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Herb Toor of Carnegie-Melon ( PDF )
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Introducing Behavioral Science Into An Engineering Laboratory ( PDF )
A Foreign Study Program ( PDF )
Teaching Undergraduate Mass and Energy Balances ( PDF )
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c e g e education
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recruiter when he comes to your campus.
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And as you know by now, we're
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The chemistry is what counts.
EDITORIAL AND BUSINESS ADDRESS
Department of Chemical Engineering
University of Florida
Gainesville, Florida 32611
Editor: Ray Fahien
Associate Editor: Mack Tyner
Business Manager: R. B. Bennett
Editorial and Business Assistant: Bonnie Neelands
Publications Board and Regional
SOUTH: Charles Littlejohn
Chairman of Publications Board
Homer F. Johnson
University of Tennessee
Vincent W. Uhl
University of Virginia
CENTRAL: Leslie E. Lahti
University of Toledo
Camden A. Coberly
University of Wisconsin
WEST: William H. Corcoran
California Institute of Technology
George F. Meenaghan
Texas Tech University
SOUTHWEST: J. R. Crump
University of Houston
James R. Couper
University of Arkansas
EAST:G. Michael Howard
University of Connecticut
Thomas W. Weber
State University of New York
NORTH: J. J. Martin
University of Michigan
Julius L. Jackson
Wayne State University
Edward B. Stuart
University of Pittsburgh
NORTHWEST: R. W. Moulton
University of Washington
Charles E. Wicks
Oregon State University
D. R. Coughanowr
Stuart W. Churchill
University of Pennsylvania
UNIVERSITIES: John E. Myers
University of California, Santa Barbara
Chemical Engineering Education
VOLUME VIII NUMBER 2 SPRING 1974
74 Introducing Behavioral Science
Into An Engineering Laboratory
E. R. Haering and M. A. Larson
82 Teaching Undergraduate
Mass and Energy Balances
D. Woods, G. Bennett, G. Howard
56 The Educator
Herb Toor of Carnegie-Mellon
58 Departments of Chemical Engineering
66 Views and Opinions
The Changing Role of the Chemical
Engineer, N. A. Copeland
A Foreign Study Program
D. L. Ulrichson and M. A. Larson
An Inexpensive Time Bomb
N. de Nevers
Comments on Gibbs' Equation: The
Condition for Chemical Equilibrium in
Open Systems, A. H. Larsen and C. J. Pings
94 Application of Perturbation Techniques
To Analog Computing, J. F. Paul
90 Problems for Teachers
CACHE Computer Problem
102 Book Review
CHEMICAL ENGINEERING EDUCATION is published quarterly by the Chemical
Engineering Division. American Society for Engineering Education. The publication
is edited at the Chemical Engineering Department, University of Florida. Second-class
postage is paid at Gainesville, Florida, and at DeLeon Springs, Florida. Correspondence
regarding editorial matter, circulation and changes of address should be addressed
to the Editor at Gainesville, Florida 32611. Advertising rates and information are
available from the advertising representatives. Plates and other advertising material
may be sent directly to the printer: E. O. Painter Printing Co., P. O. Box 871,
DeLeon Springs, Florida 32028. Subscription rate U.S., Canada, and Mexico is $10 per
year, $6 per year mailed to members of AIChE and of the ChE Division of ASEE,
and $4 per year to ChE faculty in bulk mailing. Write for prices on individual
back copies. Copyright @ 1974. Chemical Engineering Division of American Society
for Engineering Education, Ray Fahien, Editor. The statements and opinions
expressed in this periodical are those of the writers and not necessarily those of the
ChE Division of the ASEE which body assumes no responsibility for them. Defective
copies replaced if notified within 120 days.
The International Organization for Standarization has assigned the code US ISSN
0009-2479 for the identification of this periodical.
Summer Program on Modeling and Optimization
A special summer program will be held July 29 through
August 7, 1974 on the topic "New Developments in Mod-
eling, Simulation and Optimization of Chemical Processes"
at Massachusetts Institute of Technology.
This special summer program will present basic prin-
ciples necessary to understand and apply new techniques
for computer-aided design and control of industrial-scale
chemical processes. Topics to be covered include steady-
state process simulation, process optimization, dynamic
modeling and simulation of chemical processes, computer-
aided process synthesis, and comprehensive problem-ori-
ented computing systems for chemical process design. Par-
ticipants will use M.I.T. computing facilities for solution
of case-study problems. Please contact:
Director of the Summer Session
M. I. T., Room E19-356
Cambridge, Massachusetts 02139.
Lawrence B. Evans
Massachusetts Institute of
CHEMICAL ENGINEERING EDUCATION, in co-
operation with the CACHE (Computer Aides
to Chemical Engineering Education) commit-
tee, is initiating the publication of proven com-
puter-based homework problems as a regular
feature of this journal.
Instructions for submission of problems pre-
cede the first of these articles which appears on
page 90 of this issue.
Parsons is a Good Place to Work!
There is no limit to the opportunities offered
by Parsons-high salaries, good benefits, ad-
vancement, professional freedom-and a work
environment unequalled anywhere.
Parsons is expanding its operations. Our new
world headquarters will be completed in the
summer of 1974. This $20 million, 400,000
square-foot facility was designed specifically
for our business. It is located in a suburban
area near the Rose Bowl in Pasadena, Cali-
fornia, close to some of the country's famous
universities in case you want to further your
academic career-with Parsons' tuition aid plan.
Parsons is one of the leaders in the engineer-
ing design and construction of petroleum re-
fineries, metallurgical plants and chemical
plants. We have prepared a booklet describing
the advantages of working for Parsons-for
your copy of "Parsons is a Good Place to Work,"
write to Personnel Manager,
The Ralph M. Parsons Company
617 West Seventh Street, 7
Los Angeles, Ca. 90017
AN EQUAL OPPORTUNITY EMPLOYER
CHEMICAL ENGINEERING EDUCATION
I Ivew etc &7wjau~...
Help your students explore the latest
contributions to chemical engineering.
by John S. Newman, University of California, Berkeley
NEW-a unified framework for the analysis of problems in
electrochemical systems. Introduces the beginning student to the
development, design, and operation of electrochemical synth-
eses, processes, energy conversion and storage devices, and
1973, 440 pp., $18.95
Optimization and Design
by Mordecai Avriel, Israeli Institute of Technology, Marcel
Rijckaert, and Douglass Wilde, University of Connecticut
Integrates a collection of advanced survey articles, examples,
and discussions of the impact of optimization theory on en-
gineering design. Focuses appropriate parts of optimization
theory on the peculiarities of engineering design in an attempt to
revolutionize design methods.
1973, 528 pp., $18.95
Polymer Materials Science
by J. Schultz, University of Delaware
Suitable for graduate level, this new text explores polymeric
materials for students whose interest centers on the properties of
the final, solid polymer. Aids in understanding the correlations
between structure and bulk properties and in considering how
processing conditions might affect such properties.
January 1974, approx. 496 pp., $19.95
Basic Principles and Calculations in Chemical
Engineering, Third Edition 1974
by David Himmelblau, University of Texas, Austin
Basic introduction to chemical engineering that includes mat-
erial balances, energy balances, and the basic principles of
physical chemistry encountered later in chemical engineering
design, analysis, and control.
1974, approx. 544 pp., $15.95
by Dale Rudd, University of Wisconsin; Gary Powers, M.I.T.;
and Jeffrey Siirola, Tennessee Eastman Co.
An introductory undergraduate level book that deals with
synthesis of processes combines synthesis methods with
material and energy balancing to form a new introduction to
1973, 320 pp., $15.95
Chemical Kinetics and Reactor Design
by A. R. Cooper, and G. V. Jeffreys, both of the University of
Sound basis of chemical reactor concepts, this text features
liberal graphical representation of the results of illustrative cal-
culations of real systems within the book.
1973, 400 pp., $18.95
Modeling Crystal Growth Rates From Solution
by Makota Ohara, Yoshitomi Pharmaceutical Industries, Ltd.,
and Robert Reid, M.I.T.
Provides a critical analysis and evaluation of theories which
purport to predict crystal growth rates of solutes from solution.
1973, 288 pp., $19.95
Mathematical Methods in Chemical Engineering
Volume III: Process Modeling, Estimation, and
by John Seinfeld, California Institute of Technology and Leon
Lapidus, Princeton University
A comprehensive self-contained treatment of the mathemati-
cal techniques of process modeling that emphasizes probability
theory, stochastic processes and parameter estimation relating to
1974, approx. 544 pp., $19.95
The Elements of Chemical Kinetics and Reactor
Calculations: A Self-Paced Approach
by H. Scott Gogler, University of Michigan
Offering a different teaching approach to learning chemical
reaction engineering, this text provides an excellent way to bring
graduate students from varying backgrounds in reaction kinetics
up to a common level
1974, approx. 448 pp., $21.00
Thermodynamics and Its Applications in Chemi-
by Michel Modell and Robert Reid, both of M.I.T.
Provides advanced treatment of chemical engineering ther-
modynamics with an emphasis on the application of fundamental
concepts to solve practical problems.
1974. approx. 528 pp.. $18.95
For more information write: Robert Jordan, Dept. J-915,
Prentice-Hall, Englewood Cliffs, New Jersey 07632
The Professor's Dean
THE ChE DEPARTMENT FACULTY
Pittsburgh, Pa. 15213
Herb Toor, a former chemical engineer, is now
Dean of Carnegie Institute of Technology, the en-
gineering arm of Carnegie-Mellon University. He
is a very good dean. He provides a plethora of new
ideas, only a few good, but all are stimulating. He
is very tolerant of initial mistakes, which makes
us try that much harder. Herb has effectively
focused the college's new efforts, particularly in
scientific design and engineering in public affairs,
and has sharply pruned inefficient programs. At
the same time, he is a professor's dean because he
talks in four-letter words that professors under-
stand-words like "dumb", "good", and "cash".
These aren't the only words; one faculty wife sug-
gested he should be the "Professor of Anglo-
How Herb got this way isn't clear. His aca-
demic record is usual the mixed bag. Born in Phil-
adelphia, he was an undergraduate at Drexel,
where he partially supported himself by repairing
pinball machines. He went to Northwestern for his
doctorate, where he worked on heat transfer under
Professor Leon Stutzman, now at the University
of Connecticut. Because he had no job on gradua-
tion, he followed his wife to England on her post-
doctoral fellowship. While there, he worked for
Monsanto. He came to Carnegie in 1953; and, ex-
cept for a year in India as a UNESCO scholar, he
has been here since. He became associate professor
in 1957, professor in 1961, department head in
1965, and Dean of Engineering in 1969. These
dates are approximate because Herb's file was
accidentally burned, apparently a case of spon-
Herb has effectively focused the college's new efforts.
One's first impression when seeing Herb lec-
ture is that he must always be surrounded by a
small black cloud. Herb starts an hour's lecture
with two cigars; he then switches to his pipe; and,
he finishes the class by bumming cigarettes from
the students. During the lectures, Herb changes
the notation in his equations. He does this without
a hint, and rotates the symbols so that what was
once flux becomes the concentration, and what was
once the concentration becomes the flux. He fills
all of the blackboards; then goes back to write
over everything with a series of arrows and other
mnemonics. At the end of the lecture, all the
boards look like extremely intricate oriental rugs
woven by drunken Arabs.
These eccentricities are coupled with a lucid
physical insight into the problems being discussed.
Herb has a very strong feel for what is actually
happening. He easily makes approximations which
make almost anyone else blanch, but then quickly
returns to show that these approximations are, in
fact, justified. He is a master at constructing and
using homework or class exercises with a keen
sense of balance between analytical techniques and
the real physical nature of the problem. In short,
he teaches judgment on when to use a sophis-
CHEMICAL ENGINEERING EDUCATION
ticated technique or model, and when and how to
make a simple guess sufficient for the purposes at
Herb's research is also characterized by these
rapid, incisive approximations based on physical
insight. The mathematical level of his work is not
particularly great, and his experimental work can
be incomplete and abortive. At the same time, the
research is excellent because it undertakes im-
portant problems and solves their limiting cases
of behavior. Herb started with studies of mass
transfer, then generalized these studies to multi-
component systems, climbed almost immediately
to problems of turbulent mixing, and extended
these to the study of fog. In all these efforts, new
physical insight is the basic foundation; and, in
all these cases, he discovered most of the im-
portant effects involved.
The work on fog is a good example of this in-
sight. This problem was originally connected with
cooling tower design. Fog formation involves
coupled heat and mass transfer, but because fog
forms in air, the Prandtl and Schmidt numbers
are about equal. As a result, the continuity and
energy equations have the same form and can be
uncoupled and solved. In this way, one can predict
when and where fog forms to a surprising degree
This willingness to make approximations in
research has something of a social parallel in the
parties which Herb gave for the entire department
when he was department head. At these parties,
he was once famous for singing Slovanian Christ-
mas carols with Larry Canjar. The parties are
symbolized by Artillery Punch. The recipe for
this is given in Table I. The effect of even a small
glass of this punch is immediate. New students
disappear after only one deep breath of the vapor.
One graduate student drove her husband and three
others home only to find on arrival all asleep in
the back seat with their arms around each other.
She had no way to unload them.
Since Herb is Dean, he is no longer quite as
Herb's research is also characterized by
these rapid, incisive approximations based
on insight... the research is excellent because
it undertakes important problems and
solves their limiting cases of behavior.
Toor's Artillery Punch
1 bottle-Soda Water
Juice of 6 Lemons
1/2 cup Sugar
human as he once was. He does still come out with
an occasional eccentricity. For example, he once
attended a luncheon meeting wearing a somewhat
unusual costume: jeans, with holes in the knees;
sneakers, with holes in the toes; and a green and
blue shirt with one hole neatly circumscribing his
navel. After this experience, he took a trip to
Brooks Brothers, walked in, and said he wanted
to buy a suit that would make him look like a
banker. After the salesmen stopped laughing, they
did sell him the suit.
Since Herb is Dean, he is no longer as human.
We have enjoyed working with Herb because
this same honesty in buying a suit extends
throughout his professional association. He is ex-
ceptionally good at avoiding win-lose arguments,
so that it's increasingly hard to take a stand with-
out his agreeing with the most sensible part of
what you're saying. He does have very strong
opinions which sometimes require "subjective
logic", which means shouting that you are right
and everyone else is a goddamn fool. As a depart-
ment, we all regret not seeing more of Herb's
honesty, his objectivity, and his insight. We all
look forward to the day when he stops fooling
around at that dean's job and returns to some-
thing more reasonable-like being a professor in
chemical engineering. D
M. H. CHETRICK and FRAN MURRAY
Michigan State University
East Lansing, Michigan 48823
CHEMICAL ENGINEERING HAS been taught
at Michigan State University for more than
60 years. The first course offerings were described
in the 1912-13 catalog, although a department was
not formally established until 1931. Engineering
instruction at Michigan State University actually
dates back to 1885, when at the then Agricultural
College of the State of Michigan-the name of the
institution has been changed five times-a me-
chanical engineering program was offered. In
1892 a civil engineering program was established,
followed by one in electrical engineering in 1896.
In its 1912 course offerings, the Chemistry De-
partment included engineering electives for sen-
iors, and in the following year "engineering chem-
istry" became one of four "group" options for
juniors and seniors. The first class of four grad-
uated with a B.S. in this option in 1914.
Over a period of time the chemistry courses
were expanded, and in 1930 the department be-
came "Chemistry and Chemical Engineering." A
separate chemical engineering department was
established in 1931, with Professor Harry S. Reed
transferring from the Chemistry Department to
head the Chemical Engineering Department.
Transferring with him were Professor Henry
Publow, who succeeded Professor Reed as depart-
ment head in 1935, and two graduate students.
Professor C. C. Dewitt became head of the de-
partment in 1940, and in the following year the
Dr. M. H. Chetrick, Chairman of the department.
CHEMICAL ENGINEERING EDUCATION
department was renamed Department of Chem-
ical and Metalurgical Engineering. At this same
time, approval was granted to offer the Ph.D. de-
gree in chemical engineering.
In 1950, the department was split into two
separate departments, the Department of Chem-
ical Engineering and the Department of Metal-
Dr. Donald K. Anderson and doctoral candidate do
biomedical research on transport of ions out of muscle
lurgical Engineering, with Professor Dewitt re-
maining as head of Chemical Engineering. Profes-
sor C. Fred Gurnham succeeded Professor Dewitt
as Department Chairman in 1952 and served in
this capacity until 1961. The present Chairman is
Professor M. H. Chetrick who assumed this posi-
tion in 1963 when he first came to Michigan State
INNOVATION MARKS CHANGES
INNOVATION HAS marked the successive
changes and growth in the department since its
beginning. The major innovations came during
the past 10 years with the miniaturization of lab-
oratory equipment, with several major overhauls
of the curriculum, and with the reduction of credit
hours required for a B.S. degree (from 212 to 180
quarter hours). Present evidence indicates that
these pioneering steps have been in the right di-
rection, resulting in more knowledgable graduates.
The miniaturization of laboratory equipment
came in 1963 when the department was moving
from older quarters to the new Engineering Build-
ing which houses all the departments of the Col-
lege of Engineering. This move presented an ex-
cellent opportunity to objectively reevaluate lab-
oratory instruction as the cost and time for de-
signing and installing a new miniaturized labora-
tory would be no greater than that involved in
disassembling, moving, and reassembling the
large equipment from the older quarters. The de-
cision was made to switch to miniaturized labora-
tory units in the interest of improved instruction,
more optimum use of students' time, and better
utilization of laboratory space. The smaller sized
equipment also could be readily adopted for opera-
tion under direct digital computer control, and
several such experiments were developed by Pro-
fessor G. A. Coulman. Extensive use of glass
equipment was made in order that students could
see what was occurring in their experiments. It
is of interest to note that several well known
chemical companies in Michigan sent representa-
tives to examine the new miniaturized laboratory
at MSU and then proceeded to install similar
equipment in their R & D laboratories.
The reduction in the credits required for
graduation occurred in 1964 and attracted na-
tional attention as well as a great deal of skep-
ticism. It appeared at times that the only support
Dr. Paul M. Schierholz operating an experimental drier.
which the department had for this action was
from the other departments in the College of En-
gineering at MSU who also reduced their require-
ments from 212 to 180 quarter hours. The value
of greater concentration permitted by the reduc-
tion of required credits has proved itself many
times, The current graduates have much more
depth and understanding of chemical engineering.
As an example, since 1967 and continuing each
year since then, MSU chemical engineering seniors
have won first, second, or third place or honorable
mention in the Student Contest Problem sponsored
annually by the AIChE.
The last major revision in the undergraduate
curriculum became effective in Fall, 1973. The
purpose of this change was to make the cur-
riculum more flexible and to provide better ac-
commodations for transfer students who have al-
ways represented a large fraction of the chemical
engineering graduates from MSU.
In the new curriculum, a student may elect the
conventional program of study, which includes
twenty hours of electives, or pursue a "coordinated
elective" program by including up to 32 hours of
electives in an approved area peripheral to chem-
ical engineering. If a coordinated elective plan ex-
ceeds twenty hours, a student may take up to an
additional twelve hours of electives by waiving
certain optional courses in the senior year.
s IA;E STwt, 9Ji l' 1
L MRI l i R
l ,N L .
, r -
Dr. Bruce W. Wilkinson by the nuclear reactor.
COORDINATED ELECTIVE PROGRAMS
Examples of coordinated elective programs in-
1. Biomedical Engineering
In the past few years, Chemical Engineers have
become increasingly interested in the applica-
tion of chemical engineering fundamentals to
the solution of problems which are biological
or medical in nature. Examples of these are the
artificial heart, lung and kidney machines. As
a result, the Chemical Engineering Department
has available a biomedical minor, available at
the student's option, which will provide back-
ground in physiology and biomedical engineer-
ing. The recommended courses listed below may
be substituted for electives and for selected
courses in the curriculum.
ANT 316 General Anatomy
PSL 331 Human Physiology
PSL 332 Human Physiology
*BME 411 Electric Theory Nerves
*BME 424 Materials in Biomedical En-
*BME 431 Biological Transport Mech-
*BME 481 Tissue Biomechanics
BME designates a biomedical engineering
2. Chemical Systems Science
This option can be structured to provide in-
depth knowledge for automatic control of in-
dustrial processes as well as the application of
computers to real-time supervision and optimi-
zation. This selected group may be enhanced by
EE 311 Fundamentals of Systems
EE 312 Analysis of Linear Systems 3
EE 313 Analysis of Large Scale Sys-
EE 415 Control Systems 3
EE 416 Control System Design 3
CHE/SYS 465 Process Optimization
CPS 300 Computer Programming 3
CPS 311 Assembly Language & Ma-
chine Organization 4
CPS 312 Generative Coding and In-
formation Structures 4
3. Environmental/Ecological Engineering
The interface of industry and the environment
becomes critical as man assumes a dominant
influence on the quality of his life. The op-
portunity to know and relate to the natural en-
vironment will provide the chemical engineer
with the foundation needed to effectively meet
the present and future challenges. Many
courses exist, of which a selected few are
shown, that will lead to appropriate knowledge
CHEMICAL ENGINEERING EDUCATION
PHY 364 Introduction to Modern
PHY 365 Introduction to Modern
PHY 498 Introduction to Nuclear
PHY/CEM 430 Introduction to Radioisotope
CHE 821 Theory of Nuclear Reactors
CHE 825 Radioisotope Engineering
CEM 830 Nuclear and Radiochemistry
CHE 460 Special Problems (Nuclear
a graduate student in
for acceptably working at the interface.
LBC 140 Biology I 3
LBC 141 Biology II 3
ZOL 389 Animal Ecology 4
ZOL 404 Biological and Ecological
Concepts for Engineers
and Mathematicians 3
BOT 450 Ecology 4
MPH 444 Environmental Microbiology 3
FW/ZOL 476 Limnology (Ecology of Lakes
and Streams) 3
CE 483 Environmental Engineering
II-Water Pollution Con-
CE 487 Environmental Engineering
IV-Water and Waste
Water Analysis 4
BCH 401 Basic Biochemistry 5
(Students may select up to 32 hours)
4. Nuclear Engineering
Nuclear engineering includes the application of
fission and fission processes to the generation
of energy. In addition, the application of by-
product radioisotopes to the study of various
engineering processes is also investigated.
Many of the physical principles are similar to
chemical engineering processes and the theories
involved are directly transferable from chem-
ical to nuclear engineering. Courses which can
form a nuclear engineering option include:
5. Polymer Science and Engineering
The rapidly expanding field of polymer science
and engineering is an excellent option for stu-
dents interested in the synthetic polymer in-
dustry. It is also becoming clear that under-
standing of the molecular properties of syn-
thetic polymers is an aid in the study of the
behavior of some important materials occur-
ring in nature, including the proteins, nucleic
acids, and other constituents of living organ-
isms. An understanding of these materials and
their function in the living cell is a hopeful
pathway of advancement in biology. Therefore,
in addition to the polymer science courses listed
below several of the basic Biochemistry courses
would provide a useful combination for those
interested in Macromolecular Science and Bio-
CEM 462 Theoretical Chemistry II-
CHE 446 Polymerization
CHE 442 Polymer Science and Engi-
CHE 847 Physical Chemistry of Mac-
CHE 848 Rheology and Macromolec-
ular Fluid Mechanics
CHE 460 Special Problems (Theoreti-
cal or Experimental Inde-
pendent Study of Polymer
Each year since 1967, MSU seniors have won
1st, 2nd, 3rd place or honorable mention in
the AIChE Student Contest Program.
Dr. Martin C. Hawley directing
research on coal gasification.
It is possible for chemical engineering students
to pursue an in-depth interest in chemistry.
The regular chemical engineering program in-
cludes 33 credit hours in chemistry which is
nearly equal to the requirement for chemistry
majors. Additional courses from the following
list may be taken under the coordinated elec-
tive option. The student may also choose to
develop a hybrid coordinated elective program
by selecting a few courses from this list and
courses in mathematics, physics, etc.
CEM 355 Organic Chemistry Labora-
CEM 356 Organic Chemistry Labora-
CEM 372 Analytical-Physical Chemis-
try Laboratory I 2
CEM 373 Analytical-Physical Chemis-
try Laboratory II 2
CEM 411 Systematic Inorganic Chem-
CEM 430 Intro. to Radioactivity and
Radioisotope Techniques 3
CEM 446 Polymerization 3
CEM 462 Theoretical Chemistry II 3
CEM 471 Analytical-Physical Chemis-
try Laboratory III 2
CEM 472 Analytical-Physical Chemis-
try Laboratory IV 2
CEM 473 Analytical-Physical Chemis-
try Laboratory V 2
CEM 484 Modern Physical Chemistry 3
CEM 492 Chemical Spectroscopy 3
CEM 499 Seminar on Chemical Physics 1
Chemical engineers with special talent and
background in mathematics are frequently
sought out by their colleagues and employers
to solve the difficult problems for which their
expertise qualifies them. The three programs
listed below are aimed at: I. Giving the stu-
dent a strong foundation in advanced mathe-
matics. II. Combining this with special com-
puter capability. III. Giving the student as
strong a program of mathematics as a math
I. Coordinated elective in mathematics
Theory of Matrices
Vector and Tensor Analysis
Numerical Analysis I
in addition to MTH 215 and CHE/MTH 381
II. Coordinated electives in math and computer
Theory of Matrices
Vector and Tensor Analysis
Numerical Analysis I
Assembly Language and Ma-
in addition to MTH 215 and CHE/MTH 381
III. Coordinated electives with math major equivalent
Theory of Matrices
Vector and Tensor Analysis
Numerical Analysis I
Numerical Analysis II
or STT 441
in addition to MTH 215 or CHE/MTH 381
Students interested in the business aspects of
the chemical process industries, such as produc-
tion management, may combine a strong chem-
ical engineering capability with knowledge and
expertise in business and economics. These
students may develop a coordinated elective
program in business and economics from the
following list of courses. Other courses such as
computer science may be also coordinated with
this type of program.
EC 210 Fundamentals of Economics 4
EC 318 Money, Credit and Banking 4
EC 320 Macroeconomics I 3
EC 321 Macroeconomics II 3
EC 324 Microeconomics I 3
EC 325 Microeconomics II 3
EC 426 Introductory Mathematical
EC 427 International Trade and Fi-
EC 434 Comparative Economic Sys-
EC 470 Monetary Theory 3
MGT 300 Production Management 4
MGT 306 Analysis of Processes and
MGT 310 Fundamental of Personnel
AFA 201 Principles of Accounting I 5
AFA 202 Principles of Accounting II 5
Students may select 20 to 32 credits in any
combination of the above courses, or may select
CHEMICAL ENGINEERING EDUCATION
Dr. Carl M. Cooper at a glass distillation column.
other approved courses in the school of busi-
ness. In addition to the above, other programs
may be developed by students, subject to de-
ENROLLMENT AND HONORS
DESPITE A DOWNWARD national trend of
enrollment in chemical engineering and other
branches of engineering, the number of graduates
in MSU's chemical engineering department has
continued to climb modestly. During the past four
years, the number of degrees granted to graduates
Degrees Academic Year
Granted 1969-70 1970-71 1971-72 1972-73
be ranked among the most outstanding. The past
six year record of MSU prize winners in this
competition is as follows:
1968 Third Prize-Carl L. English
1969 First Prize-Jerome L. Trumbley
Second Prize-Jon A. Branson
1970 Honorable Mention-Steven R. Auvil
1971 First Prize-Allen G. Croff
1972 Third Prize-Timothy O. Bender
1973 Third Prize-Michael J. Murry
The MSU entries in this competition during
the past six years have been coordinated by Pro-
fessor M. C. Hawley who also teaches the design
course in which the Student Contest Problem is
The department faculty have been very active
in professional organizations, especially in the
ChE Division of ASEE. Two of its faculty mem-
bers were elected to serve as Chairman of the
32 33 39
8 8 9
1 3 3
Women majoring in chemical engineering at MSU
make up almost 20% of the total enrollment in
the upper undergraduate classes.
To a large extent, the quality of an educational
program can be judged by the caliber of its grad-
uates. Perhaps the greatest satisfaction to the
faculty of a department in a university is the
honors received by its students for outstanding
performances. This not only recognizes the out-
standing students but also reflects very favorably
on the educational program and training they re-
ceived in the department.
Among the honors received by chemical en-
gineering students at MSU, their performance in
the annual AIChE Student Contest Problem must
Dr. Robert F. Blanks
and doctoral candidate work on
Division, Professor M. H. Chetrick in 1958-59 and
Professor D. K. Anderson in 1971-72. In addition
both served as secretary-treasurer and vice chair-
man during the years directly proceeding their
terms as chairman. Professor Chetrick also was
the Division's representative on the general coun-
cil (predecessor to the present Board of Direc-
tors) from 1961-62.
If a coordinated elective plan exceeds
twenty hours, a student may take up to
an additional twelve hours of electives
by waiving optional courses in the senior year.
Professor M. C. Hawley was program chair-
man of the Division for the 1973 Annual Meeting
and served with other faculty members of the de-
partment on various committees of this organiza-
THE FACULTY AND RESEARCH PROGRAM
THE GRADUATE PROGRAM has grown over
the past 10 years from a small one with a few
masters candidates to one with approximately 30
graduate students. During this period, research
funding from outside sources has grown to a
point where grants and contracts provide financial
support for most of the graduate students as well
as for its faculty.
Research interests within the department are
quite varied. In addition to research programs in
such traditional areas as distillation, thermo-
dynamics, and kinetics, there are supported re-
search programs on mass transport in blood ves-
sel walls, use of high temperature plasmas to pro-
duce chemicals from coal, and gas separation in
high speed centrifuges.
There is considerable interdisciplinary re-
search involving members of the department with
other departments of MSU. There currently are
research programs jointly conducted with the de-
partments of chemistry, physiology, biochemistry,
mechanical engineering, electrical engineering and
The increased number of graduate students
has also permitted the development of more grad-
uate courses, especially in specialty areas such as
polymer engineering, nuclear engineering, and
The present faculty consists of eight full time
members with a wide variety of professional back-
ground as well as teaching and research interests.
A summary of the individual faculty and their re-
search activities is as follows:
D. K. Anderson has been on the faculty since 1960 and
is currently a professor the department. He also holds the
rank of professor of physiology and is engaged in several
joint research projects between the Departments of Chem-
ical Engineering and Physiology. He is chairman of a Col-
lege of Engineering committee on biomedical engineering.
He was one of ten MSU faculty members who received a
Distinguished Faculty Award in 1973. Research interests
include biomedical engineering, cardiovascular physiology
and transport phenomena.
R. F. Blanks came to MSU in 1969 from Union Carbide
Chemicals and Plastics where he was a research scientist.
His research areas are in thermodynamics and rheology of
polymer systems. He is an associate professor in chemical
M. H. Chetrick has served as professor and chairman
of the department since coming to MSU in 1963 from the
University of Louisville. Also taught at the University of
North Dakota. Previous industrial experience was with
Shell Oil, Monsanto, and Battelle Memorial Institute. Also
served as a consultant for many years with the U.S.
Bureau of Mines on coal gasification. Current research
interests are in kinetics, reaction engineering, and syn-
Varin-: *.._ -_.___ -__
Dr. George A. Coulman using research equipment.
C. M. Cooper a member of the faculty since 1948, he was
previously employed with 'Phillips Petroleum and Vulcan-
Cincinnati. He is presently a professor in the department.
His research activities are in thermodynamics and phase
equilibria, modeling of transport processes, and distillation.
G. A. Coulman came to MSU in 1964 from University
of Waterloo (Canada). Aso previously employed with Dow
Corning and American Metal Products. Currently an as-
sociate professor, he is active in research in process sys-
tems theory, process dynamics and control, applied chem-
ical engineering mathematics, and environmental systems.
M. C. Hawley has been on the faculty since 1964 and
is presently an associate professor of chemical engineering.
Serves as a consultant to industry in areas of economics,
new business ventures, and computer simulations. Active
research areas include porous media transport, kinetics
and reaction engineering, and synthetic fuels.
P. M. Schierholz the newest faculty member, he joined
the department late in 1973 as assistant professor. Previ-
ous industrial experience with duPont. Research interests
in crystallization, water treatment, and chemical process
B. W. Wilkinson joined the department in 1965 after
industrial work with Dow Chemical. He was responsible
for the planning of the University Triga Reactor and has
been the supervisor of this nuclear reactor since it became
operational in 1969. Research interests are in the area of
radiation engineering, radioisotope engineering, nuclear
reactor theory, and environmental engineering. f[
CHEMICAL ENGINEERING EDUCATION
*- --- I_~i-r-
We're looking for people who are looking for the good life.
The good life involves a lot of the things we've always taken for granted. Like the availability
of enough food to feed an ever-growing population. A cure for disease. Thick forests. A
clean environment. And the time to relax and enjoy it all. Except now we're going to have
to stop looking at life through a tunnel and find ways to protect all forms of it-from our
homes to the farthest corner of the earth. Because life is fragile. And its protection is, a
major concern at Dow. So we're looking for people with scientific, engineering, manufac-
turing and marketing backgrounds who'll direct their precious talents, enthusiasm and ideas
to the development of Dow products and systems for the good life. And we'll provide a
dignified, motivational environment to work and grow. If you or someone you know loves
life and wants to live it wisely, get in touch with us. Recruiting and College Relations, P.O.
Box 1713, Midland, Michigan 48640.
0 DOW CHEMICAL U.S.A.
*Trademark of he Oow Chemical Company
Dow is an equal opportunity employer-malejfemale
*p" -* -t
views and opinions
THE CHANGING ROLE
OF THE CHEMICAL ENGINEER*
N. A. COPELAND
E.I. du Pont de Nemours & Co.
Wilmington, DE 19898
CHEMICAL ENGINEERING TO ME is a
peculiarly American institution. I was first
reminded of this many years ago when I was
studying in Switzerland. I observed that there
were no chemical engineering textbooks by Euro-
pean authors. Walker, Lewis and McAdams, and
Badger and McCabe were the standard references,
and they were available only in English. Also, at
that time there were as yet no departments of
chemical engineering in the European universities
as we had already known them in this country for
In recent years, as I have had occasion to be-
come somewhat familiar with the chemical in-
dustry in Europe, I have been struck with the dif-
ferent role of the chemical engineer over there as
compared to this country. For example, I find it
interesting that the heads of several of the leading
engineering firms engaged in the design of chem-
ical plants in Europe are not engineers but chem-
ists. Likewise, I have observed that, at least in the
German chemical industry, people with chemical
engineering backgrounds are not found in posi-
tions of high authority-much in contrast to the
situation in this country. I recall two or three
years ago that the president of one of the largest
chemical companies in Europe was quoted in
C. & E. News as saying that he did not hold chem-
ical engineers in very high esteem. He said that
he could get more done with one chemist and two
technicians than he could with one chemist and
one chemical engineer.
I have concluded that chemical engineering in
the United States is a more prestigious profession
than elsewhere and that we, perhaps better than
others, have learned the value of bridging the gap
*Presented to Delaware Valley Section AIChE, April 11,
between chemistry on one hand, and engineering
on the other, for the benefit of the chemical in-
Certainly the chemical engineer has played a
vital role in the American chemical industry for
many years. I propose to talk about how I think
that role is being changed by what is going on in
the industry and by forces outside the industry
which impinge on the profession.
CHANGES IN THE CHEMICAL INDUSTRY
THE CHEMICAL INDUSTRY has always
been a changing industry, which makes it an
interesting place to work, but it seems that the
rate of change is now faster than ever before. In
fact, it is probably changing at a rate faster than
any other high technology industry with the ex-
ception of electronics. The industry has become
large-volume, investment-sensitive, highly-com-
petitive and more prone to rapid obsolescence.
Competition to a large degree is the result of high
profit margins of a few years ago which attracted
newcomers to the industry, especially the oil com-
panies who forward integrated into petrochemical
products. We suffer from overcapacity at times,
and profit margins are not what they used to be.
The year '72, it should be noted, was the best year
for some time and '73 to date looks even better.
Further progress will depend heavily upon the
performance of the chemical engineer and, as I
will attempt to show, the engineer will be more
important than ever.
The role of research in the chemical industry
is changing. There has been considerable discus-
sion in the literature about how our industry's
research is not as productive as it once was. This
is a highly debatable point and, of course, de-
pends upon definitions of productivity. In any
event it is certainly true that research is more
competitive than ever, partly because there are
more highly capable research organizations
around than there were a few years ago. It is be-
CHEMICAL ENGINEERING EDUCATION
LARGER SCALE OF OPERATION
Norman Copeland is a senior vice president, member of the Ex-
ecutive Committee, and a director of the du Pont Company. Prior to
those assignments he was chief engineer of the company, one of the
largest private engineering organizations in the world. He is a grad-
uate of MIT and the University of Delaware (PhD '49) and is a mem-
ber of the Visiting Committees of MIT (ME), Lehigh (ChE) and Del-
aware (Research Foundation).
coming more difficult to come up with a new prod-
uct on which a completely exclusive patent posi-
tion can be obtained and with which we can pro-
ceed, with less than optimum technology to ex-
ploit the market with a comfortable margin. Then
too, the nature of research is changing in the
chemical industry. It is moving in the direction of
support for existing products or variations of
them. There are fewer examples in recent years
of a chemical company researching itself into
large, completely new proprietary areas in the
manner, say, of nylon, which is probably the all-
We have certainly learned that invention and
discovery cannot be bought merely by massive
application of dollars and platoons of Ph.D.'s.
Nevertheless, the rewards for good research, in
my view, are as great as ever. It is just a tougher
game than it used to be.
As a consequence of the foregoing considera-
tions, it seems to me that the competitive position
of a chemical company in the future is likely to
depend less on patent positions and more on tech-
nology. I am certainly not underrating the value
of a good patent position; I am saying that such
a position is harder to get nowadays. Also for
many important products of our industry, basic
patents have expired.
To me this state of affairs means that the
engineer, especially the chemical engineer, has a
more important role to play,
A S THE INDUSTRY BECOMES more com-
petitive and as more products approach com-
modity status, scale of operation becomes increas-
ingly important. Exploiting this advantage of
scale to a large extent depends upon the chem-
ical engineer. We continue to build larger and
larger single-line plants, for example, in methanol,
polyvinyl acetate, textile fibers, DMT, etc. and I
see the trend continuing. Scale-up factors seem to
be getting larger each year, calling for increasing
sophistication on the part of the chemical engi-
neer. Our engineers recently extrapolated a very
complex process form a 1 lb-per-hour mini-plant
to a 150MM lb-per-year commercial plant. After
a certain number of headaches, the plant is now
operating at capacity. A great deal of time and
money was saved by this approach as compared to
carrying the product through a pilot plant. I
should point out that this particular case involved
an intermediate for internal use, so that market
development was not involved.
The development and design of large single-
line plants inherently require superior engineer-
ing. Continuity is critical; the malfunction of a
single piece of equipment can shut down millions
of dollars of investment. Since plant utility or
time on line is so important and is the multiple
of the individual utilities of a large number of
equipment items, highly sophisticated techniques
have been developed to predict during the design
stage overall plant utility for various equipment
configurations and to select the arrangement giv-
ing the best trade-off between down-time and in-
In addition to our scale of operation getting
larger, our processes are becoming more complex.
This increasing complexity augmuents the need
for better, more sophisticated engineering. The
chemical engineer must not only comprehend basic
relationships but very complicated interactions as
well. This situation is particularly evident in proc-
ess control which, in many of our processes, ex-
... invention and discovery cannot be bought merely
by massive applications of dollars and platoons
of Ph.D.'s . Nevertheless, the rewards
for good research ... are as great as ever.
It's just a tougher game.
ceeds the ability of human operators to handle
directly. As a consequence, the industry is moving
to computer control which is developing rapidly
and has already attained an astounding level of
development. Process control has become a profes-
sion in its own right. The use of computers re-
quires more quantitative knowledge of the effects
of process variables and their interactions than
was previously necessary. The chemical engineer
must provide this knowledge and it takes an
especially good engineer to do it adequately.
As our technology becomes increasingly com-
plex, more specialized knowledge in-depth is re-
quired for optimization of plant design. The chem-
-ical engineer is becoming more dependent on other
engineering specialties. Our modern chemical
plants are developed and designed by teams of
There are, it seems to me, some important con-
sequences of increased specialization and the
growing importance of technology vs. patent posi-
tion. Specialization is possible only in a fairly
large engineering organization. Certainly outside
assistance can and should be brought in when ap-
propriate but this can present problems when we
are dealing with proprietary technology. Tech-
nology can best be kept proprietary if the engi-
neering is done in-house. Hence it seems to me
that a competitive advantage in some types of
large-scale chemical manufacture will accrue to
those companies large enough to support their
We continue to build larger single-line plants ..
whose development and design
inherently require superior engineering.
own specialized engineering organization. This
does not necessarily apply to the manufacture of
true commodity chemicals where the technology
can be readily purchased, along with turn-key
plants supplied by highly competent contractors.
ENVIRONMENTAL AND ENERGY CRISES
PREVIOUSLY, I REFERRED TO forces out-
side the chemical industry which impinge on
the practice of chemical engineering. One of the
most potent of these is the drive to clean up the
environment. In the chemical industry much of
this task falls in the domain of the chemical en-
gineer. There are certainly thousands of chem-
ical engineers engaged in finding ways of cleaning
up existing effluents to streams and rivers and
exhausts to the atmosphere from existing plants.
In some cases, they have been able to do this on a
breakeven or a profit basis by recovery of valuable
materials, recycling, etc. But this is getting more
difficult all the time and, as regulations have be-
come tighter, engineers are endeavoring to come
up with solutions imposing the least economic
penalty on the operation. Many ingenious solu-
tions to many difficult problems have already been
found. At the same time there are cases where
there is simply no way out and the operation must
be closed. As you are aware, the stated goal of
existing legislation is zero stream pollution by
1983. Strictly interpreted, of course, this means
that industrial effluents by then must be composed
of nothing but pure water. Now we as chemical
engineers know that such a goal is impossible
without limitless supply of energy for free, and
even then we would transfer much of the en-
vironmental problem to the solids waste and air
pollution areas. It is not my purpose to discuss
the wisdom of existing environmental legislation.
I know that some legislators fully realize that
absolute zero pollution is unattainable. But (pol-
itics aside) they feel that setting such a goal will
push us to the limit of technical feasibility and
perhaps inspire us to do things we didn't think
In addition to the impact on the chemical en-
gineer of the task of cleaning up existing opera-
tions, environmental considerations are strongly
affecting his activities in the design and the de-
velopment of new processes. He must now take
environmental problems into account every step of
the way. The process development is not finished
until environmental problems have been satis-
factorily dealt with, and obviously his choice of
processes is greatly affected.
Another outside force which will have an in-
creasingly profound effect on the chemical in-
dustry, and hence the chemical engineer, is the
energy shortage. This shortage is already with us
and will be getting far worse. The problems of the
environment and the energy shortage are closely
related and eventually priorities will have to be
set-just how and by whom is not clear. Unfortu-
nately, in our free society these kinds of problems
tend to be neglected until a crisis develops. We
have been hearing about the environmental crisis
CHEMICAL ENGINEERING EDUCATION
Continuity is critical . our processes are
becoming more complex ... as a consequence,
the industry is moving to computer control.
for sometime. Now the energy crisis is getting
the attention of the public. There appears to be a
growing awareness that the two crises cannot be
solved independently. Environmental regulations
have forced the substitution of oil and gas, already
in short supply, for coal, which we have in abun-
dance. Furthermore, present and future auto emis-
sions controls are resulting in much less efficient
automobile engines. This in turn means greater
demand for oil. Environmental concerns have
blocked exploitation of Alaskan oil as well as
drastically slowed up adoption of nuclear power
plants. We will be forced to import larger amounts
of crude oil from the Middle East which will re-
sult in untenable foreign trade deficits.
All of this has a great bearing on the chemical
industry, not only in regard to energy to run our
industry but, of even greater importance, on the
cost and availability of hydrocarbon feed stocks
upon which the industry basically depends and
for which there are no substitutes.
The energy shortage is already having con-
siderable influence on how we do our chemical
engineering. Energy consumption is becoming a
much more important factor in process develop-
ment and design. Increasing attention is being
given to heat and energy recovery in the design of
new plants. We used to install energy recovery
systems if they showed a return on investment at
current energy costs. Now we feel that energy
recovery should be installed on a breakeven basis
since costs can go only one way and that is up.
Rising energy costs are also making it appropriate
to restudy existing plants for opportunities for
energy conservation. We are already doing this,
and what we have found in several instances is
that in order to make significant savings in en-
ergy, we must make significant changes in our
processes. This poses a real challenge to the in-
genuity of our chemical engineers.
COMPUTERS IN THE PROFESSION
I PREVIOUSLY MENTIONED computers for
process control. No discussion of changes in
the practice of chemical engineering, or engineer-
ing in general for that matter, would be complete
without a few words about the effect of computers
and computer systems on the profession. The com-
puter has certainly increased engineering produc-
tivity many-fold and has enabled us to solve prob-
lems that we couldn't tackle previously. We have
become so accustomed to the power of the com-
puter that it is hard to visualize how we would
function without it. It has removed much of the
old drudgery from our work. I can remember
hours and hours of slide rule work until I was
bleary-eyed making a trial-and-error plate-to-plate
distillation calculation; then to find that I had
made some stupid mathematical error early in the
I am impressed with the impact that the com-
puter is having on the design function. Our engi-
neers have available to them well over a hundred
programs of various size and complexity, cover-
ing just about all phases of design activity. Com-
puter-balanced flow sheets are becoming standard
for most major projects. Computer-made piping
diagrams are becoming commonplace. Here again
computers are relieving the engineers of drudgery.
More important, they are providing him with
greater flexibility and unprecedented speed to
One area where we should be able to use com-
puters to a larger extent is in energy conservation.
There are computer programs to make overall
plant steam and water balances, but I get the im-
pression that they are not used very much and
that they are cumbersome and expensive. It seems
to me that we have more opportunities in this
field. The computer's influence on our work has
already been revolutionary and the process is still
Now, I have dwelt on the use of computers to a
large extent, and in most instances I have com-
mented on some interrelationship between the
computer and the engineer. The computer is not
lessening the role of the chemical engineer. Far
from it; it is upgrading his role.
I have tried to suggest from my point of view how
changes within the chemical industry and an increasing
number of outside forces are changing the role of the
chemical engineer. The need for chemical engineers with
the basic ability to define and solve problems is greater
than ever. Today's chemical engineer has a lot nioie
knowledge and resources to draw on; but his problems are
becoming a lot more difficult too. Change and challenge
have always made chemical engineering interesting. It
looks as though it is going to continue that way. [
COMMENTS ON GIBBS' EQUATION:
The Condition For Chemical Equilibrium
In Open Systems*
A. H. LARSENt AND C. J. PINGS
California Institute of Technology
Pasadena, California 91109
The first law of thermodynamics establishes
the existence of the internal energy E, a state
function, for a closed system. Assume that E ex-
ists and is a state function for open systems also.
Define q to be the heat transferred to the system
due to a temperature gradient, and w to be the
work done by the system in addition to that re-
quired to introduce or remove material at the
boundary. Neglecting kinetic and potential energy
changes, the first law for an open system becomes
dE = 8q 8w + I Hk) dnk(e), (1)
where 8 is a variation operator used to indicate
that q and w are not state variables, but are path-
dependent functions instead, and where Hk(e) is the
partial molal enthalpy of species k (of s species
present) entering or leaving the system, and in-
cludes the work required to transfer material
across the boundary. If the only work done by the
system is expansion work, it follows that
8w + 8D, = PdV, (2)
where 8D, is the differential of viscous dissipation
of energy. Here dD,/dt, i.e. the time derivative, is
the same quantity as denoted by Ev by Bird et al.
For an open system, the second law of thermo-
dynamics may be written
TdS = 8q + TdS f) + TdS(e), (3)
*Supported in part by the Directorate of Chemical Sci-
ences, Air Force Office of Scientifie Research, under Grant
tPresent Address: Management Information and Sys-
tems Department, Monsanto Company, 800 North Lind-
bergh Boulevard, St. Louis, Missouri 63166.
where dS ) and dS(e) are internal and external
contributions to the differential change in the en-
tropy of the system, due to irreversible chemical
reaction and viscous dissipation, and to material
entering or leaving under different conditions than
in the system. Assuming that a state function S,
established for closed systems, also exists for open
systems, dS is a perfect differential. The internal
entropy generation term dS f must be positive.
In an open system, the differential extent de
of a single chemical reaction is defined by
dnk = vkde + dnk(e), (4)
where dnk is the differential change in the number
of moles of species k crossing the boundary of the
Tds W = Ade + 8Dv (5)
where A is called the affinity of the reaction. In
the absence of viscous dissipation, eq. (5) is es-
sentially a defining relationship for the affinity
Define chemical equilibrium by the vanishing
of the chemical reaction part of dSr), independent
of the existence of irreversibilities introduced by
viscous dissipation or by material entering or
leaving the system. Then
Ade = 0 [eq], (6)
where [eq] indicates constraint to paths of chem-
ical equilibrium. Since the variation de is arbi-
trary, the necessary and sufficient condition for
chemical equilibrium becomes
A = 0 [eq], (7)
which means that the driving force for the re-
action is zero. If A Z 0 even though no reaction
occurs (df = 0), the system is not at stable equi-
librium. For example, a mixture of hydrogen and
oxygen at room temperature does not react at any
measurable rate, but may be made to do so by
CHEMICAL ENGINEERING EDUCATION
introducing a spark or a suitable catalyst, such
as spongy platinum. The spontaneous reaction is
highly irreversible, showing that dSi, is positive
or, from Eq. (5), that A z/ 0. The unreactive mix-
ture is not at true chemical equilibrium, but its
state has been termed "false equilibrium"  or
"metastable equilibrium" .
Substituting Eqs. (1), (2), (3), and (5) into
the differential of Gibbs energy,
dG = dE + PdV + VdP TdS SdT, (8)
dG = SdT + VdP
Ad + I HW) dnkP)
A general condition of chemical equilibrium for
open systems is derived . with the condition of
chemical equilibrium defined in Eq. 6, a restriction
to constant temperature and pressure is unnecessary.
material crossing the boundary. Hence the affinity
of a chemical reaction in an open system is the
same as that in a closed system. Considering the
Gibbs energy G to be a function of temperature,
pressure, and the numbers of moles of all species
present, Eq. (10) becomes
which may be considered as a form of Gibbs' equa-
tion for open systems in the absence of external
force fields . Since ds(e) depends on material
crossing the boundary, and vanishes for dnke) = 0
(k = 1, 2, ..., s), we have immediately
)T,P,nA ^ T,P,n(e)
with the use of Eq. (4). The chemical potential Mk
of species k is defined by
where the subscript n(e) indicates that the differ-
entiation is performed under the constraint of no
Cornelius J. Pings is Professor of Chemical Engineering, Dean of
Graduate Studies, and Vice Provost at Caltech, from which he re-
ceived his B.S., M.S., and Ph.D. degrees. He serves currently as Chair-
man of the Redevelopment Agency for the City of Pasadena. For his
research efforts in applied chemical thermodynamics and the physics and
chemistry of liquids, he has received awards from ASEE and AIChE.
A. H. Larsen is an engineering specialist in the Corporate Engineer-
ing Department of Monsanto Company, where he is responsible for
physical properties service and for development and application of
process simulation technology. He earned B.S.Ch.E. and B.A. degrees
from the University of Utah and a Ph.D. degree in Chemical Engineer-
ing from the California Institute of Technology.
( Dlk ) T,P,n1
where the subscript ni means that the number of
moles of each species except species k is held con-
stant. Invoking the principle of microscopic re-
versibility (Tolman) , each reaction in a mul-
tiple-reaction system at chemical equilibrium must
be independently in equilibrium. Therefore, from
Eqs. (7) and (11), it follows that
I vikk = 0 (i = 1, 2, . ., r) [eq], (13)
which is the condition of chemical equilibrium,
valid for open systems.
Using a different derivation, a number of
authors, including Hougen , Lewis and Randall,
, Moore , Van Ness , Aris , Waser
, and Luder , imply that Eq. (13), or its
equivalent, holds as the condition for chemical
equilibrium only at constant temperature and
pressure, and fail to indicate its generality. From
the above development, with the condition of
chemical equilibrium defined by Eq. (6), a restric-
tion to constant temperature and pressure or to
any other set of constraints is unnecessary. Since
the chemical potentials are intensive variables,
they possess a value at every point in a system;
hence, chemical equilibrium exists at any point for
which Eq. (13) holds. In fact, Eq. (13) is valid as
the condition of chemical equilibrium for arbi-
trary thermal and mechanical variations in an
Further information can now be obtained re-
garding the nature of dS(e), the contribution to dS
due to material crossing the boundary. The usual
form of Gibbs' equation for open systems (Pri-
gogine and Defay ) is
dG = SdT + VdP + /Lkdn,. (14)
Equating two expressions for dG, from Eqs. (9)
and (14), we have
I tkdn =- Ade + I Hk(e) dnk(e) TdS(e).
k=l k=l (15)
Substitution from Eqs. (4) and (11) results in
TdS(e)= [Hk() Lk]dn(e) (16)
S= Hk TSk, (17)
k(e) = H(e) T(e)Sk(e) (18)
where kl(e) and Sk(e) are the chemical potential and
partial molal entropy, respectively, of species k
crossing the boundary, and T(e) is the temperature
of the material crossing the boundary. Hence, Eq.
TdS(e =T I Skdnk() [H k(e) Hk]dn(e)
= T e) I Sk(e) dnk(e) + 1 [P (e) k]dnk(e).
Therefore dS(e) includes a term to account for the
differences between either partial molal enthalpies
or chemical potentials of the species crossing the
boundary and those in the system, depending on
whether the partial molal entropy terms are de-
scribed in terms of properties of the system or of
properties of the material crossing the boundary.
1. Bird, Robert B., William E. Stewart, and Edwin N.
Lightfoot, "Transport Phenomena," Wiley, New York
(1960), p. 214.
2. Prigogine, I., and R. Defay, "Chemical Thermodynam-
ics," trans. by D. H. Everett, Wiley, New York (1954).
3. Hatsopoulos, George N., and Joseph H. Keenan, "Prin-
ciples of General Thermodynamics," Willey, New York
(1965), p. 416.
4. Tolman, Robert C., "The Principles of Statistical Me-
chanics," Oxford University Press, London (1938),
5. Hougen, Olaf A., Kenneth M. Watson, and Roland A.
Ragatz, "Chemical Process Principles," 2nd ed., Part
II, Wiley, New York (1959), p. 982.
6. Lewis, Gilbert N., and Merle Randall, "Thermodynam-
ics," 2nd ed., revised by Kenneth S. Pitzer and Leo
Brewer, McGraw-Hill, New York (1962), pp. 143, 173.
7. Moore, William J., "Physical Chemistry," 3rd ed.,
Prentice-Hall, Englewood Cliffs, N. J. (1962), p .171.
8. Van Ness, Hendrick C., "Classical Thermodynamics of
Non-Electrolyte Solutions," Macmillan, New York,
(1964), p. 117.
9. Aris, Rutherford B., "Introduction to the Analysis of
Chemical Reactors," Prentice-Hall, Englewood Cliffs,
N. J. (1965), p. 41.
10. Waser, Jurg, "Basic Chemical Thermodynamics," Ben-
jamin, New York (1966), p. 160.
11. Luder, William F., "A Different Approach to Thermo-
dynamics," Reinhold, New York (1967), p. 62.
A = Affinity of a chemical reaction
D, = Viscous dissipation of energy
E = Total internal energy
G = Total Gibbs energy, H TS
H = Total enthalpy
nk = Number of moles of species k
P = Pressure
q = Heat transferred to the system due to a temperature
S = Total entropy
s = Number of species in the system
T = Absolute temperature
V = Total volume
w = Work done by the system
8 = Variation operator
/'k = Chemical potential of species k
Vik = Stoichiometric coefficients of species k in reaction i
e = Extent of chemical reaction
Superscripts and Subscripts
= Partial molal quantity
(e) = Material crossing the boundary
(i) = Material in the system
i = Chemical reaction
irr = Irreversible process
k = Species of material
n(e) = Differentiation performed under constraint of no ma-
terial crossing the boundary
CHEMICAL ENGINEERING EDUCATION
THE WORKSHOP ON THE UNDERGRADUATE
CHEMICAL ENGINEERING LABORATORY
Edited by A.J. Perna and H.S. Fogler
This volume from the 1972 ASEE Summer School for Chemical
Engineering Faculty contains
Copies of papers presented by the Con-
ference on a wide variety of topics (e.g.
computer aided, bench scale, and pilot
plant experiments; roles and philoso-
phies of the various laboratories).
Selected experiments from over twenty
universities on instrumentation, con-
Strol transport processes, chemical
kinetics and unit operations.
Summary of the survey of industry
and chemical engineering departments
on current status, philosophies, and
expected trends in Chemical Engineer-
This volume can be ordered by sending a check of $10.00
payable to the Department of Chemical Engineering, University
of Michigan to:
H. S. Fogler, Workshop Coordinator
Department of Chemical Engineering
University of Michigan
Ann Arbor, Michigan 48104
Funds collected from the sale of the Proceedings (above print-
ing costs) will be applied to the next Chemical Engineering
INTRODUCING BEHAVIORAL SCIENCE
INTO AN ENGINEERING LABORATORY
E. R. HAERING and J. B. MARTIN
Ohio State University
Columbus, Ohio 43210
THE SUCCESSFUL PRACTICE of engineer-
ing requires not only technical competence, but
also skill in working with people. A laboratory
course that includes working in groups offers an
opportunity to develop these interpersonal skills
along with the practical applications of technical
The Chemical Engineering Operations Lab-
oratory at Ohio State University is such a course.
The laboratory is offered during the Summer
quarter between the third and fourth years. The
students have completed such chemical engineer-
ing courses as Process Calculations, Thermody-
namics, Transport Phenomena and a Unit Opera-
tions theory course. The laboratory is designed
to be the fundamental laboratory course in chem-
ical engineering operations. Laboratory investiga-
tions of the operating characteristics and effi-
ciences of such chemical engineering equipment as
distillation, filtration, drying, evaporation, liquid-
liquid extraction and heat transfer equipment are
conducted by the students. Typically the students,
working in groups of five or six, spend three days
on each problem with one day devoted to defining
the problem and deciding upon the data required,
one day of experimental work and one day of data
reduction. At the completion of an experiment,
the group submits a complete technical report con-
cerning their findings.
Each group is led by a student foreman who
is responsible for seeing that a particular problem
is solved. The foremanship is rotated among all
members of the group during the course. The
squad foreman's duties include:
* determining exact nature of the problem to be studied.
* leading the squad in the development of the plan of at-
tack to be used in solving the problem.
* organizing and supervising the laboratory and calcula-
tion efforts of the squad.
* guiding the preparation of the final report.
In short, the squad foreman is given the oppor-
tunity to act as a typical technical group leader
and is presented with responsibilities that em-
phasize his managerial role. This aspect of the
course has been expanded by the introduction of
cognitive and experiential learning from the be-
W E SET AS OBJECTIVES for this portion of
1) to develop an awareness that there is a body of
knowledge about how organizations can become more ef-
fective, 2) to develop an appreciation of participative man-
agement, 3) to establish a conceptual framework for
further learning about organizations, 4) to provide an
understanding of what is meant by experiential learning,
5) to increase skill in giving and receiving positive feed-
back, 6) to help each student to appreciate his own
Objectives 1 and 3, and to some extent 2, rep-
resent an intellectual kind of learning. Since our
objectives were limited ones, requiring little depth
of understanding, we decided to impart this infor-
mation by lecture and discussion. Two one-hour
lectures were presented; one on managerial styles
and one on organization development.
A quick check with the students indicated
practically no knowledge of management theory.
A few students acknowledged a slight acquaint-
ance with Maslow's herarchy of needs, but the
names of other behavioral scientists elicited prac-
tically no response. The first lecture was, there-
fore, a survey of management and motivation
theory. The subjects covered, though superficially,
* Scientific Management (Frederick Taylor)
* Human Relations Approach (Hawthorn Experiments)
* Theory X and Theory Y (Douglas McGregor)
* Hierarchy of Needs (Abraham Maslow)
* Two Factor Theory of Motivation (Frederick Herzberg)
* Texas Instruments (Scott Myers)
* Managerial Grid (Blake and Moulton)
The second lecture defined organization develop-
ment as planned change for organizational im-
provement based on behavioral science. Typical
CHEMICAL ENGINEERING EDUCATION
steps in introducing organization development
into a system: education, team building, inter-
group problem solving and organizational rede-
sign were described. To give some meaning to the
steps, examples of activities associated with each
step were discussed.
We felt the other objectives required ex-
periential learning. Each squad met separately for
approximately 3 hours with Dr. Martin. After re-
sponding to any questions generated by the lec-
tures, he led the squad in an abbreviated team-
building exercise. Each squad was asked to pro-
duce a list of the abilities or characteristics of
individuals that contributed to effective squad
performance in this laboratory course. These lists
ranged from 12 to 37 items. Included were abil-
ities for performing particular aspects of the
work such as operator skills in the laboratory,
writing ability, graphical ability, computer skills,
mechanical skills, manual skills, and technical
knowledge. Also listed were more personal char-
acteristics such as willingness to work hard, will-
ingness to sacrifice, dependability, ability to get
Edwin R. Haering is an Associate Professor of Chemical Engineer-
ing at The Ohio State University. He is a native of Ohio and received
his B.Ch.E., M.S., and Ph.D. degrees at Ohio State. He is teaching in
the areas of chemical engineering operations, chemical kinetics, re-
actor design and process design. His major research interests are
adsorption, heterogeneous catalysis and chemical reactor design and
analysis. (LEFT ABOVE)
J. B. Martin, Adjunct Associate Professor of Chemical Engineering,
The Ohio State University, has spent his entire professional career
within research and development at The Procter & Gamble Company,
Cincinnati, Ohio. He received a BS in Chemical Engineering from
Auburn University, (1943); MS (1947) and PhD (1949) degrees from
The Ohio State University. He has been honored by the College of
Engineering of The Ohio State University as a Distinguished Alumnus.
Dr. Martin is a member of the Chemical Engineering Division of
ASEE, was a Director of AIChE (1968-70), and is Past President of
the Engineering Society of Cincinnati. He is a registered Professional
Engineer in Ohio. (RIGHT ABOVE)
along with people, and ability to organize. There
were also more specific items, including the ability
to communicate with a particular teaching as-
FEEDBACK: STRENGTH AND WEAKNESS
E ACH squad member then selected from the list
two or three (depending on the length of
the list) items which represented the greatest
strength for each other member of the squad. We
decided to emphasize strength because: 1) we
doubted that in the short time available we could
develop sufficient candor to insure a meaningful
discussion of weaknesses, 2) there would be in-
sufficient time available to deal with the feelings
generated by negative feedback, 3) we wanted to
give practice in giving and receiving positive feed-
back, because tho emphasis on feedback is so often
The choices were displayed so that the infor-
mation as to who said what about whom was
shared within the squad. Each member was then
asked to elaborate on his opinions and to cite ex-
amples of the behaviors that led to his choices.
One of the eight squads chose to repeat this por-
tion of the exercise with regard to weaknesses.
The students participated actively in the ex-
ercise. While the information shared tended to be
somewhat superficial, it was felt that there were
useful exchanges in each squad.
We asked the students for short critiques of
this insertion into the laboratory. Their reactions
were quite favorable and they recommended a
similar program for next year. The lectures were
seen as interesting, pertinent, and helpful. The
response to the team building sessions was more
mixed. About half the class were, to some degree,
dissatisfied with these experiences. In general,
those who expected an improvement in the per-
formance of the squad were disappointed. A num-
ber pointed out, quite correctly, that real improve-
ment could not be achieved without dealing with
deficiencies. In retrospect, we see that we could
have been more explicit about the limitations on
the exercise. There seemed to be satisfaction with
the exercise as a learning experience, although
several students would have preferred to have
used the time for computation and report writing.
We have concluded that this addition to the
course is well worthwhile, and hope to continue
this exposure to the behavioral sciences in engi-
neering education. O
PRINCIPLES OF NON-NEWTONIAN
G. ASTARITA, University of Naples and G.
MARRUCCI, University of Palermo. 1974, 304
pages (tent.), $19.50 (tent.)
An accessible yet rigorous treatment of non-new-
tonian fluid mechanics is provided in this ad-
vanced text. Modern continuum mechanics and
rheology are presented and developed up to the
solution of cases of fluid mechanics problems, par-
ticularly for polymeric materials. Along with a
consideration of nonlinear thermodynamics, the
book offers a critical review and classification of a
large number of constitutive equations.
THE INTERPRETATION AND USE OF
RATE DATA: The Rate Concept
STUART W. CHURCHILL, University of Penn-
sylvania. 1974, 512 pages (tent.), $19.50. Solu-
Here is a completely new treatment of rate proc-
esses in which a generalized structure is used,
greatly simplifying the number of concepts needed
to study bulk transfer, momentum transfer, heat
transfer and chemical reactions. Emphasis is on
the relationship between design and uncertainties
in measurement, and these concepts are reinforced
with over 300 problems based on raw experimental
data from the literature.
A McGraw-Hill/Scripta Book
INTRODUCTION TO METALLURGICAL
DAVID R. GASKELL, University of Pennsyl-
vania. 1973, 550 pages, $19.50
Treating in depth the thermodynamics of high
temperature systems encountered in metallurgy,
this book demonstrates the thermodynamic
method through an extensive illustration pro-
gram, using as examples real systems which have
been carefully selected to illustrate the principles
involved. The text introduces basic laws and nec-
essary thermodynamic functions and makes appli-
cations that are numerous and thoughtful.
A McGraw-Hill/Scripta Book
MOMENTUM, HEAT AND MASS
TRANSFER, Second Edition
C. O. BENNETT, University of Connecticut,
Storrs and J. E. MYERS, University of Cali-
fornia, Santa Barbara. 1974, 752 pages, $17.95.
Combining a rigorous approach to fundamentals
with an extended treatment of practical problems,
this revision treats principles of transport phe-
nomena as applied to simple geometries and then
extends the discussion to analyze practical areas
such as flow in pipes and equipment, filtration,
heat exchangers and evaporators, gas absorption,
liquid-liquid extraction and distillation.
MERTON C. FLEMINGS, Massachusetts Insti-
tute of Technology. 1974, 335 pages, $19.50. A
Solutions Manual will be available
Here is the only significant book in the field in
ten years. Building on the foundations of heat
flow, mass transport and interface kinetics, the
author presents the fundamentals and relates
them to practice. Among the processes considered
are crystal growing, shape casting, ingot casting,
growth of composites and splat cooling.
LINVIL G. RICH, Clemson University. 1973, 448
pages, $16.50. Solutions Manual
In this quantitative introduction to the subject,
Professor Rich uses a systems approach, in which
the focus is on the system as a whole and how the
components interact. Although water environment
is considered in greatest detail, also included are
air pollution and its control, solid waste manage-
ment and radiological health. The mathematics of
systems analysis and computer solutions is used
McGraw-Hill Book Company
CHEMICAL ENGINEERING EDUCATION
AN OPEN BOOK
COMPUTER-AIDED HEAT TRANSFER
J. ALAN ADAMS and DAVID F. ROGERS, both
of the United States Naval Academy. 1973, 480
A balanced approach between theory and analy-
sis/application of that theory is presented for all
three modes of heat transfer. A thorough devel-
opment of the methods for formulating mathe-
matical models in terms of non-dimensional pa-
rameters is stressed. Well documented, interactive
computer programs, written in the BASIC pro-
gramming language, are an integral part of the
APPLIED STATISTICAL MECHANICS:
Thermodynamic and Transport Properties
THOMAS M. REED and KEITH E. GUBBINS,
both of the University of Florida. 1973, 510 pages,
With emphasis on applications, this text intro-
duces the various ways in which statistical ther-
modynamics and kinetic theory can be applied to
systems of chemical and engineering interest. Pre-
sented is a fundamental, up-to-date treatment of
statistical-mechanics with primary interest fo-
cused on molecular theory as a basis for correlat-
ing and predicting physical properties of gases
CHEMICAL ENGINEERING KINETICS,
J. M. SMITH, University of California, Davis.
1970, 544 pages, $16.50
By developing principles of kinetics and reactor
design and applying them to actual chemical re-
actors, this text acquaints students with the tools
necessary to design new chemical reactors and
predict the performance of existing ones. Em-
phasis is placed on real reactions using experi-
mental rather than hypothetical data.
PROCESS MODELING, SIMULATION, AND
CONTROL FOR CHEMICAL ENGINEERS
WILLIAM L. LUYBEN, Lehigh University. 1973,
558 pages, $18.50. Solutions Manual available
from the author
Professor Luyben has devoted his book to pre-
senting only useful, state-of-the-art, applications-
oriented tools and techniques most helpful for
understanding and solving practical dynamics and
control problems in chemical engineering systems.
Written for the undergraduate student, this text
offers a unified, integrated treatment of mathe-
matical modeling, computer simulation, and proc-
HEAT TRANSFER, Third Edition
JACK P. HOLMAN, Southern Methodist Univer-
sity. 1972, 480 pages, $13.50. Solutions Manual.
Five cassette tapes with accompanying student
workbook also available. Audio Tapes, $35.00;
A brief and concise treatment of all phases of
heat transfer, featuring in this edition a set of
review questions at the end of each chapter, addi-
tional problems, use of SI units, increased em-
phasis on numerical methods in the chapters on
conduction, and expanded discussion of techniques
applicable to computer solution, additional empir-
ical relations for free convection, and a new
chapter on environmental problems.
MASS TRANSFER OPERATIONS,
ROBERT E. TREYBAL, New York University.
1968, 688 pages, $17.50
The basic approach of this revised text, which
treats the major subjects in categories of gas-
liquid, liquid-liquid and fluid-solid contact, has
been retained as has its application of modern
theories and data to practical design of equipment.
A major addition to the book includes material on'
multi-component gas absorption and distillation.
Prices subject to change without notice.
1221 Avenue of the Americas, New York, N.Y. 10020
A FOREIGN STUDY PROGRAM
IN CHEMICAL ENGINEERING
D. L. ULRICHSON and M. A. LARSON
Iowa State University
Ames, Iowa 50010
N 1971-72, THE CHEMICAL engineering fac-
ulty at Iowa State University (ISU) began
giving careful consideration to the development of
a foreign study program. Because of the increas-
ing frequency with which our graduates found
employment overseas and because of a need for
more international contacts between technically
trained people, it seemed that such study would
add an important new dimension to our degree
program. At the time this was under considera-
tion, Professor M. A. Larson was on sabbatical
leave at the University College London (UCL).
From this advantageous position he was able to
work directly with the faculty at University Col-
lege (primarily Dr. John Garside) in developing
the idea. The program that was developed with
UCL was approved by ISU in 1973 and the first
group went to London in June 1973. This group,
under the direction of Professor D. L. Ulrichson,
consisted of 14 students: one senior, ten juniors
and three sophomores.
It was extremely fortunate that unique per-
sonal contact existed between UCL and Iowa State
because UCL was ideally suited for such a pro-
gram. The University College was founded in 1826
and has grown to considerable academic prom-
inence. It was the first University in England to
offer degrees to persons who were not members
of the Church. The ChE department is one of the
most highly regarded in England and its faculty
includes some very distinguished members of the
chemical engineering profession. Professor P. N.
Rowe, head of the department, and Professor
J. W. Mullin are extremely active in leadership
positions in the Institute of Chemical Engineers.
Maurice A. Larson is Professor of Chemical Engineering at Iowa
State University. His technical areas of specialty include crystallization
and fertilizer technology. He teaches courses in Process Control and
Dynamics and Process Design. In professional activities he has been
active in the ASEE, in the AIChE where he has had several local
section offices and in the ACS. He is currently Secretary-Treasurer of
the Division of Fertilizer and Soil Chemistry. (Left above)
Dean L. Ulrichson was educated at the University of Nebraska
(B.Sc. '62), University of Illinois (M.Sc. '63) and Iowa State University
(Ph.D. '70). He has had five years of industrial experience with the
DuPont Company and has been engaged in teaching and research in
the Chemical Engineering and Computer Science Departments at Iowa
State University since 1970. His research interests are in process
modelling and simulation and energy engineering with particular
emphasis on the hydrogen economy. He has been faculty advisor of
the AIChE Student Chapter and received an Outstanding Counselor
Award in 1973. (Right above)
UCL is located near the center of London and
within easy walking distance of the British Mu-
seum and the University of London Library at
Senate House. The London Transport's bus and
subway system also provides convenient access to
the Parliament Buildings, Buckingham Palace, the
theatre and shopping districts. The cultural and
academic environment that London and Univer-
CHEMICAL ENGINEERING EDUCATION
sity College could offer made it a natural for
meaningful foreign study experience.
THERE WERE FIVE BASIC goals which
seemed both realistic and desirable for th
program: (1) provide an opportunity to stud
chemical engineering design and research prol
lems as they exist in a different country; (2
provide individual contact with persons of another
culture who are engaged in the practice of th
same profession; (3) provide an opportunity t
learn more about the impact of the expand
European Economic Community on the objective
and economics of chemical manufacturing in th
U.S. and on the foreign operations of prospective
employers; (4) provide an opportunity to wor
in the metric measurement system and learn about
the problems which U.S. industries must soon fac
when they convert to the metric system; (5) pr
vide an opportunity for individual travel in En
land and other countries both during and after th
With these objectives as a framework, a pri
gram was developed which provided for: (1) vi;
its to chemical manufacturing plants in the U.
before departure; (2) two weeks of lectures, lal
oratories, and study periods at University Colleg
London; (3) a one week tour through southwec
England and Wales with visits at University Co
lege Swansea in Wales and British manufacturing
plants; (4) two more weeks of study, lecture
and laboratories at UCL; (5) residence accomod;
tions provided in dormitories where students
other nationalities and backgrounds were als
Heat transfer experiment in UCL lab.
Because of a need for more international contacts
between technically trained people, it seemed
that such a study program would add an important
new dimention to our degree program.
staying; (6) air travel to and from London by
youth fare rather than charter so each student
could plan visits to other countries and return to
the U.S. when he desired; and (7) 12 credits
which applied toward the B.Sc. degree in chem-
ical engineering at ISU. The total cost of the
program including passport, transportation, fees,
room and board was estimated at $966 for each
DL DURING THE SPRING QUARTER of 1973,
ce the participating students attended an ori-
o- entation program which provided travel informa-
g- tion and the nucleus for required reports on the
Le history and economy of the United Kingdom. De-
tails such as travel arrangements, passport and
o- vaccination requirements and possible optional
s- tours to be arranged in England were also dis-
3- There were 24 lectures, all given by the UCL
fe staff, during the four weeks of classes. The lec-
st ture topics included University of London history,
1- the metric system and preferred numbers, the
lg development of the British and U.S. chemical in-
s, dustry and the impact of the European Economic
a- Community on these industries, and discussion of
of several of the more prominent research projects
0o at UCL. The students were offered 22 different
laboratory experiments from which they were to
choose and complete 8 experiments in 16 labora-
tory sessions. The laboratory experiments offered
were quite varied and generally unstructured.
Students were encouraged not to perform a spe-
cific set of runs in a given experiment but to in-
vestigate that aspect of the experiment which
most interested them. Reports were required on
each experiment and evaluation of these reports
was the basis for 4 of the 12 credits awarded for
satisfactory completion of the program. The bal-
ance of the credits was based on a series or re-
ports on the lecture topics and selected industrial
The other dimension of the program which
made the program quite exciting was the frequent
breaks from the classroom-laboratory routine. The
evening of the first day of classes the students
were introduced to a uniquely British institution,
the sherry party. The sherry party was held in
a UCL conference room and the students and UCL
staff had an opportunity to get acquainted while
sampling sherry, pretzels, potato chips and nuts.
A wine and cheese party, with many delightful
varieties of cheese, was held during the third week
of classes and a dinner party with a preceding
social hour closed the program on the last day of
classes. Other breaks during the program con-
sisted of visits to the chemical engineering de-
partment of Imperial College in London, the Sci-
ence Museum and Gordon's Distillery. All of the
industrial visits in the U.K. were most impressive
because of the extremely gracious hopsitality.
. .. the British way of life .. is a slower paced
life, with less emphasis on materialism and much
more emphasis on the impressive history and
time honored traditions.
The evenings and weekends were free for the
students, and they took advantage of the many at-
tractions available in London and the vicinity.
The tennis matches at Wimbledon were popular
as was the Shakespearean Theatre-in-the-Round
in Regents Park. The many theatres and movies
were not neglected and even the pubs (bars) were
After the first two weeks in London, a week
long tour to Wales via charter bus was scheduled.
The bus route took us through Stonehenge, a huge
stone monument of 15th century B.C. origin, and
Bath where the Romans built swimming pool type
baths over warm springs in the 1st to 4th cen-
turies A.D. These baths were only discovered and
excavated during the 19th century. Our head-
quarters for the week were in a dormitory at Uni-
versity College Swansea. The first day was spent
visiting the chemical engineering department at
University College Swansea and the beaches along
the Gower Coast. This area probably has the most
beautiful coastline in all of England and many
miles of lovely sand beaches. The water is a bit
cold, however, for those used to the summer
weather in Iowa. The next two days were spent
visiting B.P. Chemicals Company and the British
Steel Corporation's Strip Milling Division. Even-
ing tours to the Black Mountains and local pubs
were also organized. The return trip was sched-
uled through Stratford-on-Avon, the birthplace of
William Shapespeare. Stratford was a bit too
crowded with tourists to interest our group, but
it is an interesting place to visit particularly if
one can make arrangements early enough to see a
play performed in the beautiful new theatre.
Two more weeks of lectures and laboratories in
London then concluded the program on August 1.
Several students were brave enough to rent cars
and bicycles and venture into the surrounding
countryside during this two week period. Old
castles, some abandoned and some exquisitely pre-
served, abound for the interested tourist on such
short trips. One point of particular interest is the
Greenwich Observatory, only a few miles down the
Thames from London.
At the conclusion of the program, each student
planned to visit at least one other country. Scot-
land and France were the most popular spots, but
hitch-hiking trips through Norway and bicycling
trips through Germany were also planned. Al-
though most of the students returned to the U.S.
by August 15, two students traveled with back-
packs and Eurail passes until September 1.
The total cost of the program was a few dol-
lars less than the estimated cost of $966. The av-
erage expense of entertainment and individual
travel in and around London was about $150 to
$200 per student. This did not include the cost of
gifts for friends and relatives nor the cost of post-
Probably the most important part of this pro-
gram was simply the exposure to the British way
of life. It is a slower paced life with less emphasis
on materialism and much more emphasis on the
impressive history and time honored traditions.
Certainly it was an experience not soon to be
forgotten. A similar program is planned for the
summer of 1974.
A few quotes from student assessment are given
"The values of the course lie within the labwork and
class work to a small degree, but mainly in the lectures
and plant tours. Valuable contacts and exposure to new
topics in new ways are very good."
"I have really enjoyed it over here plus I learned
quite a lot. The teachers in the ChE department have been
grat just to talk to or when you have a problem with a lab
they are always glad to help."
"I think the program is very good, you learn a lot of
things, including some chemical engineering."
"As a learning experience the whole trip is hard to
"Good show old chap! Smashing idea." D
CHEMICAL ENGINEERING EDUCATION
WE ENCOURAGE JOB HOPPING.
In fact at Sun Oil we've just adopted a new system
that promotes it. Internal Placement System.
Here's how it works. Say you're in Production
and you decide to take a crack at Marketing.
Next opening in Marketing we'll tell you. You can
apply and be considered. First. You have freedom
to experiment and move around at Sun. You
learn more and you learn faster.
Why do we encourage job hopping? Because
,we happen to believe our mostvaluable corporate
assets are our people. The more our people
* know, the stronger we are. Now-you want to
know more? Ask your Placement Director when
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for a copy of our Career Guide. SUN OIL
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MASS AND ENERGY BALANCES-1972 +
DONALD R. WOODS
Hamilton, Canada. L8S 4L7.
GARY F. BENNETT
The University of Toledo
Toledo, Ohio 43606
G. MICHAEL HOWARD
University of Connecticut
Storrs, Conn. 06268
MICHAEL J. GLUCKMAN
The City College of New York
New York, N. Y. 10031
New needs, new challenges, new outlooks, new
knowledge-these keep the engineering curricu-
lum in a state of flux. The Education Projects and
the Undergraduate Education subcommittees of
the AIChE decided to bring together all those in-
terested in the teaching of one particular subject
to share experience, and to identify new trends
and new needs.
A questionnaire was sent to all Chemical En-
gineering Departments in United States and Can-
ada in June, 1972. Sessions were held at the New
York AIChE meeting November 1972 and at the
Vancouver meeting in August 1973. The response
to the questionnaire was overwhelming and ex-
tremely interesting; the conference get-together
was very well-received. We realize that studying
a course out of the context of a complete pro-
gram can be very misleading. The specific objec-
tives, prerequisites, the other courses in the pro-
gram and the staff and facilities available are
unique to any program at one particular depart-
ment. Nevertheless, despite these complications,
it is useful to provide a snap shot view of the
teaching of Undergraduate Mass and Energy
Balance-1972 and some hints of future trends.
We hope this is but a start of a series of critical
summaries of the courses in our educational pro-
gram. Mass and Energy balances is to many stu-
dents their introduction to Chemical Engineering.
What are the characteristics of today's students?
What are the content-objectives of the course? Is
the lecture technique universally used? What do
instructor's believe are the major challenges? and
What about the future ?-these are some questions
we try to answer.
THE CHARACTERISTICS OF THE STUDENTS
It is difficult, and perhaps even dangerous, to
attempt to generalize about the nature of students
in their sophomore year. However, we think that
it is very useful to at least try to characterize the
"consumers" to whom this course is presented.
Some characteristics are:
* The majority of the courses they have taken have been
in the sciences to broaden their knowledge of funda-
mental principles of physics, chemistry and mathematics.
* They are used to more or less memorizing "cook book"
methods of solving problems.
* They are not used to open-ended problems, ill-defined
problems requiring assumptions or problems where there
are a number of "good" answers.
* They are not accustomed to the law of optimum sloppi-
ness, or to doing "sloppy" order-of-magnitude calcula-
tions, or to the principle of successive approximation.
* They know very little about engineering hardware and
about the chemical engineering profession but are very
anxious to learn about these.
* In the early 1970's a prime concern is the relevancy of
the material and of the profession. They are less willing
to gain knowledge because we instructors say they need
it. They want to, and almost demand, to be told why
they are learning it and its potential application. They
want to be "turned on".
* They believe they have well polished logical thinking
and debating skills. Yet, for many these skills could be
* In particular for the traditional content in mass and
energy balances, they believe that they know much of
the material already.
Developing a single course to meet these di-
verse backgrounds, interests, and needs poses a
challenge for even the most skilled teacher. A sum-
mary of these challenges is presented later.
In general, the central themes of this course
CHEMICAL ENGINEERING EDUCATION
Gary F. Bennett is a graduate of Queen's University and the Uni-
versity of Michigan (Ph.D.). He is head of the University of Toledo's
Biochemical Engineering Laboratory and director of environmental
programs for their adult and continuing education division. His honors
include designation as 'Outstanding Young ChE of the Year" and "ChE
of the Year" by the Toledo Junior Chamber of Commerce. His teaching
and research interests are in the areas of water pollution and bio-
medical engineering. (ABOVE LEFT)
D. R. Woods is Chairman of the Shared Teaching Experience sub-
committee. He is presently developing a course to teach problem solv-
ing skills. His teaching interests are in process analysis, information
management and cost analysis. The separation of oil-water systems and
surface phenomena are his research interests. (ABOVE RIGHT)
are: developing problem solving ability, learning
and applying the principles of conservation of
mass, and learning and applying the principles of
conservation of energy. Associated with these is
the need for a set of units of measurement and a
unit system, some basic laws about the behaviour
of liquids and solids (physical and thermal prop-
erties and concepts), some mathematical skills,
and some skill in communicating the results of
engineering work. These associated needs can be-
come a major focus of the course or they can be
minimized to the extent that some of them are
Other objectives usually include learning at-
titudes and manual skills. Bloom et al (1954) and
Krathwohl et al (1964) classify the intellectual
and attitudinal learning regions. Development of
a professional attitude is considered to be im-
portant. Some professional concepts are listed in
Table 1. The course tries to show what profes-
sionals do and to generate an appreciation of their
role in society both now and in the future. This
includes motivation of the students toward a pro-
fessional career and the establishment of personal
goals within the profession.
Some manual skills that some feel should be
Dr. Gluckman is an Assistant Professor in the Chemical Engineering
Department at The City College of the City University of New York.
Prior to joining The City College he worked for ten years as a Senior
Process Design Engineer for the St. Regis Paper Company. Dr. Gluck-
man received the B.Ch.E. degree in 1958 from the University of Cape
Town, South Africa, and a Ph.D. (Chemical Engineering) from the City
University of New York in 1971. (NOT PICTURED)
G. Michael Howard is an Associate Professor of Chemical Engineer-
ing at the University of Connecticut. His main teaching interest re-
cently has been the development of a general first course for all
freshman engineers. He has taught courses in process dynamics and
control, transfer operations, applied mathematics, and the ChE Lab-
oratory. His research interests are in the general area of process
modeling, simulation, and control. He holds degrees from Rochester,
Yale, and Connecticut and has a variety of industrial experience.
TABLE 1: Some Affective Domain Concepts Important to
Chemical Engineers (levels 1 to 5)
USE OF ALL RESOURCES:
What products and services are useful and needed by mankind?
Does this represent the optimum long term use of natural resource
Sense of urgency of man's needs.
Willingness to compromise theory with reality in satisfying man's
VALUES OF HUMAN WORTH: plant safety, safe products, salary and
job security, human relations and effect of present operations and
products on future health of society.
MORAL AND ETHIC VALUES
micro and macroscale
-employment (seeking and hiring and firing those working for
-use of natural resources
-use of intellectual human talent
INTERACTION WITH OTHER PROFESSIONALS
Willingness to actively participate in professional organization.
Loyalty to colleagues
Confidence in one's own abilities
Initiative to start programs on one's own maturity in outlook Re-
learned include experimental techniques (such as
ability to titrate, use a balance, make a thermo-
couple, to run equipment, to set up bench scale
equipment) and skills in keypunching or patching
together an analog computer.
The course is actually taught in many different
ways as illustrated in Figure 1. These include
integrated throughout the program with no course
per se; as part of a thermodynamics course; with
the emphasis on career guidance and professional
responsibility, on stagewise processing, on solving
several large case problems, on synthesis, on
analysis or problem solving, on mathematical
methods, techniques and/or simulation, on mass
and energy balances, or on computer program-
ming and systems. Most courses are mixtures of
these approaches, and these are not mutually ex-
The textbooks and resources used are often in-
dicative of the emphasis in the course. Texts that
emphasize the conservation concepts include
Anderson and Wenzel (1961), Himmelblau
(1967), Hougen, Watson and Ragatz (1954),
Ranz (1970), Schmidt and List (1962), Thatcher
(1962), Tyner (1960) and Williams and Johnson
(1971). Whitwell and Toner (1969) emphasize
problem-solving. Henley and Bieber (1959), Hen-
ley and Rosen (1969), Blum (1971) and Dorf
(1969) have a more mathematical bent. Meissner
(1971), Shreve (1967), Stephenson (1966),
Wendland (1971) and Thatcher (1962) are ca-
reer and process oriented. Henley and Staffin
(1963), King (1971) and Brian (1972) are used
as texts by some to introduce processing equip-
ment. The thermodynamics texts used are Balz-
hiser, Samuels and Eliassen (1971), Denbigh
(1971), Smith and van Ness (1959), Sonntag and
van Wylen (1971) and Wales (1970).
Over forty schools indicated that they were
using Himmelblau's book. Whitwell and Toner,
Schmidt and List, and Hougen, Watson and
Ragatz were all used by more than five schools.
More interesting is the fact that twenty five pro-
fessors are using a very new book on their own
notes in teaching this course.
Some outstanding new textbooks on the market
that offer the opportunity to emphasize the areas
illustrated in Fig. 1 are:
SRudd, Powers, Siirola (1972) "Process Synthesis". Choice
of cases exceptionally good; illustrates breadth of Chem-
ical Engineering and the general universality of the
principles they present. Identifies steps in synthesis as
reaction path synthesis, material balancing and species
'.-,r eu hdil
FIGURE 1-Classification of Approaches Taken. Central Region repre-
sents emphasis on mass and energy conservation concepts.
allocation, (review of separation technology) strategy
for selecting separation task equipment, energy balances
and task integration. Each step is abundantly illustrated
via case examples from extremely diverse examples.
Finally, two cases (fresh water from brine via freezing
and detergents from petroleum) are discussed to il-
lustrate synthesis as one large integrated operation.
* Russell and Denn (1970) "Introduction to Chemical En-
gineering Analysis". Formulation and problem solving
are major themes. Introduces rate concepts. Interrelates
experiments, modeling and application.
* Myers and Sieder (1972) "Chemical Process Logic". Sys-
tems approach with emphasis on mathematics, the use
of the computer, solutions of sets of equations and the
use of modular executive programs. Good review of
mathematical techniques. Well organized and a good
attempt to introduce ideas of process equipment.
While these may not suit one's particular objec-
tives, they open up additional resources to us as
instructors and provide exciting new trends for
The case study approach attracts a number of
professors. In this approach, an example of a
process or a case problem is studied as a means of
learning concepts through a "need-to-know" or in
providing synthesis experience or to motivate the
students via relevant problems that also illustrate
professional responsibility. A wide variety of
background case information is available; see
Sherwood (1963) ; Bodman (1968) ; King (1971) ;
CHEMICAL ENGINEERING EDUCATION
Smith (1967 ff). While the majority of these cases
have been used for senior and graduate level de-
sign courses, nevertheless this provides back-
ground information that can be adapted to the
second year purposes. (Seagrave's (1971) first
four chapters provide interesting examples of
mass and energy balances in biomedical applica-
tions.) Some cases used by Pappano at West Vir-
ginia in the mass and energy balance course and
the corresponding objectives are:
Natural gas: alternative
Reverse osmosis for plat-
Cryogenic liquefaction of
Separation of a liquefied
methane ethane mixture
To introduce "need-to-know"
physical and chemical reac-
tion material balances, con-
servation of resources and
minimum cost criteria.
To introduce "need-to-know"
ideal gas law, work in gas
phase, first law and process
To introduce "need-to-know"
vapor pressure, Raoult's Law.
Rudd, Powers, and Siirola (1972) provide a fan-
tastically broad spectrum of case examples and
case problems to which anyone seeking to locate
sparkling examples to intrigue freshmen or for
examples in the mass and energy balance course
It is interesting to note the differences be-
tween Pappano and Rudd et al in the approach to
offering synthesis experience. Pappano uses a
number of cases each of which is solved applying
all the steps in the synthesis. Rudd, Powers and
Siirola (1972) illustrate each step. Later, they
consider several cases in detail.
In general, the course is offered after 30 weeks
of university training with about 45 hours of lec-
ture time. Some schools use tutorial time only. The
experimental laboratory has almost disappeared
from the United States schools although the Ca-
nadian schools still seem to favor this experience.
THE LEARNING ENVIRONMENT
Traditionally the lecture mode has been used
extensively in universities. For engineering, many
experimental laboratories have been popular. For
developing solving skill, traditionally we have re-
quired the students to work many problems for
homework. However, with the availability of a
variety of well written texts, movie films and film
loops, slide-tape or cassettes, programmed texts
and with the relatively small classes, many other
options are available for us to use. The learning
environments can be classified as:
Human-sender centered: lecture, sender directed prob-
lem solving, some tutorial/discussion environments,
Learner centered: homework, games, student centered
discussion, some tutorial/discussion environments,
Mechanical-sender centered: computer aided instruction,
programmed texts, self-paced audio-visual or texts
Object centered: plant tours, experiments, demonstra-
Some learning environments are in between
the centers. For example, the discussion, tutorial
and recitation usually lie between the human
sender center and the learner centered. The dis-
cussion is extremely flexible and can range from
learner group discussion, guided learner group
discussion, the guided problem-solving and guided
synthesis to lecturer-directed discussion. Links
exist between other centers where the professor is
available as an extra resource to a programmed
text. MacKenzie et al (1970) p. 32 point out that
from a learner's viewpoint, what matters most is
not the formal instruction he is given but the kind
of learning resources to which he has access.
The variety of learning environment include
lectures; demonstrations; student laboratories;
individual or group homework problems; self-
learning with textbook or printed notes, slide-
tapes, films, TV tapes, programmed text, via com-
puter simulations-interaction, and audio plus
text; student-centered discussion; student-pre-
pared lectures or reports; sender-directed prob-
lem solving or discussion; individual problems
solved with discussion and games. Some indication
of the mix of these environments is shown in Fig.
2 but this does not do justice to the wide variety
of extremely interesting resources that are being
used: plant tours oriented toward case projects,
FIGURE 2-Learning Enxironment used by Respondents.
film loops, programmed texts [Wales (1970)],
audio-visual packages and self-paced notes. Of
particular interest is the sender-directed problem
solving approach of Treybal at New York Uni-
versity and the guided design approach of Pap-
pano. Many are getting away from the lecture and
are using the time for discussion or group problem
Self-paced programs have been developed by
many in an attempt to overcome the motivational
and boredom problems faced when all the class
must proceed at the same pace. This has not been
without its problems: the fantastic amount of
time to prepare good material, the problem of get-
ting the students to use the resources effectively,
in particular to keep at the self-paced material.
One particularly appealing approach is Pappano's
working with the group as part of the team with
the evaluation being performed by someone not
associated with the course directly.
The sequencing and pacing varies greatly.
Tulsa uses 10 of its 17 units on the background
laws and equations; McGill uses 7 total units;
Clarkson uses 13 units; Arkansas uses 22 units;
and Cincinnati uses 15 units. The programs them-
selves range from the use of texts (such as Wales
(1970)), to notes that identify the learning ob-
jectives, the rationale, the learning activities and
the self-assessment task. MacKenzie et al (1970)
suggest that the replacement of one learning en-
vironment by another is not ideal; it is better to
offer two or more alternative learning environ-
ments and let the learner choose. It seems that
most have elected to go all self-paced and the two
alternatives are not offered. Cornell offers lecture
or audio visual. It is interesting that the actual
format of how the self-paced programs are run
varies from school to school. Some still retain
some lectures; some have lectures and tutorials;
some have laboratories.
SUMMARY OF CHALLENGES
Three major challenges were voiced repeat-
* To provide sufficient drill so that problem-solving, and
doing a mass and/or energy balance are second nature.
The challenge is to get the students to appreciate the
complexity of the problem yet keep each step simple so
that they learn it readily. To further complicate matters
there is a wide variation in our student's ability with
this set of knowledge; perhaps wider than that in other
courses. For some students, this is very easy; for others,
it is extremely difficult.
* To motivate the students. This is related to the first
challenge. However, we need the students to participate
sincerely in the discussions, tutorials, in the self-paced
programs. The students should be so interested that they
are willing to extend themselves. The students want to
be turned on. They seek relevancy.
* To develop self confidence maturity and professional at-
Other challenges that can be specific to a par-
ticular school include:
* The preparation of new learning environments to better
suit the needs of the students and the course objectives.
* The challenge of integrating, selecting and pacing the
material: graphical, analytical and computer techniques;
problem solving, properties, and conservation concepts;
teach as separate course or integrate throughout the
o Finding good problems and cases.
* Having enough time available.
IDEAS FOR THE FUTURE
Besides the challenges listed in the preceding
section some observations and ideas about the fu-
ture concern the following topics:
Unit Systems. There has been a lot of discussion
about metrification (see for example Kroner (1972)). Only
a few schools seem to have started to include the S1 sys-
tem. What should we be doing in view of the decision to
adopt metric units in the near future?
Everyone discusses problem solving and developing a
problem solving ability. Yet the actual generalized strategy
for problem-solving or even the strategy specific to solv-
ing mass and energy balances is not described clearly
enough. One idea is to use Polya's generalized "four step"
strategy of Define, Plan, Carry out the Plan, Look Back.
Within this framework the substeps that offer a unique
challenge to a specific type of problem could be discussed.
This has been done for design and for plant improvement
(see Figs. 4.3 and 4.4 in Crowe et al (1971) p. 76). A start
on this for solving mass and energy problems is given in
Table 3. Would it be profitable for us to spend more time
elucidating the actual strategy for solving problems since
this is such a major component of our program?
Many professors emphasize open-ended problems that
require students to locate information for themselves.
Some have this as a part of their course now, or as part of
other courses in the program. What emphasis should be
placed on searching the literature in the Mass and Energy
Balance course? Should we define a strategy for searching
the literature? A suggested strategy is given in Table 4.
Engineers need to know something about cost esti-
mation and the financial aspects of an enterprise. Some
introduce this as part of the course. Should we introduce
more or is it too early in the program?
We believe it is important to develop a professional
attitude. How do we go about "teaching" it? What com-
ponents of it should the students experience in the Mass
and Energy Balance course?
There is a need to define the criteria used by engi-
neers to make decisions. These include technical feasibility,
CHEMICAL ENGINEERING EDUCATION
TABLE 3: Generalized Strategy for Problem Solving
Identify need: accuracy &
Specify criteria: technical,
economic, financial, re-
sources, social market
Identify system parameters:
Develop models & set up
Decide on Solution Strategy
Select Mathematical Tech-
Reiterate if necessary
Thatcher (1962) Chapt 3
p. 57 to 68
Whitwell & Toner (1969) 38
p. 101 to 153
Andersen and Wenzel (1961)
Specific to Mass & Energy Bal.
Draw a neat flow diagram.
Identify boundaries or envelope.
Classify type of operation
or transient; recycle?)
Choose a basis, write stoichiometry.
Identify unknowns, degrees of free-
Identify fundamental constraints
Identify subproblems, clearly state
assumptions, Identify tie elements.
Use Method of Successive
Approximation or not?
scribed elsewhere (Walker and Delgass (1972)). Should
we publish, like the AIChE case problems, a list and
evaluation of cases useful for Mass and Energy Balances
at the freshman-sophomore level?
The content, learning environments, and stu-
dent characteristics reported for a course "Intro-
duction to Mass and Energy Balances" have been
reviewed. The content centers around problem-
solving and the conservation concepts with an
introduction of the appropriate material on units
and the properties of matter. The major learning
activity is problem-solving as homework with lec-
turing being the primary learning environment.
The students are not used to poorly defined prob-
lems or the use of order-of-magnitude calculations.
They are searching for relevency, especially in
view of the image the chemical industry has con-
cerning pollution and employment.
In general, a lot of exciting innovations are
TABLE 4: Generalized Strategy for Searching
Identify need: accuracy &
Henley & Bieber (1959 Chpt. 3
p. 11 to 15
Tyner (1960) p. 3
Himmelblau (1967) p. 33 to 34 &
Identify system parameters:
Decide on Solution Strategy:
Develop search strategy
economic, financial, environmental, socially accepted feasi-
bility. How much of this should be in this course ?
The students should have some appreciation of proc-
essing equipment, how it works and what it looks like.
Rudd, Powers and Siirola (1972) handle this primarily via
a glossary. Myers and Sieder (1972) discuss key equipment
needed for the flow diagrams and processes they discuss in
their book. Some use plant tours, others use experimental
labs. Perhaps it would be worthwhile to discuss the im-
portance and alternative approaches that could be used
to discuss this.
There seem to be relatively few movie films available
for this course. Are the ones available useful? Should
more be developed?
Finally, some are interested in learning more about
good case studies. Some are using them now, some are de-
Specific to Searching the Lit.
clear statement of information
where information sought fits in
information resources available
check in encyclopedias, dictionaries,
thesauri for good definitions, for
synonyms generate search state-
Identify "most" likely source of in-
formation (article, book, patent?
Select resources that will help lo-
Search by subject? by author.
Iterate if necessary
Woods, Stone and Black
being tried: innovations in content, in motivation
and in learning environment. The interesting
trends in content are shifts toward case studies,
design, problem solving and mathematics-systems.
The challenge in motivating the students is met by
careful choice of examples and pacing. The choice
of learning environment is extremely important.
Many are using self-paced environments. Some
points for discussion are enumerated. O
This article is a condensation of the original survey.
More details can be obtained from D. R. Woods. This survey
was made possible by the financial support of the Depart-
ment of Chemical Engineering, McMaster University, Ham-
ilton, Canada. We appreciate the assistance of Ms. Susan
Anderson, Sheelagh Swords Courtney and Charlotte Traplin
of that Department for their help in collecting and collating
Anderson, L.B. and Wenzel, L.A. (1961) "Introduction to
Chemical Engineering" McGraw-Hill, New York.
Balzhiser, R., Samuels, and Eliassen, J.D. (1971), "Chem-
ical Engineering Thermodynamics", Prentice-Hall.
Bloom, B., et al (1954) "Taxonomy of Educational Objec-
tives: Cognitive Domain", David McKay, New York.
Blum, J.J., (1971), "Introduction to Analog Computation",
Harcourt-Brace, Jovanovich Inc.
Bodman, S.W., (1968) "The Industrial Practice of Chemical
Process Engineering" The MIT Press.
Brian, P.T.L. (1972) "Staged Cascades in Chemical Engi-
Crowe, C.M. et al (1971) "Chemical Plant Simulation",
Denbigh, K.G. (1971) "The Principles of Chemical Equilib-
rium" 3rd ed. Cambridge, Cambridge.
Dorf, R.C. (1969) "Matrix Algebra: A Programmed Intro-
Henley, E.J. and Bieber, H. (1959) "Chemical Engineering
Calculations: Mass and Energy Balances" McGraw-Hill,
Henley, E.J. and Rosen, E.M. (1969) "Material and Energy
Balance Computations", Wiley, New York.
Henley, E.J. and Staffin, H.K. (1963) "Stagewise Process
Design", Wiley, New York.
Himmelblau, D.M. (1967) "Basic Principles and Calcula-
tions in Chemical Engineering". 2nd ed. Prentice-Hall,
Englewood Cliffs, New Jersey.
Hougen, O.A., Watson, K.M. and R.A. Ragatz (1954)
"Chemical Process Principles. Part I Material and
Energy Balances" second edition, Wiley, New York.
King, C. Judson (1971) "Separation Processes", McGraw-
Hill and series of case studies in design and simulation,
available from Dr. King, Dept. of Chemical Engineering,
Univ. of California at Berkeley, Berkeley.
Krathwohl, D., et al (1964). "Taxonomy of Educational
Objectives: Affective Domain". David McKay, New
Kroner, K.E. (1972). "Metrification-our Responsibility?".
Engng. Education 63 1 p. 53.
MacKenzie, Norman, Eraut, Michael and Jones, H.C.
(1970). "Teaching and Learning: An introduction to
new methods and resources in higher education".
UNESCO and the International Association of Univer-
Meissner, H.P. (1971) "Processes and Systems in Indus-
trial Chemistry", Prentice-Hall.
Myers, A.L. and Seider, W.D. (1972) "Chemical Process
Logic", Univ. of Pennsylvania, Philadelphia, Penn.
Polya, G. (1945) "How to Solve It", Princeton Univ. Press,
Ranz, W.E. (1970) "Describing Chemical Engineering Sys-
Rudd, D.F., Powers, G.J. and Siirola, J.J. (1972) "Process
Russell, F. and Denn, M. (1972) "Introduction to Chemical
Engineering Analysis", Wiley, New York.
Schmidt, A.X. and List, H.L. (1962) "Material and Energy
Seagrave, R.C. (1971) "Biomedical Applications of Heat
and Mass Transfer", The Iowa State Univ. Press, Ames.
Sherwood, T.K. (1963) "A Course in Process Design", The
MIT Press, Cambridge.
Shreve, R.N. (1967) "Chemical Process Industries", 3rd ed.
Smith, Buford D. (1967 ff) Series of case studies in process
design-simulation available from Dr. Smith, Dept. of
Chemical Engineering, Washington Univ., St. Louis,
Smith, J.M. and van Ness, H.C. (1959) "Introduction to
Chemical Engineering Thermodynamics", McGraw-Hill.
Sonntag, R.E. and van Wylen, G.M. (1971) "Introduction to
Thermodynamics: classic and statistical", Wiley.
Stephenson, R.M. (1966) "Introduction to the Chemical
Process Industries", Reinhold.
Thatcher, C.M. (1962) "Fundamentals of Chemical Engi-
neering", C.E. Merrill Books, Columbus, Ohio.
Tyner, Mack (1960) "Process Engineering Calculations",
The Ronald Press.
Wales, C.E. (1970) "Programmed Thermodynamics", Mc-
Wendland, R.T. (1971) "Petrochemicals-the New World
of Synthetics", Doubleday.
Whitwell, J.C. and Toner, R.K. (1969) "Conservation of
Mass and Energy", McGraw-Hill.
Williams, E.T. and Johnson, R.C. (1971) "Stoichiometry
for Chemical Engineers", McGraw-Hill.
Woods, D.R., Stone, E. and Black, S.M. (1969) "Resources
for Searching the Literature with examples in the field
of Business-Economics". Chem. Eng. Dept., McMaster
Univ., Hamilton, Canada.
Woods, D.R.; (1970) "Resources and Mechanics of Search-
ing the Literature with examples for the Chemical En-
gineer" Chem. Eng. Dept., McMaster Univ., Hamilton,
Walker, C.A. and Delgass, W.N. (1972) Chem. Eng. Ed.
6 No. 3 p. 124.
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at Alhambra, California and in our Eastern Engineering
Center at Murray Hill, New Jersey. For more infor-
mation, please write to C F Braun & Co, Department
K, Alhambra, California 91802 or Murray Hill, New
AN EQUAL OPPORTUNITY EMPLOYER
O a problems for teachers
The following article introduces a new feature series by
Chemical Engineering Education in cooperation with the
CACHE (Computer Aides for Chemical Engineering Edu-
cation) Committee. Proven computer-based homework
problems suitable for undergraduate or first year graduate
chemical engineering courses will be published on a regular
The current problem, together with listings and docu-
mentation, is too long for full publication so the following
article presents the problem and outlines the computer
program developed to solve it. Complete documentation of
the problem and program may be obtained for the cost of
reproduction by writing the problem author.
Problems submitted for publication should be docu-
mented according to the published "Standards for CACHE
Computer Programs" (September 1971). That document is
available now through the CACHE representative in your
department or from the CACHE Computer Problems
Editor. Because of space limitations, problems should
normally be limited to twelve pages total; either typed
double-space pages or actual computer listings. A problem
exceeding this limit will be considered. For such a problem
the article will have to be extracted from the complete
problem description. The exact procedure to distribute the
total documentation is evolving and my involve distribu-
tion at the cost of reproduction by the author, as we are
doing with the current problem.
Before a problem is accepted for publication it will
pass through the following review steps
1) selection from among all contributions an interest-
ing problem by the CACHE Computer Problem Ad-
2) documentation review (with revisions if necessary)
to guarantee adherence to the "Standards for
CACHE Computer Programs".
3) program testing by running it on a minimum of
three different computer systems.
It is hoped these problems will indeed be an aid in teaching
computing and engineering to our students.
A. W. Westerberg
U. of Florida
Gainesville, Fla. 32611
Non-Isothermal Tubular Reactor Program
R. S. KIRK
University of Massachusetts
Amherst, Mass. 01002
THIS COMPUTER PROGRAM is a numerical integra-
tion procedure for solving complex plug-flow reactor
problems. The program will handle up to ten simultaneous
reactions and ten different chemical compounds. The pro-
gram is designed to handle a constant heat flux per unit
area, but by proper choice of input data, isothermal or
adiabatic (zero heat input) cases may be treated. With
minor modification, the program has been used to calculate
the heat flux, based on radiant heat transfer to the tubes
with an internal film coefficient evaluated by the Dittus-
The specific problem considered here is problem number
29, page 899, Chemical Process Principles, Vol. III, O. A.
Hougen and K. M. Watson, John Wiley and Sons, Inc., New
York, 1947. The discussion of the program refers specifi-
cally to this problem.
IT IS DESIRED TO DESIGN a tubular heater and re-
actor for the pyrolysis of propane to produce a mixture
of ethylene and propylene. Substantially pure propane is
to be charged through a preheater which delivers it at a
temperature of 6000F and an absolute pressure not in ex-
cess of 60 lb per sq. in, to the inlet of the reactor-heater.
In order to avoid secondary and reverse reactions the ab-
solute pressure at the outlet of the reactor is maintained
at 20 lb per sq in. The gases from the reactor are com-
pressed and fractionated to recover the desired products
and substantially pure propane which is recycled to the
heater and reactor. The design is to be based on a total
propane feed to the reactor of 7000 lb per hr and a con-
version per pass of 80 per cent, corresponding to a net
fresh charge of 5600 lb per hr.
A trial design is to be prepared on the basis of passing
the entire heater and reactor charge in a single stream
through a series of uniformly sized tubes each 30 feet long
and connected together with 1800 return bends. Each return
bend has a volume equal to 3.1d3 where d is the inside di-
ameter of the tube. The equivalent length of a return bend
is 60 diameters of straight pipe, and the heated length of
each tube is 28.0 feet. Tubes are available with inside di-
ameters varying by -in. increments from 1 in. Since the
maximum operating temperature permitted by the tube
material is 14000F, the heater will be designed to raise the
charge to this temperature with a uniform heat input rate
of 8000 Btu/ (hr) (sq ft) based on the actually heated in-
ternal tube area. In order to obtain favorable heat-trans-
fer conditions the tube diameter should be as small as pos-
sible without exceeding the allowable inlet pressure. In the
CHEMICAL ENGINEERING EDUCATION
reactor section a constant temperature of 1400F will be
maintained by varying the heat-input rate.
It is required to determine the diameter and numbers
of tubes for the specified service and also the temperature,
pressure, conversion, product distribution, and heat-input-
rate distribution curves throughout the heater and reactor,
using the following kinetic data.
REACTION RATE DATA
r = rate of reaction, lb mole/ (cu. ft.) (hr)
,r = total pressure, atm.
k = A exp (-E/RT)
E = Cal./g-mole
T = temperature, K
N = mole fraction
K = exp(-AHo/RT + AS'/R)
1) C3Hs -- C2H4 + CH,
r = kirN C Ib moles CHs
A = 3.0158 x 1014; E = 66500.
2) 2CH, -> C2H6 + CsH, + CH4
r= kNrN C3H
lb moles CaHs
A = 3.6745 x 1013; E = 65000.
3) C3H,1 C3H, + H2
r= kr[NcH (NCsH) (NH1) (r/K)]
A = 9.989 x 1012; E = 60000.
AH = 30505.; ASo = 32.85
(the values for AH and ASo are at
1300F; it may be assumed K does not
vary with temperature)
4) 2C3H Hs C2H+ + CH,,
r = kr[N CNH, (N C2 ) (N )/K]
A = 2.490 x 1010; E = 54000.
K = 1.30 (substantially independent
METHOD OF SOLUTION
The material balance across a differential in-
crement of a tubular (plug-flow) reactor is:
FdX = rdV,
where F = feed rate, mass units/hr.
X = moles of reactants converted/
unit mass of feed
r = reaction rate, lb moles/ (hr)
V, = reactor volume, cu. ft.
The rate of reaction is a function of tempera-
ture, pressure and composition which vary along
the length of the reactor, and which are all inter-
related. There are four competing reactions and
thus composition is a function of the four reac-
tions rates. Thus:
r = r(T, n, X)
T = T(X)
II= in(X, T, n)
X = X(r)
Solution of this problem is a numerical inte-
gration of the four simultaneous material balance
equations for the four reactions expressed in a
difference form. The particular method of solution
used in this program is based upon choosing a
tube increment sufficiently small that the change
in conversion can be calculated from the arith-
metic average of the rates of reaction. That is:
AXi ri AVr/F
where ri is the arithmetic average of the rates of
reaction at the beginning and end of the increment
for the ith reaction. Successive increments of
volume AVr are added until the total conversion,
Y A X of propane, reaches the desired level.
The detailed calculation procedure is described
in the section Subroutine DESIGN.
N-al C al Vue
--- Call to lnittalize Values
A discussion of each subroutine follows. Their
inter-relationship is shown in the block diagram
of the program. Subroutine DESIGN, the most
important, is listed first, then the main program,
and the other subroutines in alphabetical order.
This subroutine is the executive subroutine,
providing the logic for the solution as well as
initializing the variables and printing the results.
Its operation is best described in tabular form.
Reference is made to the various subroutines in
the program. The letters A and B are affixed to
each variable to designate respectively values at
the beginning of an increment (known values, as
TA) and values at the end of the increment
(values to be calculated, as TB).
1) Convert feed data to lb. moles/hr and mole fraction
2) Initialize all variables for conditions at inlet to re-
a) Establish heat transfer area, volume, and
equivalent length for each tube increment
and return bend (SUBROUTINES GEOM
[INCR = 0] and BENDS).
b) Initialize enthalpy, HA (Subroutine ENTH)
c) Initialize rates of reaction, RAi (Subroutine
CONV [INIT = 1])
d) Set assumed conversions, DDNi 0.0
3) For each increment, establish area, volume and
equivalent length. (SUBROUTINE GEOM [INCR])
4) Calculate heat input to increment and enthalpy at
end of increment, HB. For assumed composition,
calculate outlet temperature TB by Newton-Raphson
secant procedure. (SUBROUTINES HEAT and
ENTH). If exit temperature exceeds maximum
value, TMAX, set TB = TMAX
5) Calculate viscosity of mixture at average tempera-
ture of increment (SUBROUTINE VISCON).
6) Calculate pressure drop across increment. (SUB-
ROUTINE PDROP). If pressure falls below mini-
mum set value; stop; print out results, and start
over, using next size tube.
7) Calculate rates of reaction and conversion, DNI for
each reaction and compute changes in number of
moles of each component. (SUBROUTINE CONV
[INIT = 2])
8) Check if calculated conversions DN, agree with as-
sumed values, DDN1 within prescribed tolerance. If
not, set DDNi = DNi, and repeat steps 3 through 8.
If no convergent is obtained in 15 passes through
loop (KRX), stop.
9) When satisfactory agreement between calculated
and assigned conversions is obtained, proceed to
next increment; store the results in array OUT if
the end of a tube has been reached.
Calculate the changes in temperature, (e.g.
TDEL = TB TA), conversion, and composition
of each component. Set the calculated values at end
of this increment equal to the values at beginning
of next increment. Set trial values of variables at
end of next increment equal to values at beginning
of increment plus changes in these variables oc-
curring during this increment. For example:
(TA).n+ = (TB),,
TDEL = (TB),, (TA),;
but if (TB), = (TA)n, do not reset TDEL
(TB)+,, (trial) = (TA)n,, + TDEL
Return to Step 2 and proceed.
10) When conversion of key component (CH,) reaches
desired value, stop and print out results. Depending
on input data, program will stop if a satisfactory
solution is obtained, or will continue through a
specified range of tube sizes.
The output array OUT has provision for 75 tubes; if
more are needed, the program prints a warning and stops.
Main Program, REACT
The main program merely sets the logical unit
numbers of the card reader (INP) and the printer
(IOUT) ; then CALLs SCAN (to read in the data)
and DESIGN (to perform the calculation).
Subroutine BENDS (FLBEND, VBEND, ABEND, DI)
This subroutine contains the constants for the
return bends. For the specific problem listed, the
following data is given:
Volume of return bend, VBEND = 3.1 di"
Equivalent length of straight pipe for pres-
sure drop calculations, FLBEND = 60 di
where di = internal diameter of tube, inches.
ABEND = heat transfer area of return bend.
For specific problem given here, the return
bends are not heated, thus ABEND = 0.
The constants in this subroutine must be
changed by the user, if the return bends are
heated, or if return bends with different volume
and friction loss characteristics are used.
Subroutine CONV (PB, TB, VOL)
This subroutine calculates the rate of reaction,
RB, for each reaction at the temperature TB,
pressure PB, and assumed composition at the
exit of the increment.
The conversion for each reaction is calculated
DN(K) = 0.5 (RA(K) + RB(K)) VOL/FEED
DN(K) = conversion for the kth reaction, moles/mole
RA(K) = rate at entrance of increment
RB(K) = rate at exit if increment as calculated above
VOL = volume of increment, cu. ft.
FEED = feed rate, lb. moles/hr.
The number of moles of each component is then
determined from the overall material balances.
The rate equations and material balances listed
in this subroutine are for the four reactions given
in the specific problem statement. For other prob-
lems, this subroutine must be rewritten.
Subroutine ENTH(HTOTAL, TEMP)
This subroutine calculates the enthalpy of the
CHEMICAL ENGINEERING EDUCATION
reaction mixture at a temperature = TEMP (oR).
Enthalpies are defined with respect to the ele-
ments at a base temperature of 770F. Thus:
(Hi),77 = (AHfi)1 + Ho.,- Ho"7
and TOTAL = I (XXi) (WTMOLi) (Hi) T,
Btu/lb. mole mixture
where: (Hi),T = enthalpy of component i at
temperature T, above 770F,
(AHfi), = heat of formation at 770F,
HoT = enthalpy of component i at
temperature T with respect to
liquid at -200F.
H77 = enthalpy of component i at 77F
with respect to liquid at
XXi = mole fraction of component
WTMOLi = molecular weight of component i
enthalpy change across the incre-
AH = (BMOLS HB AMOLS HA) FEED
where BMOLS and AMOLS are total moles/
mole of feed.
Thus AH, as defined here, includes the heat of re-
action as a function of temperature.
The peculiar set of base temperatures in the
first equation is necessary to use the data in the
API Technical Data Book-gaseous enthalpies
based on liquid at -200F and heats of formation
at 770F. The API book gives the following equa-
tion for HoT:
Ho' = A(T/100) + B(T/100)2 +
C(T/100)3 + D(100/T) + E
where A, B, C, D, E are constants for each
component, Btu/lb., T = R.
Any set of data may be used, as long as the
enthalpies are referred to the elements. The API
Technical Data Book provides a convenient set of
data for an enthalpy equation, rather than a heat
Subroutine GEOM (INCR)
The initial call to GEOM [INCR = 0] triggers
a call to BENDS to set the area, volume and
length parameters for the return bends. There-
after, this subroutine assigns to each specific in-
crement the proper values of heat transfer area,
volume, and equivalent length of straight pipe for
pressure drop calculation.
The complexities of the subroutine are re-
quired to handle the case of furnace tubes whose
ends and return bends are not heated and to al-
low the use of various sizes of increments in the
integration. A diagram of the furnace is below:
The program identifies three different incre-
1) The normal increment-the entire portion of the
increment is heated (if three or more increments
per tube are used).
2) Cold increments-the increment at the beginning
and end of each tube. The cold increments may in-
clude some heat transfer area if the increment size
is greater than HALFL.
3) The return bends-in this problem the bends are
cold and so ABEND (Subroutine BENDS) is set to
zero. If the return bends are heated, ABEND should
be set equal to the external surface area of the bend.
Note that regardless of the number of increments
used per tube, the return bend is treated separately.
For a furnace in which the whole tube is
heated, the input data values of TUBEL and
TUBEHL (see SCAN) should be identical.
Subroutine HEAT (HA, HB, TA, TB)
The enthalpy balance and exit temperature are
calculated in this subroutine. The exit enthalpy is
Q = FLUX AREAX
HBD = (FEED AMOLS HA + Q)/(FEED
Q = heat added, Btu/hr
FLUX = specified flux
AREAX = heat transfer area of increment (as set
AMOLS = total moles entering/mole feed
BMOLS = ditto for exit
HA = enthalpy at beginning of increment, at
temperature TA, Btu/lb mo'e of mixture
HBRD =ditto at exit temperature TB; double
FEED = feed rate, lb moles/hr.
The exit temperature TB is then calculated by a
Newton-Raphson secant iteration based on TA
(Continued on page 102.)
APPLICATION OF PERTURBATION TECHNIQUES
TO ANALOG COMPUTATIONS
JOSEPH F. PAUL
California State University
Northridge, California 91324
The object of this study is to investigate the
use of perturbation techniques for determining
the effect of small changes in parameters on the
response of a system. Perturbation techniques
have been applied to analog computation for many
years (see references). However, an attempt will
be made here to present a comprehensive tutorial
development of the theory and then illustrate its
use by applying it to a particular problem. The
problem is studied in detail by first developing
the perturbation equations and solving them on
the analog computer, and then making an error
analysis by solving the equations on the digital
computer. A summary of the results is given at
THERE ARE TWO METHODS for developing
the perturbation equations, both of which yield
the same result. They are called the incremental
method and the Taylor series expansion. The sec-
ond method is considered here. If we expand the
function Z=f(x,y) in a Taylor series and neglect
terms of second order and higher, we obtain:
f(xo + ax, YO + Ay) = f(o, yo) + Y + (1)
For a particular example let Z=XY. Note that for
I v = (2, 3)
Xo Yo 0 0 Y xo, Yo 0
zo + AZ = XoY0 + YoAX + XOAY (4)
where the error would be the sum of the higher
order terms. Breaking equation (4) into two parts
Zo= X YO; 'Z Y vLx + XA (5, 6)
This is the same result which can be obtained by
the incremental method.
Joseph F. Paul received his BS and MS degrees in ChE from Wash-
ington University and has obtained advanced study at University of
Southern California. He formerly was employed by Electronic Asso-
ciates, Inc., TRW Computer Co., and Monsanto Chemical Co. His areas
of interest include applied mathematics, computer science, and process
AN INVESTIGATION WAS MADE on a par-
ticular system which is described below. The
object was to determine the response of the sys-
tem to small changes in one of the parameters
using perturbation techniques. First of all the
perturbation equation was developed for the sys-
tem using the incremental method. A study was
then made using both the analog and digital com-
For the first phase of the study both the nomi-
nal and perturbation equations were mechanized
for the analog computer. A total of five runs
were made utilizing increments of 1%, 2%, 3%,
4%, and 5% in the system parameter which was
the mass flow rate of fluid in the system. Both the
nominal and perturbed values of temperature were
recorded on the X-Y plotter.
For the second phase, the system equations
were programmed in Hytran Simulation Lan-
guage, (HSL). This is a digital simulation lan-
guage which permits the direct programming of
CHEMICAL ENGINEERING EDUCATION
dynamic systems in block diagram format. The
integration scheme employed was fourth order
Runge-Kutta. First the nominal equation was
solved to give the steady state temperature, and
then the incremental temperature was obtained
by solving the perturbation equation and also by
perturbing the original equation and subtracting
the nominal value from it. This last value was
taken to be correct since it was computed from the
original equation to eight significant figures, and
compared to that obtained from the perturbation
equation. The percent error was computed and
compared to that predicted by evaluating the error
term in the perturbation equation. These results
are summarized later in a table.
A jacketed tank with constant level control is
being heated by steam. How long will it take to
reach its steady state temperature and what will
it be? What is the effect of a small change in flow
rate from the prescribed flow rate?
A = area for heat transfer, ft2
V = volume, ft3
U = heat transfer coefficient, Btu/hr-F-ft2
p = density in lbs/ft3
Cp = specific heat in Btu/Fo-lb
T = temperature of contents of vessel, Fo
W = mass flow rate in lb/hr
Ti = inlet temperature, FO
T, = steam temperature, Fo
The overall equation of the process is
dT ( A i T)-f 0 1 (T T) (7)
dhe CV s p d s t W =
The flow rate W is perturbed such that W == Wo
+ AW and as a result, T changes by AT, i.e., T =
dT0 + -r,
C T -V ) ( + -
dT I, W 0 -,T0+ WT 0 1
dT0 + d!T = + (9)
d d i.. s T T I I W-T + WT W T.
dr+ dr iS 0 V K, K, ---.( )
where: L =150 Btu/F-hr-ft2; A = 7.5 ft2; = 80 lb/ft ;
C = 0.8 Btu/F'-b; V = 100 ft3; Ki = UA 0.176 hr ;
P i IVP
k, = oV = 8,000 lb
Equation (9) can be thought of as the sum of
the nominal values and the incremental values. It
can be separated into two equations:
dT0 (WOT0 W0T )
dt K(TS T) K2
d-T (w0T + WITO) iWT.
dt KT K K2
The same equations can be derived by the
Taylor series expansion.
F = C ) L ( Ti)
vF T T CUA W0
O Wo 0 I ] 1 O,0- pB P0
The nominal equation becomes:
dTo VA ) o
d P V ](TI T0) (T Ti)
and the incremental equation becomes:
d- TO Ti UA W0 -T
-dt = (' J PV ~ V +PV ) -T
V.UAIABLL MA SCALE FACTOR
1o 250 1/250
Is 250 1/250
(TS T) 250 1/250
Ti 100 1/100
(T Ti) 100 1/100
LT 1 1
(Ti T )/100
NOTE that AT is scaled to a maximum of one. Although there is a five
per cent change in the parameter AW, there is less than one degree
change in temperature. The parameter 1W does not have to be scaled since
it does not appear as the output of an amplifier.
2i 2.5 -1 I
2.5 100 J 2.5K |^ 100 J
aT- ) 0 100w ( Ti
Od KI T 100
These equations agree exactly with equations
(10) and (11) and thus verify the equivalency of
the two methods.
TABLE 1. SCALED VARIABLES
j 25 250 25 (1)
100 250 ()
Equations (17), (18), (19), and (20) are mechan-
ized as depicted by Figure 2.
In addition to the present problem, for an il-
lustration of a non-linear set of equations let us
put a valve on the inlet flow W still assuming an
adequate level control at the outlet. Thus:
Pi Pa = R p2 = Pd
OF PERTURBATION EQUATION
temperature To, plus the incremental change AT
for five values of AW.
THE RESULTS OF THE ANALOG computer
runs for AT for the five increments in AW
agree with the digital computer runs. The data
from the digital computer runs are tabulated in
Table 4. The first column gives the percentage
change in AW for each run. The second column
gives the percent change in T resulting from the
increment AW. The third column gives the pre-
dicted error in the perturbation equation found
by evaluating the small term AW AT/k, which
was dropped from the equation. The last column
gives the measured error which was found by
computing AT as the difference between the nom-
inal value To and T which was calculated by per-
turbing the original equation and getting the re-
sult to eight significant figures, and comparing
where P. is upstream inlet pressure; P is atmospheric pressure; and
R is resistance coefficient of he value.
ido + APd (W + v W 0 v02 + 2R WoAW (22)
ido = R vo2 or 1o R
LPd = 2RWoU 1 or W = 2RW
W = 1000 lb/hr; Pd = 15 psi; then v = 15 x 10-
LW APd/(2 x 15 x 10-6 x 1 x 103) = APd/3 x 10-2
Thus the same configuration on the analog can be
employed except that now the flow Wo and AW
must be expressed in terms of Pdo and APd.
The plot on the following page gives the results
from the analog computer runs. It gives the steady
Comparison of Errors
E pred. E meas.
this with the value of AT computed by the per-
It can be seen that the measured error, al-
though somewhat larger than predicted, is reason-
ably small for small perturbations. It can be con-
CHEMICAL ENGINEERING EDUCATION
DIGITAL COMPUTER PRINTOUT
DEVIATION FROM 5 PERTURBATION
FROM PERTURBATIOI EQUATION AND BY DIFFERENCE
DIGITAL COMPUTER PRINTOUT
DIGITAL COMPUTER PRINTOUT
eluded then that using the perturbation equation
on the analog computer will give much better re-
sults than perturbing the original equation and
trying to take the difference of nearly equal num-
The problem with using conventional tech-
niques, especially on the analog computer, is that
the effect on the system response is slight and the
isolating of the change by subtraction of nearly
equal numbers can produce serious errors. By
solving the perturbation equation directly, we can
achieve a result which is scaled to the full range of
the computer minimizing the error. O
1. Levine, Leon: "Methods for Solving Engineering Prob-
lems", McGraw-Hill, New York 1964.
2. "8400 Hytran Simulation Language Programming
Manual", Electronic Associates, Inc. 1967.
3. Coughanowr, D. R., L.B. Koppel, "Process Systems
Analysis and Control", McGraw-Hill Book Co., New
4. Meissinger, Hans F., "The Use of Parameter In-
fluence Coefficients in Computer Analysis of Dynamic
Systems", presented at a Western Simulation Council
meeting in 1960.
5. Bush and Orlando, "A Perturbation Technique for
Analog Computers", Cornell Aeronautical Lab., Buf-
falo, N.Y., presented at the National Simulation Con-
ference in Dallas on October 24, 1958.
6. McDonnel, J.A., IBM, "Simulation Using Perturbation
Methods", Instruments and Control Systems, February
1964, pp. 127-8.
7. Luyben, William L., "Process Modeling, Simulation,
and Control for Chemical Engineers", McGraw-Hill,
New York 1973.
8. Dorf, Richard C.: "Modern Control Systems", 2nd Ed.,
K(2/5) J/R 2
SAME AS ABOVE
10 APd/iR WK2 0 APd
AN INEXPENSIVE TIME BOMB
NOEL DE NEVER
University of Utah
Salt Lake City, Utah 84112
This experiment demonstrates:
1. Bernoulli's Equation
2. Unsteady-state flow
3. Flame velocity and flame stabilization
4. Mathematical model building.
The apparatus consists of a can with a snug-
fitting lid. One-gallon paint cans or 2-lb. coffee
cans are ideal. The lid is loosely attached to the
body of the can by a 6" length of 1/8" chain or
strong flexible wire, which is soldered to both lid
and body. The can has two holes in it. One hole
about 1/4" O.D. is in the center of the lid, the
other about 1/2" O.D. is on the side near the bot-
tom. In addition the demonstrator needs a stop-
watch, a book of matches, and a roll of masking
DESCRIPTION OF DEMONSTRATION
Beforehand the demonstrator fills the can (lid
in place) with natural gas. This is done by blow-
ing gas from a gas jet in the bottom hole, while
the can is in a hood. Two to three minutes will do.
Then, before shutting off the gas, the demon-
strator tapes over the lid hole with masking tape,
then removes the can from the gas jet, and tapes
over the bottom hole.
To begin the demonstration the demonstrator
sets the can on a table, removes the bottom mask-
ing tape, then removes the tape over the lid hole
and starts the stopwatch immediately. He then
strikes a match and lights the gas issuing from the
The flame burns brightly for a while, then dies
down to the point where it is invisible in a well-
lighted room. Finally the gas-air mixture in the
can explodes with a loud bang blowing off the lid
and emitting a flash of blue flame. By watching
his stopwatch the demonstrator (who knows in
advance when this explosion will occur) can time
his lecture to reach a dramatic point just when
the explosion occurs.
The theory is easier to discuss on the assump-
tion that the hole in the bottom is very large. If it
were large the pressure drop through it would be
negligible. However, if the hole actually is large
the resulting explosion is not as dramatic as if it
We may apply the classical Bernoulli's equa-
tion across the hole in the top, with the well-
known orifice velocity formula resulting
v = C -V2 Pgas/ (1)
(See the table of nomenclature).
We will now consider the start of the experi-
ment, when the can is full of natural gas. If the
hole in the bottom is large, the gas pressure at the
CHEMICAL ENGINEERING EDUCATION
bottom of the can is Patm. The value of Ap is found
by noting the pressure drop as one moves up in a
column of gas and a column of air,
P =.P -p gA
air atm air
P =P -p gAZ
gas atm gas
P = P -P = giZ(p gas)
gas air air gas
Substituting this in equation 1 we obtain
v = C 2gaZ(pair -s) (5)
This is a steady-state solution, because the classi-
cal Bernoulli's equation is a steady-state equation.
As shown in most fluid mechanics textbooks, this
result is an excellent approximation of the in-
stantaneous velocity for unsteady-state processes
like the one here, in which the velocities are small
compared with the speed of sound.
At this point we will introduce two models of
the behavior of the gas, and determine the veloc-
ity-time curve for each. The experimental ex-
plosion time is bracketed by these calculated
curves, as we would naturally expect.
Model I-The diaphram or plugflow model
Let us assume there is no mixing between in-
flowing air and the gas in the container. Since the
gas is lighter than the air, it will always be above
the air. We may imagine it separated from the air
by a moving flexible diaphragm. If we now con-
struct the ratio v/Vo from equation (5), we get
v Z Pgas (6)
However the values of gas density on the right
o V zo (
Here AZ is the instantaneous value of the distance
from diaphragm to lid hole and AZo is the initial
If we square both sides and differentiate with
respect to time we obtain
2v dv 1 d1(Z
S d AZ dt
Now we make a volume balance, ignoring the
Noel de Nevers earned his BSChE at Stanford and his PhD at the
University of Michigan, with a year out in between to be a Fulbright
exchange student at the Technical Institute in Karlsruhe, Germany. He
spent five years with what is now Chervon Research and Chevron Oil-
field Research, before joining the faculty of the University of Utah.
He spent Academic 1971-72 on leave, working for the Office of Air
Programs of the Environmental Protection Agency. He is the author of
a textbook on Fluid Mechanics, and editor of a book of readings and
discussions on Technology and Society.
minute compressibility effects of the gas, and ob-
d = ah
Substituting (9) in (8) and cancelling we obtain
dv VO ah
dv - ~a constant (10)
This may be readily integrated, and rearranged to
v voah t
i.e., the velocity falls off linearly from its initial
value to zero when one can-volume of gas has
flowed out. This is plotted in Figure 1 for a 1-gal-
lon paint can.
Model 2-The perfectly mixed model
Now let us assume that at any time the con-
tents of the can are perfectly mixed. Returning to
equation (6) we see that the only time-dependent
quantity on the right-hand side of equation (6) is
p,,s which increases steadily as gas flows out and
air flows in. We may solve for it, as follows
mass of gas in container
Pgas volume of container (12)
dt = (mass flow rate in-mass flow rate ot
V (Pair Pgas) )
---as- = dt (15)
integrating from time zero to time t
n (Pair-as )) h =_q
(p r as) vdt (16)
here Q is the total volume of air which has flowed
into the can. This is readily rearranged to
Pgas = Pair (air-Pgaso) exp (-Q/V) (17)
If we now substitute this in equation (6), cancel
out the AZ's, and rearrange, we obtain
Vo Pg (18)
S-(1- --) exp(-Q/V)
This does not have an obvious analytical solution
for v as a function of t, but for a given value of pgo
one may easily prepare a plot of v/Vo vs. Q/V, and
solve for the v vs. t behavior numerically. Figure
1 shows such a plot for a 1-gallon paint can, to-
gether with the plot for Model 1. Note that the
curves cross in the low-time region. This appears
strange, but is consistent with the models chosen.
In the early stages the mixed model should predict
the more rapid decrease in velocity because, in
equation (1) the density of the gas (which ap-
pears in the denominator) increases for the mixed
model, but not for the diaphragm model. In the
early stages, both models show a comparable de-
crease in Ap.
FLAME SPEED AND STABILIZATION
The previously discussed models allow us to
predict how fast the gas is moving through the
lid-hole for any instant of time. As discussed in
texts on combustion (Ref. 1), in laminar flow of
combustible gas and air, a flame propagates itself
with a reproducible velocity. For methane-air, this
is a function of composition, with a maximum
value, for room-temperature gases of about 1.1
As long as the velocity through the lid-hole is
greater than the flame velocity, the flame burns
above the can. When the two velocities are identi-
cal, the flame is exactly in the plane of the lid.
When the velocity of the gas is slightly less than
the flame velocity, the flame burns into the can,
where the velocity of the gas is much less than in
the lid hole, and an explosion (deflagration) re-
sults. In this way the lid-hole acts exactly as does
the flame-stabilizer on a Fischer burner, or on a
jet-engine combustor, or the small burner orifices
on an ordinary gas stove.
If we assume that the flame velocity at the
time of explosion is 1.1 ft/sec, then we can see
the predicted time of explosion for each of the two
above models. This is shown on Figure 1. The ex-
perimental results shown on Figure 1 indicate that
the true behavior of the can is intermediate be-
tween those predicted by the two models, as com-
mon sense indicates it would be for these models.
I.0 I I I I I I I I
0.8 Mixed Model
v= 1.1 ft/sec
Time to explode with
0.2 Bottom Orifice
Area = 2.25 in2---
" 50 100 150 200 250
03 0 350 400 450
Calculated and Experimental Behavior of 1-Gallon Paint Can Bomb.
Diameter 6.75 in., Height 7.5 in., Lid hole 0.25 in.,
Assumed orifice coefficient C = 0.6, Assumed gas
MW = 17,
Calculated initial velocity Vo = 2.9 ft/sec.
COMMENTS ON THE EXPERIMENT
1. The application of Bernoulli's equation is
obvious. The teacher might note to the class that
the flow here is quite analogous to the steady-state
flow in chimneys, or for that matter to the steady-
state flow in a room with a "radiator" at one side.
2. The mathematics shown should convince the
students that unsteady-state flow is much more
CHEMICAL ENGINEERING EDUCATION
The author learned this experiment
from Fr. Pierre Jacobs, S. J. who used it
purely for dramatic effect,
at which he was very good.
difficult to analyze mathematically than steady-
state flow. It might be offered as a general rule
that an experiment which is easy to set up is gen-
erally hard to calculate, and vice-versa.
3. The two mathematical models chosen are
the only two for which simple solutions are pos-
sible. This is typical of real engineering prob-
lems: by choosing limiting cases as mathematical
models, one can bracket the observed behavior;
but seldom is a real process simple enough to be
accurately represented by such a model.
4. This demonstration can also be used for
safety lectures. If we assume that the mixture
which finally exploded was 10 mol % methane,
then a gallon can contained about 0.3 gm of meth-
ane. Its destructive potential is made clear by the
experiment. Annually in the United States several
people kill themselves by taking cutting torches to
"empty" oil drums. At the same mixture ratio, a
55-gallon drum would contain about 16 gm of
methane (about 1/2 ounce). Normally these
drums contain higher molecular weigh vapors, but
the quantity is such that they also pass for
A FEW PRACTICAL CONSIDERATIONS
1. This demonstration will not work outdoors,
or in a very drafty room; the flame blows out.
2. Make the chain strong and keep your hands
away when the can is about to explode. The can
will jump up to one foot off the table, due to the
kinetic energy of the lid.
3. Do not ever assume the flame is out because
you cannot see it in a well-lighted room. In a dark-
ened room you can always see it; the experiment
is worth watching once in a darkened room.
4. The time to explode is a function of the size
of the bottom hole. One can readily determine this
function by making a large bottom hole and cover-
ing it with cardboard orifices held on my masking
tape. If these carboard orifices have various-size
holes in them, one can make a plot of time to ex-
plode vs. hole area, and see that it asymptotically
approaches a value intermediate between that pre-
dicted by the two models as the area becomes
5. Top holes smaller than 1/8" do not work.
They quench the flame, so that it cannot get
through. This might be a good problem to go into
in a graduate class. (See Ref. 1)
6. If the demonstrator wishes to use the timed
explosion dramatically, he should time his can
several times first. Reproducibility should be plus
or minus 3 to 5 seconds in 3 to 10 minutes burning
time. Reproducibility seems to be better for small
bottom holes than large ones.
7. The author once tried to give this demon-
stration to a group of co-workers at the National
Reactor Testing Station, Idaho Falls, Idaho. There
he filled the can as described, removed the mask-
ing tapes, and applied a match. There was no
flame. Another match failed to light a flame. After
several minutes of head-scratching by the author
and mild snickering by the audience, it occurred
to the author to ask if the gas jets in the labora-
tory supplied natural gas. The answer was that
they supplied propane. Thereupon the author ap-
plied a match to the bottom hole, producing a large
flame. The can burned for 1/2 hour, and then went
out without an explosion. The demonstration is
not recommended for use with gases heavier than
1. B. Lewis and G. von Elbe, Combustion, Flames and Ex-
plosions of Gases, Academic Press (1951).
a cross sectional area perpendicular to ft2
C orifice coefficient dimensionless
g acceleration of gravity ft/sec2
p pressure lbf/in2
Ap pressure difference across the top of lbf/in2
Q volume which has flowed into the can ft3
t time sec
V volume of can ft3
v velocity through lid hole ft/sec
Z elevation ft
AZ difference in eelvation of two holes ft
p density lbm/ft3
gas pertains to gas in can
air pertains to air
o original condition, i.e. at start of demonstration
h hole (in lid)
Chemical Kinetics and Reactor Design, A. R.
Cooper and G. V. Jeffreys, Prentice Hall (1972).
Reviewed by Dan Luss, University of Houston.
This is an undergraduate text on the analysis
and design of chemical reactors. The approach is
elementary with emphasis on the underlying con-
cepts and techniques as is most proper for the
first exposure to this subject. The coverage of
several chapters is very good and the chapters on
gas liquid and liquid-liquid reactors contain more
material than most other texts. On the other
hand, several other chapters, such as that on gas
solid reactors, are rather superficial and leave
much to be desired. In several cases, the authors
make errors which indicate lack of knowledge of
the literature. For example, they state on page
167 that for a system of first order reactions, "the
reaction paths will not be straight lines," or that
"the slope condition is sufficient for stability"
even though both statements are not true in gen-
eral. Similarly, the example on p. 133 applies a
numerical solution for a problem for which an
analytical solution was published already in 1962.
Several definitions are rather unclear and that on
catalysis fails to point out its important effect on
selectivity. It is not clear why a modern text
should apply the old height of reactor unit con-
cept for design of packed bed reactors.
The book contains an appropriate number of
suitable examples. It is, however, surprising to
note that several of them have been taken, with
only slight changes in the numerical values, from
other texts without giving any proper credit to
this fact. The example on butane decomposition
is based on a 1939 kinetic investigation. In view
of the many improved and more accurate recent
studies, application of a more modern rate expres-
sion would have been desired. The text contains a
rather large number of disturbing printing
errors. For example, there is a consistent error
in the sign for the rate expression developed on
page 112. The captions for some figures are miss-
ing and in others there is no marking on the
ordinate leaving the reader guessing.
The first chapter treats chemical reactor
thermodynamics and applies them to some im-
portant processes such as methanol, SO, and NH3
synthesis. Most of this material is covered in the
U. S. in the thermodynamic course. The second
chapter discusses the kinetics of chemical re-
actions and the influence of concentration, tem-
perature and changes in volume. This is followed
by a discussion of rate expression for complex
reactions, chain reactions, and heterogeneous
catalysis. Several examples demonstrate tech-
niques for the determination of rate constants
from experimental data.
The third chapter contains a discussion of the
batch and semi batch reactor for both isothermal
and non-isothermal single reactions. A rather
comprehensive chapter on the continuous stirred
tank reactor follows. It includes a discussion of
several optimization problems as well as of the
stability and control. A description of plug flow
and laminar flow tubular reactors is contained in
the next chapter and it covers isothermal and
non-isothermal operation, optimal operating tem-
perature profile and the effect of laminar velocity
The chapter on flow characteristics and their
effects on the performance of continuous reactors
presents an analysis of residence time distribu-
tion and dispersion models and their application
to design for reactions with linear kinetics. A
rather brief chapter is devoted to heterogeneous
reactors. It describes briefly solid gas kinetics,
the effect of diffusion on a first order isothermal
reaction and non-isothermal operation. The last
two chapters discuss gas liquid and liquid-liquid
reactors, and several design examples demon-
strate the effect of the chemical reaction on the
mass transfer rate.
CACHE Computer Problem
(Continued from page 93.)
and TDEL, the assumed temperature change
across the increment.
The subroutine checks if the calculated TB is
greater than the specified maximum temperature,
TMAXO (OR). If so, TB is set equal to TMAXO
and the enthalpy at TMAXO is calculated.
The pressure drop equation for a gas phase
system at high velocities may be simplified to:*
*Hougen, O. A. and K. M. Watson, Chem Process Prin-
ciples III, p. 869, John Wilen & Sons Inc., New York
CHEMICAL ENGINEERING EDUCATION
0.0235/ _W 1.8
AP/AL= -- .-)
P/ 4.8 1000
where AP/AL = pressure drop, psi/foot of pipe
Di = i.d. of tube, inches
W = flow rate of gases, Ibs./hr.
L = viscosity, micropoises
p = density, lb./cu. ft.
This equation may be solved for AP by an itera-
tive method; however, this can be avoided by de-
fining p as:
where nI = average pressure = (PA +
Nt = average number of moles/mole
T = average temperature, (TA +
V = average specific volume
FEED = flow rate, lb. moles/hr.
Substituting  into  and grouping constant
AP = --* AL =
PA PB = CONST 1
(0.5 (PA+ PB))
PA PB2 = 2 CONST 1
PB = VPA2 2. *CONST 1
This is the final working equation for this sub-
routine. A flag, KPOP, is set to 2 if the group
(PA2 2. *CONST 1) < 0.0. In this case, calcu-
lations are stopped, and results to this point are
printed out. The program then stops or if the data
so provide, the tube size is incremented and the
calculations are started anew.
This subroutine reads in the data, checks that
the physical property cards are in the right order
and that there are sufficient cards to agree with
the specified number of components. The data is
then printed out according to the input format.
The documentation accompanying the program
listing contains detailed descriptions of the input
variables, and the data card specifications.
Subroutine VISCON (T)
Calculates viscosity according to equation pro-
posed by Chapman-Cowling, Mathematical Theory
of Non-Uniform Gases, Cambridge Univ. Press,
Cambridge (1952) as given in API Technical
Data Book, p. 11-47.
Fi 0.001989 VMiT
where i r
= viscosity, cp.
= molecular weight
= temperature, R
= Lennard Jones collision diameter,
S, = collision integral = function
e /K = Lennard Jones potential param-
Q v is given by an empirical equation as a function
of (T/E /K) between TK/e of 0.3 and 400 with
an accuracy of 0.15 %.
(See the program listing for the actual equa-
The mixture viscosity is calculated according
A mix = (S Yi i /VMi) (Z yi VMi)
where yi = mole fraction of component i.
This equation was suggested by Herning and
Zipperer, Gas Wasser-foch, 79, 49 (1936) as re-
ported in the API Technical Data Book, p. 11-51.
Values of e /K (in oK) and T are listed in
Reid and Sherwood, and many other sources. The
group T/ (e /K) must be dimensionless.
Hougen, O. A., and K. M. Watson, Chemical Process
Principles, Vol. III, John Wiley and Sons, New York
Smith, J. M., Chemical Engineering Kinetics, 2nd ed.,
pp. 214-223. McGraw-Hill Book Co., New York (1970).
Amer. Petroleum Inst., Technical Data Book-Petroleum
Refining, New York (1966).
Reid, R. C. and T. K. Sherwood, Properties of Gases
and Liquids, 2nd ed., McGraw-Hill Book Co., New York
The API Technical Data Book is a particularly con-
venient source of consistent data and tested methods of
correlation. However, the required physical and thermal
properties of compounds are readily available elsewhere.
What goes up must come down.
The tires ot most etliners lose traction
on a half inch of snow.
That means runways must be kept
free of snow and ice. Or airports must
close and the planes land somewhere
Which causes a lot of inconvenience
for passengers. Strange hotels. Long
lines. Missed relatives. And dreary
hours waiting for better weather.
But this winter the story may be dif-
ferent. Because of Union Carbide's
We discovered a new combination of
liquid chemicals that penetrates a cov-
ering of snow and ice and unglues it
from the runway surface.
so it can easily be pushed away.
It can also be laid down before a
storm to act as an anti-icer.
Last winter it was successfully used
at over 20 busy metropolitan airports.
This year we expect that more airports
will be using UCAR Runway De-Icer.
So now instead of just talking about
the weather, people can do something
CA I ID
THE DISCOVERY COMPANY
For additional information on our activities, write to Union Carbide Corporation, Department of University Relations, 270 Park Avenue, New York, New York 10017. An equal opportunity employer.
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price subject to change without notice
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