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 Front Cover
 Table of Contents
 New Mexico State University
 Richard Heist, of the University...
 Alternative applications and examples...
 Book reviews
 A course in communication skills...
 Letter to the editor
 The World Wide Web for teaching...
 Getting started
 Create a successful summer engineering...
 Development of a powder technology...
 Hazardous waste processing in the...
 A conceptual in the undergraduate...
 Quality in teaching laboratori...
 Book reviews
 Unusual three-phase flash equilibrium...
 Book reviews
 Computing in the undergraduate...
 Calculation of vapor-liquid equilibrium:...
 Back Cover


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Chemical engineering education
http://cee.che.ufl.edu/ ( Journal Site )
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 Material Information
Title: Chemical engineering education
Alternate Title: CEE
Abbreviated Title: Chem. eng. educ.
Physical Description: v. : ill. ; 22-28 cm.
Language: English
Creator: American Society for Engineering Education -- Chemical Engineering Division
Publisher: Chemical Engineering Division, American Society for Engineering Education
Place of Publication: Storrs, Conn
Publication Date: Summer 1995
Frequency: quarterly[1962-]
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Subjects / Keywords: Chemical engineering -- Study and teaching -- Periodicals   ( lcsh )
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serial   ( sobekcm )
 Notes
Citation/Reference: 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-
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Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Table of Contents
        Page 137
    New Mexico State University
        Page 138
        Page 139
        Page 140
        Page 141
        Page 142
        Page 143
    Richard Heist, of the University of Rochester
        Page 144
        Page 145
        Page 146
        Page 147
        Page 148
        Page 149
    Alternative applications and examples in undergraduate thermodynamics
        Page 150
        Page 151
        Page 152
        Page 153
        Page 154
        Page 155
        Page 156
    Book reviews
        Page 157
    A course in communication skills for the corporate environment of the 1990s
        Page 158
        Page 159
        Page 160
    Letter to the editor
        Page 161
    The World Wide Web for teaching chemical engineering
        Page 162
        Page 163
        Page 164
        Page 165
    Getting started
        Page 166
        Page 167
    Create a successful summer engineering project
        Page 168
        Page 169
        Page 170
        Page 171
    Development of a powder technology option at CCNY
        Page 172
        Page 173
        Page 174
        Page 175
        Page 176
        Page 177
    Hazardous waste processing in the chemical engineering curriculum
        Page 178
        Page 179
        Page 180
        Page 181
    A conceptual in the undergraduate ChE curriculum: An integrated approach
        Page 182
        Page 183
        Page 184
        Page 185
    Quality in teaching laboratories
        Page 186
        Page 187
        Page 188
        Page 189
        Page 190
    Book reviews
        Page 191
    Unusual three-phase flash equilibrium problems
        Page 192
        Page 193
        Page 194
        Page 195
        Page 196
    Book reviews
        Page 197
    Computing in the undergraduate ChE curriculum: An integrated approach
        Page 198
        Page 199
        Page 200
        Page 201
        Page 202
        Page 203
    Calculation of vapor-liquid equilibrium: A simplified method
        Page 204
        Page 205
        Page 206
        Page 207
        Page 208
    Back Cover
        Back Cover 1
        Back Cover 2
Full Text





















Richard Heist~U~~ I L LIl















EDITORIAL AND BUSINESS ADDRESS:
Chemical Engineering Education
Department of Chemical Engineering
University of Florida
Gainesville, FL 32611
PHONE and FAX: 904-392-0861
e-mail: cee@che.ufl.edu

EDITOR
Ray W. Fahien
ASSOCIATE EDITOR
T. J. Anderson
CONSULTING EDITOR
Mack Tyner
MANAGING EDITOR
Carole Yocum
PROBLEM EDITORS
James 0. Wilkes and Mark A. Burns
University of Michigan
LEARNING IN INDUSTRY EDITOR
William J. Koros
University of Texas, Austin
-PUBLICATIONS BOARD

CHAIRMAN *
E. Dendy Sloan, Jr.
Colorado School of Mines

PAST CHAIRMEN
Gary Poehlein
Georgia Institute of Technology
Klaus Timmerhaus
University of Colorado

MEMBERS
Anthony T. DiBenedetto
University of Connecticut
Thomas F. Edgar
University of Texas at Austin
Richard M. Felder
North Carolina State University
Bruce A. Finlayson
University of Washington
H. Scott Fogler
University of Michigan
J. David Hellums
Rice University
Angelo J. Perna
New Jersey Institute of Technology
Stanley I Sandler
University of Delaware
Richard C. Seagrave
Iowa State University
M. Sami Selim
Colorado School of Mines
James E. Stice
University of Texas at Austin
Phillip C. Wankat
Purdue University
Donald R. Woods
McMaster University


Summer 1995


Chemical Engineering Education


Volume 29


Number 3


Summer 1995


DEPARTMENT
138 New Mexico State University,
Stuart H. Munson-McGee, James M. Eakman

EDUCATOR
144 Richard Heist, of the University of Rochester, Harvey J. Palmer

CURRICULUM
150 Alternative Applications and Examples in Undergraduate Thermody-
namics,
Eva Marand, Elaine P. Scott, Monique Jackson, Kathryn Plunkett
158 A Course in Communication Skills for the Corporate Environment of
the 1990s,
Carol McConica
172 Development of a Powder Technology Option at CCNY,
Gabriel I. Tardos
178 Hazardous Waste Processing in the Chemical Engineering Curriculum,
Dianne Dorland, Dorab N. Baria
182 A Conceptual Design Problem in Mass Transfer Operations,
Andrew L. Zydney
198 Computing in the Undergraduate ChE Curriculum: An Integrated
Approach,
Muthanna H. Al-Dahhan

CLASSROOM
162 The World Wide Web for Teaching Chemical Engineering,
Henry Bungay, William Kuchinski
204 Calculation of Vapor-Liquid Equilibrium: A Simplified Method,
Jack Winnick, Dennis E. Senol

RANDOM THOUGHTS
166 Getting Started, Richard M. Felder, Rebecca Brent

LEARNING IN INDUSTRY
168 Create a Successful Summer Engineering Project, Robert W. Bedle

LABORATORY
186 Quality in Teaching Laboratories, John F. Stubington

CLASS AND HOME PROBLEMS
192 Unusual Three-Phase Flash Equilibrium Problems,
Maria A. Barrufet, Kai Liu
157, 191, 197 Book Reviews
161 Letter to the Editor


CHEMICAL ENGINEERING EDUCATION (ISSN 0009-2479) is published quarterly by the Chemical Engineering
Division, American Society for Engineering Education, and is edited at the University of Florida. Correspondence
regarding editorial matter, circulation, and changes of address should be sent to CEE, Chemical Engineering Department,
University of Florida, Gainesville, FL 32611-2022. Copyright 0 1995 by the Chemical Engineering Division, American
Society for Engineering Education. The statements and opinions expressed in this periodical are those of the writers and
not necessarily those of the ChE Division, ASEE, which body assumes no responsibility for them. Defective copies replaced
if notified within 120 days of publication. Write for information on subscription costs and for back copy costs and
availability. POSTMASTER: Send address changes to CEE, Chemical Engineering Department., University of Florida,
Gainesville, FL 32611.










n department


Chemical


Engineering at...


NEW MEXICO



NNew Mexico State University is:
A Carnegie Research I Institution
SEighteenth nationally in Industry-supported R&D
Fifth nationally in University-based total engineering I
Chemical Engineering at NMSU has:
SFull ABET accreditation I
SThirteen faculty members r
Approximately 200 undergraduate students

UNI VERSI Approximately 50 graduate students





STUART H. MUNSON-MCGEE, JAMES M. EAKMIAN
New Mexico State University Las Cruces, NM 88003


Responding to the growing needs of the burgeoning
Southwest, in 1924 the Board of Regents at New
Mexico State University (NMSU) decided to insti-
tute a curriculum in chemical engineering. The first assistant
professor of chemical engineering arrived on campus in
1926 and the Department of Chemical Engineering was
formed in 1944, making it New Mexico's oldest chemical
engineering department.
A department is partially defined by the success of its
graduates, and ours have had success in a variety of fields.
One of the first graduates, Bruce Sage, went on to become a
professor at Cal Tech and established an international repu-
tation in thermodynamics. Another of our graduates, Robert
Davis, became President of Chevron Chemical Company,
and yet another alumni, Charles Johnson, is probably the
only PhD chemical engineer ever to quarterback a National
Football League team.
Las Cruces is New Mexico's second largest city and has a
population of about 65,000. Situated at one of the United
States' major gateways to Latin America, NMSU is thirty-
five miles from the border cities of El Paso, Texas, and
Ciudad Juarez, Mexico. The area has a combined population
of over two million.


The Department's location capitalizes on the strengths of
national research facilities in New Mexico, including Sandia
National Laboratory, Los Alamos National Laboratory, White
Sands Missile Range, the Air Force Phillips Laboratory, the
NASA White Sands Test Facility, and the Army Atmo-
spheric Science Laboratory. The Department has helped
NMSU earn the distinction of being designated as
A Carnegie Research I institution
Third in the nation in NASA research and development
(R&D) expenditures
Fifth among the nation's universities in university-
based engineering R&D expenditures, as ranked by
the American Society for Engineering Education in
1992
Eighteenth among the nation's universities in indus-
try-funded R&D
Recent trends in the Department show growth in student
population (see Figure 1), number of faculty, and levels of
research funding. Since 1988, the undergraduate student en-
rollment has increased almost 150% to its current level of
198 students. During the same period, the graduate student
enrollment also increased to 29 Master's and 19 Doctoral
candidates. As the Department has grown and changed over
the years, scholarly research has also significantly increased.
Chemical Engineering Education


Copyright ChE Division ofASEE 1995












Underpinning our approach to undergraduate education is a firm commitment to
providing a quality program with fundamental science and engineering
principles integrated into a curriculum-wide emphasis on
design and creative problem solving.


UNDERGRADUATE PROGRAM
During its formative years, the Department developed an
educational philosophy focused on the students' needs and
on preparing them for a variety of careers. Underpinning our
approach to undergraduate education is a firm commitment
to providing a quality program with fundamental science
and engineering principles integrated into a curriculum-wide
emphasis on design and creative problem solving. Thus,
during the first two years, in addition to twelve semester
credits of mathemat-
ics, sixteen credits of 250
chemistry, and six /-
credits of physics, 2n. S
NMSU chemical engi- -m!
neering students take !
an additional nineteen Iso
credits of engineering
science and design. Of o0
these credits, ten are z
from the Chemical En-
gineering Department
while the others build
a broader engineering 0 Fall89 Fall 9
knowledge in statics,
dynamics, and circuits. r; ....r rm;,in; .nm.lrmnt. ,


The first two years and concern for
of chemical engineer-
ing classes are structured to develop the students' problem-
solving skills and to provide a sound basis in mass and
energy balances in addition to computer programming and
applications. In fact, computer skills are introduced in the
very first class and are continually developed throughout the
four-year program. Early in the program, the students gain
experience with standard PC-based software (including
graphics packages, spreadsheets, and word processors),
high-level language programming in C, a symbolic equa-
tions processors, and an introduction to the Aspen Plus
process simulator.
During the junior and senior years, classes focus on the
traditional foundation of chemical engineering and also pro-
vide opportunities for the students to explore the emerging
frontiers of our discipline. Thermodynamics, transport phe-
nomena, staged operations, engineering materials, and a
chemical engineering instrumentation laboratory are all taught
during the junior year. During the senior year, reaction ki-
Summer 1995


stud


netics, process control (including a laboratory for hands-on
experience in closed-loop computer control of interacting
systems), engineering economics, and two additional labora-
tories are taught. Three chemistry classes (physical chemis-
try and two electives) are also a part of the student's final
year. Engineering electives taken in the last two years come
from areas as diverse as advanced materials, biochemical
engineering, computer-aided engineering, environmental sci-
ence and engineering, food science, and waste management.
We do not believe,
however, that provid-
ing only the fundamen-
tals will truly develop
a student's full poten-
tial. We have therefore
integrated open-ended
design problems
throughout the curricu-
lum, culminating in
two capstone process
design courses (one
each semester during
91 Fall 92 Fal 93 Fal 94 the senior year) within
ster the core curriculum.
istrate the department's quality The first capstone de-
ent well being, sign course is fairly tra-
ditional, using indi-
vidual, small-group, and large-group design projects. The
second design course uses the annual American Institute of
Chemical Engineers (AIChE) design problem with all
its accompanying rules and regulations, including the
thirty-day time limit, as a final exercise in individual design.
These design projects include the typical process develop-
ment and refinement stages, but in recognition of the
changing roles and responsibilities of chemical engineers,
they also include significant emphasis on ethics, environ-
mental, safety, and health issues. This emphasis is also re-
flected in the nationally used safety manual coauthored by a
department member. L1
Significant courses are also taken in composition, commu-
nication skills, and technical writing. Reflecting our value
on communication, a writing guide coauthored by a faculty
member[21 is used throughout the curriculum as a model for
all written work. Completing the student's coursework are
classes establishing both a breadth and depth in the humani-
139


Fall
Semes
pmoi


L 6U~ VIIIUII) I11llllrlL UI5V










ties and social sciences.
Co-op, internship, and summer employment programs
are also strongly supported and encouraged by the De-
partment. We feel that, in today's marketplace, a gradu-
ating senior with relevant work experience is more em-
ployable than one without such experience. Therefore,
our courses are scheduled so having a co-op, intern, or
other industrial position has a minimal effect on the
student's graduation date.
Students completing this curriculum have been trained
to be practical, problem-solving engineers ready to con-
tribute to industry or to continue their education at the
graduate level. Many of our students have been nation-
ally recognized for their excellence. AIChE-sponsored
awards won by NMSU in recent years include:
Mark Montoya: First Place, AIChE National
Student Design Competition (1988)
Michelle Fullerton: Honorable Mention, AIChE
National Student Design Competition (1992)
Kathy McKinney: Marx Isaac's Award for the
Best Student Published Newspaper, AIChE (1992)
Karol Holmes: First Place-Environmental Divi-
sion, AIChE Annual Meeting Student Poster
Session (1992)
Richard Blauw: Marx Isaac's Award for the Best
Student Published Newspaper, AIChE (1994)

GRADUATE PROGRAMS
NMSU offers both Master's of Science in Chemical
Engineering and Doctor of Philosophy graduate degrees,
and we currently have 29 and 18 students enrolled in
those programs, respectively.
The goals of the Master's program are threefold:

To increase the student's understanding of chemi-
cal engineering fundamentals
To deepen the student's knowledge within a spe-
cialized area of chemical engineering
To broaden the student's knowledge in basic sci-
ence and engineering

These goals are achieved by a combination of required
courses, elective courses, and independent thesis research.
The required courses are in thermodynamics, transport
phenomena, reaction kinetics, and advanced engineering
analysis. Elective courses come from the areas listed
above for the undergraduate program and also from out-
side the department and the college. Popular courses
outside the college are taught by the chemistry and bio-
chemistry, the experimental statistics, the mathematics,
and the physics departments. The research topics are
given in a subsequent section in this paper.
140


Individualized help outside the classroom is available from all faculty mem-
bers. (Shown, left to right: Janice Jenks, Dr. Mark Montoya, and Aijaz Ali.)


Computer-aided design and process simulation using ASPEN PLUS' is intro-
duced at the freshman level. (Shown, left to right: Stephen Stocke, Dr. Stuart
H. Munson-McGee, Kimber Rawdon, and Khaled Al Hajeri.)


The program's design emphasis includes the opportunity to participate in the
Waste-Management Education and Research Consortium (WERC) sponsored
annual international design contest. (Shown: David Garcia.)
Chemical Engineering Education










The goals of the Doctoral program are to develop exper-
tise within a field of chemical engineering, breadth in ad-
vanced engineering topics, an ability to conduct independent
research, and an aptitude for identifying significant research
issues. The Doctoral candidate is not formally admitted to
candidacy until after passing both a qualifying examination
and a comprehensive exam. The first exam, usually taken
after the first semester, covers the fundamentals of chemical
engineering practice, including ther-
modynamics, transport and unit op-
erations, reaction kinetics, and engi-
neering design and economics. The
comprehensive examination, usually
taken nine to twelve months after the
qualifying exam, focuses on the
candidate's proposed research-it's
scope, objectives, and justification.
During this time, the required
coursework is also being completed
through courses selected with the ap-
proval of the candidate's advisor.
Once the qualifying exam has been
passed, candidates focus on their re-
search. These projects are tailored to
the interests of the students such that
the scope of the research satisfies both
the requirements for the degree (spe-
cifically, originality and a combina-
tion of both theoretical and experi-
mental work) and the requirements of
the funding agency. Frequently, the
candidate is able to significantly in-
fluence the direction of the research
based on knowledge gained while pre- An early-April a
paring for the comprehensive exam. Rae Ann Boisve
outside hist
FACULTY
NMSU has eight full-time tenured and tenure-track fac-
ulty positions. The current faculty members, the year they
came to NMSU, and the areas of their research interest are:

Ron K. Bhada; 1988; environmental engineering,
waste management, pollution control, energy
conversion
James M. Eakman; 1993; computer-aided design,
particle technology, environmental engineering,
reaction engineering
Richard L. Long; 1981; transport phenomena,
bioengineering, environmental engineering, separa-
tions
Stuart H. Munson-McGee; 1991; advanced
materials, composites, environmental engineering,
experimental techniques
Summer 1995


ftern
rt an
oric (


Mark Montoya; 1994; advanced materials, model-
ing and simulation, statistical thermodynamics
The faculty will shortly be increased by three new mem-
bers. Sarah Harcum (from the Food and Drug
Administration's Center for Biologics Evaluation and Re-
search) will be joining the faculty this summer to enhance
our bioengineering research program. David Rockstraw
(from Conoco/DuPont) has accepted an offer for an Assis-
tant Professor position and will join
us for the fall 1995 semester, and
we are conducting an international
search for a third candidate whom
we hope to have aboard by the
spring 1996 semester.
In addition to the faculty listed
above, additional expertise is
brought to the department by our
emeriti (J. Patton, R. Roubick,
and E. Thode) and research (re-
ferred to as "College") faculty
members (F. Del Valle and S.
Holbrook). Assistant Dean Joe
Creed also actively participates in
the department's laboratory teach-
ing program, and Paul Anderson,
taking his sabbatical from Purdue
University, is currently teaching the
freshman computer programming
class and developing research top-
ics in improved mass transfer in
electrochemical reactions using a
rotating disk electrode.
Our faculty has an unusual
doon finds students wealth of industrial experience.
d Britt Brownfield
Goddard Hall. Only two of the faculty joined
NMSU without at least four years
of industrial experience, and the
faculty average of eleven years of industrial experience en-
ables us to explain to our students the need for mastering the
subjects within the curriculum and to examine the role that
knowledge will play in their future jobs.

RESEARCH PROGRAMS
Research at NMSU is conducted by students at all
levels: undergraduates, Master's candidates, and Doctoral
candidates. An important component of this research
is that the students each have their own project, regardless
of their level, tailored to their abilities and interests. Thus,
we do not have students who are "dishwashers" for more
advanced students.
Table 1 lists some selected titles from current student
research. These projects are being supported by over $565,000
this year in research contracts and grants. This funding has
141











grown 46% in the last year and is expected to continue to
grow at this rate as new faculty members come on board.

INTERDISCIPLINARY PROGRAMS

In recognition of the changing roles of chemical engi-
neers, the evolving interdisciplinary teamwork is also
strongly reflected in the department's research and edu-
cation projects. In particular, four broad areas have been
identified as critical to the future of the department: envi-
ronmental engineering, advanced materials, food engi-
neering, and bioengineering.
The environmental program is led by Ron Bhada,
Associate Dean and Director of the Waste-Manage-
ment Education and Research Consortium (WERC).
This consortium, funded principally by the Department
of Energy, includes Los Alamos and Sandia National
Laboratories, the state's research universities (NMSU,
University of New Mexico, and New Mexico Insti-
tute of Mining Technology), many of the state's junior
colleges, and private industry. This $13 million/year
program supports a wide variety of research, educa-
tion, outreach, and technology transfer programs across
many academic disciplines, including chemical en-
gineering, chemistry, civil engineering, mechanical engi-
neering, biology, public policy, and government affairs,
among others.
The second major interdisciplinary program within the
department focuses on advanced materials, including com-
posites, liquid metals, ceramics, and polymers. The re-
search and education are broad-based. Topics cover new
manufacturing technologies to long-term (20 year) per-
formance and range from technology demonstration to
theoretical studies. Headed by Stuart Munson-McGee
and Mark Montoya, this program includes members from
the chemical, mechanical, and civil engineering depart-
ments as well as from engineering technology.
The food engineering program, a collaborative effort
with the College of Agriculture, is growing from a foun-
dation placed by Francisco Del Valle. The program is
poised to grow significantly as the agricultural industry
in southern New Mexico shifts from selling raw produce
to out-of-state processors to more in-state processing.
This effort will focus especially on regional commodities
such as dairy products, chilies, pecans, cotton, onions,
and other truck-farm items. One of the unexpected results
of this program is a developing collaboration between the
food engineers and the materials scientists resulting from
the significant similarities between the two disciplines.
For example, both can involve similar process technolo-
gies (such as extrusion).
The department has a vigorous research program in
biochemical engineering focusing on optimization of re-


combinant systems being led by Sarah Harcum. Previous re-
search projects have included scale-up of xanthan gum and
acetic acid fermentation, waste-water treatment using novel bio-
logical reactors, experiments in high-pressure fermentation, and
the theoretical modeling of biological processes such as human
muscle contraction/extension. Contributions to interdisciplinary
projects have included algae cultivation for wastewater treat-
ment and as a food additive with the Chemistry Department, and
development of control systems for growth chambers with Biol-
ogy. Currently, the department operates a 75-liter fermenter in
cooperation with Chemistry and has a fully operational micro-
biological laboratory.

FACILITIES
The department's educational facilities are adequate for our
current teaching load. We have a variety of experiments that the
undergraduate students can conduct (see Table 2). The research
laboratories strongly reflect the needs and interests of the faculty



TABLE 1
Selected Current Research Topics and Principal Investigators

Analysis of a Liquid-Liquid Extraction Process Using a Two-Phase,
Plug-Flow Recycle Reactor R. Long
Aspen Plus Flowsheet Models for Waste Cleanup Processes J.
Eakman
> Calculation of Liquid-Vapor Equilibrium for Metallic Systems M.
Montoya
> Calculation of Thermodynamic and Transport Properties Using
Molecular Dynamics and Monte Carlo Methods M. Montoya
> Coupling of ATP Hydrolysis with Mechanical Work in Muscles R.
Long
Dirac Delta Function Approximations in the Kernel Method R. Long
0 Encapsulation of Hazardous Wastes S. Munson-McGee
0 Estimation of Kinetic Parameters from Multi-Reactor, Multi-Response
Data J. Eakman
0 Experimental and Theoretical Studies of Magnetic Materials Process-
ing and Synthesis M. Montoya, S. Munson-McGee
Fundamental Behavior of Fluidized Beds with Broad Particle Size
Distributions J. Eakman
Kinetics and Thermodynamics of the Combustion of Chlorinated
Hydrocarbon Mixtures S. Holbrook
> Mass Transfer in the Laminar Ripple Flow of the Conical, Centrifugal
Film Reactor R. Long
> Mass Transport in Bubble Column Reactors S. Holbrook
> Multivariable Control of Continuous Processes C. Skowlund
> Performance of Conducting Ceramics in Acidic Environments S.
Munson-McGee
> Probability Density Function Model of Concentration Fluctuations
Over Kuwait Oil Fires R. Long
1 Removal of Condensable Acidic Gases and Entrained Droplets from
Digester Exhaust Gases S. Holbrook
> Robust Control of Batch Processes C. Skowlund
> Theoretical Study of Liquid Phase Atomic Structure M. Montoya


Chemical Engineering Education


142










with each faculty member or
group equipping his or her labo-
ratory in the most suitable man-
ner. For computing require-
ments, the department has its
own state-of-the-art PC cluster
with a variety of educational
software as well as common
commercial software applica-
tions. In addition, a network of
ten UNIX workstations is be-
ing installed in the department.
At the University level, our stu-
dents have access to several
campus mainframes as well as
a CRAY supercomputer.

FUTURE PLANS
In the coming few years the
department will continue its ex-
cellence in engineering educa-
tion and to do so is undertaking
three major projects that will
effect the entire program:

Expansion and renovation
of Jett Hall
Facilities enhancement


The New Mexico legislature
has approved a new engineering building
at NMSU, and when it is completed in 1997
additional space will become available
in Jett Hall, nearly doubling the
department's present square footage.


TABLE 2
Experiments that Enhance Undergraduate's
Understanding of Basic ChE Principles and Practice

Basic Principles of Chemical Engineering
Computer-aided data acquisition
Physical and theological property measurement
Excessive properties of mixing
Fluid flow
Transient heat transfer
Unit Operations Experiments
Fluid mixing
Characteristic behavior of pumps
Co-current and counter-current heat exchange
Batch reaction
Residence time distribution
Staged Operations Experiments
Fractional distillation
Packed tower performance


Distance learning using instructional television

The department is currently housed in approximately 15,300
square feet in Jett Hall. The space includes offices, teaching
and research laboratories, and shops as well as classrooms.
The New Mexico legislature has approved a new engineer-
ing building at NMSU, and when it is completed in 1997
additional space will become available in Jett Hall, nearly
doubling the department's present square footage. Plans are
already well underway to renovate and modernize these
expanded facilities.
As part of the expansion, we are aggressively pursuing
upgrading our basic teaching laboratories. In particular, new
unit operations (including an industrial pilot-scale distilla-
tion column with interchangeable tray and packing sections,
and a computer data acquisition and control system inte-
grated throughout the department's laboratories) and reac-
tion engineering laboratories are being planned. With the
assistance of our Industrial Advisory Board, these experi-
ments are being designed to give our students an understand-
ing of the basic principles involved and also to give them a
taste of the types of facilities that may be available to them
after graduation. Furthermore, the Advisory Board in assist-
ing us in acquisition of the new equipment and software.
One characteristic of New Mexico that significantly ef-
fects our secondary and post-secondary education is our
Summer 1995


semester. This method has


great geographic proportions
combined with a small popula-
tion. In fact, New Mexico's
population of 1.54 million cov-
ers 122.000 square miles-to
have the same population den-
sity, New York city's popula-
tion would have to be spread
over an area greater than the
fourteen Atlantic Coast states
plus Ohio, Pennsylvania, West
Virginia, Kentucky, Tennessee,
and Alabama (e.g., the eastern
sixth of the United States)!
Effectively reaching this
population requires that we use
the tools and methodologies of
distance learning to the fullest
extent possible. The department
is currently offering graduate-
level courses by instructional
television. One of the four
graduate core courses is offered
each semester in a cycle that
repeats every two years. A mini-
mum of one additional gradu-
ate course is also offered each
proven to be very effective in


delivering graduate instruction to Masters and PhD candi-
dates with full-time employment at widespread locations.

SUMMARY
New Mexico State University's chemical engineering pro-
gram is based on a tradition of building strong fundamental
skills, but also has additional emphasis on design and open-
ended problem solving throughout the curriculum. Our stu-
dents, who have won a number of national awards, are
recognized for their common sense and their practical ap-
proach to solving engineering problems. Our faculty has a
strong industrial background that brings a realistic perspec-
tive to the classroom and laboratory. The department's ca-
maraderie is based on our genuine concern for the students'
educational and professional development. Research within
the department is varied and research expenditures are grow-
ing as we explore both the traditional and nontraditional
fields of chemical engineering. As the future beckons, we
anticipate continued growth and evolution to meet the de-
mands of a changing profession.

REFERENCES
1. Whitmyre, G., and R.L. Long, Guide to Safety in the Labora-
tory for Chemical Engineers (1987)
2. Long, R.L., B. Barna, C.W. Bridges, A. Rakow, and D.B.
Wilson, Guide to Writing and Problem Solving for Chemical
Engineers (1985) 7









educator


The University of Rochester's




Richard


Heist


HARVEY J. PALMER
University of Rochester
Rochester, NY 14627-0166
R ichard Heist, Associate Professor of Chemi-
cal Engineering and Associate Dean for
Graduate Studies at the University of Roch-
ester, began his professorial career at the University
of Rochester in 1974. His contributions to the edu-
cation of countless undergraduates and graduate stu-
dents through excellent teaching, innovative laboratory de-
velopment, and meticulous, creative research collaborations
with both graduate and undergraduates students are, and
continue to be, of lasting significance to the department.
Dick grew up in the small town of Birdsboro, a close-knit
community in southeastern Pennsylvania. The principal prod-
uct of the area was steel, and Dick's father was the foreman
of the electrical maintenance staff at the local steel mill. In
retrospect, it should have been self-evident that Dick was
destined to establish a career in experimental research in-
volving chemistry. Dick, like many of us, recalls a childhood
of curiosity and scientific exploration. But rather than be
contented with disassembling anything mechanical or spend-
ing countless hours examining the natural world with magni-
fying glass or microscope, Dick's inquisitiveness and unin-
hibited enthusiasm for invention led to more active pursuits.
He and a few close friends were in the habit of procuring
substantial quantities of "energetic" chemicals, such as very
fine grade (photograde) magnesium, potassium nitrate, and
sulfur, for use in a wide variety of "chemistry-related activi-
ties" that Dick would dream up with the help of various
chemistry texts that he found buried among the history and
Copyright ChE Division ofASEE 1995


literature books that he enjoyed reading at the public library.
Legend has it that Dick's ingenious concoctions were used
not only to produce colorful campfire displays during Boy
Scout outings (he was very active in Scouts for about twenty
years), but also for mischief of a more explosive kind. Need-
less to say, when these chemicals were constrained in empty
CO2 canisters and ignited, the energy stored in the chemicals
became fully apparent. In hindsight, Dick admits that these
activities were quite dangerous; fortunately, he and his friends
escaped any serious consequences of their experimental in-
vestigations. I guess Dick knew what he was doing even
back then-teaching his friends about chemistry, developing
a creative style, learning by doing-a teaching philosophy
that has stayed with him to this day. A generation of students
at the University of Rochester can attest to his love of teach-
ing, his propensity for experimentation, and his special
attention to detail.
In high school, Dick continued his experimental explora-
tion of chemistry in a more legitimate fashion. His science
teachers gave him the run of the chemistry lab and encour-
aged him to present demonstrations to the class. At that time,
he was very interested in organic chemistry and recalls the
Chemical Engineering Education











Dick knew what he was doing even [as a kid]-teaching his friends about chemistry,
developing a creative style, learning by doing-a teaching philosophy that has
stayed with him to this day. A generation of students at the University of
Rochester can attest to his love of teaching, his propensity for
experimentation, and his special attention to detail.


day he put half the class to sleep (literally!) by
mixing acid with alcohol to produce ether. The
ensuing evacuation of the school earned Dick a
modest degree of notoriety.
Needless to say, his parents were relieved when
Dick went off to Catawba College in North Caro-
lina in 1963. There was even the possibility that he
might study history-a subject in which he had
developed a deep and abiding interest "due to the
influence of a rather remarkable high school his-
tory teacher." But at Catawba, the freshman chem-
istry class was small, with about thirty students,
and the chemistry professors quickly tapped into
Dick's enthusiasm for experimental chemistry, giv-
ing him the run of their labs-the rest is history!
He served as a teaching assistant for lower-level
chemistry courses from his sophomore through his
senior year and was one of three chemistry majors
who graduated in 1967. Dick credits his seventh
grade science teacher, as much as any other person
in his life, for turning him on to science and ulti-
mately determining his career pathway. But, obvi-
ously Dick also had a long-standing fascination with chem-
istry and what chemicals could do under carefully controlled
circumstances, and he had a strong predisposition toward
experimentation and improvisation for self-discovery.
Dick has many positive memories of his four years at
Catawba, where he became a serious student, was president
of the sophomore class, and made lasting friendships. By the
time he reached his senior year, his initial plan to seek
immediate employment had been altered by his love of sci-
ence. As Dick puts it, "Chemistry and physics had become a
terrific adventure; it was really neat and I just had to do
more." His chemistry professors convinced him to apply to
graduate school, and he chose Purdue.
Dick recalls his four years at Purdue as being among the
happiest days of his life. He had a research assistantship of
$225/month, was single, and owned a car (which he admits
he didn't use very much). His advisor was a young, enthusi-
astic fellow named Frank Fong (who received his PhD at
Princeton), and Dick recalls with fondness the intellectual
intensity of his advisor and his research group, "working 24
to 36 hours at a clip." Although he still liked organic chemis-
try when he entered Purdue, he was lured by physical
chemistry's reputation of being "really tough." He also liked
Summer 1995


The Heist

family-
Molly,
Amy,
and Dick.



the mathematical rigor and the detailed nature of the subject.
Purdue was quite a change from Catawba. The number of
people in the chemistry department alone was nearly the
same as the total number of people at Catawba College. The
facilities at Purdue were first-rate, and Dick prospered under
Fong's mentorship, doing research in solid-state physical
chemistry and chemical physics, using spectroscopy to study
alkali- and alkaline earth-halide crystals doped with rare
earth ions and the resulting charge compensations that occur
inside the crystal.
Prior to joining Purdue, Fong had worked at the North
American Aviation Science Center in Thousand Oaks, Cali-
fornia, where he was a colleague of the Director, Howard
Reiss. Later, when Dick was in the final stages of his disser-
tation, Reiss, now Professor of Chemistry at UCLA, was
looking for a first-rate experimentalist to fill a post-doctoral
opening in his research group, and Fong recommended Dick
for the position. Dick was by this time married to Molly, a
hometown girl who had grown up only half a mile down the
road from his parents. Although he and Molly were child-
hood friends, they had never dated until he returned to
Birdsboro during the summer before his third year in gradu-
145










A study in contrasts: sailing, one of Dick's
favorite and as-frequent-as-possible
pastimes, shown here with good friend
Howard Saltsburg ..
and shoveling multiple feet of snow (where
are your friends when you need them?), a
less-than-favorite and all-too-frequent
wintertime activity in Rochester.


ate school. They renewed their acquaintance at the commu-
nity pool, started dating, and were married a year later, the
summer before his fourth year. In August of 1971, Dick
completed his PhD in physical chemistry, and he and Molly
moved to Los Angeles, where he spent three intense, pro-
ductive, and enjoyable years as a post-doc with Howard
Reiss, learning about handball and nucleation phenomena,
and exploring the potential of the diffusion cloud chamber as
a detector for studying the kinetics of photochemical reac-
tions such as the photo-oxidation of sulfur dioxide (the reac-
tion of SO, with itself in the absence of oxygen to form SO3).
In the fall of 1974, Dick joined the chemical engineering
faculty at the University of Rochester. This outcome was
initiated somewhat serendipitously by a visit to UCLA by
Howard Saltsburg, one of Howard Reiss' first PhD students
at Boston University in the early fifties. The U of R Chemi-
cal Engineering Department was in the market for an assis-
tant professor in the general area of interfacial phenomena,
and Dick was in the market for a faculty position. When
Saltsburg met Heist, he seized the opportunity and con-
vinced Dick to consider Rochester for his academic career,
albeit in a chemical engineering department.
Upstate New York has provided many opportunities for
community and family activities for Dick, Molly, and their
daughter Amy, who will be a sophomore majoring in biol-
ogy at Valparaiso University this year. Dick is an Elder in
his church and enjoys the outdoors: canoeing, cross-country
skiing in the winter, and spending every chance he gets
sailing on his 27-foot Hunter sailboat in the summer, except
for his customary one-week vacation on Lake George in the
Adirondack State Park. Rumor has it that he "never gets


lost," and if you can get him in a homespun mood, he might
even tell you about how he is a descendant of Daniel Boone.
He is still an avid handball player (almost unique at Roches-
ter), managing to hustle up a match two or three times a
week, and enjoys cooking homestyle Pennsylvania Dutch
food.

INTEGRATION OF COMPUTERS
INTO THE UNDERGRADUATE LABORATORY
Howard Saltsburg and Dick Heist share a common interest
in interfacial science and a common philosophy regarding
the value of "hands-on" educational experiences. Thus, it
was inevitable that they would team up to make major con-
tributions in undergraduate education through innovation in
the undergraduate laboratories. In the mid-seventies, under-
graduate laboratory experiments in most engineering cur-
ricula typically were tied inextricably to lecture courses and
were designed to demonstrate the fundamental principles
taught in class. Furthermore, instead of planning experimen-
tal strategies for investigating the scientific and technologi-
cal issues embodied in the experiments, students spent count-
less hours on data collection, analysis, and regression, be-
cause the data were collected with analog instrumentation
such as strip-chart recorders, pH meters, etc., or by manual
means such as titrations. "Students were spending too much
time trying to make things work, and too little time deciding
what the data meant." Dick and Howard realized that if the
students could be liberated from a lot of the busy work
associated with data collection, then more time could be
spent on the creative process of self-discovery in the labora-
tory.
It was in the '70s that the first affordable and easily pro-
grammable microcomputers (such as the Apple, Commo-
dore PET, and the Radio Shack TRS-80) appeared in the
marketplace, and a hobby subculture emerged that espoused


Chemical Engineering Education


Lt.~`'L,
'Z


j

P










the potential capabilities of these machines. Dick recalls
giving a seminar at Westinghouse in the mid-seventies where
a colleague described the new microprocessor technology as
the greatest thing since "sliced bread." It perked his interest,
and thus he and Howard began to read the pertinent hobby
magazines like BYTE and the now-defunct MICRO to learn
more. The breakthrough for the undergraduate laboratory
came when an article appeared in MICRO that described
how a microcomputer could be used to measure temperature
with a thermistor coupled to a common 555 timer microchip.
The microcomputer, with its internal clock, is used to mea-
sure the time between pulses of a 555 chip, the time period
being determined by the resistance thermistor across two of
its terminals. Howard and Dick immediately applied the
concept to an unsteady-state heat transfer experiment, repre-
senting possibly the first use of a microcomputer for auto-
matic data acquisition in an undergraduate laboratory envi-
ronment.
Dick and Howard quickly realized that other experimental
parameters, in addition to temperature, could be measured
with resistance-based transducers. Beginning in 1978, they
applied the generic concept of a 555 chip as a simple A/D
converter for a PET computer to a whole host of undergradu-
ate laboratory experiments. Soon after their first success in
computer interfacing, the department hired Thor Olsen, a
chemical engineer who had been working at the UR School
of Medicine and Dentistry, to assist in the implementation of
computers for data acquisition in the undergraduate labora-
tory. Thor gravitated to the computer programming and ex-
perimental design aspects of the project and, in addition,
recognized that colorimeters based on LED/photocell sys-
tems also could easily be interfaced with the PET. Thus,
shortly after he had joined the team, Thor had a continuous-
flow stirred tank (CSTR) experiment up and running in
which students could study the residence time distribution of
dye pulses in a series of stirred tanks by monitoring the
optical density of flow streams at various positions with the
LED circuit multiplexed to the PET computer.
Using microcomputers for data acquisition and real-time
analysis gave students more time to think about why they
were doing the experiments in the first place. To capitalize
on this still further, the faculty decided to make the under-
graduate laboratory experiments discrete from the lecture
courses. By bundling experiments into separate laboratory
courses, students could be introduced to chemical engineer-
ing principles within the context of open-ended problems
that combined the disciplines discretized in traditional lec-
ture courses. Under the combined leadership of Dick, Howard,
and Thor, the undergraduate laboratory courses have evolved
into a set of experiences that teach students how to deal with
real-world problems. Students decide on the aspects of the
problem that need to be investigated, the experimental strat-
egy and conditions, and the process of data analysis.


Interestingly, the microcomputer technology has migrated
from the undergraduate labs to the graduate research labs at
Rochester, an unusual path. Furthermore, the innovative use
of microcomputers in the undergraduate laboratory has had
an international impact through publications, presentations
at ASEE conferences, and numerous visits from professors
in the U.S. and Europe who have implemented these con-
cepts in their home institutions. For several years, Dick,
Howard, and Thor held successful summer workshops at
Rochester and at ASEE conferences to educate professors on
the simplicity and versatility of microcomputers as data ac-
quisition tools in the undergraduate laboratory. Students at
Rochester still get their first exposure to the use of micro-
computers as a tool for data acquisition in the "air box"
experiment, which is included in the CACHE anthology on
computer applications in the undergraduate laboratory (1988).

Howard Saltsburg and Dick Heist
share a common interest in interfacial science
and a common philosophy regarding the value of
"hands-on" educational experiences. Thus,
it was inevitable that they would team
up to make major contributions in
undergraduate education through innovation
in the undergraduate laboratories.


The box, invented in 1981 by Dick, Howard, and Thor,
contains a thermistor, a heater, a fan, and "doors to the
outside"; and students learn to use the microcomputer not
only to measure the temperature inside the box but also to
restore the temperature to a desired set point in an optimal
fashion, after a sudden thermal disruption.

RESEARCH IN
NUCLEATION OF SUPERSATURATED VAPORS
Dick and his research group are interested in nucleation
and nucleation-related phenomena; that is, the physical pro-
cess whereby one phase makes a spontaneous transition to
another more stable phase. In nature, we see the process of
nucleation in the formation of rain and snow and in the
boiling of liquids; but these are examples of heterogeneous
nucleation, which rely on "seed" particles to lower the acti-
vation energy by providing the initial surface area for growth
of the new phase. By contrast, homogeneous nucleation oc-
curs under somewhat more special conditions, in the com-
plete absence of foreign surfaces or "seeds" to initiate the
nucleation process.
In spite of the immense practical significance of nucle-
ation and in spite of the fact that scientists and engineers
have been studying it for decades, there is much we do not
yet understand. For example, we know that if we shine light
of certain wavelengths on certain supersaturated vapors, we


Summer 1995



























Scenes from the 1995 E3 Fair (Engineering, Explora-
tion, and Experimentation). As General Chairman,
Dick led the team that organized the E3 Fair and
involved more than 300 participating middle school
students and over 50 professional societies, industries,
and colleges


can make the vapor nucleate. Even though this process has
been investigated for a number of years and even though it
occurs to a significant extent in our own atmosphere (e.g.,
smog and gas-to-particulate conversion), we still do not
really understand how it works. One of Dick's ongoing
research efforts is to learn more about photo-induced nucle-
ation and how it can be used for other scientific and engi-
neering applications. In one such project, he is studying the
photo-induced nucleation of organo-metallic vapors, such as
nickel carbonyl, as a means of producing ultrafine metallic
(nickel) particles. Because these particles are so small (as
small as 10 nm) and are produced under such unusual condi-
tions, they are expected to have novel chemical, physical,
and electronic properties that may make them valuable
commerically. Currently, Dick is examining the catalytic
properties of these ultrafine nickel particles by forming them
by photo-induced nucleation in the presence of various reac-
tants and then examining the reaction products using gas
chromatography and mass spectroscopy.
Phase transitions have long interested researchers in sci-
ence and engineering. Unfortunately, theoretical descrip-
tions of the underlying physical phenomena tend to be com-
plex, and the length and time scales associated with the
148


formation of the first fragments of the new phase (clusters of
molecules) are such that detailed experimental information
is difficult to obtain. One approach to the experimental prob-
lem is to investigate phase transitions in the critical region,
since both the length and time scales increase as the critical
point is approached. Dick and his students are probing the
nature of intermolecular interactions in close proximity to
the critical point, by studying nucleation phenomena in a
diffusion cloud chamber designed to function at high pres-
sures and temperatures. Dick says, "These types of measure-
ments are normally quite difficult to make, but the results are
of considerable scientific, engineering, and practical inter-
est." For example, in modern technology, the process of
chemical vapor deposition (CVD) is bound up with nucle-
ation and growth processes.
While studying nucleation at elevated pressures and tem-
peratures, Dick has also discovered that the presence of
other, non-nucleating gases (background gases) can give rise
to extraordinary behavior during nucleation. Nucleation re-
searchers tend to ignore the presence of non-nucleating back-
ground gases in descriptions of nucleation phenomena and
in the interpretation of results obtained from nucleation ex-
periments. But the experiments of Dick's students show that
Chemical Engineering Education










the nucleation process can be profoundly affected by both
the amount and kind of background gas present in the sys-
tem. There is a clear connection to recent CVD observations
where similar effects are observed.

PROFESSIONAL SERVICE
Dick joined the ASEE and the AIChE soon after he be-
came a faculty member at Rochester. His interest in under-
graduate education has been intense and constant over the
years, and ASEE has provided an ideal forum
for him to examine innovative ways to en-
hance undergraduate education. When Dick Dick ha
began the project of integrating microcom- lead
puters into the undergraduate laboratory, he develop,
(with Howard and Thor) presented several be
workshops on the topic at the ASEE Chemi-
cal Engineering Summer School. These ini- organic;
tial activities inevitably led to active involve- p
ment in the DELOS division of the ASEE, an
organization for which he served as Program par
Chair in 1993 and Division Chair in 1994. He middle-
is currently a Director of the Division. He is believes
also a member of the AIChE and Instrument de
Divisions of the ASEE. technolc
Locally, Dick has been active in the Roch- society i
ester Section of the AIChE for many years children
and is currently the Section's Vice Chair. in sciei
Thus, he organizes the monthly meetings of tei
the Section and will succeed as Chair of the
Section next year. In recent years, Dick has
also played a leadership role in developing connections be-
tween the professional organization and the public schools,
particularly at the middle-school level. He believes that the
key to developing a technologically literate society is to
interest the children in grades 6-8 in science, math, and
technology. If we wait until the high-school years to expose
students to the career opportunities in science and engineer-
ing, Dick feels it may be too late since by then students have
already self-selected their career options through the courses
they took in grades 7 through 10.
Dick has been proactive in this effort by spearheading a
program known as the E3 Fair (Engineering, Exploration,
and Experimentation), which is both a technology fair and a
competition similar to the national "Odyssey of the Mind"
contests, but with a specific focus on technological innova-
tion. The E3 Fair was created as part of the National Engi-
neers Week celebration, the goal being "to focus the atten-
tion of students on the exciting world of engineering, sci-
ence, and technology, as well as to motivate them to seek
careers in these technical areas." It is now in its fourth year,
and Dick is both the 1995 Chair of the E3 Fair and the AIChE
representative to the E3 executive board.
At the E3 Fair, middle-school students display projects that
Summer 1995


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rshi
ing
twee
ofes8
zatio
ic s
:ula
scho
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s to
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chno


demonstrate engineering principles and have them evaluated
by teams of judges who are practicing engineers or engineer-
ing students. Local industries, engineering societies, area
schools and colleges present "hands-on" activities, demon-
strations, and exhibits that illustrate various aspects of tech-
nology. As Dick says, "It is a great opportunity for industries
and professional societies to show students what engineers
do and why they do it." But the heart of the fair is the
competition among teams of middle-school students to solve
a particular engineering design problem.
This year, the problem solving activity was
io played a to construct (using a LEGO kit of parts
p role in provided by the fair organizers) a station-
connections ary machine capable of lifting a basket of
en the weights a given height in a given time.
sional Student teams work for about six weeks
n and the on a solution to the problem, usually
c mentored by practicing professional engi-
S neers from the community. Students then
rly at the bring their best solution to the fair along
ol level. He with a design journal that documents their
t the key to problem solving process. Teams are judged
ping a not only on how well their device per-
illy literate forms but also on their problem solving
interest the strategy as documented in their journal.
grades 6-8 EXCELLENCE IN
math, and UNDERGRADUATE TEACHING
logy.
ogy. Dick has taught a variety of undergradu-
ate and graduate courses at Rochester since
he joined the faculty in 1974, including
the introductory mass and energy balance course, reactor
design, and, of course, the laboratory courses. But his fort
in the undergraduate curriculum is thermodynamics. Every
year, the students rank this course among the very best that
they have taken at the University, and in both 1993 and 1994
they named Dick "Teacher of the Year." In addition, Dick
teaches a graduate course in his research area, the kinetics of
phase transitions, and team-teaches a course in molecular
sciences with Eldred Chimowitz; both courses are very popu-
lar with the students. In an attempt to reduce attrition among
freshmen who have expressed an interest in chemical engi-
neering, the department last year instituted half-semester,
elective courses for freshmen. These courses focus on con-
temporary issues that have a major chemical engineering
component and are intended to teach students how chemical
engineers formulate and solve real-world problems. This
spring, Dick is teaching one of these courses. Titled "Atmo-
spheric Pollution: An Engineering Perspective," it is packed
with demonstrations and hands-on experiences, in typical
Dick Heist fashion.
In summary, Dick Heist has played a leadership role in
both his professional and community activities, and we look
forward to many years of continuing contributions. 0










W curriculum


ALTERNATIVE

APPLICATIONS AND EXAMPLES

IN UNDERGRADUATE

THERMODYNAMICS


EVA MARAND, ELAINE P. SCOTT, MONIQUE JACKSON, KATHRYN PLUNKETT
Virginia Polytechnic Institute and State University Blacksburg, VA 24061


he undergraduate engineering population is becom-
ing increasingly diverse, not only because of the
increased number of women and minority students,
but also as a result of the variable backgrounds of the major-
ity students. In addition, the technical needs of our society
are rapidly changing. For example, environmental concerns
are increasingly important for engineers."' But many text-
books, particularly in core undergraduate courses such as
chemical and mechanical thermodynamics, often provide
examples and problems applied to standard-type processes
that are based on using the backgrounds of what many con-
sider to be "traditional" engineering students. Typical chemi-
cal engineering thermodynamics examples include reactors
and steady-state flow through pipes, while automobile en-
gines and steam turbines are often used in textbooks geared
toward mechanical engineering students.
Thermodynamics is a particularly important subject be-
cause it is often one of the first core courses in many chemi-
cal and mechanical engineering curriculums. It is not the
intention here to completely replace traditional types of prob-
lems, which obviously are fundamental in the study of both
of these fields, but to present the subject manner in such a
way that it builds on the backgrounds and interests of a
wider variety of students.
Felder and Silverman121 reported that how much students
learn depends on three factors: 1) their native ability, 2) their
background, and 3) the match between their learning styles
and the instructor's teaching style. The authors furthermore
stated that the only tool that teachers have at their disposal is
their own teaching style. A student's background cannot be
changed, but if teachers could take advantage of the back-
ground of a nontraditional student rather than treat it as a
hindrance, then not only learning but also the field of engi-
neering as a whole could be enhanced.
As faculty members responsible for teaching undergradu-
150


Eva Marand is Assistant Professor of Chemical Engineering at Virginia
Tech. She received her PhD in Polymer Science and Engineering from
the University of Massachusetts at Amherst. While her background is in
polymer spectroscopy, her research interests also include microwave
processing of materials and the characterization of transport properties
of polymeric membranes.
Elaine P. Scott is Associate Professor of Mechanical Engineering at
Virginia Tech. She received PhDs in Mechanical Engineering and in
Agricultural Engineering at Michigan State University, and her MS and
BS from the University of California, Davis. Her background and inter-
ests are in the thermal characterization of biomaterials and composite
materials through parameter estimation and in the solution of inverse
heat conduction problems.
Monique Jackson is an undergraduate student in the chemical engi-
neering department at Virginia Tech.
Kathryn Plunkett is an undergraduate student in the mechanical engi-
neering department at Virginia Tech.

ate thermodynamics in both chemical and mechanical engi-
neering, we formulated a joint effort to address these issues.
Note that our efforts were focused on incorporating these
ideas into core undergraduate courses where they could have
a positive early impact. First, we sought to identify topics
that are of interest to nontraditional engineering students
(with the focus on women in particular) and that have na-
tional and/or global significance. The next step was to assess
the use of these types of problems in various curriculums
across the country. Concurrently, we defined three different
problem classifications and then developed and implemented
problems for each classification into our own thermodynam-
ics courses. The two undergraduate students noted as coau-
thors to this paper provided much-needed student input into
the development and assessment of these problems.

TOPICS FOR
ALTERNATIVE EXAMPLES AND PROBLEMS
As noted above, the first step in accomplishing our goals
was to identify key areas of interest to nontraditional stu-
Copyright ChE Division ofASEE 1995
Chemical Engineering Education










dents that also have global significance. Although the over-
all goal of this project was not meant to specifically focus on
the needs of women, the initial efforts were concentrated on
these needs. It has been documented that women tend to be
attracted to fields that are based on humans, that make a
direct impact on the quality of life, and that are based on the
biological and chemical sciences.31 In addition, one of the
biggest obstacles young women perceive is that they have a
lack of practical experience compared to their male counter-
parts.'i Using alternative problems could serve to balance
the playing field and consequently to improve the confi-
dence of the women students. This is an important factor in
the retention of young women in engineering.51


TABLE 1
Survey Questions Used to Determine
Use of Alternative Problems

Group Problem Type Yes No

Recycling Plastics
Paper
Biodegradables
Composting

Energy Conservation Solar
Wind
Alternate Energy Sources

Environmental Impact Pollutants
Ozone
Global Warming

Biomedical Applications Organ Preservation
Cryosurgery

Other Food-Microwave Processing

Other


15 -


0 1 2 3 4 5 6 7 8 9 10 11 12 13 1-
No. of Types of Proolems Usec

Figure 1. Number of different types of problems used.
Summer 1995


Several broad areas that represent these interests, and which
have significant engineering applications, are related to the
environment, the medical field, and the processing of
biomaterials. Based on these areas, the specific topics of
recycling, energy conservation, environmental impact, and
biomedical applications were chosen as the focal topics for
the development of alternative problems.
In the area of recycling, specific examples such as the
recycling of plastics, paper, and biodegradable materials
were considered. Examples of problems concerning energy
conservation include the use of solar, wind, and other alter-
native energy sources. With regards to the environment, a
variety of examples can be found, including problems re-
lated to pollutants, the ozone layer, and global warming.
Biomedical applications provide very interesting thermody-
namic problems, such as those related to organ preservation
and cryosurgery. Other related problems, such as those in-
volving microwave heating of foods, were also considered.
Note that many of these topics fall within the category
of "Green Engineering," a focus area of national attention
on many campuses, such as our own at Virginia Tech.
This illustrates how capitalizing on the variety in students'
backgrounds could help to elevate the engineering profes-
sion as a whole.

SURVEY OF
THE USE OF ALTERNATIVE EXAMPLES


k survey was developed to assess the current use of alter-
ive problems in chemical engineering undergraduate ther-
idynamics courses. The survey was sent to chemical engi-
ering departments throughout the country; sixty-six were
turned. In the survey, participating faculty were asked
ether or not they used various types of alternative ex-
ples and problems in their thermodynamics courses; cop-
of the problems used were also requested. The types of
problems were divided into the chosen target groups,
with specific types of problems listed under each
Group. The survey questions are shown in Table 1.


The results of the survey indicated that very few
alternative problems are used in chemical engineer-
ing thermodynamics courses today. As shown in
Figure 1, over fifty percent of the faculty indicated
that they did not incorporate any (or used only one)
type of alternative problems in their classes, and
less than twenty percent indicated that they had
used five or more different types of problems. As
seen in Figure 2, of those who indicated positive
responses the majority cited using examples related
to the "Environmental Impact" group, in particular
air pollution. The second most popular group was
"Energy Conservation." These two groups repre-
sented almost eighty percent of the total number of
positive responses.












In the survey, the faculty were also encouraged
to provide example problems that they had used.
A number of problems were sent to us (if de-
sired, they can be obtained from the authors of
this paper), and many of the participants also
provided some interesting comments. Many of
the respondents indicated that they did not use
any alternate problems because of the lack of
such problems in the textbook they were using.
In addition, some of the respondents were inter-
ested in receiving copies of any available prob-
lems. These comments suggest that there is at
least a perception of need for these types of prob-
lems in our current courses.

DEVELOPMENT AND USE OF ALTERNA-
TIVE EXAMPLES AND PROBLEMS

Problem Development Three problem classi-
fications were formulated to utilize alternative
examples and problems. The first category in-
cluded simple problems that could be used as
classroom examples. Ideally, these would include
visual aids (e.g., videos of actual recycling pro-
cesses or alternative energy sources). The second
category of problems was typical homework
problems, which are consequently more involved
than the in-class examples. Reference materials


TABLE 2
In-Class Example No. 1


SRefrigeration Cycle for Organ Preservation


Problem Statement
Transplant of the corneal tissue can cure a victim of blindness due
to the loss of corneal transparency. In order for the transplant to be
successful, the corneas must be preserved at a constant tempera-
ture of -4'C. A vapor-compression cycle can be used for this
purpose. Find the maximum C.O.P. of a system that operates with
an evaporator temperature of -4C and a condenser temperature of
400C.

Solution
Given: Vapor-compression refrigeration system with
known evaporator and condenser temperatures.
Find: Maximum Coefficient of Performance (C.O.P.).


3 2
Condenser

Expansion = T -4oC
Valve Compressor T = T =-40C
T, = T3 =40C


Assumptions: Steady state; reversible adiabatic compression and
expansion
Analysis:

From the first law: W + Q QH+ = 0 or W = QH -QL

Using the maximum C.O.P. defined by the second law:


C.O.P.= = QL
W QH -QL

TL T1 269 K
max TH -TL T2 T1 313 K 269 K




Comments: Note that this problem is very simple; but the application
is unique. Also, one might want to assign a homework problem for the
students to compare this efficiency with that of a refrigeration cycle
between the same two temperatures, but with a saturated vapor at
State I and a saturated liquid at State 3, an isentropic process between
States I and 2, and a constant enthalpy process through the expansion
value (between States 3 and 4).


'52 Chemical Engineering Education


100
90
80
70
(D
ao
V 60
O
0
0 50
Cs
O 40
C)
S30
0 20
N 10
0


Vo L 0 ,1 t- -o CC 0) ) 0 C Co
" C g U C 0 c ) or c

< o
0 0 C


Recycling Energy Environmental Biomedical Other
Conservation Impact
Subject Area


Figure 2. Types of problems used by positive
survey respondents.











were provided as needed to solve these types of problems.
The final category was geared toward the design of
either individual or group term projects that require com-
plex computer analyses and/or library research and which
are consequently more involved than either of the other
problem categories.
In order to encourage student participation, the two under-
graduate students participating in this project conducted lit-
erature searches to provide the necessary background mate-
rial for development of the problems. They also, in coopera-
tion with the faculty coauthors, formulated problems related
to the targeted alternative topics in the three different prob-
lem categories. These problems were integrated into the
undergraduate thermodynamics courses in both chemical
and mechanical engineering.
Examples of the problems used are provided for each


category (e.g., in-class example, homework problem, and
project). Note that the introduction of alternative example
problems does not necessarily require that the entire prob-
lem be "nontraditional," or that it be complex. For instance,
the in-class example given in Table 2 is a simple problem
involving the determination of the maximum coefficient of
performance for a refrigeration system. But the students are
told that the application of this system is to preserve corneal
tissue for transplants; thus, this could stimulate the interest
of those inclined toward biomedical applications. Also, this
problem can be easily extended into a homework assign-
ment, as indicated in the comments at the end of the solution.
The second in-class example, shown in Table 3, provides the
instructor with an opportunity for class discussion on alter-
native energy sources such as solar energy; again, the actual
calculations are very simple.


TABLE 3
In-Class Example No. 2

Reactions Driven by Solar Energy


Problem Statement
The production of simple compounds widely used by the
chemical industry (i.e., hydrogen, carbon monoxide, or nitric oxide
from free or cheap raw materials such as water, carbon dioxide,
carbonates, or air) is typically carried out with the aid of electricity at
low temperatures. These reactions, however, can also be driven at
high temperatures without any mechanical or electrical power input.
It has been suggested that an original and efficient way to carry out
such endothermic reactions may be via the use of concentrated solar
energy.161 Solar furnaces can deliver thermal power close to P = 1.5
kW at a 12x10-3m wide focal spot. A temperature above 3000 K can
be obtained at the focus.
The solar method is simple in principle and can be adapted to
many endothermic gas phase reactions. In this particular case, we
wish to consider the following reactions; the direct decomposition of
carbon dioxide, the thermal splitting of water, and the synthesis of
nitric oxide from the components of atmospheric air (i.e., nitrogen
and oxygen). In this process, water or other considered reactants are
continuously injected into a small zirconia reactor located at the
focal zone. In this dissociation reactor, partial reaction occurs within
10-3 to 10'2 seconds. In order to avoid any recombination between the
evolved products, the gas is quickly cooled with four turbulent argon
jets. All gases are analyzed by gas phase chromatography. The
volumetric flow rate of the product gases, Qp, is


Q (105kg si):


6.5 H20 <->H2+ 1/2 02


10.0 CO2 ,- CO+1/202

1.5 1/2N2 +1/2 02 -NO

An energetical yield, nT, has been defined as the ratio of the
chemical energy stored in the products to the available thermal
power, P.
Q AH
P
P
where AH is the heat of formation of the products at the reaction


temperature. Estimate the yield of the process for the three different
reactions. Compare with energetical yields obtained via conven-
tional electrochemical means, whenever possible.

Solution
This problem illustrates the need for heat capacities of gases as a
function of temperature in the calculation of the product formation
enthalphy at the reaction temperature
AH = AHo +AH9 + AHo
3000 R 298 p

Reactants at 3000 K Products at 3000 K

AH', AH,

Reactants at 298 K Products at 298 K
AH,,,K

( 3000 3000
AH -000 AH 98 + n "Cdt n JCdt
Products 298 Reactants 298
Using value of Cp(T) from tables found in Smith and Van Ness,171 in
the case of water,
AH000 =54,778 cal/gmol
and the energetical yield is

(6.5 x 10-5kgsec-')(54,778 cal/gmol) 1 kgm2/sec2
1.5 x 103kgm2 sec-3)(8 x 10kg/gmol) 0.2390 cal

n = 0.552

Comments: Here, the instructor can work out the solution for the
first reaction and leave the other two for the students to work on in
class or for homework.


Summer 1995 15-











The first homework problem example, given in Table 4,
again demonstrates that traditional problems can be modi-
fied to address issues such as waste utilization. Here, a
typical steam power plant-type problem is modified for the
processing of waste material. Additional problems could
also be developed on the air pollution issues related to the
burning of waste. The second homework problem, shown in
Table 5, serves several purposes. First, it provides a means
of introducing recycling and provokes an interesting discus-
sion of the use of the second law. In addition, reading and
reviewing articles, such as this, could aid in improving the
students' comprehension skills.


Alternative problems can also provide a means of linking
different subject materials together. For example, the analy-
sis in the Thermal Model of the Human Body project, shown
in Table 6, is a relatively simple application of the first law;
but the students are also introduced to the different modes of
heat transfer. Thus, they see first-hand how thermodynamics
is related to heat transfer. In addition, the students will find
that there is a limited design space (all velocity and tempera-
ture combinations cannot provide the desired energy bal-
ance), and therefore the interpretation of the results is equally
important as the ability to calculate the numerical answer.

Another side bonus in using alternative examples, espe-


TABLE 4
Homework Problem No. 1

Waste Power Plant

Problem Statement


In a certain waste-to-energy facility, 750 tons/day of waste (h=4450
Btu/lbm) are collected. The waste undergoes combustion using 2.25
MW of power and forms the products of steam, water, ash, and metal.
The system loses 3/4 of the waste's initial energy content in the form
of water, ash, and metal. The useful product, steam, exits the
combustion process at 700 F, 600 lbf/in and enters a turbine where it
expands to 50 lbf/in2 and 97% quality. The facility is in operation 8
hours/day.
a. How much steam is produced per hour (lb/hr) in the combustion
process?
b. If 65% of the remaining products (water, ash, and metal) are metal,
how many tons per day of metal are produced?
c. How much power (kW) is generated from the steam in the turbine?

Solution
Given: Waste-to-energy facility which uses waste to supply energy for
a steam power cycle with known waste and energy input.
Find: steam. turbine' mmetal

Schematic and Given Data:

mwasr, h. Y Q OoWmsaon

Combustion

mYnsewn,1, hsteam,z

Turbine s Wan


Smateam,2, hsleam,2


waste = 750 tons/day
waste = 4450 BTU/lb
Combustion = 2.25 MW
Tsteam, I = 700F
Psteam, = 600 lbf/in2


Psteam,2 = 50 lbf/in2
Xsteam,2 = 97%
Losses = 75% waste energy
Operation 8 hr/day


Properties: At 700F and 600 Ibf/in2, h eam, = 1350.6 BTU/lb
At 50 lbf/in2 and 97% quality, hem.2 = 1146.7 BTU/lb


Analysis: Assume steady-state, steady-flow.
a) Applying the 1st law to the combustion process:


waste waste+ Qcombustion losses steam steam,l
where


therefore


Losses 0.75 mwastehwaste

0.25 riwastehwaste + Qcombustion
msteam,I h
steam, 1


hence, using the values given previously,
msteamI = 160,130 lb/hr
b) Find mtal : Apply conservation of mass to combustion process:


waste "steam losses = 0


"metal = 0.65 losses
solving for inmetal:

r metal = 0.65 (mhwaste steam)
therefore
Metal = 109.5 tons/day

c. Find Wturbine: Apply the 1st law to the turbine:

m steam (hsteam, hsteam, 2- turbine = 0
or

Turbine = msteam(hsteam,l hsteam2)

Substituting in values for steam, hsteam,, and hsteam,2

W =32.6x 106 BTU/hr 1MW = 9.6 MW
turbine 3.412 x 106 BTU/hr



Comments: Note that the instructor can also use this example to
introduce the general concepts of combustion processes. The students
could also be asked to determine the isentropic efficiency of the
turbine.


'54 Chemical Engineering Education











cially in projects, is that since typical textbooks do not
discuss these types of problems in any depth, the student
often has no choice but to go to the library to seek additional
background information. This can have obvious future ben-
efits for the student as he or she approaches the senior-year
design project.

STUDENT RESPONSE
The overall student response to these problems has been
positive. An interesting note was that when alternative home-
work was provided as extra credit, a higher percentage of the
women students completed the assignment. Another inter-
esting result, however, was that the positive responses were
not limited to the nontraditional students. The project pro-
vided in Table 6 was assigned to several first-term mechani-
cal engineering thermodynamics classes. Several of the
women in these classes commented that they enjoyed the
project because of its different perspective.
It was a surprise that some of the most in-depth reports,
complete with extensive library research, came from stu-
dents with what many often think of as very traditional
mechanical engineering backgrounds (i.e., they were attracted
to mechanical engineering solely due to their love for auto-
mobiles). Thus, this demonstrates that including alternate
problems in curriculums could have a positive impact on the
student body as a whole.


SUMMARY
We feel that using alternative problems could have a very
positive impact on increased learning and retention for non-
traditional students. Although this initial effort was prima-
rily focused on women students, the same ideas could be
applied to capitalize on the backgrounds of minority stu-
dents. Note also that these efforts can benefit the learning
experience of all students and not just women.
These ideas could also be used to take advantage of the
different approaches people have to solving problems. For
example, team projects could be designed to capitalize on
interpersonal skills found to be particularly characteristic of
women. It should be noted that the focus should always be
on taking advantage of the backgrounds of diverse students
to enhance the engineering profession as a whole.
As the global market becomes more and more competi-
tive, we increasingly will see a need for the best and bright-
est of all of our young people to study engineering. Incorpo-
rating these types of problems into the curriculum does not
always mean that major revisions are needed; sometimes
very effective problems can be formulated from simple modi-
fications of traditional existing problems, as noted for the
problems shown in Tables 2 and 4.
We are continuing our efforts to introduce nontraditional
problems into our curriculum, and we would be happy to


TABLE 5
Homework Problem No. 2

Thermodynamics of Resource Recycling


The students are encouraged to critically examine pertinent
publications, thus questioning their in-depth understanding of
thermodynamic principles. For example, an article written by W.B.
Hauseman on the "Thermodynamics of Resource Recycling"181
proposes to treat the economic efficiency of a closed resource cycle
using a definition analogous to the elementary thermodynamic
definition of overall thermal efficiency.
Here, the overall economic efficiency is given as the ratio of the
total value delivered by a system to the total cost of making it run. A
value-entropy diagram was generated for the case of aluminum
which can exist in a number of different states, ranging from bauxite
ore to ingots, new cans, cans of beer, used cans, emptied cans, cans
in a landfill, etc Each state of aluminum has associated with it a
particular value and entropy. Thus, value is a measure of potential
for some economically useful purpose. For waste materials, value is
negative, approximated by the cost of disposal. Entropy change
between any two states can be approximated as

AS =C fn V2
V1 )

where V, and V, are the initial and final values, and C is the cost of
effecting the change in $W/$V-lb. Here $V is the value or price, and
$W is the dollar equivalent of man-hours or Btu of work done.
The students were asked to comment on the validity of this


approach. Is the cycle (new cans -> cans filled with beer -) used
cans -> emptied cans -> reclaimed cans -> scrap -> ingots -> new
cans) truly a closed cycle?
What is the meaning of entropy in this case? For example, a ton
of empty aluminum beer cans has a higher entropy when spread
along ten miles of beach and highway than when it is in a neat pile
awaiting reclamation.'j
Finally, the students were asked how they would go about
estimating the efficiency of effectively recycling a just-emptied can
into a can of beer ready for consumption, compared to the efficiency
associated with manufacturing a can of beer from aluminum
generated from raw bauxite ore. Since there were no hard numbers
given in the V-S diagram for aluminum, the students simply had to
state that the efficiency of each process will be given by
A-B
B

where A = economic value of a can of beer (in $W)
B = dollar-equivalent man hours necessary to transform
emptied can or bauxite ore into a can of beer ready
for consumption (in $W).
Here, A and B can be obtained from the V-S diagram in the
article by calculating the appropriate product of (AS V).


Summer 1995 15












TABLE 6
Project

Thermal Model of the Human Body


In 1984, President Reagan made a decision to develop a perma-
nently manned space station by 1992, although this dream has yet to
become a reality. The space station, however, could serve as a place to
live, work, explore, and experiment. The gravity-free environment offers
significant opportunities for producing medicines, manufacturing rare
materials, and performing scientific experiments. It could be a stepping
stone or base camp for trips to the moon, the asteroids, Mars, or even
beyond. The space station provides the next logical step in space
exploration.
You are part of the design team working on this space station, and it
is your responsibility to ensure the comfort of the inhabitants. One of the
comfort requirements of this controlled environment is to maintain the
thermal balance of personnel through regulation of environmental
parameters. Maintaining a state of thermal equilibrium at all anticipated
levels of activity requires a thermodynamics model of the human body
using a first-law analysis. There are many very complicated simulation
models of the body in existence that define the energy exchange
mechanisms. Unfortunately, these models include a very large number of
variables that are not easily defined. For instance, environmental
parameters such as temperature, vapor pressure, and air velocity all play a
major role in determining the body's comfort. In addition, the body state
(including its size, position, physical condition, metabolism rate, level of
activity, and type of movement) as well as the type of clothing, have a
significant impact. These variables are not only numerous but are also
very difficult to define because they are derived from experimental data
and approximations.
You, however, are only required to find a preliminary result. Your
model will be simplified by concentrating on only three of the above
variables: temperature, air velocity, and level of activity. You are to
provide recommendations of how the temperature and air velocity inside
the space station should be varied to obtain the desired thermal response
of a human body for various activity levels. You must keep in mind,
however, that there are several factors that must be considered when
determining the thermal model of the human body. These are:
1. The body produces metabolic energy at a rate that can be equated to
the rate of change of internal energy within the body.
2. The comfortable skin temperature is 92.3'F. Above 940F sweating
occurs, and below 860F shivering occurs.
3. The body's rate of work (power) output is approximately equal to
15% of the metabolic rate. A sedentary person has a work output of
45 BTU/hr, a semi-active person's output is 90 BTU/hr, and a very
active person produces 150 BTU/hr.
4. Ten percent of the body's energy produced by metabolism is lost in
the form of heat due to respiration.
5. There is a minimum heat loss due to evaporation ( ) where
QE = 0.125 M + 50 BTU/hr
and M is the metabolic energy,
6. There is also a heat loss due to air convection ( Q):
Q = Ah(T.-T)
where To = clothing temperature (F)
T = temperature of the surroundings (F)
A = surface area of average human; A =19.375 ft2
h = heat transfer coefficient for the air;
h = 0.021(PV)05 BTU/hr-ft2R
where V = air velocity (ft/min)
P=atmospheric pressure: P = 14.7 psia
(Use these units.)
7. The heat loss due to radiation (QR) is defined by the following


equation:


QR =EA(T4 -TA4)


where a = 1.714x 10- BTU/hr-ft2'R
e = emissivity of skin and clothing = 0.95
TA = clothing temperature (R)

TA = temperature of the surroundings (R)
A = surface area of average human; A = 19.375 ft2
8. The skin and clothing temperature are related by the following
expression:
QT =Ak(T, T)/L
where QT = total rate of heat loss through the clothing (BTU/hr)
T = skin temperature (oF)
L/k = 0.528 F-ft'-hr/BTU
A = surface area of average human; A = 19.375 ft2
T- = clothing temperature (F)

Assignment

You are to determine the required air velocity needed to keep the
body comfortable when the surrounding temperature is in the range of
600F 850F, considering a sedentary, a semi-active, and a very active
person. Your report should contain the following
1. Introduction Present the problem in your own words, and state
your objectives. You are encouraged to go to the library to seek
out articles pertaining to this problem to add additional back-
ground information to your introduction. Cite all references.
2. Theoretical Methods Starting from the first law, present the
equations necessary to determine the velocity required to achieve
a given skin temperature. Use text to describe these equations; all
equations should be numbered.
3. Computer Code You are required to write a computer program
to calculate the required velocity for surrounding temperatures
within the range of 60F to 85F in increments of 2.50F and skin
temperatures within the desired range (86-94C). Document your
program. A copy of the computer program should be included in
the appendix.
4. Results and Discussion Plot your results of air velocity vs.
surrounding temperature for the three cases given, and discuss the
implications of your findings. Also, include a table of numerical
values. All figures and tables should be numbered with a title.
Discuss your recommendations for the space station. Justify your
recommendations. Note that the same recommendations do not
have to be used to satisfy all activity levels. Also discuss whether
or not your solutions for each activity level are valid over the
entire temperature range. In addition, discuss the feasibility of
your solutions in terms of reasonable maximum velocities. If the
solutions are not feasible under the given conditions, make
recommendations for improvements. Also discuss the accuracy of
your results and the assumptions that were made.
5. Conclusions Base your conclusions on your results and
discussion.
6. Nomenclature Define all variables used and include units.
7. References Cite all references used (articles, books, etc.).


Comments: Note that this is a design problem and the students must
be very careful in their selection of the design parameters (velocity and
surrounding temperature) such that the human body is maintained at
the desired temperature and the velocities are limited to a practical
maximum level.


56 Chemical Engineering Education











share our efforts with those who are interested. In addition,
we encourage anyone who has used these types of problems
to share them with others. For those who are interested in
other problem examples or have problems to share, please
contact either Professor Marand or Professor Scott at Vir-
ginia Tech.

ACKNOWLEDGMENT
The authors greatly appreciate those who responded to the
survey and those who, in addition, provided comments and
their own alternative examples and problems. Support for
this work was provided by a Virginia Tech Teaching/Learn-
ing Grant and the Departments of Chemical Engineering and
Mechanical Engineering at Virginia Tech.

REFERENCES
1. Stimpson, B., "Reclaiming the High Ground: An Engineer-
ing Ethic for the New Age of Engineering," Eng. Ed., 81(4),


372 (1991)
2. Felder, R.M., and L.K. Silverman, "Learning and Teaching
Styles in Engineering Education," Eng. Ed., 78(7), 674 (1988)
3. Shinberg, D., Women in Engineering, Engineering Man-
power Bulletin No. 118, American Association of Engineer-
ing Societies, Washington, DC (1992)
4. Henderson, J.M., D.A. Desrochers, K.A. McDonald, and M.M.
Bland, "Building the Confidence of Women Engineering
Students with a New Course to Increase Understanding of
Physical Devices," J. of Eng. Ed., 83(4), 337 (1994)
5. Meade, J., "The Missing Piece," ASEE Prism, p 19, Septem-
ber (1991)
6. Lapicoue, R., J. Lede. P. Tironneau, and J. Villermaux,
"Solar Reactor for High-Temperature Gas Phase Reactions -
(Water and Carbon Dioxide Thermolysis and Nitric Oxide
Synthesis)," Solar Energy, 35(2), 153 (1985)
7. Smith, J.M., and H.C. Van Ness, Introduction to Chemical
Engineering Thermodynamics, 4th ed., McGraw-Hill, Inc.
(1987)
8. Hauserman, W.B., "Thermodynamics of Resource Recycling,"
J. Chem. Ed., 65(12) 1045. 7


SMbook review


> HOW TO SOLVE PROBLEMS (4th Edn.)
by Donald Scarl Dosoris Press, Glen Cove, NY (1994)
> STRATEGIES FOR
CREATIVE PROBLEM SOLVING
by H. Scott Fogler, Steven E. LeBlanc
Prentice-Hall, Englewood Cliffs, NJ (1995)
> PROBLEM-BASED LEARNING:
HOW TO GAIN THE MOST FROM PBL
by Donald R. Woods
Donald R. Woods, Waterdown, Ontario, Canada (1994)

Reviewed by
Richard M. Felder
North Carolina State University

In the traditional approach to teaching science and engineering,
the instructor presents formulas, algorithms, and illustrative prob-
lems and solutions in lectures and readings, then calls on the
students to solve similar problems on homework assignments and
tests. The unspoken assumption is that this approach will somehow
endow the students with the analytical, creative, and critical think-
ing skills necessary to function effectively as professionals in their
fields. Regrettably, it usually doesn't work that way: problem-
solving skills (like all other skills) can only be effectively devel-
oped through training, practice, and feedback.
Three paperback books designed to help students become better
problem solvers have recently been published. How to Solve Prob-
lems, by Donald Scarl, presents tips for setting up and solving
elementary problems in freshman physics and engineering. Strate-
gies for Creative Problem Solving, by Scott Fogler and Steven
LeBlanc, gives methods to define and solve realistic and challeng-
ing open-ended problems and evaluate the solutions. Problem-
Based Learning, by Donald Woods, is intended to help students
develop a broad range of problem-solving, teamwork, and self-
Summer 1995


assessment skills.
How to Solve Problems begins with general suggestions about
classifying equations, approaching homework and tests, working in
groups and organizing and completing the solution of quantitative
problems. It then provides detailed guidance on individual prob-
lem-solving steps-paraphrasing the problem statement, convert-
ing the statement and given data into diagrams and equations,
doing the required math, checking the result, and writing out the
solution in a way that makes it easy for the grader to see clearly
both the final result and the procedure used to obtain it. The next-
to-last chapter suggests steps the student can take when unable to
solve a problem, and the final chapter presents tips for the effective
use of spreadsheets in problem solving.
Scarl's book is well written and clearly aimed at students. It
contains numerous examples and chapter-end exercises, most of
which are drawn from elementary mechanics, and a collection of
twenty-five problems and worked-out solutions in the author's
suggested format. Many students (particularly sensors on the Myers-
Briggs Type Indicator) will welcome the detailed checklists pro-
vided for every step of the problem-solving process; other students
and many professors (MBTI intuitors) may find the presentation
excessively prescriptive and some of the suggested methods too
busy (e.g., the student is instructed to write out all relevant equa-
tions twice-first in their general forms and then again with known
variable values substituted into them). Moreover, the inclusion of
some chemistry problems and more varied engineering problems
among the examples and exercises would have made the book more
useful for first- and second-year engineering curricula. Neverthe-
less, both students and instructors will find the book a good source
of practical ideas for solving quantitative homework and test prob-
lems in basic science and engineering courses.
Strategies of Creative Problem Solving, by Fogler and LeBlanc,
is less concerned with well-defined, single-discipline, single-an-
swer problems than with realistic and complex problems that re-
quire creativity and critical evaluation of alternatives to arrive at an
acceptable solution. The foundation of the suggested approach is
the McMaster five-step problem-solving heuristic (define the real
Continued on page 165
157











curriculum


A COURSE IN

COMMUNICATION SKILLS

For the Corporate Environment of the 1990s


CAROL MCCONICA
Colorado State University Fort Collins, CO 80523

he engineering curriculum traditionally acknowledges

the importance of written and oral communication
skills to the success of its graduates. Oral communi-
cation skills most frequently are interpreted to mean speak-
ing to groups. In many companies, however, interpersonal
interaction assumes greater importance in a graduate's suc-
cess than the rare group presentation.
Having recognized this importance, companies have be-
gun training engineers in interpersonal communication skills
and social styles. With training, engineers are able to recog-
nize that many personal work and communication styles
differ from their own. They learn to value and respect these
differences and learn how to best interact with people who
use these other styles.
At Colorado State University (CSU), we now include in-
terpersonal communication skills in our one-credit, senior
chemical engineering course on oral and written communi-
cation (see Table 1). Human behavior and time management
topics provide the core material for practicing oral and writ-
ten communication. The course gives students an insight
into the differences that exist among people and even within
one person as he or she ages. The goal is to balance the effect
of science education and its assumption that there is only one
right answer. This assumption, actually a belief system, of-
ten overflows into interpersonal relationships. In this course,
we show that interpersonal interactions are diverse, as people
are, and that success on the job often will depend upon
recognizing and adjusting to that fact.111

COURSE CONTENT
Initially, students are introduced to the concept of para-
digms-i.e., multiple ways of modeling or perceiving real-
ity. A person's behavior, and ultimately their time manage-
ment, results from their chosen paradigm. Paradigms are
unique to cultures as well as to professions. Each person has


Copyright ChE Division ofASEE 1995


Carol McConica, a full professor at Colorado State University, earned
her MS and PhD degrees from Stanford University. Prior to joining CSU,
she spent three years developing new integrated circuit (IC) processes for
Hewlett Packard. Her research areas include waste minimization during
IC processing, multimedia education, and power/gender issues in the
workplace. She co-advises students in psychology and counseling. On
the weekends she can be found racing her Austin Healey bug-eye Sprite
with her husband, mountain biking with her son, or rock climbing with her
daughter... or kayaking, snowboarding, windsurfing, etc.

a unique set of paradigms. The book The 7 Habits of Highly
Effective People, by Stephen R. Covey, is used as a training
tool. It helps students to identify their own paradigms and to
recognize those "Aha!" paradigm-shifting experiences. Imag-
ine the behavior shift that results when a person first under-
stands that disease is caused by germs rather than by spirits.
We manage ourselves and others most effectively from the
"inside-out," namely by understanding the paradigms by
which we all live.121
Covey offers several examples of paradigms that control
time management. Examples include being spouse-centered,
money-centered, work-centered, pleasure-centered, posses-
sion-centered, or principle-centered. Interestingly, some stu-
dents disagree with Covey's claim that the principle-cen-
tered paradigm is superior; this is not a curriculum concern,
however. The students must make formal oral presentations
on each book chapter, but are free to disagree. By being open
and accepting of varying student perspectives, the professor
models the very philosophy he or she seeks to teach-that is,
the value of different viewpoints. Because of this openness,
students are comfortable, learn, and become fluent in Covey's
approach to time management.
The course also introduces students to the Social Style
Profile used by both Hewlett Packard and Dow Chemical
Company in their interpersonal training courses.31 This ap-
proach is discussed as one model of human behavior in
which "control versus emote" and "ask versus tell" are the
axes for defining social style. The model's resulting quad-
rants are labeled as analytical, driver, expressive, and ami-
able. Students learn to recognize 1) their own primary social
Chemical Engineering Education











style, 2) the strengths of others, and 3) how modifications to
their social style increase effectiveness when dealing with
others who have different styles. As an example, when inter-
acting with "drivers," one should use bullets in written com-
munication, keep to the point, and state the bottom line first.
The driver needs freedom to take risks, wants control, and
will need others to listen. When interacting with "analyticals,"
one should include the details, cover all bases, remove risk
whenever possible, take time, be exceedingly prepared, know
the facts, and be reassuring.
Students inevitably feel uncomfortable with being catego-


TABLE 1
Course Schedule

Lecture Content
1 Define paradigm; give examples that demonstrate how easily
behavior is changed when viewpoint is changed; assign text
reading and tapes/book.
2,3 Explain Social Style Profile used by Dow and HP; give
examples, strengths and weaknesses of each quadrant; break
into pairs and work to identify each other's primary and backup
styles; exercises to modify style.
4 Meyers-Briggs Type Indicator; discussion of categories led by
counselor.
5 Student Team Presentations (STP) and discussion begin;
Overview of the text 7 Habits (Covey);
Summary of The Hero Within (Pearson)
6 STP: Being Proactive (Covey)
From Innocent to Orphan (Pearson)
7 STP: Begin With the End in Mind (Covey)
The Wanderer (Pearson)
8 STP: Put First Things First (Covey)
The Martyr (Pearson)
9 STP: Think Win/Win (Covey)
The Warrior (Pearson)
10 STP: Seek First to Understand (Covey)
The Magician (Pearson)
11 STP: Synergize (Covey)
The Return (Pearson)
Sharpen the Saw (Covey)
12 Guest lecture on diversity in the workplace; paradigms on
gender and intergender communication; (by Associate Director
of Women's Studies).
13 Guest lecture on negotiation styles and benefits (by the
University Ombudsman).
14 Conflict resolution; assessment of student styles and comparison
to styles of industrial managers.
15 Team building using Legos" to make a structure when only one
person on the team can see the structure and he/she is not
allowed to do the building (led by career development
counselor).
Final Exam: Written short-answer exam over concepts.

Summer 1995


rized and plotted as a data point on the social-style map. A
need to be viewed as a more complex being opens them up
to exploration of other paradigms of human interaction lead-
ing to the Myers-Briggs Type Indicator (MBTI) scale of
modeling personal behavioral tendencies. The MBTI scale is
not formally administered to the students, however; the cat-
egories are discussed as another paradigm that helps people
understand themselves and others. A guest speaker from the
counseling center presents the MBTI material.
The course also uses Carol S. Pearson's text and tapes
titled The Hero Within: Six Archetypes We Live By, which is
based on Jungian psychology. Here the students learn of a
paradigm that views humans as fluid and growing, focusing
on the archetypes of Innocent, Orphan, Martyr, Warrior,
Wanderer, and Magician. There are low and high levels for
each archetype, and according to the theory, we spend our
lives spiraling through them. For example, a low-level mar-
tyr is "other-centered" and expects to be pitied or rewarded
for self sacrifice, while the high-level martyr expects no
such reward and sacrifices on the basis of personal prin-
ciples. The Pearson resources help the students to learn how
to help a coworker through a low-level stage that may be
destructive to a work team. Another example includes a
worker caught in low-level Orphan, who acts victimized and
needs to be nurtured and reassured so that he or she can
become proactive about life. Then, there is the low-level
warrior, caught in "win-lose," who needs to be reassured
that when others win, individual worth is not diminished.
A self-administered test at the end of Pearson's book helps
students find their own distribution among the archetypes.
At times, they are completely surprised when they realize
their self-view and behavior are not aligned. The text re-
views the strengths and weaknesses of each archetype and
gives exercises for achieving higher levels of each stage.
At this point, the course circles back to Covey's text and
draws comparisons between his different paradigms and the
archetypes. Examples include drawing comparisons between
Warrior and "enemy-centered," or between Martyr and
"other-centered." The ultimate level of performance in
Pearson's paradigm is that of Magician, which is directly
analogous to Covey's "win-win or don't play" paradigm.
The students recognize that the competition in engineering
leads many of them to "win-lose," or even to "lose-lose,"
mentalities. Both are very destructive in the workplace.
The professor pairs the students and assigns an oral pre-
sentation on one of the archetypes. Those students who do
not like reading psychology books can check Carol Person's
tapes out of the chemical engineering office for up to a week
to prepare for their oral presentations. Each presentation
should explain the archetype clearly and contrast it with the
stages of personal development given by Covey. The other
students grade the presentations on content, clarity, enthusi-
asm, and presentation types. The presenters are required to
159










involve their audience and to assign a homework exercise to
the class.
Eventually, the students are asked to apply this philo-
sophical learning to issues in the workplace. They must
write a paper and are given a choice of books to read and
review (see Table 2). Ideally, they would take both Covey's
and Pearson's concepts and interpret their chosen text from
the point of view of these paradigms. The papers, due at the
end of the semester, are graded for content, spelling, and
grammar. They range in length from three to ten single-
spaced pages. An essay-format final exam is also given at
the end of the semester. The purpose of the exam is to test
the student's understanding of the texts by Covey and Pearson
and the students' ability to analyze the various materials.
Favorite books in 1994 included Disclosure (by Michael
Crichton), Conceptual Blockbusting (by James Adams), You
Just Don't Understand (by Deborah Tannen), and The Fifth
Discipline (by Peter Senge). Crichton's book stimulates an
excellent paradigm shift in telling the story of a man who
was sexually harassed by a woman superior in management.
The male students understood the reality of sexual harass-
ment and that the misuse of power transcends gender. Con-
ceptual Blockbusting details the phenomenon of being stuck
in a paradigm and how to shift. It is directly relevant to the
course, and the students who reviewed it recommended that
the text be required reading for all engineering students. The
female students resonated with Deborah Tannen's book and
found excellent explanations for their sense of isolation within
the engineering field. Tannen details how the "win-lose"
style of communication, which often exists in engineering
organizations, works to erode the self-esteem of women.
The women who read this book realize that they will have to
jump to Covey's "win-win or refuse to play" paradigm if
they are going to survive in engineering. The Fifth Disci-
pline is less personal in nature, but offers a completely
different perspective of organizations. Students began to
realize that vital organizations are dynamic, just as vital
people are dynamic.
Within the course, it has been important to have a range of
texts that correspond to the range of psychological develop-
ment found in the students. While some students need a very
personal "Aha" experience, as given by Crichton, others
need a more objective one, such as given by Senge. Because
they chose their own books, the students felt comfortable
with what they reviewed.
A number of other related topics are also covered in the
course: the University Ombudsman lectured on negotiation
styles; a guest speaker from the Women's Studies Program
helped students recognize that diversity is an issue as broad
as the number of people in the workplace. This speaker
showed how each person has a unique culture and thus a
unique paradigm, and that an optimal work environment
would embrace each unique individual. Diversity is not sim-
160


ply about race or gender. Rather, it is about being an indi-
vidual, whether poor, rich, creative, analytical, religious,
driven, growing, expressive, short, tall, or amiable.

DISCUSSION
The course is unique in the engineering curriculum. Its
content is such that it is best "facilitated" rather than pre-
sented in a lecture format. The professor arranges for guest
speakers, sets the assignments, and guides the discussions
toward the educational mission. The students present their
material in a formal manner with handouts and overheads.
They are encouraged to create participatory demonstrations
for the class. Debate is encouraged as long as arguments are
substantiated with facts. "I" statement expressions of feeling
are encouraged.
Students often experience paradigm shifts because of the
course. One student realized that his poor performance in
school was the result of not aligning his behavior with his
values. What Covey's book communicates so well is that
success can only come from congruency between beliefs and
behavior. This student realized that what he truly valued was
being a high-school teacher and a coach, not an engineer. As
a result, efforts to change his behavior from the outside-in
had just never met with success. Recognizing this, he brought

TABLE 2
Texts Used in Course
Required Texts
The 7 Habits of Highly Effective People, Stephen R. Covey; Simon
& Schuster, NY, 1989
The Hero Within, Carol S. Pearson; Harper, San Francisco, NY,
1989

Recommended Texts
Women in Engineering, Gender. Power. and Itorkpiace Culture,
Judith Mcflwee and J Gregg Robinson. Stae Uni, eriitq of New
York Pres.. 1992
That's Not What IMeant, Deborah Tannen; Ballantine Books, New
York. 1986
You Just Don't Understand, Deborah Tannen; Ballantine Books,
New York, 1990
Intercultural Communication, Larry A. Samovar, Richard E. Porter;
Wadsworth Publishing Company, Belmont, CA, 1990
Women's Reality, Anne Wilson Schaef; Harper San Francisco, New
York, NY, 1992
Re-Inventing the Corporation, Hohn Najbit. Patncia Aburdene;
Warner Books, Megatrends Ltd., New York, NY, 1985
The Fifth Discipline: The Art and Practice of the Learning
Organization, Peter M. Senge; Doubleday/Currency, New York,
NY, 1990
Conceptual Blockbusting, James Adams; San Francisco Book
Company, 1976
Principle Centered Leadership, Stephen Covey; Fireside Book,
Simon and Schuster, 1991
Disclosure, Michael Crichton; Alfred A. Knopf, Inc., New York,
NY, 1993

Chemical Engineering Education










his behavior in line by studying for a second degree in
education and shifting paradigms from "other-centered" (what
he perceived society values) to that which he values.
A powerful shift occurred for another young man when he
stated, "I wish we could go back to the 1950s. It was so easy
then because everything was fair before diversity. Men were
hired simply on their qualifications." This statement resulted
in a class discussion on hiring practices throughout history.
The students decided that hiring has never been fair, even for
white males. In Boston, getting a job in the past may have
required a degree from Harvard or being a member of the
correct yacht club.
The skills taught in this class help students to cope with
today's job market. Covey's "be proactive" is analogous to
the effort needed to leave the Orphan archetype. In the last
two years, hiring has been slow and students are quick to fall
into Orphan, blaming others for their predicament. An in-
tense class discussion occurred when the students were asked
to list their attitudes about the job situation and then to
identify the archetype that represented their behavior. They
realized that blaming professors, women, minorities, and
equal opportunity for the lack of a job is very low-level,
orphan behavior. They spent time listing proactive behaviors
and ways to solve the problem. In the spring of 1994, this
proved to be the most emotional exercise of the semester,
and correspondingly, the most useful in terms of applying
the course material.
The student response to this course has been consistently
bimodal for the last four years. About 80% of the students
love it absolutely and wish that they had learned these con-
cepts as freshmen. When I see these students several years
after graduation, they report that it remains one of the most
influential courses they took in engineering college-while
they long ago forgot differential equations, they continue to
look at their boss and ask, "I wonder what his/her assump-
tions are? What is his/her paradigm?" Course comments
include: "Great!! The most important thing I've seen in four
years as a ChE student. Should be supported and valued by
other professors," and "Excellent, great topics, really made
me start to think," and "The class I feel should be a two-
credit class that is required for every engineer to take each
year of his engineering program and should include stress
management and more role playing."
The remaining 20% of the students remain skeptical to the
end. They see no relationship between social science and
engineering. They are so immersed in their own paradigms
that they simply cannot shift. They seem to believe that the
workplace is just like a classroom -"do your homework
and get an 'A'" becomes "solve the technical problem and
earn a promotion." Sample comments from these students
include: "It introduced me to new topics, but didn't teach me
anything," and "It was alright. Didn't learn anything I really
need to know. Liked the teacher."
Summer 1995


Letter to the editor


PHASE BEHAVIOR CASSETTES AVAILABLE
Dear Editor:
In the late 1960s, I prepared some instructional films
(remember films?) on phase behavior (both single com-
ponent and binary) with the help of the National Science
Foundation and the Chevron Oil Field Research Com-
pany.
These films have now been transferred to video cassette
and are available at cost from the Department of Chemi-
cal and Fuels Engineering, University of Utah, Salt Lake
City, UT 84112.
For ordering information and a written description of
the content of the films, please call or write
Noel de Nevers
801-581-6024
ndn@che.utah,edu

Interestingly, in the eight years that I have taught various
versions of this course, fewer than a handful of women have
been in the skeptic group. The women are either inherently
interested in social issues or are so tired of being the 'out'
group that they hunger for validation of their obviously
different paradigms. Applying the concept of paradigms to
issues of race and gender in the workplace has resulted in
useful class discussions. Today, white males are often at a
loss as to what behaviors are problematic and what behav-
iors are perfectly acceptable. Giving both women and men
the skill to shift paradigms and shift belief structures will
allow them to be more successful at work.
In conclusion, we are offering a course that broadens the
definition of communication. It trains students to communi-
cate successfully at the interpersonal level in the workplace
of the 1990s. They should leave with a vision of the work-
place as a fluid system filled with people who are constantly
growing and changing. A corporation is a wonderfully di-
verse stew-teams peppered with different points of view
are potentially the most satisfying and innovative. As a
result of including new communication skill material, our
"minority" students leave more prepared to be successful in
their careers and our "majority" students can claim greater
knowledge of diversity issues and interpersonal skills.

REFERENCES
1. Kuhn, Thomas S., The Structure of Scientific Revolutions,
University of Chicago Press, Chicago, IL (1970)
2. Covey, Stephen R., The 7 Habits of Highly Effective People:
Restoring the Character Ethic," Simon and Schuster, NY
(1989)
3. Managing Interpersonal Relationships, Wilson Learning
Corporation (1989) 0











= classroom


THE WORLD WIDE WEB

For Teaching Chemical Engineering


HENRY BUNGAY, WILLIAM KUCHINSKI
Rensselaer Polytechnic Institute, Troy, NY 12180-3590


he World Wide Web (WWW) is an impressive re-
source and has the potential to change education.
Navigating the WWW is part of an expanding use of
computers in Rensselaer Polytechnic Institute's (RPI) courses
in chemical engineering and environmental engineering. This
paper addresses ways of using networking and the WWW in
teaching.
User-friendly software, such as Mosaic, for navigating the
WWW can present material in a highly entertaining man-
ner.[11 Assignments with the WWW in courses in environ-
mental engineering and chemical engineering at RPI are
popular with the students, but the best ways of using the
WWW for teaching are still to be discovered. Our experi-
ences will provide some insight into that potential of the
WWW and will raise questions about how to best exploit its
vast informational resources.

BACKGROUND
The RPI system is typical of how a research university
handles computing. The campus mainframes or servers em-
ploy Unix and programs for the usual editing, spreadsheeting,
and drawing, and compilers for various languages (such as
C++ and Pascal and the like), as well as a wide variety of
less common programs. About a dozen classrooms have a
permanent computer, a VCR, and a projector. In our chemi-
cal engineering department, there is one mobile station with

Henry Bungay teaches environmental engineer-
ing and chemical engineering at Rensselaer Poly-
technic Institute. He has written several books that
are integrated with computerized teaching and has
published numerous educational computer pro-
grams.


MAJ. William Kuchinski, a 1984 graduate of the
United States Military Academy at West Point,
New York, is on active duty pursuing a Masters
Degree in Chemical Engineering. His next assign-
ment will be as an instructor in the Department of
Chemistry at West Point.
Copyright ChE Division of ASEE 1995


a computer and a high quality projector that can be wheeled
into various classrooms that have jacks connected to the
campus network. There are jacks in student dormitory rooms
to connect with the network at high baud rates, and modems
can be used from other locations. Many students do not own
a personal computer and must use public terminals or work
stations that are scattered throughout the campus and in
computer laboratories. Practically every computer on cam-
pus can connect to our network (actually a number of sepa-
rate networks that are interconnected).

EDUCATIONAL COMPUTING
Freshman and sophomore courses use math programs (such
as Maple), and banks of classroom computers promote the
teaching of physics, chemistry, and mathematics. By the
time students take chemical engineering courses, they ex-
pect to use computers routinely. Anywhere from 30-90% of
the students regularly use e-mail as they embark on the
departmental courses. Prof. Wayne Bequette emphasizes
Matlab in his process control course to the extent that our
students become experts, and telecommunication and the
WWW are stressed in the biochemical engineering course
and in two environmental courses. Using BASIC and per-
sonal computers for running teaching programs has been
described in a previous article in this journal.2' Simulations
are also demonstrated in class, using the projector to explore
terms in equations. The files that are used in class are in the
instructor's public directory where students can copy them.
Easy interchange of graphics files is also becoming impor-
tant. One class assignment requires using a program for
converting file formats; the students can take a file from just
about any computer system and convert it to the format used
by a different computer. We also find picture files and clip
art on the Internet for free downloading.
Some student computing accomplishments are:
Deriving differential equations that describe
processes, translating them to computer code, and
learning from computer simulation.
1 Familiarity with mathematical programs and
Chemical Engineering Education











knowing when to use them.
Navigating the Internet and downloading information;
organizing and interpreting the information from
lectures, assignments, and the WWW.
Using full-featured programs that manage text, data
bases, and images to prepare reports that can be
printed but are often transmitted by e-mail or posted on
bulletin boards or newsgroups for the courses. (Our
newsgroup addresses are rpi.courses.bioengr and
rpi.courses. environmental.)
The students have mastered several ways of solving problems
with computers. Even better, they use their computer tools
without being told to do so in senior courses. In other words,
they appreciate computerized methods and recognize when to
use them.

TEACHING MATERIALS ON THE WWW
Some very nice materials of interest to chemical engineers
are on the WWW. Two examples, and addresses, are:
A multi-author book about computer science with a
particularly valuable chapter about the Internet.
http://compsci.cas.vanderbilt.edu/csep/html
and
> An environmental archive at the University of Natal,
Durban, South Africa, with emphasis on separations,
especially membranes.
http://www.und.ac.za/prg/prg.html
We have our own archive for biochemical and environmental
engineering. It includes compressed collections of teaching pro-
grams that run on personal computers, digitized images that are
shown during lectures (the quality of color images when pro-
jected is superb), and hypertext tutorial packages. The address
for anyone on the WWW is
http://winston.eng.rpi.edu/dept/chem-eng
or
http://www.eng.rpi.edu:80/dept/chem-eng/
Some nice hypertext tutorials have been contributed by stu-
dents. Among the options for term projects is creating a teach-
ing aid for the WWW. We have over thirty new WWW pack-
ages that represent the work of about forty-five students be-
cause some prefer to have a partner. Two such packages pre-
pared by the instructor were provided as templates for the
students. They had to learn almost nothing about the .html
language used for the WWW-they merely had to "cut" from
the template files and "paste" in their own materials in the
appropriate places. Table 1 lists our current collection of
hypertext presentations.
None of us has had much experience in developing hypertext
teaching presentations, and as a result our results vary from
amateurish to pretty good. But the students said it was fun and
Summer 1995


challenging to devise a teaching aid, and they enjoyed seeing
their project distributed to the world (most term projects
over the years have been filed away and lost). An unex-
pected but nice feature added by several students was a
personal touch. They incorporated clip art from the Internet
for light touches, and some went as far as including a page or
two on their views of life. We very much hope that others
here and elsewhere will improve our presentations or even

S.. navigating the WWW can present material
in a highly entertaining manner.11 Assignments
with the WWW in courses in environmental
engineering and chemical engineering at
RPI are popular with the students,
but the best ways of using the WWW
for teaching are still to be discovered.



TABLE 1
RPI Hypertext Presentations

For Both Environmental and Biochemical Engineering
Adsorption
Growth Rate Relationships
Biochemical Oxygen Demand (BOD)
Microfiltration
Sedimentation
Ion Exchange
Coagulation/Flocculation
Microbiology of Waste Treatment
Microbial Degradation of Aromatic Hydrocarbons
Membrane Diffusion
Aeration
Granular Activated Carbon
Laboratory Safety
Quiz
Principally for Biochemical Engineering
Purification-Early Steps
Brewing #1
Brewing #2
Chromatography
Immobilized Enzymes #1
Immobilized Enzymes #2
Fermentation
Biotechnology Overview
Precipitation
Principallyfor Environmental Engineering
Troy Water Treatment Plant
Fluoridation
Incineration
Albany Waste Treatment Plant
Guilderland Waste Treatment Plant
Glens Falls Waste Treatment Plant
Septic Tanks
Environmental Systems Engineering
Artificial Intelligence Terminology
Neural Networks
Expert Systems
Hardy Cross Introduction
An ESE Quiz










attempt to surpass us. Through evolution some outstanding
teaching aids should become available.

HYPERTEXT
Hypertext depends on interlinking. The user is presented
with lists, paragraphs, and options that include "buttons" or
"hot words" to click on to link to different files that can be text,
sounds, simple images, or video clips. Links can go anyplace
on the Internet, but remote materials are very unlikely to have
further links that can maintain the same thought pattern. You
simply click on "BACK" to return to the home presentation.
With color, animation, and sound available, computer presen-
tations can surpass books and lectures, and the interactive
features are superior to movies and videos.
One concept of hypertext is layers of information, giving the
user the option of browsing casually or delving deeply. Some
of our presentations allow following a main thread or digress-
ing. Equations can be written with little explanation or deriva-
tion because there are "hot words" that will bring up the details
if needed. Even the derivations can be layered; algebra that is
easy for some is not so obvious to others who may wish to
click on "very simplified algebraic manipulations." We have
some duplication of term topics. These can be interlinked so
that material is presented again in different words or is supple-
mented with selections from the other presentation.
The instructor's goal is to have teaching aids that supple-
ment or replace traditional lectures or recitations. (Thus far,
only two or three lectures in our courses have been totally
replaced by a WWW session.) This adds flexibility to a course;
illness or travel need not mean a lost lecture when a teaching
presentation on the WWW can fill the gap.
Although hypertext is clearly a great way to present informa-
tion, computers can also teach with simulation and with inter-
active games. Most of our simulation and gaming programs
were written in BASIC and run nicely on personal computers.
Teaching programs for the courses are compressed into groups;
the student takes one compressed file from a campus account
to a personal computer, invokes the decompression program,
and all of the programs pop out in decompressed form, ready to
run. Some programs for which we have a classroom license
cannot be in the public directory because anyone in the world
could download them. These have to be distributed individu-
ally to the students. But we have some freeware and shareware
programs in the archive.
Since our teaching packages are in the public domain, there
is no financial reward for our hard work. There wasn't much
choice in this respect because with over two hundred BASIC
programs and the WWW projects with contributions from
many students, and it would be impossible to apportion the
money if we had a commercial publisher.

EVALUATION
Much of our networking is local, with course descriptions,


TABLE 2
Teaching Tips

Get the file of student names from the registrar. This can be cast
into spreadsheet format for grading in just a few minutes.
Put the grading spreadsheet in a public directory so that students
can inspect it at any time. Use aliases instead of names to ensure
confidentiality. By comparing their grades to others, students can
learn how they stand.
Put course information on the WWW. Less paper is then handed
out in class and updating is easy. Course descriptions can be good
advertising to bring students to your institution.
Digitize slides, photos, and drawings for projection in class. Put
them on the WWW so your students can include them in notes
and reports, as can anyone on the Internet.
Use e-mail as the main method for communication outside of the
classroom. E-mail is less frustrating and more convenient than
making an appointment or standing in line to see someone. Phone
calls tend to come at the most inconvenient times!
Post assignments in a public directory or in the class newsgroup.
This saves paper and facilitates corrections.
Collect homework, reports, and term projects that are not large by
e-mail to the teaching assistant. A student puts large project files
in his or her public directory. Downloading from the student
account works better than having them hand in floppy disks
because the different densities, formats, and operating systems
create problems.



assignments, tips, instructions, some lecture notes, and grade
spreadsheets on line. Navigating the WWW to search for
useful materials at other institutions is becoming routine.
There is no doubt that students find the network useful. They
quickly appreciate Mosaic, and they also use ftp for file
transfers. They are provided with addresses of archives of
tens of thousands of files for downloading, including com-
puter utilities, spreadsheet programs, languages, and almost
anything else that can be imagined. This availability got one
of our older students in some trouble after he showed his
twelve-year old son how to download and his wife later
found that the son was using their computer in the dead of
night to capture raunchy pictures that he was selling to
classmates.
The WWW and RPI's computing systems are in place.
The cost to us is nearly zero, but we must assess whether the
payoff from heavy emphasis on computing is worth the
bother. The students are enthusiastic because most of the
computing is fun, and navigating the WWW is highly enter-
taining. Furthermore, recent graduates state that computer
skills helped them find jobs and enabled them to perform
well in comparison to alumni of universities that place less
stress on extensive computer training. Knowing how to search
the scientific and engineering literature is important, and
finding relevant information can impact their lives in many
ways. The problem is interpreting such a vast amount of
information. Some educators fear that cruising the WWW
Chemical Engineering Education











may just replace watching television as a distraction that
keeps people from really being educated.

CHANGES IN TEACHING
Key concerns are whether education is improving and
what the professors are doing differently. Students who de-
velop hypertext presentations learn more about the topic
they wish to teach and better appreciate the problems of
devising good explanations. Students who learn from the
presentations benefit because they can progress at an indi-
vidual pace, going fast when they wish and branching back
when a concept needs reinforcement. The visual aids tend to
be elegant compared to hasty sketches done in class. Our
best presentations compare well with a lecture, although
there is still room for improvement.
If the evolution of teaching materials on the WWW makes
lectures obsolete, there may be little future need for profes-
sors-but the professor's role can change. While it is not


much fun or much of a challenge to give the same old
elementary lecture year after year, we may finally have the
time to develop first-rate laboratory courses with extensive
computer interfacing and with programs that help collect
and interpret data. The lectures that remain can be advanced
and exciting, with the latest gleanings from research litera-
ture. Our most important role could well be guiding students
through the glut of information on the Internet.
It is too early to summarize since teaching with the WWW
is still in its infancy. Our hypertext packages are far from
finished, and they may never be. A little more of the flavor
of chemical engineering computing at RPI can be gleaned
from the teaching tips in Table 2.

REFERENCES
1. Hayes, B., "The World Wide Web,"Amer. Sci., 82, 416 (1994)
2. Bungay, H.R., "Biochemical Engineering, With Extensive
Use of Personal Computers," Chem. Eng. Ed., 20, 122 (1986)
n


REVIEW: Three Books on Problem Solving U
problem, generate possible solution plans, decide on one, imple-
ment it, evaluate the solution). Many models and algorithms are
suggested for implementing the steps, e.g., brainstorming tech-
niques developed by Osborn, Adams, and deBono, Kepner-Tregoe
(KT) problem analysis to obtain a clear problem definition, KT
decision analysis to choose the best solution from a number of
alternatives, resource allocation tools like Gantt charts and critical
path analysis, and a host of evaluation checklists. Each chapter
concludes with a reference list and a set of exercises. The authors
have also prepared eleven interactive computer modules that supple-
ment the text coverage of critical aspects of the proposed problem-
solving methodology.
The book could have been dry to the point of unreadability if the
authors had simply chronicled the recommended strategies. Fortu-
nately, they have done much more, making the text one that stu-
dents will actually read. Every suggested procedure is illustrated by
case studies and anecdotes (some humorous) about disasters that
can or did result from failure to adopt a systematic problem-solving
strategy. The typographical layout is rich in visual content-high-
lighted boxes, marginal notes, and clever hand-drawn sketches.
Some of the exercises in early chapters may strike some students
and professors as too "touchy-feely" (like "Choose three of the
habits of highly effective people and explain how you will practice
them during the coming weeks"), but most are ingenious puzzles-
familiar crises (like having your car break down on the way to an
important appointment), brainstorming exercises, logical brain teas-
ers, and real industrial problems. In fact, the examples and chapter-
end exercises alone justify the cost of the book, being both enter-
taining and potentially valuable sources of problem material for
many engineering courses.
The third book, Woods' Problem-Based Learning, is addressed
to students in a class built around problem sets or case study
analyses done by largely self-directed and self-assessed student
teams. The book summarizes the instructional features, difficulties,
and benefits of the PBL approach and provides tips for developing
the problem-solving, independent and interdependent learning, and
Summer 1995


Continued from page 157.
self-assessment skills that the approach is designed to foster. An
instructor's guide and a 26-minute videotape are available from the
author.
The book is a lot like its author. Don Woods probably knows
more about teaching and assessing problem-solving skills than
anyone else in the world, and he is generous about sharing his
expertise. As anyone who has ever gotten into conversation with
him knows, ideas about teaching methods and assessment devices
come pouring out of him like water from a dam release, leaving the
listener scrambling to retain a fraction of the ideas and wishing for
a tape recorder. The book is similar-a dense forest of elaborate
concept maps, checklists, rules-of-thumb, and tabular comparisons
of different learning and problem solving and information process-
ing styles. I cannot imagine many students actually reading all this
material. Moreover, the examples are few and very general (e.g., a
detective puzzle about a jewel robbery) and will do little to help
students relate the text material to their own lives and career inter-
ests or to apply them in their own disciplines.
On the other hand, the book's wealth of material makes it a
valuable reference for instructors using some form of problem-
based learning or any active or cooperative learning techniques in
their classes. It offers an insightful analysis of why some students
are likely to resist any nontraditional teaching method and gives
explanations, motivating messages, checklists, exercises, assess-
ment instruments, and an exhaustive list of references for each of a
broad assortment of problem-solving, critical thinking, and inter-
personal skills.
Taken collectively, Scarl's practical tips for solving basic prob-
lems, Fogler and LeBlanc's strategies for attacking more sophisti-
cated problems and their splendid collection of real-world ex-
amples and exercises, and Woods' compilation of barriers to skill
development and methods to overcome them provide all the tools
instructors might ever need to convert their students into confident
and creative problem solvers and engineers. I recommend these
three books as valuable additions to any engineering professor's
bookshelf. 1











Random Thoughts ...






GETTING STARTED


EDITORIAL NOTE: Beginning this month, the Random Thoughts Column written by Richard Felder will
occasionally be coauthored by Dr. Rebecca Brent, an Associate Professor in the School of Education at East
Carolina University in Greenville, North Carolina. Dr. Brent has published articles on a variety of topics including
writing across the curriculum, educational simulation, and cooperative learning in higher education. She regularly
presents teaching workshops with Dr. Felder on campuses around the country and abroad.




RICHARD M. FELDER North Carolina State University, Raleigh, NC 27695-7905
REBECCA BRENT East Carolina University, Greenville, NC 27858


he first day of a course may not determine how well
the rest of the course works, but it goes a long way. A
good start can carry the instructor through several
weeks of early shakiness, and a bad one can take several
weeks of damage control to overcome.
Instructors have come up with many ways to get courses
started-some effective, others less so. A relatively ineffec-
tive way is to stride into class, announce your name, the
course, and the coure text, and start to write differential
equations on the board. Following is an alternative approach
with somewhat better prospects.

Opening Formalities. Introduce yourself and hand out the
following items:
1. A syllabus containing the course name and catalog
description, your name, office number, and office
hours, the course prerequisites, and required and
supplementary texts. In addition, if you plan to use
e-mail or a list server for student conferencing (a
fine idea), include the necessary information on the
syllabus or a separate handout.
2. A list of instructional objectives-the things you
expect the students to be able to do (calculate, esti-
mate, explain, design, create,...) by the end of the
course. This list serves several purposes. It helps
you plan lectures and class activities and prepare
homework assignments and tests, helps the students
understand the course structure and prepare for ex-
ams, and tells faculty colleagues who teach subse-
quent courses exactly what students who pass this
one should know.m' The list may be nontrivial to
construct initially, but it is easy to modify in subse-
quent course offerings.


3. An assignment schedule with dates for all reading
and problem assignments and examinations. Hand-
ing out a complete assignment schedule on the first
day can help you stay on track during the semester,
and setting all exam dates on Day 1 cuts down
considerably on the griping about time conflicts that
always occurs when instructors schedule tests a week
or less in advance.
4. A statement ofpolicies andprocedures. Answer ques-
tions like "What counts toward the final course grade
and by how much?" "How many tests?" "Open-
book or closed-book?" "Is the lowest test grade
dropped or given less weight than the other test
grades?" "What happens if a student misses a test
with a valid excuse? Without one?" "Will home-

Richard M. Felder is Hoechst Celanese Profes-
sor of Chemical Engineering at North Carolina
State University. He received his BChE from City
College of CUNY and his PhD from Princeton. He
has presented courses on chemical engineering
principles, reactor design, process optimization,
and effective teaching to various American and
foreign industries and institutions. He is coauthor
of the text Elementary Principles of Chemical Pro-
cesses (Wiley, 1986).

Rebecca Brent is Associate Professor of Educa-
tion at East Carolina University. She received her
BA from Millsaps College, her MEd from Missis-
sippi State University, and her EdD from Auburn
University. Her research interests include appli-
cations of simulation in teacher education and
writing across the curriculum. Before joining the
faculty at ECU, she taught at elementary schools
in Jackson, Mississippi, and Mobile, Alabama.
She received the 1994 East Carolina University
Outstanding TeacherAward.
Copyright ChE Division ofASEE 1995
Chemical Engineering Education











work be accepted late?" "May students work in
groups on homework?" "Must they do so?"
"What's the attendance policy?"
Spend time in class only on Item 4, concentrating on
policies that may be new and unfamiliar to the students.
Putting all of the information in Items 1-4 on handouts
and not taking up class time for most of it buys time for
some of the first-day activities to be suggested.
We strongly recommend putting your policies and pro-
cedures in writing and handing them out on the first day
of class. Students will accommodate to any set of rules
you give them up front, as long as the rules are clear,
reasonable, and consistently enforced. It's when you make
them up as you go that the lawyers come out of the
woodwork, and you end up spending much more time on
explanations and arguments during and after the course
than it would have taken you to prepare the handout
before the course.

Do something that will help you learn the students'
names. For example, circulate sign-up sheets by rows
and ask the students to keep their seats for at least a few
weeks. Prepare a seating chart after the class and use it
thereafter to associate names with faces. In small intro-
ductory or elective classes where the students are mostly
unknown to you and possibly to one another, you might
have them all give their names and state a hobby or
something unusual about themselves while you take notes.

Do something to motivate the students' interest. Fol-
lowing are possible things you might do in the first one or
two class periods.

C Show a graphic organizer (concept map, flow
chart)for the course, perhaps linking the topics to
topics from prerequisite courses and/or to the in-
structional objectives. Reference 2 contains an
illustrative organizer for the stoichiometry course.
A visual outline of a course is particularly helpful
for students whose learning styles are visual (most
students) and global.'3
C Have students anonymously write and hand in a
list of things they know about the course content
and questions they have about it. Reading their
lists will help you decide how to begin the presen-
tation of the course material. This exercise is par-
ticularly useful in a course that draws students
from different backgrounds.
) Share advice from previous students collected at
the end of the last course offering. This is also a
great exercise for the stoichiometry course. If the
idea appeals to you, next time you teach that
course collect suggestions on index cards during
Summer 1995


the final week, compile them, and use them at the
beginning of subsequent course offerings. You'll
find that the suggestions will be pretty much the
same ones you would make, the difference being
that the new students are more likely to hear them
when they come from other students.
C Have students write goals for themselves (grades,
intention to keep up with assignments,...). Collect
them and pass them back as reminders a few
weeks into the semester.
) Present some problems-preferably with real-
world connections-that the students should be
able to solve by the end of the course. The sens-
ing, inductive, and global learners[31 in the class
will all benefit from this stage-setting. You might
then choose one of the problems and get students
to work in groups to generate ideas for solving it.
(Assign the same problem near the end of the
course, at which point they should be able to solve
it and so get a better appreciation for how far
they've come.)
0 If you plan to use much cooperative (team-based)
learning in or out of class, say something about
why you're doing it and run an introductory team-
building exercise. (See Johnson, Johnson, and
Smith141 for ideas.) Some students will initially be
uncomfortable or hostile when they find that they
have to work in teams;15' a little preliminary sales-
manship can be invaluable in countering their re-
sistance.

Don't attempt to implement all of these ideas in a single
class: it would take too long and would overwhelm most
students. Rather, glance through the list before the course
begins, pick one or two activities that look like they might
be appropriate for your class and your students, and give
them a try. Afterwards write a few notes on how well or
poorly each exercise worked and what you would do
differently next time. It should only take a few iterations
to find the optimal combination of exercises for each
course you teach.

REFERENCES
1. Wankat, P., and F. Oreovicz, Teaching Engineering,
McGraw-Hill, New York, NY, 47 (1993)
2. Felder, R.M., "Knowledge Structure of the Stoichiometry
Course," Chem. Engr. Ed., 27(2), 92 (1993)
3. Felder, R.M., "Reaching the Second Tier: Learning and
Teaching Styles in College Science Education," J. Coll.
Sci. Teaching, 23(5), 286 (1993)
4. Johnson, D.W., R.T. Johnson, and K.A. Smith, Active
Learning: Cooperation in the College Classroom, Interac-
tion Books, Edina, MN (1989)
5. Felder, R.M., "We Never Said It Would Be Easy," Chem.
Engr. Ed., 29(1), 32 (1995) D










MM learning in industry


CREATE A SUCCESSFUL

SUMMER ENGINEERING PROJECT



ROBERT W. BEDLE
DuPont-Merck Pharmaceutical Company PRF Bldg (Sl) Deepwater, NJ 08023


any of us had experience either as summer engi-
neers during our university experience or as engi-
neering mentors to others during a summer as-
signment. While there is no doubt that a summer engineer
can benefit by gaining experience in an industrial setting, the
summer assignment can also benefit the industrial firm, pro-
vided that adequate preparation, planning, and common sense
are demonstrated on the part of the sponsoring or mentoring
engineer. The following areas should be considered.

Project Selection
*A good concept to use in selecting a project is, "I'd like
to ..., but my boss, duties, etc., do not allow me to." To
some extent, a summer project can be an opportunity to
explore a concept or an assignment that you believe can
be valuable, but which you cannot find the resources to


study personally. Don't be afraid to gamble on an idea if
it seems to have potential. The enthusiasm you have for
a project will be reflected in the enthusiasm of the
summer engineer.
* Be sure that the selected project makes obvious business
sense so it will be well supported not only by manage-
ment but also by your co-workers.
* If necessary, tailor the project to fit the abilities of the
summer employee. It should not be easy, but neither
should it be overwhelming. Carefully consider the
intern's experience and educational level. Try to match
both the skills and the interests of the intern.
* Finally, have a backup project available "just in case."

Preparation
This can be the key to avoiding frustration since
the summer engineer may have only ten weeks
to complete the project.
* Before the summer engineer arrives, prepare a 1-2 page
summary of the project. Include sources of background
information (people, reports, etc.), the project objectives,
the available resources, and a suggested starting approach.
* Have a workplace ready and the necessary tools for the
job assembled (e.g., safety equipment, lab space and
equipment, telephone, personal computer, e-mail account)


Copyright ChE Division ofASEE 1995


Chemical Engineering Education


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


Robert W. Bedle is a Principal Research Engi-
neer with the DuPont-Merck Pharmaceutical
Company in Deepwater, New Jersey. He has
nearly twenty-five years of research and pro-
cess engineering experience with DuPont-
Merck, DuPont, and Exxon. Rob has a BSChE
from the New Jersey Institute of Technology
and a MSChE from the University of Virginia.
He is a Registered Professional Engineer in
Delaware.










so the employee won't waste valuable time waiting to
get started. Ask yourself, "What would I need in order to
start work immediately?" Don't wait for the summer
engineer to arrive to begin gathering things together, or


(even worse) don't expect the engineer
thing without help.
Discuss the project with your co-work-
ers and enlist their support before the
summer engineer arrives. Make arrange-
ments for any necessary hands-on train-
ing, and consider scheduling pertinent
meetings.
Since we are often out of the office on
business or vacation, be sure to make
arrangements for a co-worker to be a
surrogate sponsor during any absences.

Project Implementation
Implementation will follow naturally if
the sponsor's project selection, planning,
and preparation have been adequate. The
project implementation has two phases:
Initial Phase During the first two to


to find every-

While there is
that a summer.
can benefit b
experience
industrial se
summer assig
also benefit thi
firm, provi
adequate pre
planning, an
sense are den
on the par
sponsoring or
engine


three weeks, the student will settle into the new surround-
ings, will become familiar with the necessary background
information, and will start "doing something." During this
time the sponsor should be especially tuned both to the scope
of the project and to the student's abilities. Does the summer
engineer understand what is expected? Is the project too
hard or too easy? Are adequate resources available? Does
the project still look workable? Are there any other con-
cerns? The answers can be found by spending time with the
student and watching how he or she approaches the problem.
Don't panic if progress is slow at this point, but be ready to
implement a backup project if it appears that the current
project is neither suitable nor workable.


Progress Phase During the ensuing weeks the summer
engineer should be making steady progress toward project
completion. As a sponsor, you should be ready to give ad-
vice and aid in overcoming any resource or bureaucratic
obstacles that might be encountered, and you should be
encouraging even when the student's
s no doubt approach differs from your own. After all,
r engineer an inquiring mind has been hired, not
just a pair of hands! But don't neglect
ly gaining
your responsibility to manage the
e in an project if the approach is unreasonable.
tting, the Periodically sit down with the summer
nment can engineer and formally review the results
e industrial to date. Confirm that a notebook is
led that being adequately kept and reiterate that a
written report will be expected by the end
'paration, of the summer.
d common
onstrated Wrap-Up
t of the The wrap-up should occur during the
mentoring final two weeks of the assignment, and in
some ways it can be the most challenging
e. period. A well-written report is essential
for both the summer engineer and for the
employer. For the intern, it provides a tangible measure of
accomplishment and a valuable educational experience.
For the employer it documents the work and the con-
clusions which have been reached. It also represents the
'product that the company has purchased.' Without a com-
plete and well-written report, the summer's efforts can eas-
ily become lost when the time comes to build on the work
completed by the summer intern. Often the sponsor will
need to do some prodding and editing to be sure that
the report is complete.
Finally, don't neglect showing the summer engineer your
appreciation for the work accomplished before he or she
returns to school.


CASE HISTORY

DEVELOPING A CORRELATION FOR PARTICLE SIZE VS. MIXER PARAMETERS
FOR A DOUBLE PLANETARY MIXER


0 Background
The DuPont-Merck Pharmaceutical Company (DMPC)
has embarked on the development of a novel polymeric
substance for a medically related application. The polymer
is produced by the addition-controlled reaction of a low
viscosity monomer solution to a premix of a second mono-
mer in a viscous (100,000 cp.) premix. The final product of
the reaction is an insoluble polymer in the form of a solvent
swollen polymeric mass composed of discrete polymer par-
ticles with the look and consistency of mashed potatoes. The
Summer 1995


control of the discrete polymer particle size is an important
consideration for the purification process following the reac-
tion step. To provide adequate mixing during this reaction
process, a 'double planetary' mixer-reactor (also called
'change-can mixerm) is used.
The DMPC engineers and chemists have been challenged
to aggressively move the process for this polymer into com-
mercial scale equipment. This product had been produced in
a 1-liter lab unit and in two different styles of 150-liter
reactors, one US based (see Figure 1, next page) and one
169










European based (Figure 2) in vendor trials. The selected manufacturing
site had an existing 500-liter reactor of a third configuration (Figure 3).
Due to time constraints and the lack of published criteria for the scale-up
of these reactors, the suitability of these reactors was determined by full-
scale tests. The test process conditions were selected to insure bracket-
ing the product requirements.
Based on the above experiences, a strong intuitive understanding of
the reaction process had been developed. Test data logs and retainer
samples were accumulated. The data had never been fully analyzed,
however, nor had a quantitative relationship been developed between
the polymer particle size, the reactor type, and the conditions.

Project Assignment
The challenges posed to the summer engineer were:
1. Learn to use a Malvern laser light scattering instrument to mea-
sure the particle size of the products from the reactor tests on a consistent
basis. This instrument measures the diffraction pattern of a suspension
of particles and transforms the information into particle size distribution
data. Find the most suitable liquid media for dispersing the particles for
the Malvern measurement.
2. Develop an empirical scaling relationship between particle size,
reactor mixer geometry, and reaction conditions. This entails consolidat-
ing, on a common basis, the mass of data available from the various
reactor tests.
3. Confirm any correlations developed by using the 1-liter lab reac-
tor.
While this may seem to be an overly ambitious project for a ten-week
summer assignment, the summer engineer had just completed his BSChE
degree with excellent grades, had significant prior summer work experi-
ence, and was headed to graduate school.

Preparatory Work
The sponsoring engineer had drafted a one-page letter outlining the
proposed assignment. Lab space was located with a functional lab reac-
tor and a personal computer with the necessary software. Arrangements
for training on the Malvern were made, and copies of reports from the
various reactor tests were made available. A meeting with a mixing
consultant was held to insure that the appropriate parameters would be
included in the work. This meeting was scheduled prior to the arrival of
the summer engineer in order to minimize the time required for him to
get organized.

Project Results
The summer engineer's assignment revealed the following results.
1. A liquid medium in which the raw polymer reaction mass would
disperse was found, and retainer samples were analyzed for particle size
distribution on the Malvern.
2. The summer engineer adopted a reaction monitoring scheme that
was under development by one of the process chemists. This scheme
was used to follow the reaction and to assign when the particle size was
"fixed" during the reaction process. Armed with this information, it was
then possible to characterize the reactor conditions (temperature and
170


Figure 1.
Reactor

Mfg.
'R'














Figure 2.
Reactor

Mfg.
'D'















Figure 3.
Plant
Reactor
Type
'L'


Chemical Engineering Education


SRpml


Rpml

Rpm2
















S R1 9


H
R2
j rl\











mixer speed) for each of the reactor tests at which the par-
ticle size was fixed.
3. Considerable effort was spent analyzing all data col-
lected in the various reactor tests, understanding the reac-
tors' different geometric configurations, and then develop-
ing plots of parameters. (This was accomplished using Excel
4.0 spreadsheet.)
4. Several lab runs were made in the 1-liter reactor to fill
in gaps in the data. A correlation was developed for particle
size and mixer speed and geometry (see Figure 4).
The summer student's starting point for the correlation
developed in Figure 4 was based on data reported in Oldshue121
that showed a relationship between average particle size and
impeller speed for liquid-liquid emulsions. As would be
expected, the average particle size decreases with increasing
impeller speed. Log-log plots of average particle size vs.
impeller speed for the data developed for our mixer/reactors
resulted in a series of parallel lines for each reactor size and
manufacturer. The goal was to develop a correlation which
could unify the data for all of the reactors evaluated.
A published analysis'31 of dispersion in mixing vessels
where the power number and geometry for mixing vessels
are similar leads to the following partly empirical, partly
mechanistic relationship:

Dp (Nw 3/5
D
where
Nwe= N2D3p, / (Weber number)


0.001l


0.0001 +


D, = particle diameter
D = mixer impeller diameter
Pc = density of the continuous phase
a = surface tension

It should be noted that the referenced analysis was for
dispersion in mixing vessels and not a reacting system that
forms insoluble (solid) polymeric particles in a thick, pasty
reaction mass. While data for p / a was not available for the
reacting system under study, it was not required for the
correlation as other product considerations necessitated that
the reaction recipe remain constant and the reactor tempera-
ture profile be fixed. Hence, there should be little variation
in p / a between all of the reactor runs, and it was assumed
to be constant. Thus, it might be expected that

D' =N2D3)a
D
Armed with this knowledge, the relationship presented in
Figure 4 was developed. The sizes of the reactors used in this
study were 1 liter (lab), 150 liters (pilot plant), and 500 liters
(small commercial unit). The correlation's fit is more than
adequate to guide our future scale-up efforts.
5. Finally, a comprehensive report was prepared to docu-
ment the above results.
This project allowed both the summer engineer and the
company to profit. The summer engineer not only received a
stipend for his work but also gained additional work experi-
ence. DMPC benefited by gaining a more rigorous under-
standing of the reaction conditions required for the scale-up
of an important process parameter.


Pilot Reactor Type R
Lab Reactor- Type R
A Pilot Reactor Type D
E x Commercial Reactor- Type L
Best Fit for all Reactor Types



d /x dolD = 6.5358x10- x IN'D3'043
R2 = 0.91


X*

N is Impeller RPM
D is Impeller Diamter, meters
d50 is Average Particle Size, meters


I I I
I 1 0 100 1000
N2. D


Figure 4. d50/D vs. N2D7
Summer 1995


ACKNOWLEDGMENT

I would like to acknowl-
edge the work of Martin
Chandler who was the sum-
mer engineer for the case his-
tory discussed in this paper
and who developed the data
in the figures.

REFERENCES
1. Perry, R.H., D.W. Green,
J.O. Maloney, Perry's
Chemical Engineers' Hand-
book, 6th Ed., McGraw Hill,
New York, NY, 19-14 (1984)
2. Oldshue, J.Y., Fluid Mix-
ing Technology, McGraw-
Hill, New York, NY, page
127(1983)
3. Uhl, V.W., and J.B. Gray,
Mixing Theory and Prac-
tice, Vol II, Academic Press,
New York, NY, page 21
(1967) 1


0.00001










Mwcurriculum




DEVELOPMENT OF A

POWDER TECHNOLOGY OPTION

AT CCNY


GABRIEL I. TARDOS
City College of The City University of New York New York, NY 10031


Powder technology defines the field of dry powder
processing, including such operations as characteri-
zation, storage, transport, mixing, classification, grind-
ing, and agglomeration. Taken more broadly, powder tech-
nology includes all operations where fine solid particles are
involved either by themselves or in combination with a fluid,
therefore encompassing a wide range of subjects in materials
synthesis and processing, rheology, and colloid and aerosol
science.
Funded by NSF, the project at CCNY aims to develop
undergraduate courses in the more restricted area of powder
science and technology and to integrate them into a chemical
engineering curriculum. The purpose of this paper is to
present the program at CCNY, the courses developed, the
books used, and the teaching methodology of the subject as
it is combined with an undergraduate laboratory. The core of
the program is a basic course, "Powder Technology," that is
described in some detail in this paper. Other courses which
form the group of electives (option) associated with the
above course are "Fluidization and Fluidization Technol-
ogy" and a "Unit Operation Laboratory II" that has most
experiments associated with powders. These courses are
also described in this paper.

BACKGROUND
Dry powders are assemblages of large numbers of small,
irregularly shaped, solid particles resting on each other.111
Their sizes range from several microns up to 200 pm, and in
some cases up to 1 millimeter. The space between particles
is filled by a fluid (usually called void space) so that the
overall density of the medium is much smaller than the true
material density of the solid. Since particles touch at well
defined points of contact, short range interactive forces com-
bine with surface friction to give the so-called bulk powder
many interesting properties which neither the solid nor the
Copyright ChE Division ofASEE 1995


Gabriel I. Tardos is Professor of Chemical Engi-
neering at The City College of CUNY. He received
his DiplEng from the Polytechnic Institute in
Bucharest, Romania, and his MSc, ME, and his
PhD, ME, from Technion, Israel Institute of Technol-
ogy. He has been at the City University of New York
since 1978, serving as Chairman of the department
Sr,:m 1987 to 1990. His research has concerned
,, ,ration in granular and fibrous filters, fluidization,
r n der storage and transport, granulation, electro-
slauc effects, and pneumatic conveying.

interstitial fluid possess. Some of these properties include
"liquid-like" behavior in that powders exhibit a "free sur-
face" and also "flow" when poured from a container. Due to
internal friction, however, they exhibit (unlike liquids) an
angle of repose when poured into heaps.
Another interesting property is the high chemical reactiv-
ity that is due to their large, exposed surface to the fluid. A
typical example is the explosive behavior of coal dust dis-
persed in air, while large chunks of coal can be ignited only
with great difficulty. Good examples of bulk powders are
beach sand, cement, sugar, wheat flour, salt, and ground
coffee. Some authors even go so far as to suggest that pow-
ders are a fourth state of matter, but this view does not hold
water since it can be shown that all thermodynamic proper-
ties are linear superpositions of the properties inherent in the
component phases.
Powder technology is a relatively new branch of engineer-
ing that has experienced rapid development in the last thirty
years or so. In a restricted sense, it defines the field of dry
powder processing, including the operations of characteriza-
tion and measurement, storage, transport, mixing, classifica-
tion or separation, comminution or grinding, and agglomera-
tion or size increase. Taken more broadly, powder science
and technology includes all operations where fine solid par-
ticles are involved either by themselves or in combination
with a fluid, thereby encompassing a wide range of subjects
Chemical Engineering Education










in materials synthesis and processing, rheology, and colloid
and aerosol science. In the present program, powder technol-
ogy is used in the restricted sense, although such subjects as
pneumatic conveying, slurry flow, fluidiza-
tion and fluid-particle systems in general are Powder
also presented. relatively
relatively
The introduction of powder technology as engine
an academic discipline was first achieved in experi
Germany in the 1960s;121 today, more than a e
dozen universities teach the subject through- de
out Germany. Teaching powder technology thirty y
was later developed in other countries such as Fundec
Japan, the United Kingdom, the Netherlands, project ai
Australia, and New Zealand. The emphasis in develop
these countries was more on the study of course,
powder processing than on the initial effort in restrii
design and development of special machin- powder
ery, as was the case in the German schools, tech
The urgent, large-scale need for powder integra
technologists and scientists was recognized chemicc
in England as early as 1981, and a serious c
effort was funded by the British Government
to develop teaching and research centers in
the field."3 Eighty-six grants were awarded to about twenty
institutions on the following subjects: particle (powder) for-
mation and synthesis, handling and processing, and solid-
liquid phenomena. At least four Schools of Powder Technol-
ogy exist in the United Kingdom today, with many other
departments, mostly in chemical engineering, teaching the
subject on both the graduate and undergraduate levels.
The effort in Japan is even more elaborate since it enjoys
funding by both private companies and the government. The
Powder Technology Society of Japan coordinates the more
than six hundred researchers and teachers in the field. There
are twenty-eight active research centers in Japan, and the
Association of Powder Process Industry has over three hun-
dred companies supporting the effort.

POWDER TECHNOLOGY IN THE U.S.
In a recent paper published in Chemical Engineering
Progress, [4 a group from DuPont describes the sad state of
affairs of research and teaching of powder science and tech-
nology in the U.S. They write, "...while other nations have
long recognized the importance of powder technology, the
U.S. lags seriously behind. Industry, government, and aca-
demia all must play key roles if we are to improve our
mastery of powders ... and our competitiveness."
In another article,"51 a senior engineer at DuPont stated that
60% of the company's 3000 products are in particulate
form. Another 20% of DuPont products use particles to
improve the required properties of the products. He further
indicated that plants using finely divided solid feed (e.g.,
powders), may operate at as little as 50% of design capacity.
Summer 1995


Summarizing his concern about university education, he
writes that a young engineering graduate joining his com-
pany has an 80% probability of having an assignment


that while the


technology is a
new branch of
-ring that has
enced rapid
nent in the last
ears or so....
Iby NSF, the
t CCNY aims to
undergraduate
s in the more
acted area of
science and
ology and to
te them into a
rl engineering
Triculum.


level, several consulting companies teach short courses at
chemical engineering (and other) meetings as well as at
corporate centers for postgraduate learning. The need for
powder technologists is enormous, and companies that need
engineers in these specialties must train them on the job or
hire them from overseas.
A survey of about forty chemical engineering departments'6'
showed that only West Virginia University offered a course
in powder technology, and that at the graduate level only
(see Table 1, next page). Other universities offer other courses
that cover the broader area of powder technology, but no
undergraduate degree is offered in the field. (It should be
noted that the survey was not exhaustive of the chemical
engineering departments nor of material science and/or min-
ing engineering departments where subjects in powder tech-
nology are sometimes covered.)
The lack of focus on powder and particle technology in the
U.S. has begun to be recognized in the last three to four
years, and there is a recent movement (initiated mainly by
the DuPont Company and the Fluid/Particle Separations So-
ciety) to develop particle technology curricula. During the
same time period, NSF initiated start-up of Centers of Excel-
lence in the field at the Pennsylvania State University and
the University of Florida and also supported various other
initiatives to strengthen powder technology in the U.S. (It
should also be mentioned that AIChE formed a "Particle
Technology Area" in 1990 and a "Powder Technology Fo-
rum" in 1992.) The present effort to develop powder tech-
nology curricula at CCNY, along with programs started at


involving particulate processing for
which he is totally unprepared and that
typical fluid mechanics and other courses
being taught "inadequately prepare
graduates to solve, or even recognize, these
... problems."
Even though major discoveries in the
theory of powders, such as the direct appli-
cation of soil mechanics principles to stor-
age hopper (bin) design, were made in the
U.S. in the mid-fifties, and although pow-
der engineering is practiced on an enor-
mous scale in the U.S., no center for teach-
ing the subject in American universities
has developed. The area is scattered through
many fields, such as civil engineering, ma-
terials science, metallurgy, and chemical
engineering, and there is no concerted ef-
fort to teach the subject at the undergradu-
ate level. It must be mentioned, however,
subject is not taught at the undergraduate











the Universities of Pittsburgh and Minnesota (albeit with a somewhat
different focus) are all part of the same process.

POWDER TECHNOLOGY COURSES AT CCNY

The powder science related courses that have been taught in the
Department of Chemical Engineering at CCNY since 1963 are de-
scribed in some detail in Table 2. The course in fludization is a
comprehensive study of fluidized beds and their application as indus-
trial heat exchangers, reactors, filters, granulators, etc. The students are
first introduced to the hydrodynamics of a particle moving in an
infinite medium, followed by the study of flow in packed beds and the
minimum fluidization conditions. Various measurements in the fluid
bed and the characterization of the particles involved are also de-
scribed. Bubbling and fast (circulating) fluidized beds, their interesting
properties and behavior, are presented in detail, both theoretically and
practically, in the associated laboratory (see Table 3).
The last part of the course is dedicated to the study of heat transfer
and chemical reactions in fluidized beds with such applications as the
Fluid Bed CAT cracker and the Fluid Bed Granulator. We anticipate
that this course will be offered at both the graduate and the undergradu-


TABLE 1
Results of Survey of Courses on
Powder Technology and Materials Processing
(after Chase, 1993161)
(Legend: G=Graduate, U=Undergraduate; B=Both graduate and undergraduate)


STATE/SCHOOL 1
FLORIDA
FAMU/FSU
GEORGIA
Georgia Institute of Tech.
ILLINOIS
Illinois Institute of Tech.


IOWA
University of Iowa
MASSACHUSETTS
Worcester Polytech. Inst.
MISSOURI
U. of Missouri-Columbia
NEW YORK
City University

Clarkson University

Comell University
PENNSYLVANIA
University of Pittsburgh
TEXAS
Texas A&M, Kingsville
Texas A&M
WEST VIRGINIA
West Virginia University


'EVEL COURSE TITLE


Mechanics and Rheology of Composite Fluids


B ITechnology of Fine Particles


U Fluidization
B Applied Particle Technology
G Fluidization and Gas-Solid Flow Systems

G Microstructural Processes in Materials

U Dynamics of Particulate Systems

B Particulate Systems Engineering


Fluidization
Fluid-Particle Systems
Fine Particle Technology
Bubbles, Drops, and Particles
Fluid Mechanics of Suspensions


G Fluidization and Pneumatic Transport

B Problems in Particle Mechanics
U Processing of High Technology Materials


G Fluidization Engineering
G Powder Technology


ate levels and will be integrated into the undergradu-
ate group of electives.
The course in "Fluid Particle Systems" is an ad-
vanced, graduate-level study of special topics on the
flow, heat, and mass transfer of solid particles,
bubbles, and drops in low and high concentration
systems with such applications as pneumatic convey-
ing, slurry flow, filtration, etc., and is not offered
at the undergraduate level. Additional graduate
courses in interfacial phenomena and non-
Newtonian fluid flow are offered at least once a year,
and with these courses the Chemical Engineering
Department is at the forefront of teaching these sub-
jects. In fact, the overall strength of the department is
concentrated in the "broad" area of powder technol-
ogy and related fields.


TABLE 2
Graduate Courses in Powder Technology
and Related Fields at CCNY

Fluidization: The Theory and Practice of Fluidization
(3 class hours, 3 credits)
General behavior of fluidized beds both static and
flowing; mass transfer and heat transfer; modeling of
chemical reactions in fluidized beds.
Textbooks
0 Kunii, D., and 0. Levenspiel, Fluidization
Engineering, John Wiley and Sons, NY (1990)
0 Geldart, D., Gas Fluidization Technology,
Wiley-Interscience (1986)
Topics
Hydrodynamics of single particles
Characterization of fluidized beds
Bubbling fluidized beds
High velocity fluid beds
Fluid bed heat transfer
Applications


Fluid Particle Systems (3 class hours, 3 credits)
Basic equations of multiphase systems; transport
processes of rigid and deformable particles; drag
coefficients; heat and mass transfer rates; turbulence
effects; transport properties of clouds of particle; pipe
flow of a suspension; filtration of aerosols and industrial
filters.
Textbooks
> Clift, R., J.R. Grace, and M.E. Weber,
Bubbles, Drops, and Particles, Academic Press,
NY (1978)
> Dullien, F.A.L., Porous Media-Fluid Transport
and Pore Structure, Academic Press, NY (1979)
Topics
Introduction
Flow, heat, and mass transfer to a particle in an
infinite fluid
Flow, heat, and mass transfer in a porous media
Applications

Chemical Engineering Education











The Powder Technology Group of Electives The under-
graduate chemical engineering curriculum at CCNY con-
tains a group of technical electives that bear 5-6 credits. The
powder science and technology group of courses (option)
was designed to fit these requirements and is composed of
the "Powder Technology" course (see Table 4) and the un-
dergraduate version of the "Fluidization" course (see Table
2). In addition, seniors are required to take "Unit Operations
Laboratory II," which was transformed and reorganized to
include mostly powder-related experiments (see Table 3).
Books in Powder Technology The first book dedicated
exclusively to the study of fine particles and powders was
compiled by Dallavelle'71 in the early 1940s. It is a compre-
hensive presentation of methods to measure particulate prop-
erties and to manufacture powders, and it describes unit
operations containing such processes as mixing, transport,
segregation, etc., It was subsequently translated into Japa-
nese and became the starting point of that country's strong


TABLE 3
Unit Operations Laboratory II (2 credits)

The laboratory contains eight stations on the following topics:
1. Particle size and size distribution measurement
a) Standard set of sieves*
b) Malvern laser scattering particle size analyzer
Sand and CAT cracking catalyst are used with sieves; zeolite
is used with the Malvern; data from both sets of measurements
are fitted to standard two-parameter models (such as the
Rosin-Rammler distribution)
2. Electron* and Optical Microscopy
Experiments are performed and pictures taken to study the
surface of powders and granules; powders used are glass
beads, CAT cracking catalyst, and an agglomerate granule
from experiment #6.
3. Characterization of a powder using BET pycnometry** and
mercury porosimetry**
Materials from experiment #2 are characterized.
4. Determination of a Material Yield Locus using a Jenike Cell*
Noncohesive (fine sand) and cohesive zeolitee) powders are
used with different degrees of precompression.
5. Fluidization experiment
A bubbling bed of fine glass particles is used to demonstrate
bed defluidization due to the presence of a sticky liquid. The
bed is also used for heat transfer studies.
6. Granulation of a fine powder in a high shear mixer
A mixture of fine glass powder and zeolite is granulated in an
Eirich mixer. Granule size and size distribution is correlated
with binder properties and operating conditions.
7. Production of a ceramic powder
The dilatometer*/chemical reactor** system is used to
produce aluminum nitride from a carbon and aluminum oxide
polymeric precursor by carbothermal nitridation at 1500 C
8. Extrusion of a suspension in a Brabender Rheometer
Suspension viscosities are measured in the rheometer as a
function of solid concentration.

Experiment being upgraded
** Experiment in the process of development

Summer 1995


development of the field after World War II.
The contribution of Dallavelle was not widely used in the
U.S. and only gained some recognition after C. Orr pub-
lished a book on Particulate Technology in 1966 that ex-
panded the material, introducing other unit operations such
as grinding, storage, granulation, etc. Then, in 1981, a major
development was achieved through the publication of Par-
ticulate Science and Technologyl91 which, in addition to de-
scribing unit operations associated with powders, gave de-
tailed descriptions of microlevel phenomena in surface sci-
ence and physical chemistry that helped explain overall bulk
properties. This author drew attention for the first time to the
simplistic "black box" approach to the study of powders and
to the U.S. need to study the field at both graduate and
undergraduate levels. The book has been used extensively to
teach the subject during the last ten or so years.
Table 5 gives a partial list of books published in the field.
Two groups are presented: textbooks and topical books.
They are not presented in any preferred order, nor is the list
exhaustive. It reflects, rather, the availability of the books to
the author and the ease with which undergraduate students
who took the course over the last two years related to the
individual works. The list of topical books is also incom-
plete, and the table gives information on the chapters used
for the preparation of the undergraduate course under the
heading "Advantages." Of the textbooks mentioned in the

TABLE 4
Undergraduate Powder Technology Course

Powder Technology (3 credits)
Metrology: characterization of particles and particle assemblies.
Packing of granular solids; powder mechanics and the design of
hoppers; interparticle forces and tribology in particulate
systems. Bulk powder processing: mixing and separation,
agglomeration, and communition, conveying, and storing.
Textbooks
> Rhodes, M.J., Principles of Powder Technology, John
Wiley and Sons, NY (1990)
Rumpf, Hans, Particle Technology, translated from
German by F.A. Bull, Chapman and Hall, London and
NY (1990)
> Beddow, J.K., Particulate Science and Technology,
Chemical Publishing Co., NY (1980)
> Shamlou, P.A., Handling of Bulk Solids: Theory and
Practice, Butterworth & Co., Ltd. (1988)
Topics
Characteristics of particle assemblies; particle size and
distribution; particle metrology
Packing of granular solids
Powder mechanics; design of hoppers
Interarticle forces, adhesion and friction; prediction of bulk
behavior from single particle properties
Bulk powder processing: separation, mixing, agglomeration,
conveying, and feeding
Prerequisites
Transport Phenomena I
Unit Operations I











table, all except the second entry (Principles of Powder
Technology, edited by Rhodes) are out of print.
Since no particular book fits the needs of the undergradu-
ate course by itself, three books were chosen to be used
together: Particle Technology, by Rumpf, and Principles of
Particle Technology, edited by Rhodes, were used to cover
all topics in particle characterization and metrology, powder
mechanics, and hopper design, etc. (see Table 4), while
Handling of Bulk Solids, by Shamlou, was used for the
study of powder transport and pneumatic conveying and
feeding. In addition, materials from other books listed
in Table 5 were used.
Powder Technology Course The syllabus, textbooks
used, and the main topics covered in the course are given in
detail in Table 4. The course starts with such basic principles
as characterization and particle measurement, the theory of
packing and powder mechanics, and interparticle forces of
interaction. Unit Operations such as powder mixing and
separation, agglomeration and comminution, and feeding
and transport are subsequently presented. The material is
structured such that chemical engineering principles in ther-
modynamics, fluid flow, heat and mass transfer, and strength
of materials are extended to the study of particles and their
assemblies. It is also shown that bulk behavior can be ex-
plained from first principles and from basic properties of the
particles and fluids which form them. Whenever possible,
bulk properties are correlated to individual particle proper-
ties while the special measuring techniques used to assess
these properties are both described theoretically and demon-
strated practically in the "Unit Operations" laboratory at-


tached to the course (see Table 3).
As an example of how teaching powder technology lends
itself to a useful application of first principles to technically
important problems, computation of the strength of a pow-
der from the knowledge of interparticle forces is given. This
concept and the need for studies to accomplish this and
similar generalizations from first principles to industrial prob-
lems is eloquently described by Ennis, et al.141 One starts by
describing in detail the short-range interactions between two
powder particles at their contact point, which can be due to a
multitude of phenomena, the simplest of which is the pres-
ence of a liquid. Other interactions can result from simple
deformation and/or the presence of adhesion, electrical, and
other short-range forces. Statistical consideration of the dis-
tribution of these contacts over one particle and within the
entire powder mass, first suggested by Rumph and later
improved by Kendall101o and others,1"1 leads to the prediction
of the overall yield strength of the bulk powder. This charac-
teristic can, in turn, be measured experimentally using a
shear cell, invented in the early 1960s by Jenike. Students
are shown methods to measure both the interparticle force
and the bulk shear strength and at the same time they are
given the theoretical procedure detailed above, allowing them
to assess the validity of the assumptions used. The same
approach is followed for prediction of the resistance to flow
of a gas or liquid in a powder mass. The concepts of flow in a
pipe and around a free particle are generalized with appro-
priate assumptions and complications to arrive at the gener-
alized form of the Ergun correlation (see Ref. 12).
Powder Technology Laboratory The Unit Operations


TABLE 5
Partial List of Books in Powder Technology


Title, Author; Publisher (Year)

TEXTBOOKS
* Particle Technology, Rumpf (translator, Bull); Chapman and Hall (1990)

* Principles of Particle Technology, Rhodes (ed.); Wiley & Sons (1990;1993)
* Particulate Science and Technology, Beddow; Chemical Pub. Co. (1980)

* Particulate Technology, Orr; Macmillan Co. (1966)

TOPICAL BOOKS
* Particle Size Measurement, Allen; Chapman and Hall (1968;1990)
* Powder Surface Porosity, Lowell, Shields; Chapman and Hall (1979,1984)
* Theory of Particulate Processes, Randolph, Larson; Academic Press (1988)
* Handling of Bulk Solids: Theory and Practice, Shamlou; Butterworth (1988)
* Bulk Solids Handling, Woodcock, Mason; Chapman and Hall (1987)

* Mixing in the Process Industries, Hornby, et al.; Butterworth (1985)
* Size Enlargement by Agglomeration, Pietsch; John Wiley & Sons (1991)
* Slurry Flow: Principles and Practice, Shook, Roco; Butterworth (1991)
* Pneumatic Conveying of Solids, Marcus, et al.; Chapman and Hall (1990)
* Gas Fluidization Technology, Geldart (ed); John Wiley & Sons (1986)
* Trihology in Particulate Technology, Brisco, Adams (eds); Adam Hilger (1987)


Advantages


Intended as an undergrad textbook

Postgraduate textbook
Detailed presentation of underlying
physico-chemical principles
Treats P.T. as unit operations


The most authoritative in this field
Engineering oriented
Chaps. 1-3 only
Useful text for students
Text for student; unit operations for
bulk transport
Detailed text for engineers (Chaps. 1-3)
Chaps. 2,3; interparticle forces
Chaps. 1-4; particle-fluid interaction
Chaps. 2-4; gas-particle conveying
Chaps.2,4; basics of fluidization
Part 2: Adhesive forces & powder flow
Part 4: Attrition and agglomeration


Remarks


Originally published by Carl Hansen (1975)
in German (out of print)
Contains solved problems (very expensive)
Out of print

Out of print


Fourth edition
Useful technical information for students
Size distribution and population balances
Used for bulk flow of powders
Powder transport equipment presented

Used only for characterization of mixtures
Monograph on agglomeration
Monograph
Monograph
Contains solved problems
Interesting new topics in particle technology


'76 Chemical Engineering Education










Laboratory II course is taken by seniors during the seventh
semester of study. The laboratory has been reorganized to
contain experiments related to powder technology and is
offered as an elective to support the two theoretical courses
within the option. The lab is composed of eight stations that
are covered within fourteen weeks (five hours each) of study.
The eight stations are briefly described in Table 3; four
experiments are in the process of being upgraded, while two
(#3, Characterization of Powders, and #7, Production of a
Ceramic Powder) are in the process of development from
scratch, e.g., new equipment is being purchased, installed,
and incorporated into the lab.
The students are first introduced to powder characteriza-
tion such as particle size and size distribution (#1), surface
structure and composition using optical and electron micros-
copy (#2), and surface area and pore volume using gas
adsorption (BET gas pycnometry) and mercury intrusion
(#3). A major improvement in these experiments will be
achieved by the purchase of new instruments to measure
surface area and granular pore size. Further characterization
of bulk powders is achieved in the Jenike Shear Cell, where


material and wall yield loci are obtained for different pow-
ders at different initial compression levels. This is a special
instrument, characteristic of powder engineering, used to
determine powder flowability characteristics as well as for
the design of powder storage vessels such as hoppers and
bins. Two powders, one cohesive or nonflowing such as
zeolite (used extensively in the chemical industry as a cata-
lyst) and another noncohesive or free flowing, such as fine
dry sand, are used to show the great difference in behavior
due to cohesion. The results are also used to design a hopper
for a powder tested during this experiment zeolitee).
The next set of three experiments demonstrates different
unit operations with powders such as fluidization (#5), granu-
lation or size increase (#6), extrusion or flow through a small
orifice at high pressure (#8), and a chemical reaction to
produce a powder (#7). These are all well-developed experi-
ments used in the past and taken over from previous research
projects. The chemical reactor is in the process of being
retrofitted with a newly acquired mass spectrometer that will
be installed at the gas exit port. This will enable the study of
reaction kinetics of the gas-solid reactions taking place in


The MikroPul Hosokawa Micron Powder
Characteristics Tester provides seven me-
chanical measurements with one easy-to-use
instrument, including 1) angle of repose, 2)
compressibility, 3) angle of spatula, 4) cohe-
siveness, 5) angle of fall, 6) dispersibility,
and 7) angle of difference.
Measuring such properties has great impor-
tance in the design of storage hoppers, feed-
ers, conveyors and other powder processing
equipment. The analyzing of such character-
istics is also a daily routine for quality con-
trol of powdered products. Conventionally,
these properties were each determined manu-
ally, using several different instruments. Now


the Powder Characteristics Tester offers
quick and reliable measurements with a
single unit. With controlled mechanical
means, far more consistent and accurate data
can be obtained than by manual methods.
Measurements obtained from the Powder
Characteristics Tester can be directly con-
verted into the flowability or floodability
index with the use of "Flowability Index
Tables" prepared by R.L. Carr, Jr.. of BIF
and published in McGraw-Hill's Chemical
Engineering (Vol. 28, January 28, 1965).
The index thus obtained is a reliable guide
for the trouble-free handling of the powder.


Figure 1. The Powder Characteristics Tester apparatus
Summer 1995


the reactor.
With this hands-on experience, the students
taking the powder technology option will be
in a position not only to recognize processes
in which powders are used, but also to address
and solve practical problems relating to such
powder operations as characterization, stor-
age, fluidization, agglomeration, etc. The prac-
tical experience will also reinforce the theo-
retical concepts assimilated in class.

MODULE DEVELOPMENT
The behavior of liquids and gases is taught
and demonstrated in most physics courses and
in mechanical and chemical engineering cur-
ricula. Students, especially freshmen and
sophomores, are rarely if at all exposed to the
study of dry powders: their production, use,
and very peculiar behavior. A demonstration
module was developed to provide freshman
students with hands-on experience with pow-
der handling, the measurements of some of
the most important bulk properties, and the
use of the measurements to characterize a pow-
der. The main objective of this effort was to
develop a package and purchase an instru-
ment to demonstrate to students at the fresh-
man level the substantial difference between
the behavior of fluids and dry bulk powders
during storage, emptying of a vessel, flow in a
pipe, and dispersion in air.
Continued on page 181.











r, curriculum


HAZARDOUS WASTE PROCESSING

In the Chemical Engineering Curriculum



DIANNE DORLAND, DORAB N. BARIA
University of Minnesota, Duluth e Duluth, MN 55812


As our nation's tolerance for pollution in general has
decreased, the use of chemical engineering skills in
waste management has steadily increased. This is
particularly true where pollution prevention at the source has
been emphasized over "end of the pipe" treatment. Second-
ary wastewater treatment will continue to be the principal
public health shield for our sewer discharges, but tertiary
wastewater treatment is frequently mandated for an indus-
trial facility and is becoming more common for wastewater
treatment in publicly owned treatment works (POTWs).
Wastewater treatment, or sanitary engineering, has tradi-
tionally been part of civil engineering, and more recently of
the relatively new field of environmental engineering. Sani-
tary engineers have satisfactorily designed and operated
wastewater and sewage treatment plants without ever having
taken courses in chemical kinetics and reactor design, chemi-
cal thermodynamics, or unit operations. Most of these plants
were, basically, primary treatment facilities, with some of
them including secondary treatment. The fact that most of
the facilities did not face major problems was because sani-
tary engineers had acquired, and could draw on, a large body
of empirical information on wastewater treatment and plant
operation. Efficient operation and the use of advanced or
tertiary wastewater treatment were not prime considerations.
Due to the growing consciousness of hazardous wastes
and incidents such as Love Canal and Times Beach, the
public has demanded that federal, state, and local govern-
ments get involved in the control and management of haz-
ardous substances and wastes. This demand has led to for-
mation of the Environmental Protection Agency (EPA) as
well as the Clean Air Acts, the Clean Water Acts, the
Toxic Substances Control Act, the Resource Conservation
and Recovery Act (RCRA), the Comprehensive Environ-
mental Response, Compensation, and Liability Act
(CERCLA), and the Superfund Amendments and Reauthori-
zation Act (SARA).
Copyright ChE Division ofASEE 1995


Dianne Dorland is Associate Professor of chemi-
cal engineering at University of Minnesota, Duluth.
She received her BS and MS from the South Da-
kota School of Mines and Technology and her PhD
from the West Virginia University (1985). She cur-
rently teaches the Hazardous Waste Processing
Engineering course sequence for chemical engi-
neers, and her research interests include industrial
wastewater treatment and hazardous waste man-
agement.

Dorab N. Baria is Professor of chemical engi-
neering at the University of Minnesota, Duluth. He
received his PhD in chemical engineering from
Northwestern Universtiy in 1971. He subsequently
worked for the U.S. Atomic Energy Commission
at the Ames Laboratory, Iowa State University, as
a research fellow for fifteen months and then was
a chemical engineering faculty member at the
University of North Dakota until 1985, when he
joined the UMD faculty.


All this activity has given rise to the field of environmental
engineering, which is now replacing sanitary engineering in
many civil engineering programs. According to the state-
ment of purpose published by the Environmental Engineer-
ing Division of the American Society of Civil Engineers,[1]
environmental engineering deals with solutions of problems
of environmental sanitation, notably the provision of safe,
palatable, and ample public water supplies; proper disposal
or recycling of wastewater and solid wastes; adequate drain-
age of urban and rural areas for proper sanitation; control of
atmospheric, water, and soil pollution; and the social and
environmental impacts of these solutions. It is also con-
cerned with engineering problems in the field of public
health, such as control of arthropod-borne diseases, elimina-
tion of industrial health hazards, provision of adequate sani-
tation in urban, rural, and recreational areas, and the effect of
technological advances on the environment.
The above areas that come under the working umbrella of
chemical engineering include the proper disposal or recy-


Chemical Engineering Education










cling of wastewater and solid wastes, and the control of
atmospheric, water, and soil pollution. A common method
of disposal is incineration. Design and operation of efficient
incinerators that meet federal standards require a knowledge


of chemical thermodynamics, kinetics, and
while control of pollution uses the principles
learned in mass transfer operations, filtra-
tion, sedimentation, chemical reactions,
chemical thermodynamics, and kinetics and
reactor design. A thorough knowledge of
organic chemistry and stoichiometry is re-
quired for solving most problems dealing
with environmental engineering.
Hazardous substances and wastes, as de-
fined by various federal and state statutes,
are produced by most chemical industries.
In many instances they can be modified into
nonhazardous substances, or destroyed by
chemical means, but newer methods of pol-
lution control and safe disposal of wastes
must be developed; more importantly, newer
processing methods that will not produce
hazardous wastes need to be developed. In
order to do this, a thorough understanding
of the thermodynamics and kinetics of
chemical processes is needed. Chemical en-
gineers are best equipped to design and op-


stoichiometry,


including a final, and homework counts twenty-five percent.
The remaining twenty-five percent of the grade is for a
written report on an engineering design of a system handling
hazardous wastes, individually produced by each student.
Several texts and references have been used for this course,


Because of the
strong influences
of transport phe-
nomena and eco-
nomics in air
pollution preven-
tion and control,
the chemical engi-
neer is singularly
equipped to design
and implement air
pollution control
systems.


rate equipment or systems for the proper disposal and recy-
cling of wastewater and solid wastes and to make process
modifications to avoid production of hazardous wastes.
It was with these insights that the chemical engineering
program at the University of Minnesota, Duluth (UMD)
decided to include in its ABET-accredited curriculum a se-
quence of two courses that deal with processing of hazard-
ous wastes. Increasing numbers of our graduates are now
finding places as chemical engineers with environmental or
waste management responsibilities.

COURSE STRUCTURE
Hazardous Waste Processing Engineering I-II is a sequence
of two 4-credit courses taught in the winter and spring quar-
ters of the junior year. The class meets thirty times a quarter
for sixty-five minutes per lecture. Prerequisites include a
year of organic chemistry and a year of engineering physics,
with physical chemistry as a corequisite. Chemical engineer-
ing majors have also completed stoichiometry and fluid me-
chanics, and concurrently take mass transfer, chemical ther-
modynamics, and kinetics (in physical chemistry).
The overall goals of the courses are to identify hazardous
substances and their effects, study federal and state regula-
tions, design waste treatment processes to meet effluent
standards, and to understand the management of hazardous
wastes. Fifty percent of the grade is based on examinations,
Summer 1995


including Davis and Cornwell,[' Allen,
et al.,[2] Dawson and Mercer,131
Eckenfelder,"4] Peavy, Rowe, and
Tchobanoglous,"5' Tavlarides,[j6 Wark and
Warner,171 and Wentz.[8' Because of the broad
subject area, no one text has proven entirely
satisfactory, and a large component of the
teaching material is excerpted from recent
journals such as Chemical Engineering, En-
vironmental Engineering, Waste Manage-
ment, Environmental Progress, Combustion
Science Technology, and Chemical Engi-
neering Progress. Materials dealing with
state regulations, available from the Minne-
sota Pollution Control Agency, are also fre-
quently used. Course content is continually
developing in response to current legisla-
tion and technological progress.
Protecting and improving the environment
are now recognized imperatives for sound
management. Chemical engineers will face
important challenges in the future: design-


ing inherently safer and less polluting plants and processes,
improving air and water quality, and managing hazardous
wastes responsibly. These challenges have important impli-
cations for chemical engineering education, which is the
reason this course was developed.

COURSE CONTENT
The first topic covered is the definition of pollution, gener-
ating lively discussion as the legislative, industrial, personal,
and aesthetic viewpoints are presented. Throughout the
course, an attempt is made to maintain this parallel perspec-
tive of what is ethical and what is defined by law. Presenting
the history of federal regulations and the current status of
key legislation leads into the global issues of acid rain,
greenhouse effect, and ozone depletion problems.
The next major topic is air pollution, starting with a defini-
tion of air pollutants, their origins and effects, and the differ-
ence between primary and secondary air pollutants. Meteo-
rological effects, particularly atmospheric stability and plume
behavior, are reviewed before introducing basic concepts of
dispersion modeling. EPA-approved dispersion models are
downloaded from the Internet and used by the students.
While models of varying levels of complexity are available
from this source, the easiest EPA model to use is the
SCREEN2 model. When possible, real data from local in-
dustries are used to study dispersion of pollutants. This
179










includes the Toxic Release Inventory (TRI) information avail-
able on CD-ROM in the University library.
This leads into particulate, SO,, and NO, control. The
basic design of various particulate control equipment for
handling the 200-micron to sub-micron particles is studied.
These include a settling chamber, cyclone, venturi scrubber,
electrostatic precipitator, and bag house filter. A range of
wet and dry desulfurization processes is considered, from
first-generation processes using lime/limestone slurry scrub-
bing to second-generation processes such as alkali scrub-
bing, dry adsorption, catalytic oxidation, and dilute sulfuric
acid scrubbing (Chiyoda) processes, and future-generation
processes such as the Bureau of Mines citrate process. The
difficulty of meeting NO, standards through modifications
in operating conditions leads to the discussion of modifica-
tions of burner design and the development of novel fur-
naces to meet the standards.
Removal of NO, after its formation from flue gases by
catalytic and non-catalytic decomposition, reduction, absorp-
tion, or membrane separation processes completes this sec-
tion of the course. If time or opportunity permits, subjects
such as photochemical reactions, smog formation, and hy-
drocarbon removal may be presented. The influence of eco-
nomics on the choice of pollution control processes is also
an important concept that must be recognized by the stu-
dents. Because of the strong influences of transport phenom-
ena and economics in air pollution prevention and control,
the chemical engineer is singularly equipped to design and
implement air pollution control systems.
Water and wastewater treatment are discussed next. Physi-
cal, chemical, and biological water-quality parameters are
defined, with emphasis on their origin, impacts, and mea-
surement. Purification to drinking water standards leads the
class to wastewater treatment. The basic design of various
water treatment processes and equipment, including coagu-
lation, mixing, flocculation, sedimentation, filtration, and
disinfection, is studied. The settling and filtration of primary
treatment, aerobic and anaerobic reaction systems in second-
ary treatment, and advanced technology used in tertiary treat-
ment, are presented in terms of the unit operations and unit
processes that chemical engineers design and operate in all
areas of the chemical industries. Discussion of advanced
technology in tertiary treatment includes mass transfer, bio-
logical and chemical oxidation, adsorption, ion exchange,
and membrane processes.
The definition of hazardous wastes and waste manage-
ment terminology are presented next. Designation of hazard-
ous wastes by the listing and the criteria methods is
discussed, identifying the hazardous parameters of con-
cern and their threshold values. Alternate methods of han-
dling wastes, such as waste reduction, waste separation
and concentration, waste exchange, and energy/material re-
covery, are examined.
180


Engineering ethics and the responsibility of the engineer
to the public are frequent discussion topics as regulations
such as SARA, RCRA, CERCLA, and the Clean Water and
Clean Air Acts and their amendments are presented. Materi-
als such as the video Gilbane Gold, developed by the Na-
tional Institute for Engineering Ethics of the National Soci-
ety of Professional Engineers, are used to reinforce the twin
responsibilities of personal and professional ethics and
pollution prevention. Gilbane Gold also deals with the re-
sponsibilities of the engineer to his or her employer and
the public, and with the question of whistle-blowing and
its consequences.
Many methods are used for the control, alleviation, or
removal of hazardous waste. These include physical, chemi-
cal, and biological processes, and they present many oppor-
tunities for the chemical engineer. This is especially obvious
in hazardous waste applications such as incineration, gas
absorption, and solvent extraction. The question of ultimate
disposal is posed for discussion, recognizing that many pol-
lution control processes produce other process residuals.
Land disposal is a frequently chosen option, and the design
and operation of landfills is considered, along with other
disposal options such as deep-well injection.
At this point it is easy to reemphasize the philosophy that
the best method of pollution control is to change the process
to decrease or eliminate the initial waste production.
Examples of eliminating the formation of hazardous sub-
stances by use of selective catalysts or change in process
conditions, such as temperature and pressure, are pre-
sented. All these methods are tailor-made for application
by chemical engineers.
Case studies are frequently used to provide examples of
waste generation, pollution control, and ultimate disposal,
and examples such as Love Canal are used to present some
of the more spectacular failures and their consequences.
Local, regional, national, and global current events continu-
ally provide the class with abundant examples for discus-
sion. Students are encouraged to bring news articles of inter-
est to class, and approximately ten minutes of daily class
time is devoted to exchanging ideas on current problems and
how they fit into the course material. The class has a dedi-
cated bulletin board for posting these articles that generates
a great deal of public interest and is frequently read by
casual passersby. This forum becomes a vehicle for develop-
ing the student's ethical attitudes and philosophy in conjunc-
tion with a technical education.
Individual design problems are also assigned during the
two quarters, one for a liquid waste stream and another
for gaseous waste. The student is free to look at eco-
nomic recovery, novel removal technology, or conventional
disposal techniques, but must design a system that will
meet all federal standards for the wastes in question. The
final design report must present the problem, discuss the
Chemical Engineering Education










options considered, and present the solution chosen, with
supporting calculations. Good writing skills are required
not only in the formal report, but also throughout the course.
The design problem counts for twenty-five percent of the
grade in that quarter.
This course is exciting and dynamic With the interaction
between coursework and current events, there is always an
abundance of material for consideration. For example, a
June 1992 railroad accident in Superior, Wisconsin, resulted
in a mixture of chemicals, including benzene, being spilled
both on land and in the Nemadji River. The resulting cloud
caused the evacuation of thousands of residents, the largest
evacuation to date in the U.S. due to a spill of hazardous
materials. Resources from the regulatory agencies in Wis-
consin and Minnesota are available to present this local case
study in class, and discussion touches on the areas of spill
response, hazard assessment, reporting, cleanup, and panic.

SUMMARY
Hazardous waste management is a relevant area for chemi-
cal engineering skills that are not in the realm of civil engi-
neering, and it is vital that chemical engineers have a firm
foundation in pollution prevention. The capability to de-
velop and change process structure places responsibility for
waste management firmly in the chemical engineer's do-


main. It is an area vital to the long-term health and growth of
the chemical engineering profession, both from an industrial
and personal viewpoint. Chemical engineers are best equipped
with the knowledge for designing and operating equipment
or systems for the proper disposal and recycling of waste
water and solid wastes, for proper pollution control, and for
process modifications to avoid production of hazardous ma-
terials. This educational program will meet future needs for
maintaining and improving the environment.

REFERENCES
1. Davis, M.L., and D.A. Cornwell, Introduction to Environ-
mental Engineering, 2nd ed., McGraw-Hill, New York, page
4(1991)
2. Allen, D.T., N. Bakshani, and K.S. Rosselot, Homework &
Design Problems for Engineering Curricula, AIChE, AIPP
& CWRT (1992)
3. Dawson, G.W., and B.W. Mercer, Hazardous Waste Man-
agement, Wiley-Interscience, New York, NY (1986)
4. Eckenfelder, Jr., W.W., Industrial Water Pollution Control,
2nd ed., McGraw-Hill, New York, NY (1989)
5. Peavy, H.S., D.R. Rowe, and G. Tchobanoglous, Environ-
mental Engineering, McGraw-Hill, New York, NY (1985)
6. Tavlarides, L., Process Modifications for Industrial Pollu-
tion Reduction, Lewis Publishers, Chelsea, MI (1985)
7. Wark, K., and C.F. Warner, Air Pollution: Its Origin and
Control, 2nd ed., Harper and Row, New York, NY (1981)
8. Wentz, C.A., Hazardous Waste Management, McGraw-Hill,
New York, NY (1989) 1


POWDER TECHNOLOGY COURSE
Continued from page 177

The Mikro-Pul Hosokawa Company's Micron Powder-
Characteristics-Tester is a measuring instrument that is com-
mercially available and is used for demonstration. A sche-
matic representation of the apparatus and a list of all mea-
surements that can be performed with it are given in Figure
1. The students can measure the angle of repose (the angle
which a heap of powder makes with the horizontal),
flowability (capacity of a powder to flow out from a vertical
cylindrical vessel with a hole in the bottom), and dispersability
of a powder in air (talc and sand in this case) and compare it
to the behavior of a liquid. The demonstration module is
being introduced into a general engineering course given to
all engineering students in the first semester of study.

ACKNOWLEDGMENT
This work was supported by NSF Grant #CTS-9224463.
Support of the program by Mr. Charles F. Irwin from Unilever
Research U.S. Inc., Dr. Reg Davis from DuPont, and Dr. M.
Roco from NSF is greatly appreciated.

REFERENCES
1. Rietema, K., The Dynamics of Fine Powders, Elsevier, Lon-
don and New York (1991)
Summer 1995


2. Rumpf, H., "Mechanical Process Engineering as a Branch of
Science Within the Scope of University Education," Eng.
and Sci., Third Annual Number (1962)
3. Ford, L.J., "The Specially Promoted Program (SPP) in Par-
ticulate Technology," Powder Tech., 65, 1 (1991)
4. Ennis, B.J., J. Green, and R. Davies, "Particle Technology:
The Legacy of Neglect in the U.S.," Chem. Eng. Prog., p. 32,
April (1994)
5. Tilton, J.N., "Fluid Mechanics in Chemical Engineering Edu-
cation: The Costly Omission of Multiphase Flow," J. ofFluid
Part. Sep., 2 (1989)
6. Chase, G., "Closing the Education Gap in Fluid-Particle
Processes," J. of Fluid-Part. Sep., 6(1), 1 (1993)
7. Dallavelle, J.M., Micromeritics: The Technology of Fine Par-
ticles, Pitman Publishing, New York, NY (1943)
8. Orr, C., Particulate Technology, Macmillan Co., New York,
NY (1966)
9. Beddow, J.K., Particulate Science and Technology, Chemi-
cal Publishing Company, New York, NY (1981)
10. Kendall, K., K.L. Johnson, and A.D. Roberts, Proc. Roy.
Soc., A324, p. 301 (1971)
11. Briscoe, B.J., and M.J. Adams (eds.), Tribology in Particu-
late Technology, Adam Hilger, Bristol and Philadelphia, PA
(1987)
12. Bird, R.B., W.E. Stewart, and E.N. Lightfoot, Transport
Phenomena, John Wiley & Sons, New York, NY (1960) 0
181











e curriculum


A CONCEPTUAL DESIGN PROBLEM

IN


MASS TRANSFER OPERATIONS


ANDREW L. ZYDNEY
University of Delaware Newark, DE 19716

Over the last fifteen to twenty years, the mass transfer
operations course at the University of Delaware,
like those in most other chemical engineering de-
partments around the world, has evolved from a course
focused primarily on distillation and other equilibrium stage
processes into a much broader course that tries to expose
undergraduate students to the wide range of separation pro-
cesses employed in the chemical, petrochemical, pharma-
ceutical, and chemical-related industries. This evolution, and
the content of current courses in separations, was discussed
in some detail in a previous issue of Chemical Engineering
Education." The mass transfer operations course at the Uni-
versity of Delaware is taught during the first semester of the
senior year, and it covers material on membrane separations,
pressure swing adsorption, ion exchange, and chromatogra-
phy, in addition to the more classical material on distillation,
absorption, and extraction.
One of the real challenges in a course of this nature is
trying to provide students with a perspective on how to
properly compare different process alternatives that might
exist for a given separation, e.g., gas separation membranes
and distillation for the removal of H2S from a waste gas.
This analysis of process alternatives, which Douglas and
Kirkwood121 describe as conceptual or Level I design, is an
absolutely essential component of the design process, but it
is typically given minimal coverage throughout the under-


graduate chemical engineering curriculum. This is true even
in the capstone design course, which tends to focus on the
optimization of a given process flowsheet and the detailed
design of the individual pieces of equipment within that
flowsheet (generally referred to as a Level II design analy-
sis) instead of the initial evaluation of a much broader range
of process alternatives.
Conceptual design is a creative activity in which the engi-
neer must consider a large number of process alternatives
under near optimum design conditions in order to develop an
approximate outline for the best flowsheet. Conceptual de-
sign problems are thus characterized by the combinatorial
nature of the number of possible solutions. This makes it
very difficult to expose our undergraduates to this type of
conceptual design analysis, particularly given the enormous
time constraints that currently exist in the undergraduate
curriculum in most departments. This paper describes one of
the approaches currently being used at the University of
Delaware to remedy this situation and to enhance the overall
design experience in chemical engineering.

PROJECT DESCRIPTION
The mass transfer operations course is in many ways ideal
for introducing students to many of the key principles in-
volved in conceptual design. The new design problem that
has been developed as part of the mass transfer operations
course at Delaware does this and at the same time provides
an extremely effective review for the wide range of material
that is covered in the course. The assignment is for the
students to develop a preliminary economic analysis of
several different process alternatives for the separation
of a methane-carbon dioxide gas stream, including speci-
fic recommendations for the future development of this pro-
cess. A detailed discussion of many of the technical and

Copyright ChE Division ofASEE 1995
Chemical Engineering Education


Andrew Zydney is currently Associate Profes-
sor in the Department of Chemical Engineering
at the University of Delaware. He received his BS
from Yale University and his PhD from the Mas-
sachusetts Institute of Technology. He recently
received an Excellence in Teaching Award from
the University of Delaware. His research inter-
ests are in biomedical engineering, membrane
processes, and bioseparations.










economic considerations in-
volved in the purification and Conceptual design
production of methane gas, in- which the engineer
cluding analysis of the CO,-CH4 number of process
optimum design condo
separation, is available in a num- op d
er of references34 an approximate outli
Conceptual desil
The methane-carbon dioxide characterized by the
gas separation was chosen for the number of
several reasons. First, and prob-
ably most important, a large TA
number of very different pro- Methan
cesses have in fact been suc-
cessfully commercialized for the
CO2-CH4 separation, including ProduIt Co
cryogenic distillation, gas sepa- Waste as
ration membranes, pressure Low Energy Gas l
swing adsorption, and absorp- Medium Energy Gas 4
tion using a variety of chemical High Energy Gas 7
and/or physical absorbents (e.g., Pipeline Gas
the ethanolamines). Each of Liquefied Natural Gas <50
these processes has its own dis-
tinct economic and technical advantages and disadvantages,
depending in large part upon the specific characteristics of
the feed stream. Second, the problem itself is very self-
contained, allowing the students to focus on the different
separation processes that can be used without having to
consider the design of a reactor or the development
of a complex separation train. This "simplicity" also makes
it possible to perform a fairly extensive conceptual
design analysis without being completely overwhelmed by
the sheer number and complexity of the design calculations.
Finally, there is a wealth of thermodynamic and transport
data available in the literature on both CO, and CH4 and
on many of the different separating agents that can be used
in the purification.
The overall objectives of this project were for the students
to explore the behavior of a number of different processes
for the CO,-CH4 separation, to determine the relative eco-
nomic benefits of each of the processes, and to then prepare
a formal written report (possibly in combination with an oral
presentation) that summarizes the key results and makes
specific recommendations for the future development of this
project. The design analyses were to focus on the overall
economic behavior of these processes without getting overly
involved in the details of the specific design calculations
(e.g., in the sizing of the various pumps or the consideration
of different construction materials). This type of design prob-
lem thus complements the more detailed design calculations
that our students encounter in the capstone (senior-year)
design course taught in the semester that follows the mass
transfer operations course. In addition, since the students
were specifically asked to evaluate the economics of both
equilibrium-stage (e.g., distillation and absorption) and mass


is a
r mu,
alter
ition
ne f
gn pr
com
poss


BLJ
e Ec(

CHI
ncentrat
<10%
0-409
0-709
'0-909
98%
Ippm


Summer 1995


transfer-limited (e.g., pressure
creative activity in swing adsorption and membrane
st consider a large separation) processes, the
natives under near project provides an ideal review
is in order to develop
s in order to deelo for the wide range of material
r the best flowsheet.
rtobems are thus that is covered in the current
oblems are thus
binatorial nature of mass transfer operations course.
ible solutions. In order to make the project
more realistic, and at the same
E 1 time to increase the open-ended
nomics character of the design analysis,
students were provided with
ellingPrice economic data on a variety of
ion Specifications ($MMBTU) CH4 products that could poten-
tially be recovered and sold,
1.2 each with its own physical char-
b 2.0 acteristics and selling price (see
3.0 Table 1). In addition, the CO2
600 psig 4.0 could either be vented to the
CO2 600 psig 5.0 atmosphere or could be recov-
ered at a purity of 99% CO2 and
sold at a price of $0.013/standard cubic foot for the subse-
quent production of dry ice. This product flexibility means
that the students must consider a wide range of product
specifications in developing their designs. This is really a
very important aspect of this type of conceptual design analy-
sis, and it provides the students with a very different per-
spective than that obtained from the more standard home-
work problems in mass transfer operations in which the
product purities and/or recoveries are an integral part of the
initial specifications for the given design problem. Just as
important, this range of potential products allows the less
selective separation processes (like gas separation mem-
branes) to effectively compete with a much more selective
process like cryogenic distillation.
Although the students were encouraged to obtain the nec-
essary thermodynamic data for the CO,-methane system
directly from appropriate literature sources, I have generally
provided some of the more obscure data in handouts that
accompany the project assignment. This includes, for ex-
ample, information on the CO, and methane permeabilities
through available gas separation membranes as well as data
on the equilibrium adsorption isotherms for both CO2 and
CH4 adsorption onto activated carbon.
Since most of our students have had only minimal expo-
sure to engineering economics at this point in the curricu-
lum, every effort was made to simplify the economic analy-
sis so that they could really focus on the conceptual aspects
of the design problem. They were told to estimate the total
capital costs for the cryogenic distillation column directly
from the number of plates, e.g., the average cost per year
(accounting for depreciation, maintenance, labor costs, etc.)
was simply estimated as $300,000/plate. The operating costs

183










for the cryogenic distillation were assumed to be dominated
by the refrigeration costs, which were estimated directly
from the electrical power requirements for the condenser.
Similarly, the capital costs for the absorption columns were
estimated directly from the number of plates (in this case,
$50,000/plate). The operating costs for the column were
dominated by the required inventory of the absorbent (as-
sumed to be a one-day supply that had to be replaced on a
yearly basis to make up for the inevitable losses in the
absorbent during operation of the column), along with any
required heating, cooling, or pressurization. The capital costs
for the membrane unit were assumed to be directly propor-
tional to the membrane area, with the operating costs domi-
nated by any required pressurization of the feed and/or re-
cycle streams, with the pressurization costs determined di-
rectly from the power requirements for the compressor. These
costs were developed from available economic data on the
processes, with necessary adjustments made to insure that
the design calculations resulted in processes that were in fact
economically competitive. Additional information on the
economic data used for the different unit operations are
available directly from the author upon request.
Although these economic analyses were clearly oversim-
plified, they were carefully developed to capture the key
design features of each of the processes. Thus, by providing
information on both the capital (cost/plate) and operating
(refrigeration) costs for the cryogenic distillation, the design
analysis correctly leads to an optimal reflux ratio for the
distillation column. In this case, the use of a very low reflux
ratio resulted in a process that was no longer economical
because of the large capital costs associated with the col-
umn, while the use of a very high reflux ratio was uneco-
nomical because of the large refrigeration costs for the con-
denser. And of course, the detailed choice of this optimal
reflux ratio depended upon the specific temperature and
pressure chosen for the column operation as well as the
choice of the product specifications used in the design calcu-
lations. Similar effects were seen with each of the other unit
operations as well, with the balance between the operating
and capital costs providing specific constraints on the oper-
ating pressure, membrane area, and number of stages for the
membrane unit; the column length and diameter for the PSA
system; and the number of stages, absorbent flow rate, and
operating temperature in the absorption column.

SPECIAL FEATURES
Since this assignment was really quite extensive, the stu-
dents were required to work in small groups (typically of 3-4
students). Generally, the groups divided up the work so that
each student became an "expert" on one of the processes. It
was critically important, however, for the entire group to
work together to develop an appropriate strategy for attack-
ing the design problem and for considering the different


possible products and the wide range of possible operating
conditions for the different processes. In many ways, this
was one of the most difficult aspects of the project, and
several of the groups had some very heated discussions
about how to most effectively approach this type of very
open-ended problem.
The most effective groups realized that it was possible to
quickly eliminate some of the processes from further consid-
eration based on the results of simple approximate calcula-
tions focusing on the behavior of highly "idealized" pro-
cesses. For example, in some cases it was possible to show
that absorption was economically uncompetitive even if the
system were operated at the minimum absorbent flow rate
using the minimum possible number of plates (with Nmin
calculated assuming infinite liquid flow). Even though this
type of column could never actually be built or operated, the
analysis of this type of best-case scenario provided the stu-
dents with considerable insights into the overall behavior of
the different processes, and it made it possible for them to
really focus their analysis on those processes that were most
likely to lead to an effective separation of the particular CO2-
CH4 feed stream.
In order to improve the overall effectiveness of the assign-
ment, each group of students was provided with one of three
very different "scenarios" for the source of their particular
CO2-CH4 gas mixture:
1. Our gas exploration division has recently identified a new
natural gas well in the United States. Results from our
initial drilling indicate that the well gas is an essentially
pure CO,-CH4 mixture (with negligible H2S contamina-
tion). We are interested in determining the commercial
prospects for the production of this well gas.
2. Our company has recently acquired a large landfill in the
Northeast corridor of the United States. The landfill
generates methane gas through anaerobic decomposition of
the solid waste. This methane gas has a relatively high CO2
concentration and is available at essentially atmospheric
pressure. The gas is currently vented to the atmosphere,
which is a potential contributor to the problem of global
warming. We are interested in the possibility of upgrading
this gas for subsequent resale and need to determine the
economic viability of this process.
3. Our gas recovery group has proposed using an enhanced
oil recovery system to extend the effective life of one of our
Texas oilfields. This field is currently shut down, but
additional gas can potentially be obtained from the field by
injecting high pressure CO2 into the ground around the
periphery of the field to force the gas up through the
existing well. We need to determine the economic feasibility
of this project using 5 MMSCFD CO2 at 1000 psi (with less
than 5% CH, contamination) to recover the gas. The
required high pressure CO2 is to be generated directly from
the purification of the outlet gas stream.
In addition, each group of students was provided with their


Chemical Engineering Education










own specific set of characteristics for the CO,-CH4 mixture.
Thus, one group of students was given a well gas (scenario
1) that had 20% CO2 and was available at a pressure of 500
psig and a flow rate of 10 MMSCFD (10 million standard
cubic feet per day), while another group was to analyze a
similar well gas but with 10% CO,, a pressure of 700 psig,
and a flow rate of 5 MMSCFD. Likewise, one group of
students studying the landfill gas might have a feed at a
pressure of 1.2 atm and a 50% CO, content, while another
group had a pressure of 1 atm and a 40% CO, concentration.
A summary of the range of specifications for the different
feed scenarios that have been used in previous years is
given in Table 2. Thus, each
group was, in at least some
sense, provided with its own TA
unique design problem (with- Range of Feed S
out having to provide a differ-
ent set of economic data and Feed Senario CO Concenta
process information for every Natural Gas Well 7 30%
group of students). Landfill Gas 40 50%
The advantages of this ap- Enhanced Recovery 60-90%
proach were several-fold. First,
it tended to discourage groups
from simply "copying" from one another (although they
were still able to share general ideas and approaches to the
design problem). Second, it eliminated much of the anxiety
that occurs when different groups of students get different
"answers." This is particularly important if there is a group
of very strong students whose results would tend to preju-
dice the work of the rest of the class. In fact, by properly
choosing the feed characteristics (and economic informa-
tion) it was possible to design the project so that it generated
many different "correct" answers depending on the feed
properties and the design approach. This included the possi-
bility that the best process was actually to do absolutely
nothing, e.g., for some choices of the feed stream character-
istics it turned out that all of the proposed separation pro-
cesses were economically unattractive.
An interesting aspect of the final (written) report for this
project was the requirement that the students prepare a set of
specific recommendations for the future development of the
process. These recommendations not only gave the students
an opportunity to think about how their results might ulti-
mately be used by a real company, but it also provided a
chance for the students to perform a self-evaluation of their
own design analyses. Thus, many of the groups included
specific comments on the weaknesses in their calculations,
the need for improved physical property data under certain
conditions, the need to strengthen some of the economic
assumptions, and the possibilities for reducing overall costs
through more effective process integration (e.g., the intro-
duction of heat exchangers). These self-critiques were really
very insightful, and they provided the students with an inter-

Summer 1995


testing perspective on their own work as well as on the
project as a whole.
In order to reduce the time burden associated with this
project, I have made a concerted effort to assign problem
sets throughout the semester that revolve around the CO,-
CH4 system. For example, one of the homework problems
on distillation was to examine the use of cryogenic distilla-
tion to separate a particular CO2-CH4 mixture. But in this
case the column temperature and pressure, as well as the
distillate and bottom compositions, were all specified in the
problem statement, with the students simply asked to deter-
mine the number of plates required for the separation at a
given reflux ratio. Similarly, one
of the homework problems on
E 2 absorption focused on the use
iCharacteristics of monoethanolamines for
Prere o CO, removal, including the de-
-- velopment of the appropriate en-
0- 800 psig 5- 30 MMSCFD thalpy balances required to de-
- 1.5 atm 1 5 MMSCFD termine the temperature profiles
S- 200 psig 5 -30 MMSCFD within the column (an excel-
lent discussion of this parti-
cular problem is provided by
King151). In each case, the students were encouraged to
develop appropriate computer programs for the analysis,
with the specific goal of having these programs in hand
for use in the final project.
These problem sets not only reduced the amount of time
required for completing the final project, they also insured
that all of the groups were able to make an effective start on
the design calculations. In fact, many of the students
began their work on this project by pulling out their old
problem sets and carefully reexamining the detailed design
calculations for the different unit operations, thus providing
an ideal review for much of the material that was covered
early in the semester.

SUMMARY
Overall, I have been extremely pleased with the response
to this design project. It has provided our students with an
important introduction to the principles and approaches re-
quired for the development of this type of conceptual design
and for the analysis of different process alternatives for a
given separation. This type of expanded design experience is
also very much in line with the new ABET guidelines for an
enhanced design component throughout the curriculum (and
not just in a single capstone design course). The project has
also served as an excellent review for the wide range of
material covered in the mass transfer operations course, and
it has "forced" students to go back and reexamine and then
actually apply the governing design equations for distilla-
tion, absorption, membrane separations, and pressure swing
Continued on page 190


LBLI
trean

tion
40
1
4











W laboratory


QUALITY IN

TEACHING LABORATORIES



JOHN F. STUBINGTON
University of New South Wales Sydney 2052, Australia


In today's world, increasing attention is being focused on
quality in higher education, including chemical engi-
neering. The mission statement of a chemical engineer-
ing school could well be defined as: "The mission of the
school is to serve the needs of the country by providing first-
class teaching and research of the highest quality within the
disciplines of chemical engineering and industrial chemis-
try."
The statement refers to "first-class teaching" and to "re-
search of the highest quality." But, how can we demonstrate
the quality of teaching and research?
The Australian Federal Government has recently changed
its funding model for universities, providing some central
funds for competitive distribution on the basis of quality.
With the advent of the associated quality surveys and the
provision of quality money, it is no longer acceptable to
simply "know" or "assert" that our teaching and research are
of the highest quality-we must provide concrete evidence
of that quality. This paper presents our approach to the
problem and provides one answer to the question posed
above as it concerns teaching laboratories.
We believe the quality of our teaching is high, based on
informal feedback from industry employers on the standard
of graduates from our school. Although the quality of our
teaching laboratories is likewise high, we believe there must
be room for improvement in the quality of these laboratories.
We have chosen to focus initially on the laboratories to
develop the methods and a system for quality improvement,


John Stubington is a chemical engineer on the
staff of the Department of Fuel Technology within
the School of Chemical Engineering and Industrial
Chemistry at UNSW. His present research inter-
ests are in coal devolatilization, fluidized bed com-
bustion, and gas burner design.

Copyright ChE Division ofASEE 1995


With the advent of the associated quality
surveys and the provision of quality money, it is
no longer acceptable to simply "know" or "assert"
that our teaching and research are of the
highest quality-we must provide
concrete evidence of that quality.


which we plan to later extend to other aspects of teaching.
The objectives of the teaching laboratories must be de-
fined carefully in order to formulate quality measures that
accurately reflect performance in achieving these objectives.
Only then can the effectiveness of actions taken to improve
the quality be assessed. If the objectives are not specified
correctly, we will chase the wrong measures. The process of
quality improvement thus involves definition of objectives,
measurement of present quality standing, identification of
improvements, introduction of improvements, and measure-
ment of the resulting quality.
This paper describes our approach to the problem of mea-
suring the quality of existing teaching laboratories. With the
large number (sixteen) of laboratory courses taught in our
School of Chemical Engineering and Industrial Chemistry
and the diversity of the individual experiments in each of
those laboratory courses, a common methodology for qual-
ity measurement was sought. It should be noted that this is
not the comprehensive approach of TQM, inasmuch as it
does not focus intensely on the broad interrelationship be-
tween the laboratory and the relevant lecture courses) or on
the specific objectives of each individual experiment. Such
intense focus would make the development of a common
approach difficult, if not impossible, and has been deferred
to the stages of identification and introduction of improve-
ments.

OBJECTIVES OF TEACHING LABORATORIES
The overall objectives of our teaching laboratories have
Chemical Engineering Education











been defined for the student:
To develop skills in the acquisition and analysis of
engineering data
To develop the ability to communicate experimental
findings in written and oral form
To reinforce in a practical way theoretical concepts
taught in lectures
In addition to these overall objectives, each experiment has
its own specific objectives which should be spelled out for
the benefit of all personnel concerned.

QUALITY OF TEACHING LABORATORIES
Definition of quality What is meant by quality? Quality
seems to be a nebulous concept that is difficult to define in
an academic context, particularly when it is viewed nar-
rowly in terms of statistical quality control. But Deming's
approachl' to quality improvement offers a way to over-
come this difficulty. His approach has been applied and
developed in Japan, where it is included as part of KAIZEN.1"'
A complete contrast exists between the traditional Western
results-oriented approach and the process-oriented approach


advocated by Deming and embraced by KAIZEN.
Results-Oriented Approach In a results-oriented quality
control system, products are inspected at the end of the
process and accepted or rejected on the basis of measure-
ments made during this inspection. Such measurements are
termed R(esult)-criteria and are widely used as part of the
Western management style. While this approach ensures
that poor-quality products are not sent out of the factory, it
does nothing to improve the quality of products produced by
the process.
At the University of New South Wales, two types of
student survey are used to provide such R-criteria-one for
subject evaluation and one for teacher evaluation. Within
each survey, there are a number of standard questions and a
bank of optional questions, with those relevant to laboratory
subjects and laboratory teaching being given in Table 1.
From comparison between these questions and the general
objectives of the teaching laboratories given above, it is
apparent that the surveys provide more of a customer-satis-
faction rating than an assessment of how well the overall and
specific objectives of the teaching laboratory were met. Ad-
ditional questions, specifically related to the achievement of


TABLE 1
Student-Survey Questions


Subject Evaluation Questions
Standard questions
(Each question rated on a I-7 point scale, with 0 points if not relevant.)
1. How well have the objectives of the subject been made clear?
2. To what extent was there agreement between the documented
objectives of the subject and what was actually taught?
3. Does the weight given to the assessments so far reflect the
importance of the topics assessed?
4. How adequate has been the feedback on your progress?
5. How well coordinated were the various components of this
subject? e.g., lectures, tutorials, assignments, laboratory work
6. How appropriate have been the assessment tasks in the subject?
7. How adequate have been the physical facilities (rooms,
laboratories, etc.)?
8. How helpful were the tutorials and seminars?
9. How helpful were the demonstrations/laboratory sessions/field
trips, etc.?
10. How adequate were the support structures within the subject?
e.g., counseling, advice, and help with problems
11. How well structured were the materials in this subject?
12. Overall, how useful were the texts and/or supplementary
materials?
13. Overall, how useful were the reference materials?
14. How would you rate the overall quality of the teaching in this
subject?
15. How appropriate was the difficulty level of the subject compared


with other subjects?
16. To what extent would you recommend that another student, like
yourself, study this subject?

Teacher Evaluation Questions Specifically on Laboratory Teaching
Optional questions
(Each question rated on a 1-6 point scale, with an additional option of
not applicable.)
801. Sufficient time has been given to complete work in these
laboratory classes.
802. There has been a clear and supportive relationship between these
laboratory classes and the lectures.
803. There has been adequate access to equipment needed to complete
assignments during these laboratory classes.
804. I have been encouraged to work independently in these laboratory
classes.
805. Clear and concise instructions have been given in these laboratory
classes.
806 Marker's comments and criticisms on assessable work have been
helpful in these laboratory classes.
807. Laboratory assignments were reasonable in length and complex-
ity.
808. Equipment, materials, etc., have been reliable and in working
order in these laboratory classes.
809. The instructor ensured that purposes and procedures of practical
exercises were understood by students during these laboratory
classes.


Summer 1995











these objectives, need to be formulated. The subject evalua-
tion survey allows for the inclusion of up to nine such
questions.
KAIZEN's Process-Oriented Approachm2' KAIZEN is
an umbrella concept covering the Japanese practices that
have recently achieved such worldwide fame. A KAIZEN
strategy maintains and improves the working standard through
small, gradual improvements, whereas innovation provides
radical improvements as a result of large investments in
technology and/or equipment. Both KAIZEN and innova-
tion are necessary to maintain a competitive advantage, and
the emphasis placed on innovation by the traditional West-
ern management style has led to neglect of the opportunities
for continual improvement of existing systems. KAIZEN is
synonymous with continuing improvement involving every-
one-managers and workers alike.


Another important aspect of KAIZEN has been
phasis on process. KAIZEN is a process-oriented
thinking and a management system that supports
knowledge people's process-oriented efforts for ii
ment. This is in sharp contrast to the Western mana
practice of reviewing people's performance strictly
basis of results and not rewarding the effort
made. "Building quality into the process" is the
KAIZEN philosophy, thus ensuring that quality
products result.


The process-oriented approach analyzes all
of the individual steps in the overall process
and provides measurements which indicate the
quality of the individual process steps. These
measurements are termed P(rocess)-criteria and
provide concrete ways for gradually improving
the quality of each step in the process, in con-
trast with the R-criteria, which only measure
the quality of the final product.

PROCESS MODEL FOR
A LABORATORY EXPERIMENT
During initial discussions, it was commonly
assumed that the "student mark" was an indica-
tion of the quality of the teaching experiment,
although many academics were unhappy with
this as a quality measure because the student's
assessment should reflect the performance of
the student rather than the quality of the labora-
tory. Therefore, we sought an approach to qual-
ity measurement that allowed separation of stu-
dent assessment from measurement of the qual-
ity of the teaching laboratories.
We chose a process-oriented approach toward
improving the quality of each experiment in
each laboratory. A single laboratory experiment


the em-
way of
and ac-
mprove-
agement
I on the


can be depicted as a "process," as shown in Figure 1. The
process steps have been separated into those performed by
the students doing the experiment and those for which aca-
demic staff and technical support staff are responsible. The
quality of the students' process steps depends on the ability
and effort of the students and is reflected in their mark
achieved for the experiment. As academics, we have no
direct control over the quality of the student's process steps-
hence the difficulty in defining quality.
We do control the process steps for the academic and
technical staff, however. The KAIZEN approach of continu-
ally improving these steps in the process will improve the
quality of the overall process. Measurement of the quality
based on this process model then requires the definition of
quality measures for those steps under the direct control of
academic and technical support staff.

QUALITY MEASUREMENT
OF TEACHING LABORATORIES
An initial in-house survey of staff to identify quality mea-
sures for the teaching laboratories provided a wide range of
responses, many of which measured efficiency or cost rather


Figure 1. "Process" flow-sheet for a typical laboratory experiment, show-
ing the process steps for which academic staff, students, and profes-
sional/technical support staff are responsible.


Chemical Engineering Education


Academic Staff Student Professional Staff


Specify Experiment -- -- - -- -- -- -


Lab Notes Prior Preparation


Set Assessment Assess Preparation


Perform Experiment - Experiment Setup


Analyze & Interpret Data Analyzer
Results DatAnalyer


Report-Writing Write Report


Prepare Marker Assess Report


Lab Mark
- - D Indicates a service whose quality is under our control











than quality! Cost and quality are different objectives, as observed by
the president of the IChemE, who noted, "The driving down of unit cost
is damaging the quality of engineering, and chemical engineering in par-
ticular, in universities."'31 This idea that improved quality and lower
cost are conflicting objectives is directly challenged by KAIZEN's long-
term philosophy of continual improvement, leading ultimately to both
improvement in quality and lower cost. The confusion of the issues of


QUALITY MEASUREMENT
CEIC TEACHING LAB EXPERIMENTS


LABORATORY
EXPERIMENT

1. Specify experiment

Age of Standard Test used/Calibration of equipment?

Average age of equipment/instrumentation?

2. Lab notes/instructions

Time since last revision by academic?

Comprehensiveness-does it include: C
Aim of experiment
Relationship to lecture courses)
Equipment description
Equipment operating instructions
Data analysis requirements/use of results
Reference data
References
Assessment requirements

3. Assessment of prior preparation

Written standardized procedure for prior assessment?
Is the consistency of marks assessed?

4. Marker preparation

Are written instructions provided to markers?
Is a model report and marking scheme provided to markers?


5. Experiment setup
Yes
Is there a written setup procedure for this experiment? OE
<2
Number of equipment malfunctions during the lab this year? OE


6. Report assessment


Is the consistency of marks assessed?
Is feedback provided to the students?

Turnaround time for feedback to the students?

TOTALS (sum of number of ticks in each column):


Date:


0-5 yrs N/A
O O
0-5 yrs 5-10 yrs
O OE


>5 yrs
F-
>10 yrs
O


3-5 yrs 5-10 yrs >10yrs
EO O OF


complete Incomplete
El E
E El
E El
lO E
EO O
El E
EO O
El F


N/A




N/A
O
El


N/A
El
2-4
El


N/A
El

1-2 wks
OE


Yes
OE
OE
< wk
OE


None





O




No




No
O1
El
El





O


No
El
>4



No
El
El

>4






> 2 wks
D:


A=] B=D C=E]


QUALITY INDEX = (A C)/2 =


Figure 2. Quality measurement form for teaching laboratory
experiments, including the definition of the quality index.


quality and cost highlights the difficulty of de-
fining quality and has led us to adopt KAIZEN's
process-oriented approach which neatly side-
steps this difficulty.

We have identified a series of P-criteria Qual-
ity Measures appropriate to each of the process
steps in Figure 1 under our control. These mea-
sures are fairly universal for all our teaching
laboratories, even though the specific objec-
tives of the individual laboratories and indi-
vidual experiments differ. These measures have
been assembled into the quality measurement
survey given in Figure 2, which has been slightly
modified to be more applicable for the comput-
ing and pilot plant laboratories only. Note that
report-writing, although a major objective, is a
student process step and is not covered by this
form. Each tick in a box in Figure 2 counts as 1,
and an overall quality index for the experiment
is calculated according to the formula at the
bottom of the form. The quality index is de-
signed to range from a minimum of -10 to a
maximum of +10, with column B ticks count-
ing zero so that the index is non-linear towards
both extremes.
The quality index has been calculated for each
experiment in each of our laboratory courses to


#of hrs/ Av.
expmts exprmt Quality
Laboratory Index

Polymer Chemistry 5 4 1.6
Chemical Engineering Lab 1 7 3 6.6
Chemical Engineering Lab 2 7 3 5.2
Instrumental Analysis 1 12 3 8.58
Instrumental Analysis 2 3 4 8.5
Chemistry of Physical Processes 12 2 9.17
Environmental 3 3 9.33
Fuel Analysis 8 3 -0.4
Fuel Plant 6 12 -1.7
Valve Calibration 2 0.75 -0.5
Pilot Plant 12 3.5 -4
Computing 10 2.35
Hydrometallurgy 4 42 4.13
Mineral Engineering Processes 5 4 3.2
Industrial Processes 4 21 -0.5
unspecified
Figure 3. Average quality indices for the
experiments in each laboratory course.


Summer 1995










provide a baseline measurement of the present quality, with
the average results being presented in Figure 3 and ranging
from -4 to 9.3. The quality surveys then indicate areas for
improvement of each experiment, and academic and profes-
sional staff are presently using them to improve the quality
of our laboratory courses by targeting those areas high-
lighted as deficient by this quality measurement. We then
plan to apply the same quality measures next year, to assess
the effectiveness of the actions taken to improve the quality
of the processes in our teaching laboratories.

CONCLUSIONS
This paper has described a KAIZEN process-oriented ap-
proach for improving the quality of existing teaching labora-
tories that provides relevant quality measurements and indi-
cates how the quality could be improved. Use of such
P(rocess)-criteria neatly sidesteps the difficulty of defining
quality for laboratory experiments and allows separation of
student assessment from quality measurement. Efforts made
to improve the quality can then be assessed by the improve-
ment not only in these P-criteria but also in the R(esult)-
criteria measured by the standard student surveys for subject
and teacher evaluation.

ACKNOWLEDGMENTS
My thanks go to John Zubrickas of Johnson-Matthey and
to colleagues in the School of Chemical Engineering and
Industrial Chemistry at UNSW who have provided many of
the individual ideas on which this paper is based.

REFERENCES
1. Deming, W.D., Out of the Crisis-Quality, Productivity and
Competitive Position, Cambridge University Press, Cam-
bridge, UK (1986)
2. Imai, M., KAIZEN-The key to Japan's Competitive Suc-
cess, Random House, New York, NY (1986)
3. Reported in The Chemical Engineer, Inst. of Chem. Eng.,
Rugby, England, 28 July, 4 (1994) O



CONCEPTUAL DESIGN PROBLEM
Continued from page 185.

adsorption. The students were also given at least a flavor of
how these different processes are able to compete economi-
cally, depending upon differences in the feed specifications
and product requirements.
The scope of the actual student reports has varied enor-
mously. Some groups tended to get overly involved in the
minutiae of the design calculations (e.g., constructing nu-
merous McCabe-Thiele diagrams at different temperatures
and distillate/bottoms compositions for the distillation) while
other groups have made very effective use of available ap-
proximate methods like the Fenske and Gilliland equations.
Some groups have actually tried to integrate heat exchangers
190


into several of the processes in order to reduce the overall
energy costs. And many of the groups have examined the
behavior of several hybrid processes for the CO2-CH4 sepa-
ration, e.g., using a combined membrane and distillation
system to obtain high purity CO, and CH4 products at a
significantly reduced overall cost.
Although it is always difficult to judge student response to
an assignment of this nature, my impression is that the
students have found this project to be a very positive addi-
tion to the mass transfer operations course and to the overall
coverage of engineering design. Almost all of the students
have appreciated the "reality" of the project and the enor-
mous range of possibilities that they were able to explore.
I think they have also been fascinated by the different
answers obtained by the individual groups arising simply
from the differences in the feed characteristics (often
coupled with differences in the design strategies used by the
different groups).
Some of the students have been frustrated by what they
viewed as a lack of "structure" for the project. While these
students often had a great deal of difficulty developing an
effective approach to the design analysis, even they
seemed to develop a much better appreciation for the
underlying principles of engineering design and of the criti-
cal importance of developing an effective strategy for
attacking this type of open-ended design problem (instead
of simply using the type of brute-force approach that gener-
ally works so well for most standard chemical engineering
homework problems).
Overall, I feel that this project has had an extremely posi-
tive impact on the teaching of mass transfer operations, and I
can strongly recommend using this type of conceptual de-
sign analysis in similar classes at other universities.

ACKNOWLEDGMENTS
I would like to acknowledge the invaluable input provided
by David Hilscher and Russell Boyd, two of the Graduate
Student Teaching Assistants at the University of Delaware
who have worked with me in teaching this course over the
last few years.

REFERENCES
1. Wankat, P.C., R.P. Hesketh, K.H. Schulz, and C.S. Slater,
"Separations: What to Teach Undergraduates," Chem. Eng.
Ed., 28, 12 (1994)
2. Douglas, J.M., and R.L. Kirkwood, "Design Education in
Chemical Engineering: Part 1. Deriving Conceptual Design
Tools," Chem. Eng. Ed., 23, 22 (1989)
3. Newman, S.A., Acid and Sour Gas Treating Processes: Lat-
est Data and Methods for Designing and Operating Today's
Gas Treating Facilities, Gulf Publishing Co., Houston, TX
(1985)
4. Kohl, A.L., and Reisenfeld, F.C., Gas Purification, 4th Ed.,
Gulf Publishing Co., Houston, TX (1985)
5. King, C.J., Separation Processes, 2nd Ed., McGraw-Hill,
New York, NY (1980) O
Chemical Engineering Education












re M. book review



POLYMER SCIENCE AND ENGINEERING:
THE SHIFTING FRONTIERS
NationalAcademy Press, 2101 Constitution Ave., NW, Wash-
ington, DC 20418; 348 pages, $34.95 (1994)

Reviewed by
Donald G. Baird
Virginia Polytechnic Institute


In 1992 a committee was established by the Board of Chemical
Sciences and Technology of the National Research council to as-
sess the research frontiers in polymer science and engineering. In
particular, the goals were to examine the recent advances in poly-
mer research and to identify new thrusts in the context of current
and long-term needs and concerns. This book represents a report on
the committee's findings. Here the significance of their report,
along with the key findings, are reviewed.
The report is based on certain underlying tenets and facts. First,
the chemical industry, of which polymers make up a major portion,
is one of two major U.S. industries with a positive trade balance. In
order to maintain this trade position, the U.S. must continue its
consistent and rigorous commitment to polymer research. Second,
polymers are extremely versatile materials and have a wide range
of applications. For example, the same polymer with different
molecular features and processed differently can be used to make
cheap articles such as toys and bags on one hand, while on the other
it can be used to produce lightweight but high strength, stiff materi-
als which can replace metal. Third, roughly 50% of chemists and
chemical engineers are involved with polymers at some time dur-
ing their careers, but educational opportunities at most universities
are still lacking. Finally, the generation of a polymeric article with
desirable physical properties is a complex function of polymer
chemistry, processing, and structure. In other words, progress in
the development of new materials requires a combined effort of
chemists, material scientists, and engineers. These facts, which are
emphasized throughout the report, serve as a basis for establishing
the significance of polymer research and education and justifying
the committee's conclusions and recommendations.
The report begins with a summary of the findings and recom-
mendations. Five recommendations were given which in essence
deal with the carrying out of polymer research and education.
Recommendation 1 is concerned with the importance of
maintaining active corporate research groups, development
of governmental policies which encourage long-term
research, and nature of funding which promotes interaction
between universities, industry, and national laboratories.
In Recommendation 2, the importance of an integrated
approach between polymer science and engineering and
other areas, such as housing, medicine, transportation, etc.,
is emphasized.
In Recommendation 3, specific areas of research for
which a high priority of support should be given are listed.

Summer 1995


Recommendation 4 deals with environmental issues, and it
is merely suggested that a panel at the national level be
appointed to handle these matters.
Finally, Recommendation 5 is concerned with the
importance of collaborative efforts (both in research and
education) within polymer subdisciplines and across the
boundaries of other fields.
With the exception of the recommendation pertaining to environ-
mental issues (I don't think that anyone knows what to do in this
case) their recommendations are sound, informative, and concrete.
The remainder of the book consists of four chapters which serve
primarily to support their major premises and recommendations.
Chapter 1 (National Issues) discusses some of the direct societal
benefits derived from polymer science and engineering and illus-
trates how it can contribute to the solution of some of the pressing
problems facing the United States and the world. Yet, it points out
some of the disturbing facts which could jeopardize the advantage
the U.S. presently has in polymers. Most major companies have
down-sized their polymer research and development activities. The
past level of education in polymers of scientists and engineers has
been extremely low. It is indicated that polymer science and engi-
neering must become part of the core curriculum for chemists,
chemical engineers, and material scientists.
Chapter 2 (Advanced Technology Applications) is concerned
with how new classes of polymeric materials with unique applica-
tions are being introduced into two areas: health and medicine, and
information and communications. This chapter serves to, more or
less, illustrate the versatility of polymers and how they can be used
in other areas of science and technology. Although most of the
examples illustrate present applications, suggestions of future de-
velopments and needs are given.
Chapter 3 (Manufacturing: Materials and Processing) is prima-
rily a review of existing polymeric materials and their properties. It
is a very good overview of the classifications of polymeric materi-
als and their applications. At the same time, it emphasizes the fact
that final properties are a function of composition and processing
history and thereby establishes the importance of developing pro-
cess models to aid in design of processing conditions and methods.
There is much to be done here both in the development of numeri-
cal methods and improved constitutive equations (in spite of what
is reported concerning the value of the Doi-Edwards constitutive
equation).
Finally, Chapter 4 (Enabling Science) starts with the premise that
polymer synthesis provides the basis for all advances in polymeric
materials. It then proceeds to give an overview of factors which can
be controlled by the polymer chemist to give a polymer a desired
set of properties. The chapter also contains an overview of tech-
niques used to characterize polymeric systems.
The book is readable by a diverse audience. It is useful for
polymer research specialists searching for new ideas and applica-
tions. Chapters 3 and 4 are actually good overviews of polymeric
materials and polymer synthesis and could be used as an introduc-
Continued on page 197











f class and home problems


UNUSUAL THREE-PHASE FLASH

EQUILIBRIUM PROBLEMS


MARIA A. BARRUFET, KAI Liu
Texas A&M University College Station, TX 77843-3116


A four-credit senior-level course in the Petroleum
Engineering Department at Texas A&M Univer-
sity, "Phase Behavior of Hydrocarbon Fluids," cov-
ers thermodynamic and transport properties of reservoir flu-
ids and fluids used in oil recovery applications. From the
surface to the reservoir, oil and gas pressures vary from
atmospheric to over 1000 MPa, and temperatures vary from
near zero to about 3000C. An important portion of the course
is devoted to the evaluation of various correlations and mod-
els, including equations of state (EOS), to solve the phase
equilibria at these conditions.

INTRODUCTION
The evaluation of a two-phase flash problem has become a
common exercise in any thermodynamics course in chemi-
cal or petroleum engineering. Equilibrium and material-
balance relations lead to the common flash function, which
can be stated in many different algebraic forms in terms of
feed compositions (z,), molar fraction of feed vaporized, (f,),
and equilibrium K-values.[l'2 But phase equilibria in en-
hanced oil recovery processes such as steam flooding is
complex and usually involves three or more equilibrium
phases. In steam-flooding processes, steam is injected into a
well to displace oil within the reservoir to a producer well. In
this process, heat and mass transfer mechanisms cause
multiphase separations. The phases considered are a vapor
phase, a hydrocarbon-rich liquid phase (known as the oleic
phase), and an aqueous phase. Since chemical species can
distribute in all the three phases, there will be three different


partition coefficients or K-values. Only two of them are
independent since the third can be evaluated as a linear
combination of the other two.
Three-phase flash problems are not commonly taught, al-
though they can become an important tool in teaching funda-
mental aspects of phase equilibria. We have found interest-
ing examples in three-phase equilibrium problems that are
thought-provoking and are very useful for verifying the con-
sistency of common assumptions, screening models for con-
sistency, and analyzing experimental data.
In this paper, we present some of these examples with
two- and three-component systems.

Maria A. Barrufet is an assistant professor of
petroleum engineering at Texas A&M University.
She received her BS, MS, and PhD degrees in
chemical engineering from the National Univer-
sity of Salta, the Southern National University of
Bahia Blanca, and Texas A&M University. Her
research programs include modeling and predic-
tion of phase equilibria of mixtures as applied to
enhanced oil recovery, and experimental mea-
surements of transport and PVT properties.



Kai Liu is a research assistant and a PhD can-
didate at Texas A&M University. He received
his BS and MS degrees from Southwest Insti-
tute of China. His research interests include
numerical methods for solving phase equilibria,
data analysis with error propagation and para-
metric sensitivity, and reservoir simulation.


Copyright ChE Division ofASEE 1995


Chemical Engineering Education


The object of this column is to enhance our readers' collections of interesting and novel
problems in chemical engineering. Problems of the type that can be used to motivate the student
by presenting a particular principle in class, or in a new light, or that can be assigned as a novel
home problem, are requested, as well as those that are more traditional in nature and which
elucidate difficult concepts. Please submit them to Professor James O. Wilkes (e-mail:
wilkes@engin.umich.edu) or Mark A. Burns (e-mail: maburs@engin.umich.edu), Chemical
Engineering Department, University of Michigan, Ann Arbor, MI 48109-2136.










THE GENERALIZED THREE-PHASE FLASH
A commonly asked question is whether the phase equilib-
rium compositions depend upon the overall mixture compo-
sition. The answer to this problem can be seen in Figure 1, a
sketch of a system in three-phase equilibria brought into
equilibrium at overall composition zi' with the valve open.
The oleic, vapor, and aqueous phase compositions are xi, yi,
and w,, respectively. If the valve is closed at constant pres-
sure and temperature, the system above the valve will have
an overall composition z,2 different from zi', but the phase
compositions xi, y,, and wi will not change. Therefore, phase
equilibrium compositions are independent of the overall mix-
ture composition. The same principle applies to a two-phase
system-this is an important concept that should be stressed.
When a system exhibits three phases, there will be two
objective functions (flash functions) to be zeroed simulta-
neously. As with the two-phase flash problem, there are
several algebraic expressions for these objective functions,
and Peng and Robinson131 recommended the following:

n n
F1= xl- y= 0 (1)
i=l i=l

F2= wi-l=0 (2)
i=1

Phase equilibria in three-phase systems require two sets of
equilibrium ratios or K-factors: the vapor-aqueous (Kva)
and the vapor-oleic (Kv") equilibrium ratios, which are de-
fined as


Kva Yi
w.
I


and Ko =


The objective functions expressed in terms of these K-values
are


z.Kvar 1
F,(ff0o) = I = 0 (4)
I+ K _1 fo+ Kva-1)fv



F(fv,fo) = zI 1=0 (5)
n
i= (Ka (5)
l+ KV-I f + (Kva 1) f



The K-values can be obtained from EOS, from correla-
tions, or from liquid solution models. If the correlations are
composition independent, we can demonstrate that the same
model cannot be used for both since that will yield a singular
Jacobian matrix from the two flash equations.'41
A very common assumption for solving phase equilibria
Summer 1995


of hydrocarbons with water is to neglect the solubility of
hydrocarbons in the aqueous phase. This is equivalent to
having the vapor-aqueous K-values for all hydrocarbon spe-
cies infinite, and the vapor-aqueous K-value for water equal
to its mole fraction in the vapor phase. For the vapor-oleic
K-values, one could use EOS or correlations.[51

I Example
SExample 1

As an example, we evaluated phase equilibria on the ter-
nary system of heptane/decane/water using Wilson's151
correlation for the K-values, which is widely used in
petroleum engineering applications at pressures up to 2 MPa.
In the example presented, we evaluated phase equilibria at
T = 173.63'C and P= 0.48 MPa. Wilson's correlation for the
equilibrium ratios is

KV= exp 5.37 (1 -) (6)
P L

After substituting Ky0 into Eqs. (4) and (5) and ignoring
the solubility of hydrocarbons in water, we solved the flash
functions and obtained multiple roots for the three-phase
equilibria. This pathological behavior could be attributed to
using a wrong model for the water equilibrium ratios, al-
though numerical problems, false solutions, and non-physi-
cal answers have been reported in multiphase calculations of
systems with water, even using more elaborate models.16'
Table 1 (next page) shows some of the multiple roots
obtained for this system. Note that the equilibrium composi-
tions obtained are all different. The student can verify that
all these roots satisfy the mate-
Srial balance constraints. Figure 2
.... vapor (next page) illustrates the shape
. phase of the objective functions defined
.. . in Eqs. (4) and (5) versus the
sum of the vapor and oleic frac-
oleic tions at the temperature and pres-
phase
phase sure of study. Only a few curves
have been shown for clarity.


Figure 1. Three-phase
equilibrium system.


K-FACTORS
RELATIONSHIP
IN A BINARY
THREE-PHASE
SYSTEM
If a two-component system co-
exists in three-phase equilibria,
according to the Gibb's phase
rule, there is only one degree of
freedom. If three phases exist,
there will be a unique three-phase
pressure for a given temperature.
The set of equations for a bi-
193











nary, three-phase system is

zI = fwl + fox + fl

Z2 =f2 +fx2+fvy2

f +f +fv =


The determinant of the coefficient matrix of the linear equa-
tions above is


wl XI YI
2 X2 2
I I 1


Since


2 2 2
Xi = yi= Wi=1 ()
i=I i=l i=l

substitution of Eq. (11) into Eq. (10) yields a zero determi-
nant. Thus, these equations are linearly dependent, and infi-
nite roots of fa, f, and fo can be found. From this determi-
nant, we derived the following relationship among the K-
factors of a three-phase binary system


1 1
Kva K/VO

1 KI
Kva Kvo
K2 K2


temperature of a binary system. The equilibrium molar com-
positions, aqueous w,, oleic xi, and vapor y,, are determined
(7) from the following expressions:


K(K a -1
x K (K vaK


Kva I
Wl K va va
K2 -KI


(10) and the vapor compositions y, from the vapor-oleic K-value
relation.


I 02-l I I I


0.0+


(12)


If we have functional forms of the equilibrium values in
terms of pressure and temperature, Eq. (12) could be used as
a scheme to find the three-phase equilibrium pressure or


-0.2-
0.0


0.2 0.4 0.6 0.8 1.0
0.2 0.4 0.6 0.8 1.0


Figure 2. Flash functions at T=173.63 C and P=0.482
MPa for the ternary system of Example 1.


Chemical Engineering Education


TABLE 1
Three-phase flash multiple solutions when the solubility of hydrocarbons in water is neglected and the
K-values are composition independent.

p = 0.482 MPa T = 177 (C)

Component (i) (1) (2) (3)
Heptane Decane Water
Overall Composition Mole Fraction z(i) 0.40 0.20 0.40
Aqueous Composition Mole Fraction xa(i) 0.00 0.00 1.00

Rt# ff f f x, x, x3 y, Y Y3

1 0.367817 0.625861 0.006322 0.630706 0.318852 0.050442 0.832917 0.070085 0.097000

2 0.346768 0.587909 0.065323 0.593317 0.332078 0.074605 0.783541 0.072992 0.143466

3 0.317383 0.546094 0.136523 0.550670 0.347161 0.102169 0.727220 0.076307 0.196473

4. 0.280020 0.503986 0.215994 0.506823 0.362672 0.130506 0.669315 0.079717 0.250965

5 0.232139 0.460717 0.307145 0.461715 0.378624 0.159661 0.609746 0.083223 0.307030

6 0.169902 0.415049 0.415049 0.415297 0.395040 0.189663 0.548445 0.086831 0.364724

7 0.011836 0.326094 0.662070 0.333214 0.424071 0.242714 0.440046 0.093212 0.466743














1 2 .. ................... ....... ..- ................ ..... ......................... .

fa+fv+fo zi=0.4
1.0


o 0 .8 ---- -- ...... .- ................


S 0 ........... ......... ............................................. ... ......................... .
0.4



...-- .....
0.2 -
S0.0
0 .0 ......................... ........... ..................................... ....................... .
0.0 0.2 0.4 0.6 0.8
fa
Figure 3. Oleic and vapor phase fractions as a function of
aqueous phase fraction and overall compositions in the
three-phase binary system of Example 2.


V
( fv= 1, fo= 0,fa= 0)


f
a
( fv= 0, fo= 0,fa= 1)


f
(f=0o=1,a=
(fv= 0, fo= 1 -fa 0,


Figure 4. Phase fractions as a function of overall mixture
composition for the system of Example 2.


Summer 1995


Example 2
We worked a second example using published experimen-
tal data from Heidmann, et al., [7 who measured the equilib-
rium phase compositions of the binary system ethylbenzene
(1)/water (2) at 0.11 MPa and 367.6 K. These compositions
are
x, = 0.0186 Y2 = 0.726 w, = 0.000086
Students can verify Eq. (12) by using the definition of the K-
values and the compositions provided.
Figure 3 illustrates all possible solutions for the phase
fractions of Example 2 at a fixed overall composition. Figure
4 is a ternary diagram for this system at P = 0.11 MPa and
T = 367.6 K, showing all possible combinations of phase
fractions (satisfying the material balance and equilibrium
constraints) as a function of various overall compositions.
For example, the onset and disappearance of the three phases
for a mixture with 20% of ethyl benzene occur approxi-
mately at f, = 0.3 and fa = 0.8.
To obtain a unique solution, we need to find an indepen-
dent equation involving these phase fractions. One of these
relationships is the apparent total molar volume of the sys-
tem, which can be measured or fixed:

VMt = fVMv +foVMo +aVMa (15)
where VMv, VMo, and Va, are the vapor, liquid-hydrocarbon,
and aqueous molar volumes that can be evaluated from an
EOS at the pressure, temperature, and composition of the
phase. For consistency, the same EOS should have been
used in evaluating the K-values that determined the three-
phase equilibrium state. Phase compositions and phase vol-
umes could also be available experimentally.
The phase fractions will then be uniquely determined from
the following expressions:


(X1 y )V' (Z x2)V (Y2 Z2)V
f -y2)VM (Y 2 (16)
a (X2 Y2)VMa -(W2 -X2)VM (Y2 )VMo

Z2 Y -(W2 -y2 )fa
f = (17)
X, -y,

and the vapor phase fraction fv is obtained by subtracting
(fa + fo, from one.

EVALUATION OF PHASE FRACTIONS

To estimate the phase fractions for this example system,
we arbitrarily selected an overall composition of ethylbenzene
(z, = 0.4) and evaluated the phase molar volumes using the
Peng-Robinson equation of state at the experimental pres-
sure, temperature, and phase compositions. Since the pres-
sure and the temperature of this system remain constant,
each phase must keep its intensive properties (e.g., equilib-
195











rium composition, density), regardless of its relative amount
in the system. Figure 5 shows the determination of the phase
fractions from Eqs. (16) and (17). As a suggested exercise,
the student should find the values of the molar volumes.
For a three-phase ternary system, the equilibrium compo-
sitions (xi, Yi, wi) and phase fractions (f,, fv, f,) can be
determined explicitly and uniquely given KvT and KY.

EXERCISE
As an exercise the student may solve the three-phase equi-
libria on the following three-phase ternary artificial data:


Species "i"


34449.2 13509.0

1.16668 0.44

0.3 0.3


3

0.2703


4607 892.19

0.4


The following solution should be obtained:


1
0.3938
0.4594


2
0.6059
0.2703


0.0003
0.2703


wi 0.000013 0.00002 0.999967

fa = 0.29991 fo = 0.33010 f = 0.36999


CONCLUSIONS
We have presented simple three-phase equilibria problems
when water is included. This paper contains exercises that
are thought-provoking in the classroom. In particular, when
there is negligible solubility of hydrocarbons in the aqueous
phase, these problems lend themselves to further analysis
and evaluation of other equilibrium-ratio models. For a bi-
nary system in three-phase equilibria, we have presented a
constraining procedure to obtain a unique solution for the
phase splitting.

ACKNOWLEDGMENTS
The authors acknowledge the donors of The Petroleum
Research Fund, administered by the ACS, for supporting
this research.

NOMENCLATURE

f f f aqueous, oleic, and vapor phase fraction, respectively
K K-factors in a two-phase system
Ka vapor/aqueous equilibrium ratio for species "i"
Kv. vapor/oleic equilibrium ratio for species "i"
Pi critical pressure of species "i" (MPa)
T. critical temperature of species "i" (C)
Vm molar volume in aqueous phase (L3/mole)


5 10 15 20
VM,, m'/Kg mole
Figure 5. Phase fractions as a function of total molar
volume for the system of Example 2.



V molar volume in oleic phase (L3/mole)
V total molar volume in three phases (L'/mole)
VMV molar volume in vapor phase (L'/mole)
oi acentric factor of species "i"
w mole fraction of species "i" in aqueous phase
xi mole fraction of species "i" in oleic phase
y, mole fraction of species "i" in vapor phase
z mole fraction of species "i" in overall mixture

REFERENCES
1. Van Ness, H.C., and M.M. Abbott, Classical Thermodynam-
ics of Nonelectrolyte Solutions With Applications to Phase
Equilibria, McGraw Hill, New York, NY, Chap. 6 (1982)
2. Rachford, Jr., H.H., and J.D. Rice, "Procedure for Use of
Electronic Digital Computers in Calculating Flash Vapor-
ization Hydrocarbon Equilibrium," J. Petrol. Tech., 4(10),
(1952)
3. Peng, D., and D. Robinson, "Two and Three-Phase Equilib-
rium Calculations for Systems Containing Water," Canad.
J. Chem. Eng., 54, 595 (1976)
4. Barrufet, M.A., W.A. Habiballah, K. Liu, and R. Startzman,
"Warning on the Use of Composition Independent K-Value
Correlations for Reservoir Engineering," accepted in J. of
Petrol. Sci. and Engg. (March, 1995)
5. Wilson, G., "A Modified Redlich-Kwong EOS, Application to
General Physical Data Calculations," paper 15C presented
at the Annual AIChE National Meeting, Cleveland, OH
(1968)
6. Nagarajan, R.R., A.S. Cullick, and A. Griewank, "New Strat-
egy for Phase Equilibrium and Critical Point Calculations
by Thermodynamic Energy Analysis. Part I. Stability Analy-
sis and Flash," Fluid Phase Equilib., 62, 191 (1991)
7. Heidman, C., C. Tsonopoulos, J. Brady, and G.M. Wilson,
"High-Temperature Mutual Solubilities of Hydrocarbons and
Water. Part II. Ethylbenzene Ethylcyclohexane, and n-Oc-
tane," AIChE J., 31, 367 (1985) O
Chemical Engineering Education











REVIEW: Polymer Science and Engineering
Continued from page 191.
tory supplement for a course on polymer processing where these
particular topics are not covered. Researchers in other branches of
material science in search of new materials will find the book of
interest. Finally, leaders in science policy and funding will find the
book informative. 1



r M book review


ENGINEERING YOUR FUTURE:
Launching a Successful Entry-Level Technical
Career in Today's Business Environment
by Stuart G. Walesh
Prentice Hall, 439 pgs. (1995)

Reviewed by
Phillip C. Wankat
Purdue University

Engineering educators have been told repeatedly that our stu-
dents have the technical skills to succeed, but often do not have the
necessary communication, interpersonal, time management, and
business skills needed. This book is an outstanding effort to help
remedy that problem. It could be used as a text for a senior course,
for self-study by young professionals, or as a resource in short
courses.
After the introductory chapter, there is an excellent chapter on
self-management. It includes a brief discussion on the differences
between school and work (e.g., tardiness is not tolerated). The
fourteen pages on time management are too brief, but the author is
able to condense an incredible amount of useful information into
these pages. After further good advice, the author notes the impor-
tance of attitude-one can choose to be a winner. The chapter
closes with strong arguments for participation in professional orga-
nizations and for becoming licensed. This emphasis reflects the
author's civil engineering background, but is not inappropriate for
chemical engineers in a volatile employment environment.
Chapter 3, Communication Skills, will prove useful to seniors
(and professors) who think they have read everything there is to
know about communication. The chapter starts with the novel idea
that listening is a communication skill. The author states that writ-
ing best communicates facts and details, while speaking "clearly
holds the power of persuasion." Note that this implies professors
should use lectures for motivation and attitude adjustment, not to
present facts and details. The section on writing contains both
common advice and uncommon advice (e.g., write the easy parts
first). The section on speaking will also be useful to both inexperi-
enced and experienced speakers. It contains a very good list on
speaking in addition to useful comments on international audi-
ences.
Chapter 4 on management of relationships is a continuation of
Chapter 2. Topics in this chapter include: Maslow's Hierarchy of
Needs, Theories X and Y, Delegating, Managing Meetings, Work-
ing with Support Personnel, Managing Your Boss (very brief), and
"Caring Isn't Coddling." Although this is useful information, I
Summer 1995


doubt much of it will be appreciated by seniors or new engineers.
The sections on support personnel and caring should be assigned to
all students before any work assignments (COOP, summer job, or
permanent work). This chapter would benefit from an exercise
section.
Chapter 5 is on the organization of organizations. Since I would
expect most engineers to be able to determine this rather quickly on
their own, I suggest skipping this chapter.
Chapter 6, Project Management, is a gem, particularly for chemi-
cal engineers who often do not formally study these methods. The
author starts with a simple chronological list, continues with the
visually appealing Gantt chart, and finishes with a long section on
the more complex and more powerful critical path method. The
exercises at the end of this chapter will help the engineer under-
stand these methods.
Chapter 7, Total Quality Management, is written for engineers
with no knowledge of TQM. It should serve as a good introduction
to TQM for engineers who will work in a TQM organization.
The next chapter, on decision economics, covers material that is
traditionally covered in chemical engineering senior design classes.
The author is clearly serious since this chapter has by far the most
homework exercises. Chapter 9, Business Accounting Methods, is
in some ways a continuation. It is probably worth reading since it
will help new engineers interpret their company's profit-and-loss
statements. Chapter 12 on design also overlaps with the usual
senior design courses.
Chapters 10 and 11 cover the legal framework and ethics of an
engineering career, respectively. Although written from the civil
engineering point-of-view, they should also prove useful to chemi-
cal engineers. In fact, this viewpoint may be particularly useful
given the civil engineer's heightened sensitivity to liability issues
and professional responsibility. The examples are civil engineering
examples, but any engineer can appreciate them.
The Appendices contain the ASCE Code of Ethics, the IEEE
Code of Ethics, the College Placement Council Principles for Pro-
fessional Conduct, and excerpts from the Boeing Company's Busi-
ness Conduct Policy and Guidelines. The fourteen principles of the
government code of ethics are included in Chapter 11. This wealth
of information could be used in case studies to show that what may
be ethical for one engineer could be unethical for another. There are
also some good scenarios for discussion in the chapter's exercise
section.
Chapter 13, Role and Selection of Consultants, and Chapter 14,
Marketing Technical Services, are of much more interest to begin-
ning civil engineers than chemical engineers. At some point, how-
ever, chemical engineers may find this information useful.
The conclusions of the last chapter, The Future and You, can be
summed up in one sentence: Be flexible and ready for change.
How can a chemical engineering professor best use this book?
First, read selected parts. Second, recommend it to students who
are going to work, whether it is COOP, summer, or post-gradua-
tion. Third, consider using parts of it as a text in a senior seminar, or
as a supplemental text in a senior design course. I estimate that the
most important parts of this book could easily be covered in the
typical one-hour-per-week senior seminar.
Overall, I think this is a great book for civil engineers and a good
book for chemical engineers. 0











S curriculum


COMPUTING IN THE


UNDERGRADUATE ChE CURRICULUM

An Integrated Approach


MUTHANNA H. AL-DAHHAN
Washington University St. Louis, MO 63130
he influence of computers on our lives grows with
each new technological breakthrough. Today the num-
ber and types of computer applications are too vast to
count. With the development of fast, efficient digital com-
puters, the role of computing in solving engineering prob-
lems, analysis, design, text processing, graphics, communi-
cation, and accessing information has increased dramatically
and has led to a great demand for computer application skills
in the curricula and practice of various engineering disci-
plines. Hence, computer literacy has become vital in engi-
neering education, research, and practice. As a result, courses
in chemical engineering, as well as in other engineering
disciplines, have become more computer-oriented at all lev-
els of the curriculum.
Recent surveys on computing conducted by the CACHE
Corporation Curriculum Committee show that chemical en-
gineering graduates overwhelmingly considered computing
to be an integral part of the undergraduate program.1" This
raises the question as to what undergraduate chemical engi-
neering students should know regarding computers and com-
putations. It is evident that the students must
Have access to computing facilities
Be efficient in programming in at least one high-level lan-
guage (such as Fortran)
Be capable of implementing numerical computing techniques
on the computers
Be exposed to the use of available software packages for
computing, data analysis, and design
Be able to use the computer for technical calculations, prob-
lem solving, data processing, process design and simulation,
etc.
Be ready to efficiently use computing support facilities such as
operating systems, editors, etc.!2-41
Another difficult question that needs to be addressed is:
How best should undergraduate chemical engineering stu-
dents acquire these skills, systematically and effectively, at
an early stage of their academic program?
Copyright ChE Division ofASEE 1995


Muthanna H. AI-Dahhan is Assistant Professor of
Chemical Engineering and Associate Director of
the Chemical Reaction Engineering Laboratory at
Washington University. He received his Bachelor's
degree from the University of Baghdad (1979), his
Master's degree from Oregon State University
(1988), and his Doctoral degree from Washington
University (1993), all in chemical engineering. His
research interests are in chemical reaction engi-
neering, multiphase reactor systems, mass trans-
fer, process engineering, and unit operations.

Although the current practice of teaching programming in
Fortran or another language (e.g., Basic, Pascal, C, C++, etc.)
in the early years (freshman or sophomore levels) helps stu-
dents acquire some of the above mentioned skills, it does not
provide them with the vital knowledge of how to efficiently
solve engineering problems. This knowledge is essential for a
strong engineering program; enhanced understanding of chemi-
cal engineering principles at all course levels and the capability
of handling problem assignments, projects, case studies, etc.,
requires a knowledge of programming, computing techniques
for solving problems, understanding of computer capabilities
and limitations, and exposure to available software packages,
etc. Often, these skills are introduced by more than one course
at different levels of the curriculum.
For example, numerical methods and analysis are usually
offered at the senior or graduate level, clearly far too late for
the students to use the material in the curriculum. Even if the
available computing packages (such as Matlab, Mathematica,
and Spreadsheets) are taught with the calculus and linear alge-
bra courses, they do not provide the students with the highly
desirable integrated skills mentioned above.
A common practice is to cover the needed computational
skills and software for solving engineering problems through
assignments in different courses. This does not work very well,
however, since it detracts from the principles taught in the
course. Moreover, an average student often has to struggle
with the computational tools needed to solve the problem at
hand and ends up losing perspective of both the physical situa-
tion and the computational method. The grade-conscious stu-
dent focuses on getting the job done; it is viewed as a struggle,
and the student misses the learning part.
Chemical Engineering Education











It is much more beneficial to the student to have a single
course early in the curriculum that focuses on computational
literacy. Such a course can combine learning computational
skills with solving specific problems and gives the students
broad exposure to a variety of computing tools in an inte-
grated fashion. Enabling students to develop all the above
mentioned skills through a single course offered early in the
curriculum is not easy, but is essential for a productive engi-
neering program. The same conclusion has been recently
reached by Davis, et al.,111 based on the surveys on computing
managed by the CACHE Corporation Curriculum Committee.
At Washington University, we have developed and taught
an effective early-stage (freshman or sophomore year) com-
puting course that provides, in a systematic manner, the skills
mentioned above."5' The course, "Introduction to Computing
and Computer Applications," is based on the premise that
chemical engineering students should be provided with an
integrated, strong, and early introduction to computing tech-
niques and packages for solving engineering problems. The
material is presented in a form that allows students to follow
the logic involved and to understand the relationships between
the computer, programming, numerical computing, comput-
ing software packages, and practical skills for solving engi-
neering problems. This course and its approach are described
and discussed in the following sections.

COURSE STRUCTURE AND CONTENTS
The course is offered each semester every year. It is as-
sumed that the students have had little experience with the
computer and its applications in programming, computing,
analysis, graphics, wordprocessing, etc.


Week Subjects


The course is structured to achieve the following goals:
1. To acquaint the students with the computer (such as its basic
architectural components and their functions, its capabilities
and its limitations in solving engineering problems, etc.) and to
familiarize them with computing support facilities (such as the
operating system, editor, compiler, etc.).
2. To make the students efficient in programming in a high-level
language (Fortran).
3. To introduce the students to numerical methods and computing
and their effective implementation on the computer using For-
tran programming.
4. To use the commercially available and widely used computing
software and library packages such as Matlab, Mathematica,
Spreadsheets, and IMSL (International Mathematics and Statis-
tics Library).
5. To practice the acquired knowledge by solving real-world engi-
neering and scientific problems.
Achieving these goals prepares the students properly and ef-
fectively for the engineering courses at all levels.
Each week, some elements of Fortran programming, nu-
merical computing techniques and computing by commercial
software are given almost equal coverage. Engineering and
science problems are practiced through illustrated examples,
workshops, and homework assignments. Table 1 shows the
outline of the course structure and contents.

MATERIAL PRESENTED
As can be seen in Table 1, the course content is organized
into three parallel subjects that include 1) programming in
Fortran, 2) numerical computing, and 3) computing software
packages, in that order. Practical engineering problems are


TABLE 1
Course Outline: Computing and Computer Applications


1&2 Introduction to computer architectural components and their functions
Running computer programs: editing, compiling/linking, executing
Procedure for solving problems using the computer
Introduction to numerical computing and engineering problem-solving
Introduction to computing software: Matlab, Mathematica, and Spreadsheets
3 Programming: Fortran syntax / Arithmetic computations
Numerical computing: The Taylor Series
Matlab, Mathematica, and Spreadsheets: Building up calculations and data
processing
4 Programming: Simple input and output
Numerical computing: Numerical differentiation/Introduction to differential
equations
Matlab, Mathematica, and Spreadsheets: Algebraic calculations and
functions; symbolic computations/graphic
5 Programming: Control structure IF structures
Numerican computing: Root of equations and conversion criteria
Matlab, Mathematica, and Spreadsheets: Root equations computing; if
structure; graphic
6 Programming: Control structure DO loop structure
Numerical computing: Numerical integration
Matlab, Mathematica, and Spreadsheets: Computing of integrals; Doloop;
graphic
7 Programming: Data files and additional input/output features


Numerical computing: Review of basic matrix terminology and operations
Matlab, Mathematica, and Spreadsheets: Handling data files and matrices
8 Programming: Array processing
Numerical computing: Systems of linear algebraic equations
Matlab. Mathematica, and Spreadsheets: Matrix and array computations;
solving sets of linear equations
9 Programming: Subprograms functions and subroutines
Numerical computing: IMSL subroutines library package
Matlab, Mathematica, and Spreadsheets: Functions and more computations
10 Programming: Subprograms functions and subroutines
Numerical computing: Systems of nonlinear algebraic equations / IMSL
Matlab, Mathematica, and Spreadsheets: Solving nonlinear equations
11 Programming: Additional Fortran features
Numerical computing: Curve fitting and statistical analysis / IMSL
Matlab. Mathematica, and Spreadsheets: Curve fitting and statistical
analysis; graphics
12 Programming: Additional Fortran features
Numerical computing: Interpolation / IMSL
Matlab, Mathematica, and Spreadsheets: Fitting and interpolation; graphics
13 Programming: Review
Numerical computing: More differential equations / IMSL
Matlab, Mathematica, and Spreadsheets: Differential equations; graphics
14 Review


Summer 1995 19










introduced in the lectures' illustrated examples and in the
workshop and homework assignments. It is noteworthy
that programming in Fortran is covered first. It has been
my experience that this helps the students understand and
follow the algorithm steps and flowchart of the computing
techniques and to translate them to a computer program.
After a particular computing technique is covered, stu-
dents are introduced to computing packages to perform the
same computation. This sequence helps students appreci-
ate the flexibility of programming as well as the ease,
capabilities, and power of computation using software pack-
ages for solving engineering problems. Textbooks and ref-
erences used in the course are listed in Table 2.
The three key parallel topics of Table 1 are presented
and covered as follows:
Programming in Fortran There are a number of pro-
gramming languages other than Fortran that are used for
different purposes, such as Basic, Pascal, COBOL, C, C++
(which is an "object-oriented" language), etc. Although
each language has its supporters who claim its superiority
in some aspect (e.g., use, ease of learning, etc.), Fortran as
a structured language is still the dominant language in
engineering and scientific computations. It is the mother of
advanced computer languages, will likely remain preemi-
nent among its peers, and will continue to be a central
element in the training of engineers and scientists. It is
easy to learn and appropriate for beginners. Moreover, the
overwhelming majority of engineering and scientific com-
puter programs, as well as the most popular and efficient
computing packages such as IMSL, NAG, etc., are written
in Fortran.[7'81 Since knowing one computer language and
the concept of programming is helpful when learning other
programming languages, students who have learned For-
tran can more readily master the other languages.
For the reasons cited above, Fortran is used as the pro-
gramming language in this course. There are many text-
books concerning Fortran, but in general, most of them are
either wordy or very detailed. In contrast, the rules and
structure of the Fortran language have been summarized
for this course and are presented in a concise manner. The
students follow the material with ease and interest since it
contains many illustrative examples. The prepared sum-
mary is distributed to the students as class notes.[61 In
addition, a Fortran book by EtterigS is used as a reference.
Numerical Computing Knowledge of this subject is
vital for solving engineering problems-in practice the
solution of most engineering and scientific problems re-
quires the application of numerical computing techniques.
In order to use numerical methods efficiently in learning to
use the computer and programming in solution of engi-
neering problems, an effective numerical computing text,
matching the level of the class, was developed and printed
200


in the form of course notes.1i It provides an early and focused
introduction to numerical methods and engineering problem
solving using the computer. It consists of an introduction to the
computer and its elements, the procedure for solving problems
using the computer, numerical computing techniques, introduc-
tion to the IMSL subroutine library, and recommended refer-
ences. The covered numerical methods, which represent the
core of the text, are the common techniques used in many
engineering and scientific applications.
One unique feature of the text is that all the numerical meth-
ods are presented in a simple, easy-to-understand manner. Each
technique is covered by: 1) a short introduction describing the
mathematical basis for the technique; 2) steps of the algorithm
needed for implementation; 3) illustrated examples by hand
calculator, following the algorithm steps for the technique; 4)
translation of the algorithm steps into a programming flowchart
that can be readily implemented in a computer program; 5)
programming recommendations and comments, if necessary.
Introduction to the IMSL subroutines is covered with simple
and understandable examples that illustrate the implementation
of this library.
The sequence of introduced and discussed numerical methods
is chosen in such a way that it is well integrated with the
covered Fortran topics necessary for implementation of a par-
ticular numerical method, as illustrated in Table 1. In other
words, we let the students practice programming by implement-
ing numerical computing. For instance, when a DO loop struc-
ture in Fortran is covered, numerical integration is presented
where a DO loop is implemented; when array processing is
introduced in Fortran, matrices and numerical methods for solu-
tion of sets of linear equations are discussed in order to use the
newly acquired Fortran knowledge, etc. This approach provides
an efficient way to learn both the numerical techniques and
programming, as also confirmed by Chapra and Canale.[101
Computing Software Matlab, Mathematica, and Spread-
sheet (Excel) are commercial software packages for interactive


TABLE 2
Course Textbooks and References
I Al-Dahhan, M., "Introduction to Numerical Computing," Chemical
Engineering Department, Washington University, St. Louis, MO (1991, 1995)
> Al-Dahhan, M., "Class Notes," Chemical Engineering Department,
Washington University, St. Louis, MO (1992. 1995)
1 Etter, D.M., Structured Fortran 77for Engineers and Scientists, 4th Ed.,
Benjamin/Cummings Publishing Company, Inc., (1993)
Wolfram, S., Mathematica-A System for Doing Mathematics by Computer,
2nd Ed., Addison-Wesley Publishing Company, Inc. (1991)
0 Matlab User's and Reference Guides, Matlab-High Performance Numeric
Computation and Visualization Software, The Math Works Inc., (1993)
1 The Student Edition of Matlab for MS-DOS Personal Computers, The Matlab
Curriculum Series, The Math Works Inc., (1993)
1 Handout on Excel Spreadsheets, Mathematica, and Matlab, Center for
Engineering Computing (CEC), Washington University (1994)
> User's Manual, FORTRANSubroutinesfor Mathematical Applications, IMSL
(International Mathematics and Statistics Library) Inc. (1991)
Chemical Engineering Education











numerical computation, data analysis and processing, and
graphics. They are available with detailed user manuals and
monographs, as shown in Table 2, and on-line help is avail-
able within the system. These software packages are intro-
duced in the early weeks of the semester, followed by simple
examples and assignments designed to familiarize the stu-
dents with them. Then, each week a set of selected rules and
functions is discussed, summarized, and linked to the nu-
merical computing that is covered during the same week.
The summary and notes for using Matlab, Mathematica, and
Spreadsheets in solving engineering problems are distrib-
uted to the students.5'6" The manuals related to these pack-
ages are also available in the computer lab for more detailed
explanations. The purpose of exposing the students to all
these packages is to provide them with the broad spectrum of
skills needed for solving engineering problems and to dem-
onstrate the differences in the packages' capabilities for
solving different engineering problems.


It is noteworthy to mention that in spite of the capability of
the computing packages for performing computations encoun-
tered in typical undergraduate courses, there is still a need for
numerical computing and programming. This need is illus-
trated by the fact that sometimes these packages cannot solve
a problem encountered in course work, research, or engineer-
ing practice. The students then recognize that a knowledge of
numerical computing and programming is essential to get the
job done. Moreover, the best use of these packages and librar-
ies (such as IMSL) rely on the knowledge of the basic theories
underlying the numerical methods.
The above discussed approach to computing helps the stu-
dents effectively achieve the following: 1) a realization of how
the acquired knowledge of Fortran can be implemented in
solving engineering problems; 2) an understanding of the nu-
merical techniques; 3) the ability to practice programming in
useful applications; 4) a recognition of how the commercial
computing software can be used in engineering computing


TABLE 3
Solving a Set of Linear Equations Assignment: Material Balance


Two aqueous solutions of component A are mixed in five mixers linked
together as shown in Figure 1, where Q is the volumetric flow rate (m'/h) (QI,
represents the outlet of mixer 1, which is the inlet to mixer 2), C is the concentra-
tion of A (kg/m3), and M stands for a mixer.
Since the mixers are well mixed, the concentration of A in each mixer is equal
to its concentration at the mixer outlet. These mixers are operated at steady state.
In order to characterize the system and to find the values of the five unknowns
(C1, C P, C,, C, and C,), five simultaneous mass balance equations for component
A are required (the overall mass balance cannot provide new information). The
mass balance on A for a steady-state system (i.e., no accumulation) is:
Mass in = Mass out
Hence, for mixer 1 (Ml) the mass in is
Mass in (MI)= Q,,C0o + Q,,C
while the mass out is
Mass out (MI)= Q,,C1 + QC
Therefore, the mass balance equation for mixer 1 (MI) is
Q,,C, + Q31C = QC, + QC
Substituting the values of volumetric flow rates Qo,, Q,, QW, and Q,, as shown in
the schematic diagram (Figure 1) and the known inlet concentration, Co0, yields
the mass balance equation for mixer 1 (M1)
5*10+ 1*C = 3*C1 +3*Ci
Rearranging the equation gives the final mass balance equation for Ml
6C -C,=50


Figure 1. Schematic diagram of mixers system


Using the same procedure, other mixer's mass balance equations can be developed.
Accordingly, five mass balance equations are formed as (check these yourself):
6 C C, =50 (M1)
-3 C, + 3 C,= 0 (M2)
-C, + 9 C = 160 (M3)
-C 8 C + 11 C 2 C,=0 (M4)
-3 C,- C+4C,=0 (M5)

1. Develop a computer program by using the Gauss-Jordan elimination method
to solve these equations for C,, C,, C,, C, and C,. Send the program output to
an output file.
2. Can these equations be solved by the Gauss-Siedel iteration method? Explain!
3. Use Matlab and Mathematica to solve the above set of linear equations.
4. Develop a computer program by using an IMSL subroutine to solve the above
equations.

Selected Solution by Developing a Computer Program Using Gauss-Jordan Elimi-
nation Method
The matrix form of the above set of linear equations is:

6 0 -1 0 0 C, 50
-3 3 0 0 0 C2 0
0 -1 9 0 0 C3 = 160
0 -1 -8 11 -2 C4 0
-3 -1 0 0 4 C5 0

The data file is:


The output file is:
The concentration of component A in each mixer is:
CI = 11.509 kg/m3 (mixer M1)
C2 = 11.509 kg/m3 (mixer M2)
C3 = 19.057 kg/m3 (mixer M3)
C4 = 16.998 kg/m3 (mixer M4)
C5 = 11.509 kg/m3 (mixer M5)


Summer 1995 20











and how to choose the most suitable package to solve the
problem effectively; 5) a recognition through practical home-
work assignments of how real engineering problems require
well-developed knowledge and skills in computing and com-
puter applications.

HOMEWORK ASSIGNMENTS
Homework assignments are vital in helping the students
absorb the subject properly and recognize the importance of
such skills to their engineering program and their careers.
They also help students develop hands-on experience in
solving problems by computer. Thus, in order to make the
course a practical and pleasurable experience, we use real-
world engineering and science problems.
Since this course is not a course in modeling, and that
subject is beyond the scope of the class level, the problems
are stated clearly and the physical phenomena behind the
derivation of the final models or equations are discussed.
The students recognize that such models/equations cannot
be solved analytically or by hand. Therefore, computing
knowledge and skills are required to solve these models and
equations. This helps the students appreciate the course even
more, and most develop the desire to work hard to absorb the
material. Tables 3, 4, and 5 show examples of some of the
course assignments on materials balances, thermodynamics
and reaction engineering, respectively.


COMPUTER LABORATORY WORKSHOP SESSION
The workshop sessions are organized weekly, or at least
every other week, in the computer laboratory and are overseen
by the instructor and the teaching assistants. The objectives of
these sessions are to supplement the lectures, to enhance the
skills of the students in different features of the operating
system, to practice developing different programming struc-
tures and debugging them, and to demonstrate the applications
of the computing packages in solving engineering problems.
The assignments are prepared to achieve these objectives.

REMARKS
Overall, the students' impression of this course was very
favorable, as confirmed by their comments and evaluations at
the end of the course. Also, personal contacts with the students
during the course, and later during their junior and senior
years in the program, reflect a sincere appreciation of the
knowledge and skills that they gained in this course. The
benefits of the course include: 1) producing a favorable impact
on the chemical engineering courses that use computer-based
calculations as a tool; 2) making students efficient in program-
ming of useful techniques; 3) providing a focused and early
introduction to numerical computing; 4) using efficiently the
available computing software and library packages; 5) devel-
oping skills and knowledge required to solve practical engi-
neering and scientific problems efficiently.


TABLE 4
Find the Roots of Equations Assignment: Thermodynamics


The ideal gas law is widely used by engineers and scientists. It relates the pressure,
temperature and volume. It can be written in different forms as
PV = nRT


P = RT


u=V/n


where P is pressure, V is volume, n is number of moles, R is the universal gas constant, T
is absolute temperature, and ) is the molar volume.
At a certain range of high pressures and over a range of temperatures depending on the
type of gas, the gas behaves nonideally. One of the equations of state for such nonideal
gases is the Van der Waals equation, which can be written as

P +a(D b) = RT

where a and b are empirical constants that depend on the gas.
1. Develop a computer program to perform the following:
a. Comparison between the molar volume ( u = V/n ) estimated based on the ideal
gas law and the Van der Waals equation for carbon dioxide (CO,) at the following
conditions:
P=100atm; T = 300 K; R= 0.082054 Lit. atm/(mol. K)
a = 3.592; b = 0.04267
The molar volume, u, equations are:
Ideal gas: u = RT/P
Nonideal gas: The equation is nonlinear with respect to the molar volume, u.
Therefore, use the Newton-Raphson method to evaluate the molar volume. Thus
rewrite Van der Waals equation in the following form where the molar volume, u,
represents its root.

f()= P+ (u-b) RT = 0
V v2)


The analytical first derivative of this function is
df(u) f,(2a b
du 2 23
For this case, evaluate the root to the relative error equal to 0.00001.
b. Use the read statement to supply the following data to the program:
Guessed value of the root; maximum number of iterations; error crite-
ria; pressure; temperature; a and b constants.
c. Let your output format be as follows:
Comparison between ideal and nonideal gas laws
in evaluating the molar volume of carbon dioxide
T(K) P(atm) ideal ( i) nonideal ( ) iteration no.
XXX.x xxx.x x.xxxx x.Xxxx XX
Here, xxx represents the form of the format to be printed (e.g., xxx
represents the 13 format).
2. Use Matlab, Mathematica, and a spreadsheet to perform the above
comparison.
3. Develop a computer program with the requirements listed above by
using IMSL subroutines to solve the nonlinear equation of the nonideal
gas law.

Selected Solution by Developing Program Using IMSL Library: ZBREN
Subroutine
The output file is
Comparison between ideal and nonideal gas laws
in evaluating the molar volume of carbon dioxide
T(K) P(atm) ideal ( v) nonideal ( u) iteration no.
300.0 100.0 0.2462 0.0795 5


02 Chemical Engineering Education











As a result, the course attracts students from other engineering
disciplines, and the number of students attending the course has
increased significantly (from less than twenty student to over fifty
students per term).

We believe that the course is advantageous to, and highly desir-
able for, a productive chemical engineering program, as well as for
other engineering disciplines.


ACKNOWLEDGMENT

The author appreciates the opportunity provided to him during
his graduate student days by Dr. John Kardos, Department Chair-
man, and the faculty of the Chemical Engineering Department, to
develop this course. The author is also indebted to Professor Milorad
P. Dudukovic for his constant encouragement and help and for
suggesting improvements in this manuscript.

REFERENCES

1. Davis, J.F., G.E. Blau, and G.V. Reklaitis, "Computers in Under-
graduate Chemical Engineering Education: A Perspective on Train-


ing and Application," Chem. Eng. Ed., 29(1), 50 (1995)
2. Carnahan, B., "Computing in Engineering Education:
From There, To Here, To Where? Part 2. Education and
Future," Chem. Eng. Ed., 26(1), 52 (1992)
3. Seader, J.D., "Education and Training in Chemical Engi-
neering Related to the Use of Computers," Comp. Chem.
Eng., 13, 377 (1989)
4. Seader, J.D., "A Brief History of Computing in Chemical
Engineering," Katz Lecture, Chemical Engineering De-
partment, University of Michigan, April (1990)
5. Al-Dahhan, M., "Introduction to Numerical Computing,"
Chemical Engineering Department, Washington Univer-
sity, St. Louis, MO (1991, 1995)
6. Al-Dahhan, M., "Class Notes," Chemical Engineering De-
partment, Washington University, St. Louis, MO (1992,
1995)
7. Ortega, J.M., An Introduction to Fortran 90 for Scientific
Computing, Saunders College Publishing (1994)
8. Borse, G.J., Fortran 77 and Numerical Methods for Engi-
neers, PWS-KENT Publishing Co., 2nd ed. (1991)
9. Etter, D.M., Structured Fortran 77 for Engineers and
Scientists, The Benjamin/Cummings Publishing Co., Inc.,
4th ed. (1993)
10. Chapra, S.C., and R.P. Canale, Numerical Methods for
Engineers, McGraw-Hill, Inc., 2nd ed. (1988) 1


TABLE 5
Numerical Integration Assignment: Reaction Engineering


Ethylene ranks fifth among chemicals in the United States in total pounds produced
each year, and is the number one organic chemical produced each year. Over 28 billion
pounds were produced in 1985 and sold for $.22/pound. Sixty-five percent of the
ethylene produced is used in the manufacture of fabricated plastic, 20% for ethylene
oxide and ethylene glycol, 5% for fibers, and 5% for solvents.
Determine the plug flow reactor size (volume) necessary to produce 300 million
pounds of ethylene a year from cracking a feedstream of pure ethane (a plug flow or
piston flow reactor is a pipe in which the fluid velocity profile is close to flat-hence the
name piston-plug-flow). The reaction is irreversible and elementary. It is desired to
achieve 80% conversion of ethane, operating the reactor isothermally at 1100 K and at a
pressure of 6 atm.
The design equation for the plug-flow reactor (PFR) shown in the figure is

dx
V =FAo -r
o A
where V is the reactor volume, ft3; FA, is the molar feed rate of the reactant, lb mole/s;
-rA is the reaction rate, ft's/lb mole; and x is the conversion.
The reaction is
CH6 -- C2H4 + H2
which we will write as A P + H.
The rate of disappearance of ethane (-rA) is given by -rA = kC, where k is the reaction
constant and C is the concentration of the reactant (ethane).
The parameters required are:
FA = 0.425 lb mole/s
k at 100 K = 3.07 1/s
x=0.8
C = C(l-x)/(l+ x)
C = 0.00415 lb mole/ft'; it is the initial concentration of the reactant (ethane)
E = 1; it is the factor of changing volume
E = change in the total number of moles when reaction is completed/total
number of moles at start of reaction
Substituting the above in the design equation yields
x 08
x dx 0.425 8 (1 + x)dx
V = FA kC (3.07)(0.00415) (I x)
0 0
Evaluate the PFR volume by the following methods:


Reactant Products
SReactor ----
FA0 Re r x Conversion

Schematic diagram of plug flow reactor.

A. Write a computer program that evaluates the integral numerically using
Simpson's rule. Send the program's output to a file in the following
format::
Ethylene Reactor Design Calculation
The plug-flow reactor size required to produce 300 million
pounds of ethylene from cracking pure ethane at 0.8 conversion
operated isothermally at 1100 K and 6 atm is:
Calculated reactor volume = xxx.xx cubic feet
B. Use Matlab, Mathematica, and a Spreadsheet to estimate the reactor
volume
C. Develop a computer program by implementing IMSL library to calculate
the reactor volume.
Selected Solution by Using Matlab and Mathematica
The solution by Matlab is:
The m-file "react.m":
function y = react(x)
y = (1 .+ x) ./(1 .-x);
Matlab solution:
>> diary reactor
>> intg = quad('react',0,0.8)
intg =
2.4189
>> volume = intg*0.425/(3.07*0.00415)
volume =
80.6895
>> diary off
The solution by Mathematica is:
In [1]:= intg = NIntegrate[(l+x)/(l-x), (x,0,0.8)]
Out [1] = 2.41888
In [2]: = volume = intg*0.425/(3.07*0.00415)
Out [2] = 80.6893


Summer 1995 203


Summer 1995


203











SOclassroom


CALCULATION OF


VAPOR-LIQUID EQUILIBRIUM*

A Simplified Method



JACK WINNICK, DENNIS E. SENOL
Georgia Institute of Technology Atlanta, GA 30332-0100


apor-liquid equilibrium is calculated by equating
the fugacities in each phase for each component in a
mixture:

fv = f' (1)
The reproduction of a vapor-liquid phase diagram, or even
finding the composition of the equilibrium phases at one
point, requires that these fugacities be known functions of
temperature (T), pressure (P), and composition (x in the
liquid, y in the vapor). There are two general methods for
representing these equilibria: 1) at low pressures, say below
10 bar or so, the liquid phase fugacities are described using
activity coefficients and the vapor using fugacity coeffi-
cients, and 2) at higher pressures, both phases are described
with fugacity coefficients derived from a single equation of
state.

Jack Winnick is Professor of Chemical Engi-
neering at Georgia Tech, where he has been
since 1979. Prior to 1979 he was on the faculty at
the University of Missouri. He has worked for
short stints in the private sector, in the petroelum
and aircraft industries, and for NASA, in life sup-
port. He currently consults on electrochemical
engineering and environmental topics.


Dennis Senol is Computing coordinator for the
School of Chemical Engineering at Georgia Tech.
He earned his undergraduate degree in chemical
engineering, has Masters degrees in chemical en-
gineering and electrical engineering, and is now
working on a doctorate in chemical engineering.
He is currently working with real time embedded
systems in the automotive and aviation industries.

- This is an abridged version of a chapter in the textbook
Engineering Thermodynamics, by Jack Winnick, soon to be
published by John Wiley and Sons.


Situations involving the need for reproduction of vapor-
liquid equilibria, say in distillation, are of five general types:

1. Bubble-Pressure liquid phase composition and
temperature known; vapor composition and pressure
unknown
2. Bubble-Temperature liquid phase composition
and pressure known; vapor composition and
temperature unknown
3. Dew-Pressure vapor phase composition and
temperature known; liquid composition and pressure
unknown
4. Dew-Temperature vapor phase composition and
pressure known; liquid composition and temperature
unknown
5. Flash temperature and pressure known; both phase
compositions unknown

The problem inherent in these calculations, even when all
necessary parameters are known, is that the equilibrium
equation, in almost all cases, is implicit in one or more of the
variables. We here show a new scheme, one that circum-
vents many of the difficulties encountered in the standard
computing strategies, through use of a widely available com-
mercial math library routine. Because the basic equations for
the two pressure regimes are different, we will describe the
strategies separately.

LOW PRESSURE
At low pressure, activity coefficients, yi, are used to de-
scribe the nonideality of the liquid and fugacity coefficients,
0i, for the vapor:


Copyright ChE Division ofASEE 1995


Chemical Engineering Education











The problem inherent in these [vapor-liquid equilibrium] calculations, even when
all necessary parameters are known, is that the equilibrium equation, in almost all cases, is
implicit in one or more of the variables. We here show a new scheme, one that circumvents many of the
difficulties encountered in the standard computing strategies, through use of a
widely available commercial math library routine.


fi = YiPi 0 (2a)
fiv =Yi y P (2b)

where the fugacity coefficient of the pure component, 0o, at
its vapor pressure, Pio, corrects for the nonideality of the
pure component. (The "Poynting" factor, which further cor-
rects for the difference between Po and P, the total pressure,
is neglected here.) Equations for activity coefficients are
available in several forms-the Wilson, the Margules, van
Laar and UNIFAC are a few. All are complex functions of x
and T

y=y(x,T) (3)
For example, the Wilson equation for a binary system is
expressed by the equations


y +Alx +x2 A 22-2 A 21 (4a)
nl =-e n(l 12 22 22 2 XI +A 12 X2 x+2 2X1


S(,+A| 12 x A21


fn(Oi) 2y -j n(z)
V^EA^


where


z=l+-BP B= Yj.Bij;
RT
i j


zRT
V=
P


and the component parameters are evaluated from


RT
B = (B() +oB()) c
" \Pc
B(0) 0.083 0.422
1.6

B( 0.139 0.172
) 13 T4.2
T.


In order to find Tr (i)j), a value for Tj is needed
(Tr =T/T); at these pressures the simple approximation

T=I T (9)
c C Cj


where the parameters A are evaluated from

= a
V. -
A.. = e RT
1 vi


with the constant aj independent of T. The molar volumes of
the pure liquid components, vi, are evaluated at T, but are
mild enough functions of temperature to be taken as con-
stant.
A separate equation exists for the fugacity coefficients in
the vapor:
0=0(y,T,P) (6)
where the component fugacity coefficients, 0i, are found
from the exact expression


RTinJ = RTin# = v ] dV RT en(z)
yiP V ani T, V,nj

(7)

which requires an equation of state for evaluation of the
RHS. For example, at low pressure, a form derived from the
virial equation is


is often used.
Equation (1) is now

(5) Yi iP =xi i Pio


P = Constant

Vapor





Temperature
A



Liquid


0.0 x,y 1.0

Figure 1. VLE diagram for a binary mixture at
constant pressure.


Summer 1995










which is implicit in T, P, and mole fraction in view
of Eqs. (4) and (7). Therefore, solution of Eq. (1),
for example, for x and T at any y and P (a dew
temperature calculation) becomes a matter of iterating
on x and T.
Consider, for example, a "dew-temperature" calcu-
lation; for the relatively simple case of a binary,
we can show it on Figure 1. We are looking for point
A, the first drop of condensate on bringing vapor
composition y, down in temperature until it meets the
phase envelope.
The difficulty for the student or practicing engineer
in calculating VLE lies not in finding the form of
equation to use or in evaluating the parameters-that
is an entirely separate problem. We assume here that it
has already been done, as it has for very many sys-
tems. The compilations by Gmehling, et al."1I for low
pressure, and Knapp121 for high pressure, are excellent
sources. The problem lies in the implicit nature of the
equations. For example, in Eq. (8), the fugacity co-
efficient is a function of y, T, and P, and the
activity coefficient (Eq. 4) is a function of x and T. So,
if we want to calculate, say, the liquid phase mole
fraction and temperature for a binary mixture where
the vapor composition and pressure are known, direct
solution is not possible.
Most thermodynamics textbooks describe complex
computer programs to handle this calculation,
ones that involve nested loops to iterate on the vari-
ables. These programs are necessarily specific to the
particular equations used, the temperature range, etc.
A typical flow chart for this calculation scheme is
shown in Figure 2.
Mathematics programs are now available, how-
ever, that solve these kinds of implicit equations and
make these calculations extremely simple. With
them, all that is required is to express these implicit
equations in forms that equal zero; one equation
for each variable.
The best way to illustrate is through an example.
Take the binary system: 2-Proponol-Water at 0.508
bar pressure. At a given vapor composition we wish
to find the dew temperature and composition. We
write


x, + X2 -1.0 = 0

yliP-x,l,P , =0
y2,0P- X27P'o I=0
Y22P 2X272Po 2 02


These three equations must all go to zero (actually,
some preset limit like 0.0001 is sufficient) for the
206


Figure 2. Typical flow chart for dew temperature
calculation at low pressure.


Read T, yi, physical constants
and estimates of P and xi
Initailize arguments for
IMSL routine NEQNF



I
IMSL root solver for system
of nonlinear equations:NEQNF
(Modifies: P and xi





Print results: P and xi


Figure 3. Low pressure dew temperature calculation.
Chemical Engineering Education


Subroutine CUBIC uses cubic
equation to find liquid and
vapor volumes explicitly:
vI (or z1) and vv (or zv)




User supplied subroutine FUNC
supplies functions to solve
Knowing T, xi, P, Yi,
vI and vv calculate:
f(1)= ,-y P- 0- .x-P
f(2)= "-y, P- "x2 P
f(3)= x, +x 1.0










solution. Employing the virial, Wilson, and Antoine (pure
component vapor pressure) equations, we provide expres-
sions for 0, y,and Po, respectively. Pure component param-
eters are available from texts such as Prausnitz, et al.[3] The
binary parameters required for the system demonstrated were
obtained from Gmehling, et al.14] The expressions for
0, 7,andPi are generated in a subroutine with a main pro-
gram providing initial guesses for the three unknowns: T, x,,


2-Propanol / Water

355
o Exp. (0.508 Bar)
Calculated

350



E 345



340



3 3 5 ,, I , .
0.0 0.2 0.4 0.6 0.8 1.0

Mole Fraction 2-Propanol


Figure 4. Constant pressure VLE results.


Read P, yi, physical constants
and estimates of T and xi
Initailize arguments for
IMSL routine NEQNF




IMSL root solver for system
of nonlinear equations:NEQNF
(Modifies: Tand xi)






Print results: T and xi


User supplied subroutine FUNC
supplies functions to solve
Knowing T, xi yi
calculate

f(l)-=x -O

f(2)= x2 0Y

f(3)= x, +x,-1.0


Figure 5. High pressure dew-pressure calculation.

SIMSL is a copyrighted trademark of Visual Numerics Inc.
Summer 1995


and x2. The main routine then calls the IMSL* routine
NEQNF'[S that changes temperature and liquid composition
until Eqs. (11-13) are all near zero. The technique is shown
schematically in Figure 3.
The routine is insensitive to the initial guesses for numer-
ous binary systems in a range of temperatures; the example
below was compiled with

x =x =0.5 and T=373K

As shown in Figure 4, for the system of 2-Propanol-Water,
the phase diagram is reproduced in its entirety, as shown in
the literature.[6]
While we have illustrated a series of dew temperature
calculations, the same procedure is used for bubble pressure
or temperature or flash calculations. Multicomponent mix-
tures also offer no complication; for each additional compo-
nent, there is one more equation and one more unknown.

HIGH PRESSURE
At higher pressures, say above 10 bar or so, an equation of
state (EOS) is used, one that represents both phases, so that

Ol Yi P = l1 xi P (14)
is the basic equation of equilibrium. The fugacity coeffi-
cients are once again found from the exact expression


RT n jJ -RTn, =RT T, 1 dV -RT n(z) (7)


but here we need an equation of state valid for both phases.
There are several in the literature; the form used does not
alter the calculation procedure. For our purposes we use
the Soave form of the Redlich-Kwong EOS (SRK), avail-
able in most thermodynamics texts

p RT a(T)
v-b v(v + b)


Since the phases are at the same T and P, this means
the EOS must be solved for the specific volumes of each
of the two phases. Unfortunately, these EOS's have three
real (in the math sense) roots in the two-phase region, so
some care must be taken to assure that the central, physi-
cally unreal root is not one of those used. The proper
roots for the specific volume of liquid and vapor phases
are easily handled by selecting the largest root for the
vapor phase and the smallest root for the liquid phase.
For example, when a cubic EOS is used, the cubic equa-
tion can be used as part of the minimization routine so
that the proper roots could be explicitly obtained. For
other types of EOS's, the liquid and vapor specific vol-
umes are frequently dependent on initial guesses. In this
case, a systematic "surface" search is made to allow
roots to be obtained from different starting points.
207










The standard method for solving say, a dew-pressure prob-
lem at high pressure, is similar in concept to that for the dew-
temperature at low pressure, described earlier, (Figure 2).
That is, an initial estimate is made for liquid composition
and pressure, based on an ideal solution of the vapor compo-
sition given at the specified temperature. The EOS is solved
for the vapor and liquid roots and the fugacity coefficients
found for each component in each phase. Now, new liquid
compositions are found from the equilibrium relationship,
Eq. (1), and nested DO loops are used to vary x and P so as to
simultaneously satisfy the material balance and equilibrium.

Alternatively, we can use the same strategy of simulta-
neous-equation solution as we did at low pressure. The
scheme is shown in Figure 5. A dew point pressure calcula-
tion with an EOS for a binary involves five equations with
five unknowns: x,, x2, P, v', and v'. For example, with the
SRK


P_ RT aV(T)
P + -0
v -bv v(vv+bv)

S RT a (T) = 0
+-b+ vI(v +b,)


Figure 6. VLE results obtained from SRK.


with i=1 and 2


and
S+X2 -1.0= 0 (19)

and, from the SRK, the form for the fugacity coefficients
derived using Eq. (7) is

bk A k 2 + B) (20)
enk = z- )- z-)-in 2(z- B)- -2 (20)
b B zF

where A and B are defined as

A aP/(RT)2
B bP/(RT)

We have not gone into the details of the evaluation of the
parameters in these equations; they are available in standard
sources such as Prausnitz, et al.,'17 and are directly calculated
from individual critical properties. The only required input
for the calculation are Tc,Pc,w and k12. An example of an
isothermal phase diagram calculated by this method is shown
in Figure 6. As shown, the diagram is reproduced using the
SRK EOS; in this case, it agreed very well with experimen-
tal results.[81
The procedure is somewhat sensitive to the initial values
used for mole fraction and P (or T). If a single point is
required, say a specific dew or bubble point, a spurious
result is sometimes converged upon, one in which the
"vapor" and "liquid" volume roots are equal. In this case,
slight changes in the initial guesses arrive at the correct
208


solution. But when constructing the entire phase diagram,
we start at one pure component and march across, say
at increments of 0.05 mole fraction. Here the last values of x,
y, T, and P provide convergent starting points for each
subsequent iteration.

CONCLUSIONS
A simplified method can be used to reproduce vapor-
liquid equilibrium. Instead of individualized iterative rou-
tines to solve the implicit equations, a math library program
is used along with the correlating equations. The user-writ-
ten subroutines are clearly evident to even the beginning
thermodynamics student so that the focus of any exercise
can be the comparison among the correlating equations and
experimental data.

REFERENCES
1. Gmehling, J., U. Onken, and J.R. Rarey-Nies, Vapor-Liquid
Equilibrium Data Collection, Vol. 1, Part Ib, DECHEMA,
Frankfort/Main (1988)
2. Knapp, H., Vapor-Liquid Equilibrium for Mixtures of Low
Boiling Substances, Vol. 6, Part 1-4, DECHEMA, Frankfort/
Main (1982)
3. Prausnitz, J.M., R.C. Reid, and B.E. Poling, The Properties
of Gases and Liquids, 4th ed., McGraw-Hill, New York, NY
(1987)
4. Ref. 1, p. 173
5. Visual Numerics, IMSL MATH/LIBRARY User's Manual,
Version 2.0, Visual Numerics, Houston, TX, p. 776 (1992)
6. Davalloo, P., Iran J. of Sci and Tech., 1, 279 (1971)
7. Ref. 3, p. 145
8. Reamer, H.H., and B.H. Sage, J. Chem. Data, 11, 1, 17
(1966) 0
Chemical Engineering Education


Propane / N-Decane

70
7 Exp. (510.93K)
o Exp. (410.93K)
60 Calculated SRK

50
50 -

40

| 30

20

10


0.0 0.2 0.4 0.6 0.8 1.0

Mole Fraction Propane


4 vyP I
itiP~xiP 0













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