not
suffer from the enormous internal reflux generated in
most laboratory stills. (A disadvantage is that all stor-
age vessels must be cooled by circulating water to
avoid excessive losses; and all must be vented through
a refrigerated trap.) The mixture may be analysed by
densitometry or by gas chromatography, though spe-
cial procedures had to be developed to ensure repre-
sentative sampling. Figure 3 shows the ther-
modynamic cycle for pure refrigerant 11 as overhead,
with adiabatic compression. The resulting coefficient
of performance is derived from the enthalpies of vap-
our and liquid (Fig. 3)
AHc 324 142 8.3
c.o.p. = -= 324 302 8.3
W' 324 302
One other critical choice concerns the method of
pressure control. Computers are used throughout our
laboratories for data acquisition and control, so this
was the rational choice for the pressure control loop.
Two pressures and twelve temperatures are read via


29p - -- condensing
S / throttling I c/ pression
evporti \
I / ; \
I / j/ I I

I-2 302 324
FIGURE 3. Thermodynamic cycle for heat pump working

the IEEE port and a standard interface box, and the
pressure control is effected through the user port,
with a D/A converter providing 4-20 mA output.

The design finally evolved by the students is
shown in Figure 2. The column is 3" diameter, 6' tall
packed with /4" glass raschig rings with feed at the
midpoint. The reboiler is a standard borosilicate glass
unit of 5 ft2 (0.5 m2) area with a nominal heat transfer
coefficient of 50 BTU hr-1 ft-2 F-1 (290 Wm-KK-1). Au-
xiliary heating is supplied by electrical heating tape
for starting only.
Design operating conditions are 1.1 bara in the still
base and 2.9 bara for the compressed vapour, which
thus condenses at around 57C. This gives a 12 degree
temperature difference across the condenser/reboiler,
which is more than adequate for the heat duty of 730W
(2500 BTU/hr).

-.--XX --Y--------------------
REBOILER .19 .35 41.5 0.996
BOTTOM PLATE.25 .43 39.8 0.996
OERHEAD .82 .91 27.9 0.996
FLASH VESSEL.86 .93 27.2 1.0
INLET 43 (DEGC) 0.996 OUTLET 58 (DEGC) 2.985 (BARA)
TO ALTER, HIT l,d,3,, OR U

FIGURE 4. Typical screen display

Flashing liquid from the pressure control valve is
taken to a separator; the vapour is returned to the
suction side of the compressor, while the liquid is
proportioned to reflux and storage. The column mass
balance is secured by an overflow lute system on the
reboiler, which ensures constant reboiler level at pres-
sures between 0.95 and 1.1 bara aprox. The column
pressure is controlled manually by cooling water flow
to the reflux drum, which sets the vapour pressure.
Since the computer logs both temperatures and
pressures it can compute composition at points in the
plant where there is vapour-liquid equilibrium, using


and the Antoine equations for pA* and PB*.
These are displayed on the screen together with
the pressure control variables, heat transfer rate,
compressor performance and calculations of HETP
(overall) and the C.O.P. of the system as a heat pump.
Figure 4 is a typical screen display.
Obtaining representative samples of such volatile
liquids for VPC is extremely difficult. Eventually on-
line samples were drawn through capillary tubing into
evacuated glass bulbs, from which samples of vapour
admixed with air were withdrawn by gas syringe.This
gave an independent check on the computed composi-
tions, which were in reasonably close agreement.

The pilot plant was built in two months at modest
cost, using standard components. The thermocouple
interface was a later addition which, with the as-
sociated software, greatly enhances the teaching
value of the rig. Freed from the necessity of carrying
out tedious calculations, students can rapidly ap-
preciate the effect of changing reflux ratio (for in-
stance) on HETP and heat pump c.o.p. The compres-
sor performance may also be evaluated over a range
of compression ratios. The rig has proved its worth in
both teaching and research and is currently being used
in an investigation of difficult separations at low tem-
perature lift.
A complete design report and specifications are
available from the author.

1. Freshwater, D. C., Trans Inst Chem Engrs., 29, 149-160, 1951.
2. Flower, J. R. and M. A. Jackson, Trans Inst Chem Engrs., 42
T 249-258, 1964.
3. Mostafa, H. A., Can J Chem Engrs, 59, 487-491, 1981.
4. Finelt, S., Hydrocarbon Processing, Feb. 1979, 95-98.



Pa*,PB* s.v.p. of components A, B
PT total pressure on system
R gas constant J mole-1 K-1
T temperature
W ideal work of separation, J mole-1
XA, XB mole fraction of A, B in liquid
7) (1st law) efficiency of separation
AH heat given up in cooling and condensing over-
head vapour
W' work done by compressor D

book reviews

By Attilio Bisio and Robert L. Kabel
John Wiley and Sons, New York (1985) 18 Chapters,
699 Pages, $69.95
Reviewed by
Verle N. Schrodt
Monsanto Company
Florissant, MO 63031
This is an impressive book and one that should be
on the desk of everyone who teaches transport
phenomena to chemical engineering students. The
reasons are well stated in the first and last chapters
of the book. From the first chapter, "Introduction to
Scaleup," we have the quote defining scaleup as "The
successful startup and operation of a commercial size
unit whose design and operating procedures are in
part based upon experimentation and demonstration
at a smaller scale of operation." From the last chapter,
"Scaleup: Overview, Closing Remarks, and Cautions,"
there is a classic line, "Indeed, to a very significant
extent, scaleup is chemical engineering." The book
does, in fact, describe what chemical engineers do
and, for that reason, it will also be valuable to indus-
trial people involved with developing and even trou-
bleshooting processes and to those striving to teach
potential chemical engineers how to design chemical
processes and plants.
The subject matter is introduced by describing
several processes and the pertinent experiences in-
volved in developing a concept to commercial reality.
This is followed by a general and well thought out
treatise on the use and utility of mathematical models
in the description of chemical processes. The core
chapters cover the basic subjects of reactor design
and development, flow and mixing, and mass transfer
and separations. All of these chapters begin with a
discussion of major issues pertinent to the topic. This

is followed by a discussion of fundamentals and the
chapters conclude with practical issues covering com-
mercial equipment, scaleup and uncertainties.
The last chapters cover practical matters, includ-
ing a necessary chapter on environmental problems
and the issues facing our industry today. People doing
commercial process development acquire various
"rules of thumb" from years of experience and Chap-
ter 17, in this book, has several pages of these "rules
of thumb." They make delightful reading.
The final chapter brings the book together with a
discussion of the realities that are present in scaleup/
chemical engineering.
The book had its genesis in a short course, taught
by the authors over several years, and it is the only
modern book on the subject. The 18 chapters were
written by some 17 different practitioners of the art,
but it reads as though it was written by an individual.
The authors have done a remarkable job of organizing
and integrating the chapters into a unified whole,
while allowing each chapter to stand on its own.
The chapters and authors are:
1. Introduction to Scaleup, A. Bisio
2. Mathematical Modeling, D. M. Himmelblau
3. Reaction Kinetics, R. L. Kabel
4. Homogeneous Reaction Systems, R. L. Kabel
5. Reactors for Fluid-Phase Processes Catalyzed by
Solids, G. F. Froment
6. Fluid-Fluid Reactors, Y. T. Shah and W. D.
7. Selection of Reactor Types, R. L. Kabel
8. Flow Patterns and Residence Time Distributions,
E. B. Nauman
9. Mixing Processes, J. Y. Oldshue
10. Fluidized Beds, J. M. Matsen
11. Laminar Flow Processes, E. B. Nauman
12. Stagewise Mass Transfer Processes, J. R. Fair
13. Continuous Mass Transfer Processes, J. R. Fair
14. Solid-Liquid Separation Processes, L. Svarovsky
15. The Environmental Challenges of Scaleup, P. B.
16. Evaluating Materials of Construction in Pilot
Plant Corrosion Tests, P. E. Krystow
17. Gaining Experience Through Pilot Plants and
Demonstration Units, F. G. Aerstin, L. A. Rob-
bins, A. J. Vogel
18. Scaleup: Overview, Closing Remarks and Cau-
tions, G. Astarita
This work should be a part of a chemical engineers
training and while I would not suggest that it be a
required text because of its cost, some way should be
found to introduce young engineers to its contents.


W e E classroom



Michigan Technological University ..
Houghton, MI 49931

THE EMPIRICAL determination of rate equations A Ac
From batch reactor data by the integral method o ,
occupies a prominent place in chemical engineering o n kCA 2C
kinetics courses. However, the application of the -
method is tedious and time-consuming. Students b rA = kC ACB
rarely complete homework problems involving the in- 10
tegral method. In an attempt to make these problems rA kAC2
more palatable, and also to demonstrate the potential C
of computer graphics for data analysis, a microcompu- .
ter program was written to analyze rate data by the
integral method. The program is written in Applesoft
BASIC for an APPLE@ computer having 32k of mem- r k k [A i,, -A' i C CACB-kC
ory. VCA2k R B
JC 'tCc'-\ V-CR rAC *CAC B_ I C
R22C A C rA =kCACA A A k C A
CACA -A k C I R21BR22.
I' kCA'- 2- k CR R12B CACA C
The problem can handle only constant-volume,* R
single-phase reactions of the stoichiometry I A

aA + bB rR + sS ... ..

where the stoichiometric coefficients a, b, r and s are
either positive real numbers or zero. Data can be in
the form CA versus t, XA versus t, PA versus t, or
Ptotal versus t. Initial conditions (concentrations or
partial pressures at time t = 0) must be given for all
species, including inerts. If the reaction is reversible,
the value of the equilibrium constant in concentration

Students rarely complete problems involving
the integral method ... to make these problems more
palatable, and to demonstrate the potential of computer
graphics for data analysis, a microcomputer
program was written to analyze rate
data by the integral method.

units, Kc, must be supplied. If the reaction is irrever-
sible, Kc must be set equal to zero. The first data
point must be at time t = 0.

From the data given the program calculates XA,
fractional conversion of reactant A, for each data
point. Based on the stoichiometry of the reaction the
program selects for testing a number of possible rate
equations according to the flowchart in Figure 1. The
integrated forms for each rate equation are in the for-
mat 1(XA) = kct. For ease of reference each rate
equation is coded, with the first letter (I or R) signify-
Copyright ChE Division ASEE 1986


J. M. Skaates received his B.Sc. (1957) at Case Institute of Technol-
ogy and M.S. (1958) and Ph.D. (1961) at Ohio State University in
chemical engineering. He worked at California Research Corporation
for three years before joining the faculty of Michigan Tech. His teaching
duties have included undergraduate and graduate courses in ther-
modynamics and kinetics, an undergraduate course in process control,
and graduate courses in catalysis and in process optimization. He has
been involved in research in catalysis, biomass pyrolysis, and wet

ing an irreversible or reversible reaction, the next two
integers giving the reaction order in the forward and
reverse directions, and the last letter as a supplemen-
tary identifier. In the BASIC program each inte-
grated form is computed in a separate subroutine hav-
ing the appropriate code name.

Students, working in groups of two, check out a
diskette containing the program. They also receive an
instruction booklet containing a description of the pro-
gram and directions for use. Since, surprisingly, many
students have not used a personal computer, there
are instructions on everything from how to handle a
diskette to how to turn on the machine. After the
program is loaded, detailed instructions appear on the
video monitor, and the student enters the required
data according to a series of prompts.
For each rate equation the monitor first displays
the individual data points of the P(XA) versus t plot.
After a slight pause, the linear-least-squares line is
also displayed, making it easier to judge if the data
points swerve from a straight line. The rate equation
being tested is shown on the monitor, as well as the
value of kCA determined by linear least squares. Al-
though the use of linear least squares is not strictly
correct due to the nonlinearity of the functions, more
sophisticated non-linear parameter estimation
techniques are ruled out by the limited machine mem-

Four homework problems are assigned to each stu-
dent group. Students are instructed to write down
their observations for each rate equation tested. It is
emphasized that they are to make their judgments
not on the degree of scatter of the data points, but on
their overall deviation from linearity.


Smith [1] studied the gas-phase dissociation of sul-
furyl chloride into chlorine and sulfur dioxide at
279.2C. Under constant volume conditions the follow-
ing results were obtained, starting with pure sulfuryl
SO2zC2 -> SO2 + C12 t Ptota
A R S min mm Hg
0 322
15.7 335
41.1 355
68.3 375
96.3 395
The conversion is 100% as t -> -.
Solution: From the video monitor the following were noted:
Rate equation tested Observations
rA = kCACA2 slightly concave upwards
rA = kACA1- straight kcA = 1.58 x 10-
rA = kCACA straight kcA = 2.66 x 10-
rA = kCACA0o5 slightly concave downwards

Class discussion of the homework problems high-
lights the imprecision of the integral method, a point
not adequately covered in textbooks. For an nth order
irreversible reaction, n can be estimated only to 0.2
with perfect (computer-generated) data having no
scatter, +0.5 for data with small scatter, and 1 for
appreciable scatter. It is emphasized that this impre-
cision is an inherent result of the integration of data-
suppression of noise accompanied by loss of fine detail.
Student reception of the computer graphics pro-
gram has been enthusiastic. It serves to revive in-
terest in the course at a point where the math becomes
tedious and student interest starts to flag. Further
information on this program may be obtained from
the author.

It is a pleasure to acknowledge the help of students
Thomas S. Sanicola and Michael G. Krueger in the
development of this program.

1. Smith, D. F., JACS 47, 1862 (1925). [


W 3 classroom



Georgia Institute of Technology
Atlanta, GA 30332

TRIAL-AND-ERROR calculations occur routinely in
chemical engineering design computations, and
chemical engineers are generally quite facile in per-
forming such calculations. Trial-and-error methods
may be necessary for the solution of a single equation
for a single variable, or for the solution of a system of
equations for many variables. To be sure, systems of
linear equations can be easily solved by straightfor-
ward matrix methods and do not require the iterative
methods associated with trial-and-error calculations.
However, most design relationships in chemical en-
gineering are not linear and, in addition, may not even
be represented by equations, but rather by graphs,
tables, heuristic rules, etc.
Little material has been published in the practice
literature on the organization of calculations so as
to eliminate or minimize trial-and-error effort. This
article summarizes a simple design variable selection

algorithm which: 1) identifies nested loops of equa-
tions which must be solved by trial-and-error
methods, 2) seeks to minimize such loops, 3) provides
guidance to the selection of design or decision vari-
ables, and 4) delineates the order in which systems of
equations are to be solved.
Readers interested in further technical details of
this methodology are referred to some of the early
papers by Rudd and co-workers [1,2]. In turn, the
basic theory of information flow structure underlying
these applied works was given by Steward [5,6]. A
more recent discussion of this topic, including presen-
tation of an algorithm entitled SWS (Structural
Analysis with Substitutions), is provided by Soylemez
and Seider [4].

Central to the organization of design calculations
for a given system is the determination of the number
of degrees of freedom that the system possesses.
Quite simply, the number of degrees of freedom (F)
is equal to the difference between the number of sys-
tem variables (M) and the number of independent re-
lationships involving these variables (N). That is


Jude T. Sommerfeld is professor and associate director of the School
of Chemical Engineering at Georgia Tech. He received his BChE degree
from the University of Detroit and his MSE and PhD degrees, also in
chemical engineering, from the University of Michigan. His 25 years
of industrial and academic experience have been primarily in the area
of computer-aided design, and he has published over 70 articles in
this and other areas.

Then, F of the M variables of the system may be cho-
sen as design or decision variables by the designer;
the remaining (N) variables are called state variables.
This concept is identical to the Gibbs phase rule of
classical thermodynamics. It is, of course, the de-
signer's responsibility to ensure that 1) no design re-
lationships are overlooked, and 2) the purported N
design relationships are indeed independent of one
In their excellent text, Rudd and Watson [3] iden-
tify three calculational cases, depending upon the
value of F. These three cases will be illustrated with
the aid of their simple mixing example, depicted in
Figure 1.

Copyright ChE Division ASEE 1986


CASE I: Contradiction F < 0
Let us assume that the following design relation-
ships (equations) are postulated for this mixing exam-
A + B = C (2)
K =B/A (3)
A = 1,000 (4)
C = 2,000 (5)
K =4.0 (6)
Thus, there are five independent design relationships
(N = 5) and four variables (A,B,C,K; M = 4) post-
ulated for this system. In this case, F = -1.
Mathematically, this problem is not solvable. There is
no set of values of the four variables which will simul-
taneously satisfy the five design relationships post-
ulated, and hence the name contradictory for this
case. This situation generally results from an incorrect
formulation of the design problem, and is of no practi-
cal interest.
CASE II: No Freedom F = 0
Suppose we now relax Eq. (5) in the above set of
five equations; that is, Eq. (5) need no longer be satis-
fied. In this case, the number of design relationships
(N) reduces to four, and the number of degrees of
freedom (F) becomes exactly equal to zero. There is
then a single unique solution to the remaining system
of four equations, and one is not free to arbitrarily


FIGURE 1. Simple mixing process

Having determined the number of
degrees of freedom in a given design problem,
the next step is to determine: 1) which of the problem
variables are to be selected as design variables,
and 2) the order in which the system
equations are to be solved.

assign values to any of the four system variables.
Specifically, the unique system solution is: A = 1,000,
B = 4,000, C = 5,000, K = 4.0.
This case is common to students in their basic sci-
ence courses (chemistry, mathematics, physics), as
well as in many of their engineering courses. How-
ever, while useful from a pedagogical viewpoint, this
case does not represent the open-ended design prob-
lems encountered by engineers in practice.
CASE III: Degrees of Freedom F > 0
In addition to the relaxation of Eq. (5), suppose we
now also relax Eq. (6) in the above system. In this
case, the number of design relationships (N) reduces
to three. Still with four system variables (M = 4), the
number of degrees of freedom becomes equal to one.
There is an infinite number of values for the variables
B, C and K which will satisfy the three equations for
this case. Thus, some freedom exists. Specifically, one
would have to assign a value to one of the above three
variables (B, C, K) before this system could be solved.
This case corresponds to the typical open-ended
design problem. That is, the designer must first make
some choices regarding the values of one or more of
the system variables. Clearly, experience in the selec-
tion of such design variables is a valuable aid. Also,
this case is the only one of the three which presents
any optimization possibilities. Thus, some objective
function of the design and state variables of the sys-
tem may be defined, and it may then be the objective
of the designer to maximize, minimize or otherwise
optimize this function as part of the design procedure.
The remainder of this article is concerned only
with this Case III.

Having determined the number of degrees of free-
dom in a given design problem, the next step is to
determine: 1) which of the problem variables are to be
selected as design variables, and 2) the order in which
the system equations are to be solved. Often, one or
more of the problem variables have their values dic-
tated by the environment, e.g., available cooling
water temperature, size of an available piece of equip-
ment, etc. This per force elevation of some problem
variables to design variables obviously reduces the de-


grees of freedom remaining to the designer. It will be
assumed here that the number of these remaining de-
grees of freedom is still non-negative. The objective
of the second task is to determine a calculation prece-
dence order which eliminates or at least minimizes the
need for simultaneous solution of two or more equa-
tions. Ideally, we would like a calculation precedence
order in which equations are solved in sequential
order, one at a time, with no recourse to iterative
For these purposes we first construct a structural
array or table representing the presence of the prob-
lem variables in the design relationships, using the
methods presented in Rudd and Watson [3]. The col-
umns of this array correspond to the problem vari-
ables, and the rows correspond to the design relation-
ships. The presence of a variable in a given relation-
ship is represented by some symbol, e.g., x, in the
appropriate location of this array. The actual nature
of this symbol is arbitrary; it could just as well be a
one or a dot or a T, denoting true. That is, this symbol
denotes that it is true that a certain variable appears
in a given relationship; the absence of such a symbol
or a blank denotes the absence of that variable in the
relationship. Thus, this array is Boolean or logical in
nature; graph theory tools associated with Boolean
logic will be used in the processing of this array to
determine the preferred design variables and the cal-
culation precedence order.
This procedure begins by locating a column which
contains only one true symbol, e.g., x, and then delet-
ing that column variable and corresponding row re-
lationship. The physical significance of this action re-
lates to the fact that, since this variable appears in
only one design relationship, its value may be readily
calculated if values of all of the other problem vari-
ables (more specifically, the other ones appearing in
this design relationship) are known. Thus, this vari-
able deleted will not be chosen as a design variable.
Rather, it will be a state variable and, as will be seen
shortly, will be the very last state variable to be com-
The above deletion step is repeated until, hope-
fully, all of the design relationships have been elimi-
nated. At each variable deletion step, the same think-
ing as above (only a single true entry in a given col-
umn) applies to the ability to solve directly for that
variable. The variables in the columns left over after
all of the design relationships have been eliminated
are chosen as the design variables in the system (cor-
responding to the number of degrees of freedom). Of
course, if the original number of degrees of freedom
was equal to zero, then there would be no columns left
over either. In any event, the calculation precedence

order in which the design relationships are to be
solved is the reverse of the order in which these re-
lationships were deleted. That is, given values for all
of the design variables, the first state variable is com-
puted from the last design relationship eliminated, the
second state variable from the second last, and so on.
What happens if this selection algorithm fails?
That is, at some point in the algorithm, a situation is
reached wherein there is no column with only a single
true entry. Recall that multiple true entries in the
same column correspond to the simultaneous appear-
ance of that column variable in two or more design
relationships. In this situation, a calculation recycle
loop has been detected, and this means that some of
the design relationships will have to be solved simul-
taneously. A method for handling this situation is dis-
cussed in Example 3 below.
Before proceeding to the examples, however, let
us summarize some useful rules of thumb in the im-
plementation of this algorithm. These are
1. If a variable can assume only a finite number of discrete
values (e.g., number of reactors in parallel, type of heat
exchanger, column packing size, etc), then that variable
should be first elevated to the role of a design variable
before proceeding with the algorithm. Otherwise, if it
serves as a state variable, the value computed for it will
rarely match one of the discrete values it can assume.
2. If two or more variables are initially chosen as design
variables from environmental considerations, care must
be taken to ensure that no design relationships have been
inadvertently destroyed. Thus, if in a given relationship
only two variables appear, selection of these two variables
as design variables destroys that relationship, thus creat-
ing one additional degree of freedom. This comment re-
mains valid even if the values of these design variables
were to satisfy the affected relationship, since the latter
was probably consciously or unconsciously employed in
the assignment of values. This point is returned to in
Example 2 below.
3. During implementation of this procedure, as many true
values as possible should be eliminated at each deletion
step. One will often have a choice at each step as to which
column variable is to be deleted (there will be more than
one column with only a single true entry). In this case,
that column should be deleted which results in the
maximum amount of true entries eliminated in the corres-
ponding row relationship deleted. Adherence to this pol-
icy will generally promote success of this algorithm,
thereby preventing the need to solve two or more re-
lationships simultaneously.
4. Implicit solutions for state variables should be minimized.
That is, if one again has a choice at any step in the deletion
of column variables, the corresponding row relationships
should be checked to see that the column variable is not
implicitly defined therein. Thus, even a simple relation-
ship such as z + ez = 10 represents an implicit definition
for z, and trial-and-error methods would have to be em-
ployed to solve for z. In summary, explicit relationships
(solvable in straightforward fashion) should usually be
chosen over implicit relationships for deletion.


EXAMPLE 1. Two Heat Exchangers in Series
As a first simple example of application of this de-
sign variable selection algorithm, consider the scheme
of two heat exchangers in series, as shown in Figure
2. A hot process stream with a constant mass flow
rate of mh, constant heat capacity of Ch and a temper-
ature of tho enters the first heat exchanger, where it
is contacted with a first cold stream entering with a
constant mass flow rate of mi, constant heat capacity
of cl, and a temperature of tio; this cold stream leaves
the first heat exchanger at a temperature of tif. The
hot stream exits the first heat exchanger at a temper-
ature of ti, enters the second heat exchanger at the
same temperature, and exits this latter exchanger at
a temperature of thf. The second cold stream to this
exchanger enters with a constant mass flow rate of
m2, a constant heat capacity of c2, and a temperature
of t2o, and leaves at a temperature of t2f. The types of
the two heat exchangers (e.g., finned tube, double-
pipe, etc) are as yet undefined, and are denoted by
the discrete variables K, and K2, respectively.
The design relationships postulated for this system
are summarized below

QI = mhch(tho thi)

Q1 = mlc(tlf t10)

Q, = U1AAt

U, = Ul(mhtho thi' mIt 0t lfK1)

At (t hi 10) (tho tlf)
AtI =
1 thi t10
Lil t- f
tho tlf

2 = mhh(thi thf)

Q2 = m2c2(t2f t20)

2= U2A2At2

U2 = U2(mh thi thf m2't20 t2fK2)

(thf t20) (thi t2f)
At =
Sthf t20
n thi t

Eqs. (7) and (8) represent the heat balance equa-
tions for the first heat exchanger; Eqs. (12) and (13)
do the same thing for the second heat exchanger.
Similarly, the heat transfer relationships for the first

m1 t2f m2
c1 c2

FIGURE 2. Two heat exchangers in series

and second heat exchangers are given by Eqs. (9)-(11)
and (14)-(16), respectively. The total number of design
relationships (N) is thus equal to ten. Note that the
design relationships for the two heat transfer coeffi-
cients-U1 and U2, Eqs. (10) and (15)-are very gen-
eral in nature. They conceivably could be of tabular
or graphical form, and not necessarily analytical equa-
The total number of problem variables (N) is equal
to 20

Q1 Q2 h tho thi

tIf to m1 U1 A1
At1 K1 hf 2 t2f

t 20 2 A2 At2 K2

We thus have 20 10 = 10 degrees of freedom
(10) initially. Note that we have included the two heat
transfer areas (A1, A2) as problem variables, but not
(11) the three heat capacities, which are treated as con-
stants. These latter could conceivably be defined as
some functions of the corresponding fluid's terminal
temperatures. But since we would thereby be adding
(12) four new variables and four new relationships, the
number of degrees of freedom would remain un-
(13) changed at 10.
Suppose now that we assume that the following
(14) five variables



mh tho thf 10 t20

are fixed by the environment. The first three of these
obviously specify the overall duty or job to be per-
formed. The last two specifications could conceivably
be related to coolant fluids temperature constraints.
At this point then, there remain five degrees of free-
dom. In line with Rule 1 above, we now choose to
elect the two discrete variables K, and K2 as design
variables, leaving three degrees of freedom. We then


At,I m, t, U, A, I At,

() x x X
(8) x Ixx
(9) X X X X
(1) XXXX x
(11) XX x X
(12) xx
(13) x xx
(14)- *--- --
(16) X X X X

Step 1. Deletion of A2 and Eqn. (14)


Eqn Q, I2 I tH tf I m, U, A, At, m2 t2, W2
(8) x xx
(9)X xxx
(10) xxxx
(11) X X X
(12) xx
(13) X XX
(16) -- -------. (-

Step 3. Deletion of At2 and Eqn. (16)


Eani Q, I Qi t1 I t. It m



8 Xl Ix l IXIX I
8)lx I XIXIx

51XI I 'X

Step 5. Deletion of Q2 and Eqn. (12)


SQe It. If. mt ndq(l
(f) Xl X I -1 -

Step 8. Deletion of AtI and Eqn. (11)

Step 6. Deletion of A1 and Eqn. (9)


()Step 9. Deletion of t and Eqn. (8)
Step 9. Deletion of Alf and Eqn. (8)

Eqr Q, t tn m, U, At m,
(X x

(1u) X X X

Step 7. Deletion of U1 andEqn.(10)


Step 10. Deletion of Q1 and Eqn.(7)

I Variables left over to be elected as design variables are: thi, n, m2

FIGURE 3. Application of the design variable selection algorithm to the two heat exchanger problem


1 U, A I


Qa t. 2 t, mU UI A, At1 m21 t2 U, At2
(8) X XX
(9) X XXX
(10) XXXX
(11) XX X
(12) X X

(13) X X X
(15) I
(16) X X

Step 2. Deletion of U2 and Eqn. (15)


(8) x x
(9) x x xX
(10) X X X X
(11) X x x
(12) XX

Step 4. Deletion of t2f and Eqn. (13)

wish to determine which three of the remaining thir-
teen problem variables should be elected as design
variables, so that the ten design relationships can be
solved sequentially.
The application of the design variable selection al-
gorithm to this problem is illustrated in Figure 3.
From Figure 3, the first variable eliminated is A2,
along with Eq. (14); alternately, the variable A1 could
have been eliminated first, along with Eq. (9). With
our original choice, A2 will certainly not be chosen as
a design variable, but rather will be the last state
variable to be computed. The next variable deleted is
U2, along with Eq. (15) and so on. The sequence of
deletion steps is summarized in Table 1. Note here, in

Summary of Deletion Steps for the Two Heat Exchanger
Step Variable Equation
No. Eliminated Eliminated
1 A2 (14)
2 U2 (15)
3 Atz (16)
4 t2f (13)
5 Q2 (12)
6 A, (9)
7 U, (10)
8 At, (11)
9 tlf (8)
10 Q1 (7)
Variables remaining to be elevated to design variables are: thi mi,

accordance with Rule 4 above, that one would not
want to have to calculate any of the fluid temperatures
from the two expressions for the log mean tempera-
ture differences-Eqs. (11) and (16). The algorithm is
successful in this case, and terminates with the col-
umns corresponding to thi, m1 and m2 undeleted.
Thus, this set of three variables (which is not neces-
sarily unique) can be chosen to satisfy the remaining
three degrees of freedom and construct a calculation
precedence order in which each of the ten design re-
lationships is solved in sequential fashion.
As indicated earlier, the calculation precedence
order is formed as the reverse of the deletion se-
quence, i.e., by reading Table 1 from bottom to top.
Thus, with given values of the environmentally
specified variables (mh, tho, thf, t10 t0o), the preferred
discrete design variables (K1, K2) and the above-de-
termined design variables (thi, ml, m2), the first state
variable computed is Q1 from Eq. (7). Next, tf is com-
puted from Eq. (8). The calculations proceed until the
last state variable, A2, is computed from Eq. (14).

EXAMPLE 2. Isothermal Binary VLE
As a second example of this procedure, consider
the problem of an isothermal binary vapor-liquid
equilibrium (VLE) calculation. We will assume here
that the liquid phase is non-ideal and can be rep-
resented by activity coefficient expressions, and that
the vapor phase is ideal. Hence, there will be no
vapor-phase fugacity coefficients entering into the de-
sign relationships and, correspondingly, no expres-
sions for these coefficients.
The ten design relationships for this problem are
as follows
x1 +2 = 1 (17)

S= p + P2

P1 = Plo(t)

20 = P20(t)

YI = Yl(X1,X2't)

Y2 = Y2(X1X2't)

P, = yX1 P1

P2 = Y22P20

Y, = Pl/

Y2 =P2 /1



Note here that Eqs. (19) and (20) above are general
expressions for the pure component vapor pressures
(P1 and P20) as functions of the temperature (t). These
could be Antoine equations or vapor pressure curves,
for example. Similarly, Eqs. (21) and (22) are general
expressions for the liquid-phase activity coefficients
(-Y and Y2) as functions of the liquid-phase mole frac-
tions (xl and x2) and system temperature. Again,
these expressions could be represented by Wilson,
Van Laar, UNIFAC or other similar equations.
The 12 variables of this problem are summarized

P10 P20 Y1 Y2

t n p, p2

We thus have 12 10 = 2 degrees of freedom in
this problem. Let us suppose that we choose to elect
Continued on page 154.


eMI laboratory



University of Delaware
Newark, DE 19716

U NDERGRADUATE AND graduate students in
chemical engineering are generally poorly
trained in laboratory safety and housekeeping. Or-
ganized safety efforts are usually initiated only after
a serious accident or after a potentially serious near-
miss occurs. Fortunately, no serious accident has oc-
curred in the department of chemical engineering at
the University of Delaware. However, several years
ago we realized that the state of our laboratories with
regard to safety was poor. Problems included large
quantities of compressed gas (including hydrogen) in
our building, a lack of safety and rescue equipment, a
lack of alarm systems, insufficient training of person-
nel, and a general ignorance of safe laboratory proce-
dures and housekeeping.

As a result of a special concern about compressed
gas handling, in February of 1979, Harry Dorsman,
an industrial safety expert with the E. I. du Pont de
Nemours Company, was invited to evaluate our safety
needs in this area. He was accompanied on his labora-
tory inspection tour by several chemical engineering
faculty and by the department laboratory coordinator;
this group became the nucleus of the present day de-
partmental safety committee. Although the inspection
and report focused on compressed gas safety, Mr.
Dorsman also noted a vast number of problems with
laboratory housekeeping, solvent storage, inadequate

The compressed gas summary and the
laboratory inspection notes were issued as the
first safety report. A follow-up inspection occurred
later, and a second safety report, prefaced by a
statement . requiring all laboratory personnel to
upgrade noncompliance areas, was issued.

Copyright ChE Division ASEE 1986

George Whitmyre received his BS in Zoology from Penn State in
1967 and his MS in Entomology and Applied Ecology from the Univer-
sity of Delaware in 1973. He is the Chemical Engineering Laboratory
Coordinator at the University of Delaware and is a lecturer in labora-
tory safety topics at the National Safety Council Safety Training Insti-
tute. (L)
Stanley 1. Sandier is the H.B. du Pont Professor and Chairman of
chemical engineering at the University of Delaware. He is the author
of approximately 100 papers, several books, and is a consultant to oil
and chemical companies. He received his BChE degree at the City
College of New York and his PhD at the University of Minnesota. Re-
cently he has received the Professional Progress Award of the AIChE
(1984) and a fellowship from the Alexander von Humboldt Stiftung
(Bonn, 1981). (R)

personal protective equipment, electrical safety, fume
hood use, and a lack of emergency preparedness. As
a result of this examination, it was clear that safety
awareness should become a high priority in all our
laboratories, and that all faculty, students and staff
should be committed to laboratory safety.
The compressed gas summary and the laboratory
inspection notes were issued by the department chair-
man as the first safety report. A follow-up inspection
occurred later, and a second safety report, prefaced
by a statement from the chairman requiring all labora-
tory personnel to upgrade noncompliance areas, was
issued. As will be discussed shortly, safety inspections
and reports now occur on a regular basis. Also, exper-
iments, and even whole laboratories, have been shut
down for various periods of time by the safety coor-
dinator and the department chairman because of seri-


ous safety problems or repeated noncompliance.
The departmental Safety Committee now includes
faculty, graduate students and staff. Membership ro-
tates yearly in order to involve many different people.
The Safety Committee organizes safety training pro-
grams, establishes departmental safety rules,
evaluates university policy, recommends safety equip-
ment purchases and, three times a year, conducts
safety audits followed by a written report. The de-
partment also maintains a safety reference library
which is useful in preparing process hazard reviews
described below, and in checking laboratory toxicity
and chemical reactivity hazards. A number of key
references appear in Table 1. Several of these publica-
tions provide guidelines for performing laboratory
safety inspections, checklists of common safety
hazards, and ratings of the potential severity of such
The departmental safety inspections include all
laboratories and support service areas including a sol-
vent storage building, a remote compressed gas stor-
age building, a gas cylinder loading dock and storage,
machine shop, storeroom, undergraduate laboratories
and classrooms, and offices. Ideally, the users and fac-
ulty of each laboratory should be present when an
inspection is being made. All safety hazards are
explained in detail. At the time of inspection, a com-
mitment from the users to resolve all safety hazards
is the best assurance that corrective action will be
taken. Also, previous reports are used during each
inspection to identify unresolved safety problems. The
inspection report with a summary memo is given to

Key References in Departmental Safety Library

L. Bretherick, Handbook of Reactive Chemical Hazards, 3rd
Ed., Butterworths, 1985.
Compressed Gas Association, Handbook of Compressed Gases,
Van Nostrand Reinhold Co., 1981, 2nd Ed.
Hoffman, J. M. & D. C. Master, (ed), "Chemical Process Hazard
Review," ACS Symposium Series 274, American Chemical So-
ciety, 1985.
Marc J. LeFevre, First Aid Manual for Chemical Accidents,
Academic Press, 1980.
National Research Council, Committee on Hazardous Substance
in the Laboratory, "Prudent Practices for Handling Hazard-
ous Chemicals in Laboratories," National Academy Press,
Washington, D.C., 1981.
N. Irving Sax, Dangerous Properties of Industrial Materials,
6th Ed., Van Nostrand Reinhold Co., 1984.
Norman V. Steere (ed), R & D Laboratory Safety Manual, Na-
tional Safety Council, Chicago, IL.
George Whitmyre (ed), "Laboratory Safety Manual," University
of Delaware, Chemical Engineering Department, Newark,
DE, 19716.

To emphasize the importance of safe
laboratory operating procedure, at the beginning
of each academic year a mandatory safety orientation
program is given for all new graduate students, staff,
postdoctoral fellows and visiting scholars.

Contents of Safety Manual

Chapter 1 General Safety Principles and Regulations.
Chapter 2 Assembly and Use of Apparatus.
Chapter 3 Handling and Storage of Chemicals and Solvents.
Chapter 4 Compressed Gases and Gas Regulators; Regulator
Inspection; Hydrogen Shed Entry Procedures.
Chapter 5 Safety in the Machine Shop.
Appendix 1 Eye Protection.
Appendix 2 Solvent Disposal Stations; Broken Glass Contain-
Appendix 3 References.
Appendix 4 Certification form, to be signed by individual and
included in personnel file, that the Department
Safety Manual has been read and understood.

the department chairman, who distributes copies to
the departmental community. These reports identify
specific problems and sometimes specify a time limit
for the correction of safety flaws or poor housekeep-
ing. Inspection teams recheck problem laboratories as
needed, and sometimes recommend strict action to the
department chairman.
The Safety Committee also reviews proposed
changes in university safety policy and develops the
departmental safety policy which, after approval by
the faculty, is incorporated into the departmental
safety manual. This safety manual, which is updated
each year, provides the basic structure for the safe
operations of our laboratories. This manual, the con-
tents of which are shown in Table 2, contains basic
university and department policies, and other safety
information. All laboratory users must attest in writ-
ing that they have read and understood this manual,
as well as had all their safety questions answered.
Additional accountability is mandated by the State of
Delaware's "right-to-know" law which requires
"generic" toxicity training to be supplemented by a
documented safety discussion of specific laboratory
operations, hazards and control details between each
graduate student and his advisor.

Our initial safety actions resulted from recommen-
dations in the original safety report, and involved both
procedural and structural changes. The first and im-


mediate action was to emphasize the importance of
adequate eye protection by requiring all laboratory
users and visitors to wear industrial safety glasses
with side shields. This minimum level of eye protec-
tion is upgraded when, for example, a splash hazard
requires chemical splash goggles or a face shield. An
eye protection policy is a good starting point for any
safety program because of its importance and because
compliance can be easily checked and enforced.
Further, it is a constant reminder that a safety policy
is in force. Also, depending on the materials being
used, neoprene gloves or other special safety equip-
ment may be required as a result of a safety hazard
review, which is discussed later.
Next, a remote gas storage building for flammable
and toxic gases was built and a distribution network
of 1/4" stainless steel, all-welded tubing with electron-
ically controlled shut-off solenoids was installed. Our
loading dock was enlarged and equipped with a fire-
wall, roof, lighting, clearly marked gas storage bays
and a gas cylinder cart ramp.
These two items represented the largest expendi-
tures in our safety program. Most of the costs were
borne by the administration of the University of Dela-
ware; a recognition of the institutional importance of
laboratory safety.
Also, custom computer inventory software was de-
veloped which, together with a user tag and serial
number tracking system, provides us with on-line in-
ventory control. Thus, the location of all hazardous
gases is known at all times. (Incidentally, this pro-
gram also prints a list of delinquent cylinders by user
group or location, which has been helpful in reducing
cylinder charges.)
Routine safety training was regularly scheduled
and now continues, and volunteer emergency action
personnel in the department (at any time approxi-
mately twenty faculty, staff and graduate students)
are trained in cardiopulmonary resuscitation, indus-
trial first-aid, and the use of 30-minute air-packs.
Emergency eyewash stations have been installed
throughout our laboratories and freon warning horns
have been attached to all safety showers. Carbon
monoxide and hydrogen detectors have been installed
in all laboratories in which these gases are used, and
in the remote gas storage facility. These detectors dis-
play a local audio-visual warning in the event of a leak.
When 25% of the lower explosive limit of hydrogen
(1% in air) or half the STEL of CO (200 ppm) is ex-
ceeded, the alarm state is reached. This activates the
building evacuation alarm, notifies the county fire
board, and, by electronically controlled solenoids men-
tioned earlier, stops all gas flow into the building from
the remote gas storage facility.

To emphasize the importance of safe laboratory
operating procedure, at the beginning of each
academic year a mandatory safety orientation pro-
gram is given for all new graduate students, staff,
postdoctoral fellows and visiting scholars. Topics in
this intensive two-day six-hour course, shown in Table
3, include "right-to-know" training, departmental
safety philosophy and practice, toxicology, use of fume
hoods, use of personal protective equipment, waste
disposal, safety procedures when using electricity and
compressed gases, emergency action, first aid, fire
safety including hands-on fire extinguisher training,
and emergency medical assistance. We emphasize,

Graduate Student and Staff Laboratory Safety Program
(All lectures given by departmental staff except those noted by *
which are given by Safety Division of the university.)
Day 1 General Safety Procedures
Your Right-to-Know Chemical Hazards
General Laboratory Safety
Handling Chemicals*
Personal Protective Equipment
Using the Laboratory Fume Hood*
Hazardous Waste*
Day 2 Glassware Safety Videotape
Compressed Gas Safety
Electrical Safety
Industrial Safety and First Aid*
Fire Safety and Fire Extinguisher Training*

during this safety course, that a graduate is more
likely to find employment if he has an unblemished
safety record, including documented safety training.
Further, students are encouraged to consider job
safety programs and employee safety involvement of
potential future employers.
Also, junior and senior undergraduate students in
the department receive a safety orientation lecture,
including philosophy and practice, and "right-to-
know" training at their first laboratory class meet-
ings. The contents of this lecture are given in Table
4. During the year, individual safety orientation is
provided, and specialized courses are given in the op-
eration of self-contained breathing apparatus, car-
diopulmonary resuscitation (CPR), cryogenic safety,
use of x-ray equipment, industrial first aid, and
machine shop safety.
Continual reminders of the importance of labora-
tory safety, as well as new safety information, is pro-


vided by safety bulletin boards on each floor of our
building. Also, we maintain a safety equipment dis-
play, and signs on the entrance doors to laboratory
blocks remind both departmental staff and visitors
that eye protection is required. Other safety posters
and placards also help to maintain a state of safety
awareness in our laboratories. Finally, lists of
emergency action personnel (i.e., those trained in
CPR and first aid) are posted by emergency tele-
phones on each floor, as well as being distributed to
all faculty and staff.
Also of great importance is the fact that all new
experimental equipment must undergo a hazard re-
view, which is modeled after industrial hazard evalua-
tion systems. A hazard checksheet, designed to re-
view new equipment plans and procedures as well as
providing an itemized list of mechanical, electrical,
chemical, compressed gas, and emergency safety fac-
tors, is used. Another worksheet, the failure mode
effect list, is used to determine how "worst case" com-
ponent failures effect other components. As a result
of this program, safety is built into all new equipment.
Also, information on the users, their university and
home telephone numbers, and shutdown procedures
are posted on each major piece of equipment in our

From our experience it is clear that the most vital
aspect of an ongoing safety program is the commit-
ment and complete support of the faculty. Also, the
Safety Committee Chairman and the faculty need to
continually push forward in improving laboratory
operating procedures, upgrading safety programs,
and both inspiring and demanding a serious safety at-
titude and awareness among all personnel. This is best
accomplished by setting an example and by requiring
the immediate correction of any and all safety flaws

Undergraduate Safety Orientation Program

1. Rationale for learning safe work habits in the laboratory.
2. Right-to-Know Law. (Access to hazardous chemical infor-
mation, work place chemical list, labelling information,
right to report Right-to-Know violations without retribu-
3. Protective equipment.
4. Review of special protection and handling requirements for
hazardous materials in each laboratory experiment.
5. Review of non-chemical hazards in each experiment.
6. First Aid and Emergency Procedures. (First aid, fires, spills
and broken glass, use of location of first aid kits, emergency
showers, eyewashers and emergency exits. Calling for help.)

which are found. All (especially the safety committee)
need to become proficient in recognizing potential
safety flaws before they become serious problems.
Also, departmental safety rules need to be applied
realistically and, most importantly, firmly and uni-
Laboratory safety is in everyone's best interest.
This must be realized by all those who enter
laboratories. The rewards of avoiding serious acci-
dents and/or injuries are immeasurable and greatly
outweigh the minor inconveniences of a safety pro-
(Note: A copy of the Safety Manual of the Depart-
ment of Chemical Engineering at the University of
Delaware and the Hazard Review Checksheet are av-
ailable on request from the authors.) [

books received

Chemistry and Biochemistry of the Amino Acids, Edited by G. C.
Barrett; Chapman & Hall, 29 West 35th St., New York 10001; 684
pages, $99 (1985)
Recent Advances in the Engineering Analysis of Chemically React-
ing Systems, Edited by L. K. Doraiswamy; Halsted Press, John
Wiley & Sons, NY 10158; 611 pages, $49.95 (1984)
Lubricants and Related Products, Dieter Klamann; Verlay Chemie
International, Deerfield Beach, FL 33441-1705; 489 pages, $43.60
Enzyme Chemistry, Impact and Applications, Edited by Colin J.
Suckling; Chapman & Hall, 29 West 35th St., New York, NY 10001;
255 pages, $36.00 (1984)
Chemistry of Pyrotechnics: Basic Principles and Theory, John A.
Conkling; Marcel Dekker, 270 Madison Ave., New York, NY 10016;
190 pages, $49.75 (1985)
Organic Reactions, Vol. 34, Edited by A. S. Kende, et al; John
Wiley & Sons, Inc., Somerset, NJ 08873; 412 pages, $49.95 (1985)
Nitric Acid and Fertilizer Nitrates, Edited by Cornelius Keleti;
Marcel Dekker, 270 Madison Ave., New York, NY 10016; 378
pages, $95.00 (1985)
Sixth Symposium on Biotechnology for Fuels and Chemicals,
Charles D. Scott, Editor; John Wiley & Sons, Inc., Somerset, NJ
08873; 697 pages, $74.95 (1985)
The Organic Chem Lab Survival Manual: A Students' Guide to
Techniques, James W. Zubrick; John Wiley & Sons, Inc., Somerset,
NJ 08873; 244 pages (1985)
Flame and Combustion, Second edition, J. A. Barnard and J. N.
Bradley: Chapman & Hall, 29 W. 35th St., New York, NY 10001;
308 pages, $55 cloth, $27 paper (1985)
Chemistry of Hydrocarbon Combustion, D. J. Hucknall; Chapman
& Hall, 29 West 35th St., New York, NY 10001; 415 pages, $85.00
Surface Coatings, Vol. 2-Paints and Their Applications, Oil and
Colour Chemists' Assn. of Australia; Chapman & Hall, 29 W. 35th
St., New York, NY 10001; 899 pages, $65.00 (1985)



4M -0 classroom I



Ben-Gurion University of the Negev
Beer-Sheva 84110, Israel

THE GRADUATE CHEMICAL engineer entering the
chemical industry finds a system speaking a lan-
guage which usually is partially unknown to him. He
has probably heard many of the terms, but their
meaning may be unclear or wrongly understood since
he never learned the terms formally. The language
will dominate his world and he will eventually learn it
"by ear," but his command of it would be faster and
better if he had previous exposure to the terminology.
Some of the subjects met in the course described in
this paper may be in their own right full courses at a
department of industrial administration; this should
not preclude teaching them, however briefly, both for
acquaintance and awareness.
At first sight it may appear that the subjects are
unrelated; however, they will be tied together as the
course advances. This is due to the unity of purpose
of chemical enterprises and the underlying economic
goals of such organizations.

Jacob Zabicky graduated as chemist (1956, National University of
Mexico), Ph.D. (1960, Hebrew University of Jerusalem), and chemical
engineer (1983, Ben-Gurion University of the Negev). He has carried
out teaching assignments on various chemistry and chemical engineer-
ing subjects in Great Britain, Venezuela and Israel. He has edited
various books on organic functional groups and the organic chemical
tables of the Chemical Rubber Handbook. His research interests are in
industrial chemistry and the chemistry and processing of oil shales and
coal. He is also involved in various industrial development projects.

Fourth year chemical engineering undergraduates
are preferred for their maturity. However, due to our
general curricular structure, third year students are
not discouraged from taking the course. Chemistry
undergraduates have occasionally attended.

The course is given in one semester of 3 one-hour
sessions per week. Originally it was a two semester
course at 2 hours per week, but a curricular reform
changed this.

One examination has to be passed at mid-term on
the Law of Patents. When the course was given on a
two semester schedule, an examination was also taken
on the principles of quality control. The grade on the
examination is 40% of the final mark. Every semester,
four to six papers are written on various assignments,
and their average mark is 60% of the semester grade
(which is the academic unit).

The structure of the course is shown in Table 1.
Due to the need for exercises, the unit on sources of
information is presented first, and the reading of the
Law of Patents and its ancillary papers is assigned
from the beginning. A brief description of the contents
of each unit follows.

The Productive Organization The functions and
objectives of the various managerial levels and organic
sections of productive organizations are described and
rationalized. Special emphasis is given to the chemical
plant, its physical, social, and legal environment. Also
closely seen are related sections of the organization
such as research, development, engineering, market-

0 Copyright ChE Div2sion ASEE 1986


ing, etc. In the two semester course the decision levels
were also examined. Some subjects are discussed in
the classroom as they are brought up by the lecturer
or, frequently, by students with some industrial ex-
Characteristics of the Chemical Industry Raw
materials and their derivative chain, and industries
with a chemical character, are reviewed. The chemical
industry, with few exceptions, is viewed as a supplier
of agricultural and industrial intermediates and not of
consumer or investment products.
Sources of Information The main pertinent for-
mal sources of information are reviewed and exer-
cised. These include technical encyclopedias, Chemi-
cal Abstracts (CA), Science Citation Index (SCI), and
various collections of chemical and technological infor-
mation. Acquaintance is made with Chemical Market-
ing Reporter (CMR), Chemical Economics Handbook
(CEH), import-export statistical reports, industrial
directories, "Who's Who," and company reports. The
importance of reading advertisements is stressed. An
on-line demonstration session of information retrieval
is performed on a selected subject, showing the vari-

. the student is assigned an industrial
chemical (or proposes one himself) and carries
out a search starting with encyclopedias, following
the subject through CA, SCI, CMR, CEH
statistical reports, and answering some
general leading questions.

ous files and the power of the method.
Exercises are as follows: the student is assigned
an industrial chemical (or proposes one himself) and
carries out a search starting with encyclopedias, fol-
lowing the subject through CA, SCI, CMR, CEH
statistical reports, and answering some general lead-
ing questions. The various sections of CMR are
examined. Care should be taken in choosing chemical
products that are neither overloaded with informa-
tion, as the student will sink for hours in a vast sea of
titles, or underloaded with it which leads to frustrat-
ing hours of search. Fortunately, the list of good prod-
ucts is ample.
Industrial Intelligence Emphasis is placed on
the importance of information inflow, contacts with

Course Outline


1. The productive organization
a) General structure
b) Chemical plant and closely
related sections
c) Discussion
d) Levels of decision'
2. Characteristics of the chemical
a) Classification of materials and
b) Survey of chemically oriented
manufacturing industries
3. Sources of information
a) Opening remarks. Explanation of
the 1st assignment
b) Library sources

c) Informal sources
d) On-line retrieval demonstration
4. Industrial intelligence
a) Historical notes
b) Industrial intelligence as source
of information
c) Industrial espionage and how

Oblig. Opt.


1 13


to defend against it
1 d) Discussion
5. Research and development
1 b a) Definitions and decision making
b) Historical background
1 c 6. The Law of Patents
a) Patents and patentability
b) Limitations of patents
c) Discussion
2 d) Examination
7. Technology transfer
3-7 8. Principles of quality control
a) The general concepts of quality
and control
b) Quality in industry and
La,5, specifications
10,11 c) Production line and analytical
11 laboratory relations
d) Pitfalls in analysis
e) Standards and standard
12 organizations
f) Contracts for chemical sales
12 g) Statistical principles
h) Examination'

aAcademic hours. Time schedules are elastic.
bReading material is based on availability in our main Library. This may be easily adapted to local needs and tastes.
'Given only on the two semester schedule.
dThis subject is the first to be presented, although it belongs logically here.


Oblig. Opt.

2 13,14 12

2 15
3 17a

4b,18 17b,19,20
4b,18 20



the "outer" world, the role of the sales department,
some "bleak" aspects of industrial intelligence and
what to do about it. The student carries out readings
on the subject and responds to a questionnaire.
Research and Development Formal definitions,
assessment of R&D importance to industry, flow of
information, and decisions on R&D are investigated.
The student carries out some readings on the subject
and a questionnaire is answered afterwards.
Law of Patents What patents are, the require-
ments for patentability, limitations of the state on
rights endowed by patents, patent regulations, and
international agreements on patents are studied.
Some discussions arise from questions by the stu-
dents. The lecturer should be careful in distinguishing
between awareness of the subject and technical exper-
tise in legal matters befitting a patent attorney. The
student reads the Law of Patents and other articles
and is examined on the essentials of the subject.
Technology Transfer The sale of know-how, and
the main clauses of technological transfer agreements
(subjects, ownerships, responsibilities, payments,
procedures) are discussed. The same cautionary note
to the lecturer on patents should apply here relative
to contracts. The student reads a short patent (an
agreement was also read in the two semester course)
and answers a questionnaire requiring some literature
search and some decisions of his own, which also cover
preceding units.
Principles of Quality Control Subjects reviewed
are the "philosophy" of quality, the specifications of a
product, what quality control is, some pitfalls in
analysis, the clash of interests between buyers and
sellers, contracts for the trade of chemicals, and what
standards and standards organization are. In the two
semester course some of the mathematics underlying
sampling and acceptance-rejection decisions was
learned. The student searches and reads Israeli and
U.S. standards on an assigned chemical product and
answers a questionnaire on the subject. In the two
semester course he also solves some mathematical
problems and is examined on the basics of quality con-
trol. O


1. L. J. Garrett and M. Silver, Production Management
Analysis, 2nd ed., Harcourt Brace Jovanovich, Inc., New
York, 1973, a) 1-27; b) 459 ff; c) 28-84.
2. "Chemical Origins and Markets," 5th ed., Stanford Research
Institute, Menlo Park, 1967.
3. "Chemistry in the Economy," American Chemical Society,
Washington, 1973.
4. Kirk-Othmer-Encyclopedia of Chemical Technology, John
Wiley and Sons, New York, 1978-1984, a) 16, 889-945; b) 16,

5. Ullmans Encyklopaedie der technischen Chemie, Verlag
Chemie, Weinheim, 1972-1984.
6. H. A. Wittcoff and B. G. Reuben, Industrial Organic Chemi-
cals in Perspective, Part One: Raw Materials and Manufac-
ture, John Wiley & Sons, New York, 1980, pp. 11-38.
7. R. N. Shreve, J. A. Brink, Jr., and G. T. Austin, Shreve's
Chemical Process Industries, 5th ed., McGraw Hill Book Co.,
New York, 1984.
8. "Chemical Economics Handbook," Stanford Research Insti-
tute, Menlo Park, 1975.
9. Chemical Marketing Reporter, Schnell Publishing Co., New
York, current issues.
10. J. J. McKetta and W. A. Cunningham (Eds.), Encyclopedia of
Chemical Processing and Design, Marcel Dekker, Inc., New
York, 1976.
11. Y. Wolman, Chemical Information: A Practical Guide, John
Wiley and Sons, New York, 1983.
12. P. I. S. Smith, Industrial Intelligence and Espionage, Business
Books, London, 1970.
13. Anonymous, Chem. Eng. 1966, Apr. 25, 143, 148.
14. H. Popper, Chem. Eng. 1966, May 23, 160.
15. D. M. Kiefer, Chem. Eng. News, 1975, Dec. 15, 38.
16. D. Allison, "The R&D Game," M.I.T. Press, Cambridge,
Mass., 1969.
17. The New Encyclopaedia Britannica, Encyclopaedia Britannica,
Inc., Chicago, 1979, a) 18, 21-54; b) 13, 1071-1076.
18. "The Law of Patents 5727-1967," Israel Law No. 510, Re-
shumot, Aug. 17, 1967, pp. 148 ff, The Government Press,
19. E. J. Lawson and E. A. Godula (Eds.), "Patents for Chemical
Inventions," Adv. Chem. Ser. No. 46, American Chemical Soci-
ety, Washington, 1964.
20. Scheer, International Patent, Design and Trade-Mark Law,
H. Scheer Verlag, Efferen/Koeln, 1974.
21. D. E. Brazell, Licensing Check List, Kenneth Mason Publica-
tions Ltd., Emsworth, Hampshire, 1978.
22. J. M. Juran and F. M. Gryna, Jr., Quality Planning and
Analysis, McGraw-Hill, Inc., New York, 1970, pp. a) 1-16, b)
232-248, c) 436-452, d) 191-231, e) 492-517.
23. I. M. Kolthoff, P. J. Elving and E. B. Sandell (Eds.), "Treatise
on Analytical Chemistry," Interscience Encyclopedia, New
York, 1959, Part I, Vol. 1, pp. 19-97.
24. The Standards Institution of Israel, various pamphlets. O

a Ebook reviews


By Mark E. Davis
John Wiley & Sons, Somerset, NJ 08873, $24.95

Reviewed by
Bruce A. Finlayson
University of Washington

Numerical Methods and Modeling for Chemical
Engineers, by Mark E. Davis, provides a useful step
beyond the standard undergraduate curriculum. One


emphasis of the book is to teach chemical engineers
how to use standard codes that are available for solv-
ing problems numerically. The book carefully lists the
possible codes that are available and gives examples
of their use. The use of standard codes is very impor-
tant and this book emphasizes that aspect over
generating a code to solve each problem yourself. The
use of chemical engineering examples in the text and
as problems is the book's strongest point.
The book does have some overall drawbacks that
will limit its usefulness. The presentation of colloca-
tion is clouded by the notation and is needlessly com-
plex. Orthogonal collocation is neglected altogether.
Certainly this is unforgivable, given the widespread
use of orthogonal collocation in chemical engineering.
The Galerkin finite element method is never illus-
trated for a problem where the finite element method
is needed or useful so that the reader is left to wonder
why bother. While the treatment of ordinary differen-
tial equations is quite good, the treatment of partial
differential equations is weak-it is far too limited
with too few details. Some details needed to actually
solve problems are left to the imagination and the
scope of the methods (when they are useful) is not
clear. For example, if one has a problem involving
convection and diffusion and a high Peclet number, no
mention is made of the numerical difficulties that are
in store, or what impact that kind of a problem has on
the choice of methods.
Chapter 1 discusses ordinary differential equations
which are initial value problems. Treated there are
the Euler method, Runge-Kutta methods, explicit and
implicit methods. Stability is shown in detail for the
simple methods and stated for other methods. The
question of stiffness is considered, although the num-
erical criteria for what makes a problem stiff are taken
without attribution from my own book. The discussion
of step size adjustment in the codes is also modeled
after my method applied to the Euler method. Over-
all, the reader is able to apply these methods.
Chapters 2 and 3 treat ordinary differential equa-
tions which are boundary value problems, while Chap-
ters 4 and 5 treat partial differential equations. The
transition from initial value methods in Chapter 1 is
good and relies on shooting methods for solving
boundary value problems.
The presentation of finite differences is a bare
bones treatment with flux boundary conditions han-
dled using only a fictitious point, and never a one-
sided difference (sometimes it is important in more
complicated problems to be able to use a one-sided
difference). The integrated volume technique is pre-
sented and this is a good way to handle derivation of
equations using a variable mesh. There is nothing on

interpolation of the function between grid points, due
to the decision in Chapter 1 to use Taylor series to
present the ODEs rather than interpolation methods.
This limits the user to examining the solution at the
grid points. The presentation of the finite difference
method applied to partial differential equations in one
space and one time dimension is good, including treat-
ment of implicit methods using the trapazoid rule. The
effect of stability is clear only for one case and it is
hard to generalize to other cases. This is one of those
areas where the reader will need to consult other re-
ferences. There are two important things left out: up-
wind differencing and adaptive mesh. Many problems
now being solved include large convection effects
along with diffusion effects. The reader is completely
unaware of the numerical problems in store: how to
solve them and the importance this has on the choice
of method. In my book in 1980, I briefly mentioned
adaptive mesh because it was an important new area.
Much more should have been mentioned in a book pub-
lished in 1984, since the role of adaptive mesh is now
For elliptic problems the solution methods dis-
cussed are iterative: point iterative methods are dis-
cussed in the appendix and alternating direction
methods are discussed in the text. Unfortunately,
they are not tied together and the choice of iteration
parameters is not displayed. Even though equations
are shown for simple boundary conditions with irregu-
lar meshes, there is no discussion of the impact on the
methods of solution, the bookkeeping associated with
them, rates of convergence, or their generalization to
more complicated boundary conditions. All of these
factors are important when comparing the finite dif-
ference with the finite element method.
In the presentation of the collocation method, ten-
sor methods are used over the whole space, thus limit-
ing application to rectangular domains. This is a terri-
ble limitation and newer work by George Pinder al-
lows domains that have straight sides (easy to do) and
also irregular domains. This newer work is ignored
completely. This is another example of changes that
should be made in a book published in 1984 over those
published in 1980. In addition, orthogonal collocation
is ignored despite its widespread use in chemical en-
gineering for reaction-diffusion problems. For bound-
ary value problems there is no reason given for the
use of the Galerkin finite element method and the
chapter ends by saying don't use it. For elliptic equa-
tions only regular domains are treated so that the
power of the finite element method is not realized.
Triangular grids are given which are inappropriate-
there are points ending at the mid-point on the
Continued on page 153.


M book reviews


By D. Ramkrishna and N. Amundson
Prentice-Hall, Inc., Englewood Cliffs, NJ 07632

Reviewed by
Sangtae Kim
University of Wisconsin-Madison

The past two decades have seen great strides in
the mathematical training of chemical engineering
graduate students, with impetus coming from the shift
in the curriculum towards engineering science. Func-
tional analysis, once completely absent from the chem-
ical engineering literature, has become an important
research tool for both analytical and numerical
analyses. This new text provides an introduction to
functional analysis with emphasis on analytical appli-
cations, at a level suitable for those students who have
mastered the introductory engineering math course.
This book was used as a required text in a one-semes-
ter course at the University of Wisconsin and this re-
view is based on that experience.
Most math departments place a course in real
analysis as a prerequisite for functional analysis. The
first two chapters (labeled 0 and 1) of the book take
on the difficult task of condensing the elements of real
analysis into twenty-three pages, which is then fol-
lowed by a chapter on linear spaces, Linear algebra
as described in Chapter 2 is likely to be more abstract
than that encountered in previous courses, but the
approach sets the tone for later materials.
The following concepts are introduced in Chapter
3, "Metric Spaces": the metric, convergence of se-
quences, Cauchy sequences, continuity of functions,
interior points, open and closed sets, limit points, clo-
sure of a set, compact sets, complete metric spaces,
dense sets, etc. For the uninitiated, the information
overload reaches a peak here, and since this portion
of the course generally coincides with drop week,
Chapter 3 represents the greatest challenge to both
instructor and student.
Chapter 4 introduces Lebesgue integration and the
elements of measure theory. This exposition achieves
two results: it introduces an important example of
completion of a metric space (space of Lebesgue in-
tegrable functions vs. Riemann integrable functions),
and it prepares important examples of Banach and
Hilbert spaces that appear in later chapters.

Chapters 5 and 6 cover normed linear spaces and
inner product spaces respectively. This division facili-
tates the presentation of concepts that require only
the norm instead of the full machinery of an inner
product. The natural metric induced by the norm, the
natural norm induced by the inner product, norm of
an operator, compact operators, Banach spaces, Hil-
bert spaces, the Riesz Representation Theorem and
adjoint of an operator are presented in these two chap-
Although an exact demarcation is not possible,
Chapters 0 through 6 may be viewed as preparation
for applications found in later chapters. Chapter 7 fea-
tures a rigorous derivation of the spectral theorem for
both finite and infinite-dimensional Hilbert spaces.
The derivation is essentially complete (back in Chap-
ter 6 the authors chose to omit one step in the deriva-
tion of the projection theorem). Chapter 8 presents
applications in finite-dimensional spaces such as mul-
ticomponent distillation problems.
In Chapters 9 and 10 (ODEs and PDEs respec-
tively), the conversion of self-adjoint differential
operators into integral equations via Green's functions
is discussed in the context of the construction of com-
pact inverses. Here we see the crucial distinction be-
tween a course based on Linear Operator Methods in
Chemical Engineering and the standard graduate
level engineering math course. In the latter, the in-
structor must resort to handwaving arguments when
presenting the advantage of integral equations over
differential equations. In the former, the advantage is
rigorously self-evident. The reviewer was somewhat
disappointed that a discussion on discrete spectra for
infinite-interval problems was omitted in Chapter 9
(Titchmarsh is referenced). Perhaps this could be
added in a later edition. The book ends with an intro-
duction to non-self-adjoint operators and biorthogonal
expansions (Chapter 11).
The authors have included enough material for a
two-semester course, including many thought-provok-
ing exercises. Our one-semester course covered all of
Chapters 1, 2, 3, 5, 6, 7, 9, 10 and 11. This syllabus
was intentionally weighted in favor of foundation over
applications. A more leisurely pace can be set by re-
ducing the emphasis on Chapters 1, 2, and 3. Other
combinations are mentioned in the Preface.
In summary, this book is an excellent introduction
to functional analysis and linear operator theory. The
numerous "Chemical Engineering" applications make
this book especially suitable for self-study. Those with
"mathematical modeling" in their dissertation re-
search should add this book to their personal li-
brary. O


Continued from page 131.
sizes are linked to the fermentor size, it has been
placed first in the list. The rest of the equipment
specifications can be changed by entering the new
specifications for the fermentor.
This type of table permits rapid computation of
equipment costs for different plant capacities or for
different fermentor sizes. For example, part of a de-
sign problem might be to find the optimum reactor
size for a given capacity. The solution could include
calculating equipment costs for several different reac-
tor sizes, scheduling the reactors to plan the down-
time, and determining overall process costs for each
-scenario. The student could then plot discrete solu-
tions of cost versus reactor size to graphically deter-
mine a minimum cost reactor size.


Table 4 shows the manufacturing costs for a
phthalic anhydride process. Key process design fac-
tors (capacity, stream factor, and fixed capital) needed
for computing fixed and variable costs are listed at

Manufacturing Cost Table for a
Phthalic Anhydride Process

Economic Example
Manufacturing Costs: Phthalic Anhydride



Stream Factor
Fixed Capital 1
Depreciable Cap 1
Variable Costs

Raw Materials
O-Xylene, Ibs
SO,, Ibs
Catalyst, Chem.
V205, Ibs
Ht. Trans. Salt, Ibs
Steam Credit, M Ibs
H20, M Gals
BFW Chem.
Electricity, KWH

'500 K Ib/yr
2100 K$
4900 K $

Quantity/ Cost, Cost,
Year $/Yr cts/Ib

15.50 71250000 11043750
6.50 375000 24375





Subtotal, Variable Costs




-235400 -.31
6650 .01
3375 .00
2700000 3.60
2474625 3.30
13689950 18.25

the top. These factors are inputs to cost formulas
throughout the table. This format allows the student
to change the design basis rapidly.
The last column shows the contribution of each
item to the manufacturing cost in cents per pound.
This breakout is helpful for identifying high cost por-
tions of the process and relating them to the selling
price of the product. Listing the cost per unit as well
as the quantity needed per year keeps the format flex-
ible. It is simple to assess the sensitivity of the man-
ufacturing costs to changes in raw material costs,
labor costs, worker productivity and changes in pro-
cess conversion.
We have found spreadsheet computations to be
helpful to both students and instructors in the design
courses. Spreadsheets require organization of the
problem material and generate report-quality tables
and figures. They help accomplish a rapid solution of
the base case and speed analysis of process alterna-


1. W. P. Schmidt and R. S. Upadhye, Chem. Eng., 91 (26), 67-70
2. S. Selk, Chem. Eng., 20(13), 51-53 (1983).
3. E. H. Rasmussen, Chem. Eng., 90(20), 5 (1983).
4. S. M. Goldfarb, Chem. Eng., 92(8), 91-93 (1985).
5. R. Hirschel, Chem. Eng., 92(8), 93-95 (1985).
6. M. S. Peters and K. D. Timmerhaus, Plant Design and
Economics for Chemical Engineers, 3rd Edition, McGraw-Hill,
New York, 1980. O

REVIEW: Numerical Methods
Continued from page 151.

triangle. This is a terrible mesh and is not allowed in
most codes. There is no discussion of natural boundary
conditions which is a very important advantage of the
finite element method for handling derivative bound-
ary conditions, especially in semi-infinite domains
since it reduces the computational costs significantly.
Given this presentation of the finite element method,
the reader will ask why. The book gives no answer
ether than that there are codes that are increasingly
Despite these limitations, this is a reasonable
treatment and is an improvement in the correct direc-
tion. However, the reader will find it necessary to
consult other books to solve any problems that are
significantly harder than those given in the exam-
ples. O


Continued from page 143.
x, and t as our preferred design variables; that is, it
is assumed that values have been assigned to these
two variables. Note that, in accordance with Rule 2
above, one would not want to select x, and x2 as the
design variables for, in so doing, Eq. (17) above would
be destroyed, resulting in an additional degree of free-
dom. Actually, this equation represents a subset of
one relationship and two variables, thus having only
one degree of freedom.
The initial structural array for this problem ap-
pears as is shown in Figure 4. The column-row dele-
tion procedure described above begins with the dele-
tion of variable y2 (or yj) and Eq. (26) [or (25)]. The


EqnJR x I y,

P P -
Pi1 P09 /1


(17) X X
(18) X X X
(19) X X
(2o) X X
(21) X X X X
(22)X X X X
(23) X X X X
(24) X X X X
(26) X X

D Design variables specified by the environment

FIGURE 4. Initial structural array for isothermal VLE

procedure is successful in this case and terminates
with the complete removal of all ten variables and
equations. Thus, this system can be solved sequen-
tially, with no trial-and-error calculations. The calcu-
lation precedence order for this problem, as derived
from the inverse of the deletion steps, is depicted in
Figure 5.

EXAMPLE 3. Isobaric Binary VLE
This last example is a variation of the preceding
Example 2, and illustrates what has to be done when
this algorithm fails to terminate. We choose, in this
case, x, and H as our preferred design variables.
Chemical engineers will readily recognize this prob-
lem as an isobaric bubble-point calculation-a classic
example of a trial-and-error calculation.

Equation Number
Design Variables Specified by the Environment

FIGURE 5. Calculation precedence order for isothermal
VLE problem

The initial structural array for this problem is the
same as in Figure 4, except for the present selection
of x, and I as the preferred design variables. The
algorithm again begins with the deletion of variable
y2 and Eq. (26), followed by the deletion of variable
yI and Eq. (25). At this point, the structural array for
this problem appears as shown in Figure 6 (the col-
umns for the preferred design variables x, and II are
not shown). It is clear from this figure that there are
no columns remaining with only a single true entry
(x), and thus the algorithm cannot proceed.
The situation represented in Figure 6 is that of
persistent recycle, and dictates that trial-and-error
methods must be employed in the solution of this prob-
lem. Rudd and Watson [3] present a simple method
for organizing such trial-and-error calculations, con-
sisting of the following steps
1. Apply the above algorithm and if it fails to terminate with
the deletion of all equations (as in Figure 6), go to Step 2.

Eqn. x, P' P' Y, 1, 9t P, P9
(17) X
(18) _X X
(19) X X
(20) X X
(21) x X x _
(22) x x x
(23) X X X
(24) X X X X

FIGURE 6. Detection of persistent recycle
VLE problem

in the isobaric


2. Define k = min p(zi) -1, where p(zl) is the number of
equations in which the variable zi appears.
3. Identify sets of k equations which have the property that
when the set is deleted there remains an array containing
at least one variable which appears in only one equation.
4. Delete one such equation set.
5. Apply the design variable selection algorithm to the array
which remains.
6. If no precedence order is obtained in Step 5, try another
set of k equations.
7. If the deletion of no set of k equations results in an array
that can be precedence-ordered, increase k by one and
return to Step 3.
Returning to the situation of Figure 6 and applying
Step 2 above, we determine that p(zi) = 4 for the
variables x2 and t, and that is equal to two for each of
the remaining six variables. Thus, k = min p(Zi) -1 =
1, which means that one of the remaining eight equa-
tions is to be temporarily deleted. Specifically, follow-
ing Step 3 above, equations which qualify are Eqs.
(18) through (24). Proceeding to Step 4, let us choose
Eq. (18) to be temporarily deleted or relaxed. This
temporary deletion has the effect of temporarily pro-
viding one more degree of freedom. This, in turn, al-
lows the temporary election of one more problem vari-
able as a design variable. The proper variable to so
elect is determined in Step 5; the algorithm is success-
ful in this case and results in the selection of the tem-
perature (t) as the temporary design variable. Thus,
these calculations are to be performed with initially
assigned values for the two design variables x, and HI,
and some initial estimate for the temporary design
variable t. The calculations are then to be repeated
with successively refined values of t until the relaxed
Eq. (18) is satisfied. This calculation precedence
order, with the recycle calculation loop, is illustrated
in Figure 7. Chemical engineers will again readily rec-

x21- - 2\ 1 2 25

1 t s18
x2 20 po
L -2 2724 2 26 2

L^- --------- ---------------
O Equation Number
O Design Variables Specified by the Environment

,/ Temporarily Selected Design Variable

FIGURE 7. Calculation precedence order for isobaric VLE

ognize this sequence as the customary one in which
they perform bubble-point calculations.


Methods have been presented for 1) determining
the number of degrees of freedom in engineering cal-
culations, 2) identifying information recycle loops in
such calculations, and 3) developing calculation prece-
dence orders to minimize or eliminate such loops.
These methods have been illustrated manually with
several simple examples. For more complex, realistic
systems of engineering calculations, these methods
are easily programmed on a digital computer, particu-
larly in view of the Boolean logic nature of these


1. Christensen, J. H. and D. F. Rudd, "Structuring Design Com-
putations," AIChE J., 15, 94 (1969).
2. Lee, W., W. H. Christensen, and D. F. Rudd, "Design Variable
Selection Algorithm to Simplify Process Calculations," AIChE
J., 12, 1104 (1966).
3. Rudd, D. F. and C. C. Watson, Strategy of Process Engineer-
ing, Wiley, New York, 1968.
4. Soylemez, S. and W. D. Seider, "A New Technique for Prece-
dence-Ordering Chemical Process Equation Sets," AIChE J.,
19, 934 (1973).
5. Steward, D. V., "On an Approach to Techniques for the
Analysis of the Structure of Large Systems of Equations,"
SIAM Review, 4, 321 (1962).
6. Steward, D. V., "Partitioning and Tearing Systems of Equa-
tions," J. SIAM Numer. Anal., Ser. B, 2, 345 (1965). [

Continued from page 123.

is essentially over because changes in the course are
now coming from the students themselves as they
develop new computer packages. Recent contribu-
tions by students are listed in Table 2. There have
been no controlled experiments on the effectiveness
of the course, but with very few exceptions students
have rated the course highly and praise the computer

1. J. E. Bailey and D. F. Ollis "Biochemical Engineering Funda-
mentals (revisited)," Chem. Eng. Education, Fall 1985.
2. H. R. Bungay, Computer Games and Simulation for Biochem-
ical Engineering, Wiley 1985.
3. G. Belfort, "Separations and Recovery Processes," Chem. Eng.
Education, Fall 1985.
4. R. I. Mateles, "JERMFERM, A Fermentation Process De-
velopment Game," Biotechnol. Bioengr. 20: 2011-2014 (1978)


Continued from page 114.

has a Master of Science degree as a goal. We require
twelve courses of each PhD candidate, along with a
research dissertation. Six of these courses are the core
courses taken during the first year: thermodynamics,
reactor analysis, and two semesters each of transport
phenomena and applied mathematics. The latter se-
quence is unusual for its emphasis on theoretical rigor,
but has become a popular feature of our program (see
the Fall 1984 issue of Chemical Engineering Educa-
tion for a description of this sequence). We insist on
this set of courses for all our students, so that they
will be equipped to apply advanced principles from
the entire spectrum of chemical engineering science
regardless of their areas of research specialization.
We also use observations of their approach to and per-
formance in these courses as input into the decision
regarding PhD candidacy, along with results of a com-
prehensive written examination at the end of the first
academic year. Research qualities are judged during
the oral preliminary examination over a dissertation
proposal, sometime after the second year.
In addition to the core courses, we offer a wide
variety of elective graduate courses from year to year.
Within the past couple of years, these have included
the following
Statistical Mechanics (Glandt)
Heterogeneous Catalysis (Gorte)
Nonlinear Analysis in Applied Mathematics (Ungar)
Mass Transfer (Quinn)
Heat Transfer (Churchill)
Analysis of Microbial Systems (Graves and Lauffen-
Analysis of Physiological Systems (Lauffenburger)
SNumerical Methods (Seider)
Polymers (Forsman)
Instrumentation (Graves)
Ionic Materials (Farrington)
A collegial spirit of informal research collaboration
is pervasive here, allowing students to benefit daily
from the perspective of faculty and students from dif-
ferent research groups. For instance, it is common to
see faculty and students participate in group meetings
other than their own. Joint projects are not unusual.
There are also an unexpectedly large number of joint
projects with faculty from other departments, such as
chemistry, biology, materials science, mechanical en-
gineering, and medicine, consistent with Penn's "One
University" concept. All this serves to broaden the
scientific perspective of our students as they learn to
pose and attack novel research problems.
A large measure of the quality of our program can
be seen in the graduate students themselves. We
bring in a class of only about twelve new students

A fundamental understanding of transport proc-
esses is exploited in the generation of new separation

each fall, allowing an exceptional degree of selectivity
for enthusiasm and commitment as well as intellectual
ability. Our departmental graduate student associa-
tion (ChEGA) is an active participant in policy forma-
tion for the graduate program, in addition to sponsor-
ing academic, social, and athletic activities. The
weekly noon-time student research seminars run by
ChEGA are an enjoyable highlight. The students also
play an extremely important part in our continuing
recruitment of new students. Their enthusiasm for our
program is a major reason for our success in attracting
students of the highest caliber.

It is gratifying to see that our efforts to keep the students'
education foremost is resulting in a continuing interest on their
part to educate the chemical engineers of the future. Within the
past five years, our PhD graduates have joined the ranks of
chemical engineering faculty at a number of major institutions.
Among these are included Julio Briano (Puerto Rico), Mark
Burns (Massachusetts), Yee Chiew (Rutgers), Dan Hammer
(Cornell), Patrick McMahon (Wisconsin), Jim O'Brien (Yale),
Lisa Pfefferle (Yale), Janice Phillips (Lehigh), Al Post
(Pittsburgh), George Prokopakis (Columbia), Don Ristroph
(Louisiana State), Carol Steiner (CUNY), Bob Tranquillo (Min-
nesota), and Charles White (West Virginia). We trust that their
experiences here will help them to serve as good models for the
generations of students they will encounter in the future.

To be honest, we simply hope to continue the
course that has led us to our present state: a commit-
ment to excellence, with students the highest priority.
Chemical engineering will continue to evolve, for it is,
in John Quinn's words, "whatever chemical engineers
do." We aim to be in the forefront of doing new and
interesting things, doing them well, and educating
students to carry on that tradition that is Penn Chem-
ical Engineering. D



Departmental Sponsors

The following 157 departments contributed to the support of CEE in 1986 with bulk subscriptions.

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Bucknell University
University of Calgary
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California Institute of Technology
University of California (Berkeley)
University of California (Davis)
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University of California (Santa Barbara)
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Columbia University
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University of Delaware
Drexel University
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Florida State University
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Georgia Institute of Technology
University of Houston
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University of Idaho
University of Illinois (Chicago)
University of Illinois (Urbana)
Illinois Institute of Technology
Institute of Paper Chemistry
University of Iowa
Iowa State University
Johns Hopkins University
University of Kansas
Kansas State University
University of Kentucky

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Lamar University
Laval University
Lehigh University
Loughborough University of Technology
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Manhattan College
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Oregon State University
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University of Pittsburgh
Princeton University

Purdue University
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Rutgers University
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University of Saskatchewan
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West Virginia University
University of Western Ontario
Widener University
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University of Wisconsin (Madison)
Worcester Polytechnic Institute
University of Wyoming
Yale University
Youngstown State University

If your department is not a contributor, write to CHEMICAL ENGINEERING EDUCATION,
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Chemical Engineering -
A new range of
'hands-on' teaching
i meipmt. n.



Yesterday, laboratory teaching rigs had to be large,
expensive and difficult to set up.
Today, smaller scale, easy-to-use, self-contained
cheaper apparatus is available with greater educational
Technovate offers a full range:
*Mass Transfer Reaction Engineering *Unit Operations
Ask us for more details of our equipment
CEK Liquid Mixing CET Tubular Reactor
CEL Fixed & Fluidised Beds CEV Multi-stage Mixer/Settler
CEM Liquid Phase Chemical UOP1 Climbing Film Evaporator
Stirred Tank Reactor UOP2 Double Effect Evaporator
CEN Solids Handling Bench UOP4 Solid-Liquid Extraction
CEP Dynamics of Stirred Tanks UOP5 Liquid-Liquid Extraction
CERa Gaseous Diffusion UOP7 Gas Absorption Column
CERb Liquid Diffusion UOP8 Tray Drier
CES Wetted Wall Column for our full range in Fluid Mechanics

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