Citation
Chemical engineering education

Material Information

Title:
Chemical engineering education
Alternate Title:
CEE
Abbreviated Title:
Chem. eng. educ.
Creator:
American Society for Engineering Education -- Chemical Engineering Division
Place of Publication:
Storrs, Conn
Publisher:
Chemical Engineering Division, American Society for Engineering Education
Publication Date:
Frequency:
Quarterly[1962-]
Annual[ FORMER 1960-1961]
quarterly
regular
Language:
English
Physical Description:
v. : ill. ; 22-28 cm.

Subjects

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

Notes

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

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
01151209 ( OCLC )
70013732 ( LCCN )
0009-2479 ( ISSN )
Classification:
TP165 .C18 ( lcc )
660/.2/071 ( ddc )

UFDC Membership

Aggregations:
Chemical Engineering Documents

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che m ia engineering education








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While this organization encompasses the full
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MBAs with a chemical or engineering
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in many cases a transfer to another
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where appropriate to an Engineering,
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The R&D/Product Development organization
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over 20 divisions, focuses on U.S. consumer
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EDITORIAL AND BUSINESS ADDRESS
Department of Chemical Engineering
University of Florida
Gainesville, Florida 32611
Editor: Ray Fahien (904) 392-0857
Associate Editor: Mack Tyner
Editorial & Business Assistant:
Carole C. Yocum (904) 392-0861
Publications Board and Regional
Advertising Representatives:
Chairman:
Lee C. Eagleton
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Past Chairman:
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LIBRARY REPRESENTATIVE
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Chemical Engineering Education


VOLUME XV


NUMBER 1


WINTER 1981


14 ,4a-~rd ._ectte
A New Look at an Old Fossil: Kinetics of
Coal Processing, D. D. Perlmutter

2 Departments of Chemical Engineering
ChE at Notre Dame, Faculty
8 The Educator
Richard M. Felder, R. W. Rousseau

20 ChE Lecture
Infinite Possibilities for the Finite Element,
Bruce A. Finlayson

26 ChE Laboratory
A Simple Tubular Reactor Experiment,
Robert R. Hudgins, Bertrand Cayrol

30 ChE Curriculum
Impressions of Process Control Education
and Research in the U.S.,
Kurt V. Waller

12 Stirred Pots
Sodales Princetonienses, Rutherford Aris

36 ChE News
Chemical Engineering Symposium at
Carnegie-Mellon, Michael Locke

38 Problems for Teachers
Solution: Prarie Dog Appendix,
R. L. Kabel

40 Classroom
Teaching Market Analysis, J. T. Ryan,
Bret Haugrud

25 Letter to the Editor

37 Positions Available


CHEMICAL ENGINEERING EDUCATION is published quarterly by 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 877,
DeLeon Springs, Florida 32028. Subscription rate U.S., Canada, and Mexico is $15 per
year, $10 per year mailed to members of AIChE and of the ChE Division of ASEE.
Bulk subscription rates to ChE faculty on request. Write for prices on individual
back copies. Copyright 1981 Chemical Engineering Division of American Society
for Engineering Education. The statements and opinions expressed in this periodical
are those of the writers and not necessarily those of the ChE Division of the ASEE
which body assumes no responsibility for them. Defective copies replaced if notified
within 120 days.
The International Organization for Standardization has assigned the code US ISSN
0009-2479 for the identification of this periodical.


WINTER 1981




































The ChE department is located in the new Fitzpatrick Hall of Engineering, completed in July 1979.


[ department


CHE AT NOTE DAME


PREPARED BY THE FACULTY
University of Notre Dame
Notre Dame, IN 46556

T HE CHEMICAL ENGINEERING PROGRAM at Notre
Dame began in 1909. The 1908-9 Bulletin
published in July 1909 noted that "chemical manu-
facture has developed so rapidly and grown so
exacting that there has arisen a demand for men
who not only can create and improve chemical
processes strictly so called, but who can deal with
the problems of construction and maintenance as
far as they are related to chemical industries. To
prepare young men for such work, the course in
Chemical Engineering has been designed." There
were no specific courses in chemical engineering
per se; of the total 167 semester credit hours in
Copyright ChE Division, ASEE, 1981


the curriculum there were various courses in
chemistry (58 cr hrs), mechanical engineering
(30 cr hrs), drawing (15 cr hrs) and shopwork
(14 cr hrs). By today's standards, the university
was small then, with all students numbering 995,
and only 42 faculty of which two were in chemis-
try. (Current total enrollment is 8500 and faculty
number about 700). The first undergraduate "de-
gree of chemical engineer" was awarded in June
1911 at the 67th annual commencement to
Guillermo Patterson, Jr. of New York City. (Inci-
dentally, ours is the only Chemical Engineering
Department in the world which can boast of an
alumnus named Jacques Rousseau. He did not
minor in philosophy.)
It was in the 1920-21 academic year that the
university was reorganized in a form that exists to
this date, with four undergraduate colleges in Arts


CHEMICAL ENGINEERING EDUCATION









The early chemical engineers at Notre Dame were taught chemistry by the
brilliant chemist J. A. Nieuwiand, CSC-who with H. H. Carothers of du Pont is credited
with inventing the first synthetic rubber "neoprene" -and by Knute Rockne, who was on the chemistry
faculty during 1916-22 before moving on fulltime to some other activity.


and Letters, Science, Engineering, and Business
Administration (then Commerce)-each with its
own Dean-and a separate Committee on Gradu-
ate Study, which preceded formal establishment of
the Graduate School in 1932. A department of
Law, now the Law School, was established in 1869.
The heads of various departments were also ap-
pointed in 1920-21, and the first Head of Chemical
Engineering (1920-41) was Henry B. Froning.
Froning was a distinguished chemist who joined
Notre Dame in 1920, and also served as Head of
Chemistry (1920-41) before becoming Dean of
Science (1940-43). The course "Principles of
Chemical Engineering" based on the pioneering
book of the same name by Walker, Lewis and
McAdams (1923) was added to the curriculum in
1921, replacing its predecessor course in Industrial
Chemistry. The early chemical engineers at Notre
Dame were taught chemistry by the brilliant
chemist Rev. Julius A. Nieuwland, CSC-who with
W. H. Carothers of du Pont is credited with in-
venting the first synthetic rubber "neoprene" in
the late 20's-and by Knute Rockne, who was on
the chemistry faculty during 1916-22 before
moving on fulltime to some other activity.
By 1920, there were only 11 graduates of the
department. The present undergraduate degree
"bachelor of science in chemical engineering" was
instituted in 1925. The number of graduates rose
steadily; 59 degrees in the 20's and 156 in the
30's. The headship of the department passed to
Ronald E. Rich in 1941 when Froning left to
CHAIRMEN OF ChE


Henry B. Froning Ronald E. Rich
1920-41 1941-59


devote fulltime as Dean of Science. Rich had
joined the faculty in 1933, and was a Notre Dame
alumnus (B.S. Ch.E. '28, M.S. Chem. '36); he
guided the department until 1959 when Julius T.
Banchero arrived from Michigan as Head. Other
Chemical Engineering faculty during this period
were P. J. Byrne, Jr. (1920-22), H. Wenzke (1922-
39), E. G. Mahin (1926-33), H. Hinton (1929-38),
A. Boyle (1929-39), G. Hennion (1933-40) and
E. J. Wilhelm (1938-71). The Chemical Engineer-
ing Department also moved to a then new building
in 1941.

GRADUATE PROGRAM
P RIOR TO 1945, THERE WERE NO graduate courses
offered within the Chemical Engineering De-
partment. Several graduate courses including lec-
tures and a laboratory in Applied Electrochemis-
try, Advanced Thermodynamics, Advanced Unit
Operations lectures and laboratory, and Advanced
Plant and Equipment Design were initiated in
1945-46 to accommodate the returning WWII
veterans who were anxious to renew their engi-
neering background. Allen S. Smith (Ph.D. Michi-
gan, '40), who joined the Chemical Engineering
faculty in 1946 and remained here till his death
in 1967, was a major factor in this development.
He introduced additional graduate level courses in
1946 on analysis of Distillation and Extraction,
and Applied Chemical Kinetics; these along with a
Heat Transmission course by Rich and Corrosion
of Metals and Alloys offered by Wilhelm, plus
AT NOTRE DAME


Julius T. Banchero Roger A. Schmitz
1959-79 1979-


WINTER 1981








those initiated the previous year provided sufficient
offerings to begin a formal master's program
with required thesis research. Other engineering
departments were also beginning their master's
programs at this time. The very first master of
science in engineering was awarded to a mechani-
cal engineer in June 1947; the first wave of ten
masters of science in Chemical Engineering gradu-
ated in August 1947.
Other than Rich, it was Wilhelm and Smith,
F. L. Benton (1940-56), M. T. Howerton (1949-
56), J. Treacy (1950-56), G. Parravano (1956-
59) and J. P. Kohn (1955-present) who taught
Chemical Engineering at Notre Dame during the
40's and 50's. A total of 212 bachelors degrees in
Chemical Engineering were awarded during the
40's, and 336 in the 50's. By 1959, 77 master's
degrees had also been awarded.
Due to Rich's failing health, J. T. Banchero
was acquired as Head in 1959. He came with
assurance from the administration that a doctoral
program in Chemical Engineering could be
started. By this time, G. S. John (1958-63) had
already joined the faculty, but the major addition
was that of E. W. Thiele-well known for his
pioneering contributions to two major areas of
Chemical Engineering science; the McCabe-
Thiele method for graphical design of distillation
columns for binary separations and the Thiele
modulus in the problem of simultaneous diffusion
and reaction in porous catalyst pellets. Thiele had
just retired after a long and productive research
career with American Oil Company in 1960, and
was persuaded to take on a second career at Notre
Dame. Thiele retired from active teaching in 1970
at age 75, and was awarded an honorary doctor-


Kinetics and reactor studies are conducted in the
Catalysis and Reaction Engineering laboratory.


ate in 1971 in recognition of his contributions to
Chemical Engineering and Notre Dame.
The next addition to the faculty was J. J. Car-
berry in 1961, a former Notre Dame undergradu-
ate, who had been with du Pont after receiving
his Ph.D. at Yale in 1957. Along with Banchero,
Kohn, Smith, Thiele and Wilhelm already present
then, his addition provided a major thrust towards
the growth of the graduate program. A total of
55 Ph.D. degrees in Chemical Engineering have
been awarded since the first one in June 1963 to
Joosup Shim who did his thesis research with Jim
Kohn.
During the sixties and much of the seventies,
undergraduate enrollments were about 30 in each
class, and fulltime graduate students in residence
averaged 22 per year. The graduate program
was considerably strengthened during this period.
Several other faculty members, A. H. P. Skelland
(1963-69), E. D. Crandall (1965-69), T. G. Smith
(1969-75), N. D. Sylvester (1969-73), F. H. Ver-
hoff (1969-74) and K. D. Luks (1967-79) played
a major role in this development. Various new
graduate courses were added to the program.
Three other present faculty members, W. Strieder
(1969), A. Varma (1975) and E. E. Wolf (1975)
also joined during this period.
The department moved to its present location
in the new Fitzpatrick Hall of Engineering in July
1979. Our classroom and laboratory facilities are
now among the best and most modern available
anywhere.

THE PRESENT
SITH THE RETIREMENT and elevation to emeri-
tus status of Julius Banchero in 1979, the de-
partment was very fortunate to attract Roger A.
Schmitz as Keating-Crawford Professor and
Chairman. Schmitz had taught at the University
of Illinois-Urbana since 1962, and is widely known
for his pioneering experimental research on dy-
namics and control of chemical reactors.
As with other Chemical Engineering depart-
ments, we are also experiencing a large growth in
our undergraduate enrollments. We had 30
bachelor's degree graduates in 1978-the average
per year for the preceding twenty years-and 50
in 1979. Our current senior class is 70, and we
have 87 sophomores! Female students were first
admitted to Notre Dame at the undergraduate level
in 1972; our first batch of female bachelor's degree
holders graduated in 1975. Today 22%o of our


CHEMICAL ENGINEERING EDUCATION








undergraduate students are female, which almost
equals the university figures and is significantly
higher than the rest of the College of Engineering.
Three new tenure-track faculty, all fresh
Ph.Ds, have been hired this year; C. F. Ivory and
J. C. Kantor from Princeton, and M. A. McHugh
from Delaware. We have 31 fulltime graduate
students in residence this year-which with the
present faculty strength permits excellent student-
faculty interaction.
CURRICULA

T HE B.S. DEGREE IN CHEMICAL Engineering is a
four year program requiring 128 semester
hours. The 24 hours of liberal arts required, are
well in excess of ECPD requirements. We hope to
increase that number as Notre Dame deems a


Professor James J. Carberry providing valuable
tips on reactor design.
liberal education to be of paramount importance
whatever be the students professional calling. In
addition to the usual Chemical Engineering and
allied chemical and physical sciences, there is an
engineering core including a course in the Fresh-
man year, Introduction to Engineering in which
engineering methodology is taught along with
computer training, including use of FORTRAN.
The remaining core engineering courses are in
probability, engineering mechanics, electrical engi-
neering science, thermodynamics, materials
science, and applied mathematics. Chemical Engi-
neering courses include mass and energy balances,
stagewise operations, transport phenomena, chemi-
cal reaction engineering, thermodynamics, process
design, process modeling and control, transport
processes laboratory and unit operations labora-
tory.
The graduate curriculum includes courses in


advanced thermodynamics, statistical thermo-
dynamics, mathematical methods (2 courses),
transport phenomena (2 courses), advanced re-
action engineering, heterogeneous catalysis, poly-
mer engineering, numerical methods, process
control and modeling, dynamics of reaction pro-
cesses (2 courses), heterogeneous phase equilibria,
and equilibrium state operations. In addition to
the formal courses, there is a Chemical Efigineer-
ing seminar, advanced topics in Chemical Engi-
neering, advanced studies projects, and research
projects leading to M.S. and Ph.D. degrees. There
is a research M.S. degree which requires 24 hours
of course work and a thesis. However most
students elect to pursue the non-research M.S.
degree which requires 30 hours of course work.
Graduate students are encouraged to take gradu-
ate level courses from outside the department,
particularly in chemistry, physics, mathematics,
or engineering. First year graduate students are
required to take a 3 credit special topics course in
which they choose an advisor and devote them-
selves to solution of an original problem.
The Ph.D. degree requires the course work for
the M.S. degree plus additional courses in Chemi-
cal Engineering and science deemed important to
the candidate's research area. The progress of each
Ph.D. student is reviewed periodically by his or
her research committee. Normally the M.S. degree
can be obtained in one calendar year of fulltime
study, while the Ph.D. degree ordinarily takes
from three to four years of fulltime study beyond
the undergraduate degree.


A casual discussion of important issues among
faculty members, from left: Arvind Varma, James Kohn
and William Strieder.


WINTER 1981































Graduate research in the Thermodynamics and Phase
Equilibria laboratory.

FACULTY AND RESEARCH INTERESTS
J. T. Banchero, Professor Emeritus, Ph.D.
University of Michigan, 1950. Co-author of text-
book "Introduction to Chemical Engineering" with
W. L. Badger, McGraw-Hill Company (1955), and
"Unit Operations" with G. G. Brown et al., J. Wiley
Company (1950). Dr. Banchero has interests in
liquid-phase epoxide reactions, design of chemical
reactors, and thermodynamics of solutions.
J. J. Carberry, Professor, Dr. Eng., Yale Uni-
versity, 1957. Author of textbook "Chemical and
Catalytic Reaction Engineering," McGraw-Hill
Book Company (1976), and co-editor of the journal
"Catalysis Reviews." Dr. Carberry has con-
centrated his research interests in chemical re-
action engineering and heterogeneous catalysis,
and in 1976 was recipient of the Wilhelm Award
in Chemical Reaction Engineering (AIChE).
C. F. Ivory, Assistant Professor, Ph.D., Prince-
ton University, 1980. Dr. Ivory has wide-based
interests in transport phenomena and biosepara,
tions.
J. C. Kantor, Assistant Professor, Ph.D. Prince-
ton University, 1980. Dr. Kantor is interested in
process analysis, dynamics and control, and applied
mathematics.
J. P. Kohn, Professor, Ph.D. University of
Kansas, 1955. Dr. Kohn has interests in applied
thermodynamics, heterogeneous phase equilibria,


transport phenomena, and solar energy.
M. A. McHugh, Assistant Professor, Ph.D.
University of Delaware, 1980. Dr. McHugh has
interests in high pressure phase equilibria, super-
critical solvent extraction, and application to coal
utilization.
R. A. Schmitz, Keating-Crawford Professor
and Chairman, Ph.D. University of Minnesota,
1962. Dr. Schmitz has interests in dynamics and
control of chemical reactors; instabilities and
oscillatory phenomena in chemically reacting
systems and in kinetics of gas-liquid reactions. He
won the Colburn Award of AIChE in 1970, and the
Westinghouse Award of ASEE in 1977.
W. C. Strieder, Associate Professor, Ph.D.,
Case Institute of Technology, 1963. Co-author
with Rutherford Aris of the monograph "Varia-
tional Methods Applied to Problems of Diffusion
and Reaction," Springer-Verlag, (1973). Dr.
Strieder has interests in diffusion in porous media,
kinetic theory, surface phenomena, and molecular
theory of transport processes.
A. Varma, Professor, Ph.D., University of
Minnesota, 1972. Dr. Varma has interests in chemi-
cal and catalytic reaction engineering, modeling
and simulation and applied mathematics. Varma,
with Aris, recently co-edited "Mathematical
Understanding of Chemical Engineering Systems
-Selected Papers of Neal R. Amundson," Perga-
mon Press (1980).
E. E. Wolf, Associate Professor, Ph.D., Uni-
versity of California, Berkeley, 1975. Dr. Wolf
has interests in heterogeneous catalysis, chroma-
tographic separations, and chemical reactor engi-
neering. Wolf recently translated Carberry's text
into Spanish.
In sum, the Chemical Engineering program at
Notre Dame has evolved through three stages:

An exclusively undergraduate program, 1909-1946.
An undergraduate and master's program, 1946-1960.
A B.S., M.S., and Ph.D. program since 1960.
With the appointment of Roger Schmitz as
Chairman in 1979, and the addition of three as-
sistant professors in 1980, a fourth stage of ad-
vancement is manifest insofar as our research
strength has been broadened: chemical and
catalytic reaction engineering, heterogeneous
catalysis, applied mathematics, thermodynamics
and phase equilibria, transport phenomena, and
process dynamics and control. We are happily
charged by our administration in the spirit of
Verdi's Falstaff: "Continua!". D


CHEMICAL ENGINEERING EDUCATION








INNOVATION...


Sometimes it's not all it's

cracked upto be.

However, at Union Carbide innovation continues to improve peoples' lives.
Union Carbide pioneered the petrochemicals industry. Today the Corporation's many hun-
dreds of chemicals are used in everything from automobile bumpers to shampoos. A leader in
the field of industrial gases, our cryogenic technology led to the development of the Oxygen
Walker System, which allows mobility for patients with respiratory diseases. Union Carbiders
are working on the frontiers of energy research-from fission to geothermal-at the world
renowned Oak Ridge National Laboratory in Tennessee. Our revolutionary Unipol process
produces polyethylene, the world's most widely used plastic, at one half the cost and one
quarter the energy of standard converting processes.
From sausage casings to miniature power cells, the Union Carbide tradition of innovation
extends beyond research and development activities to our engineering groups, manufactur-
ing operations, and sales forces.
Continued innovation will largely spring from the talents of the engineers and scientists who
join us in the 1980's.


:. NIO


an equal opportunity employer


We invite you to encourage qualified students
to see our representatives on campus-
or write to:
Coordinator, Professional Placement
Union Carbide Corporation
270 Park Avenue
New York, N.Y. 10017








educator




Rilahd M. qelAde



R. W. ROUSSEAU
North Carolina State University
Raleigh, NC 27650

RICH FELDER JOINED the Department of Chemi-
cal Engineering at North Carolina State Uni-
versity in July 1969. He holds the rank of Pro-
fessor and has established himself as a leader in
chemical engineering education. His contributions
in teaching, research and administration reflect
commitment to the profession and engender ap-
preciation and admiration from his colleagues.

TEACHING
RICH TEACHES UNDERGRADUATE courses in Re-
action Kinetics and Reactor Design, Thermo-
dynamics, Chemical Process Systems and Chemi-
cal Process Principles, which is the first course in
chemical engineering. In addition he teaches
graduate courses in Chemical Kinetics, Reactor
Design, Optimization, Process Modeling and
Special Topics in Coal Gasification.
His ability to establish rapport with students
makes him one of the most popular faculty mem-
bers in the Department. Undergraduate and gradu-
ate students have consistently evaluated his
courses as being among the best they have taken.
In recognition of his teaching performance he has
received a School of Engineering Outstanding
Teacher Award and has been named to the NCSU
Academy of Outstanding Teachers.
Students particularly compliment the clarity
with which Rich can present a lecture. Course
evaluation forms describe him as "always pre-
pared," "clear and easy to follow" and a "great
teacher." More than any other faculty member,


he is responsible for glowing compliments con-
sistently used by students to describe the intro-
ductory course in chemical engineering. The de-
manding nature of this course makes such atti-
tudes remarkable.
Rich has a classroom style centered about what
might be called a present-and-probe approach.
The "present" part always consists of a routine
in which the class is told first what is going to
be covered and why it is important. The concept
is subsequently presented clearly and concisely
and, finally, an example is used to illustrate its
application to a practical problem. The "probe"
part actually occurs during his presentation; he
sprinkles an oversupply of "okay"? and other
rhetorical questions throughout the lecture, some-
how sensing which points have been grasped by
students and which need additional coverage.


His ability to establish rapport with students makes him one of the most popular faculty
members in the Department In recognition of his teaching performance he has received a School
of Engineering Outstanding Teacher Award and has been named to the
NCSU Academy of Outstanding Teachers.

Copyright ChE Division, ASEE, 1981
Copyr-ight ChE Division, ASEE, 1981


CHEMICAL ENGINEERING EDUCATION










The reorganization of the
Ph.D. qualifying exam is one of Rich's
most significant administrative accomplishments.


His work with students outside the classroom
is also exemplary, both in his official capacity as
Graduate Administrator and in his unofficial role
of confidant and consultant. His concern for the
development of the complete person fosters state-
ments on student evaluations like "he is always
willing to discuss a problem, even if it is a personal
one."
In recent years Rich has given numerous in-
dustrial short courses in Basic Principles of
Chemical Engineering, Process Maximization,
Polymer Reactor Technology and Separation Pro-
cess Technology. In participant critiques of these
courses he draws raves for his clarity, style and
quantity of material covered.
Finally, no description of Rich's teaching
would be complete without mentioning his work
with countless elementary and junior high school
students. It is not unusual to see him charging
out of his class on chemical kinetics and into a
meeting with a third grade class from one of
Raleigh's magnet schools for extraordinarily
gifted and talented kids. He will have volunteered
to discuss something like coal gasification with
these children, and will do so with the same clarity
and enthusiasm he has for his senior class in re-
actor design. It is believed that he could, given a
little notice, walk into a class on almost any subject
and present a lecture that would result in students
learning the material he presented.

ADMINISTRATOR

A S GRADUATE ADMINISTRATOR, Rich coordinates
all graduate student activities in the Depart-
ment, including applications for admission, ad-
mission of new students, selection of a research
advisor and graduate committee, selection of a
minor, administration of the Ph.D. qualifying
examination and scheduling of final oral examina-
tions. Graduate students recognize him as their
most important contact, outside of their thesis
supervisor, during their stay at North Carolina
State University. The reorganization of the Ph.D.
qualifying exam is one of Rich's most significant
administrative accomplishments. It has been given
in its present format for almost 10 years without
significant complaint.


RESEARCHER
RICH'S RESEARCH IS BASED on his interests in
modeling chemical processes and the effects
of chemical processing on the environment. These
broad concerns have led to a variety of research
programs, including radioisotope applications to
process analysis, photochemical reactions, use of
polymeric interfaces for stack sampling, modeling
of electrostatic precipitators and, most recently,
environmental effects associated with coal gasifica-
tion. He has published forty-five articles in
refereed journals as a result of research in these
fields and he was recently awarded a patent for
the novel use of polymeric interfaces in stack gas
monitoring.
The Environmental Protection Agency sup-
ports his research on the development of a collec-
tion tube for use as an interface in stack sampling,
modeling the performance of electrostatic precipi-
tators and the environmental effects of coal gasi-
fication. His research on the evaluation of trace
metals and sulfur gases from coal is supported
by the Department of Energy. The NCSU Faculty


Professor Felder giving impromptu lecture on
CSTR's.
Research and Professional Development Fund has
supported the construction of a batch photoreactor,
measurement of beta spectra emitted by a slab
source, and dynamic simulation of a pulp chlorina-
tion tower.
The research efforts described above have been
marked by the same thoroughness and quality as
Rich's teaching. He was given the 1974 NCSU
Sigma Xi Research Award for superior ac-
complishments in the field of scientific research.
Rich has unselfishly contributed to other re-
search programs in the Department. His library
of computer programs is extensive and he makes


WINTER 1981























Felder with colleagues, Hal Hopfenberg (Depart-
ment Head) and Ron Rousseau.
them available to colleagues and students. Further-
more, he can generally be counted on to have the
latest information on analytical instrumentation.
When the coal gasification research project got
underway, there was a need for someone to learn
capabilities of various instruments available for
analyses of coal and char, waste water and gases
found in the gasification/gas cleaning pilot plant.
Rich accepted the responsibility and maintains an
expertise in the use of an array of instruments,
including atomic absorption spectrometer, ion
chromatograph, gas chromatographs, sulfur ana-
lyzer, nitrogen analyzer, etc.
Despite the enthusiasm Rich has for these re-
search efforts, he never loses sight of the proper
relationship between university research and
graduate students. He is concerned with their total
professional and personal development, as well as
their accomplishment of short range goals like ac-
cumulating data points and, ultimately, a degree.
None of Rich's students has the slightest re-
luctance to take their "problem of the day" to
him. His mortality and temper have been ob-
served, however, when a student has just broken
the third calibrated rotameter in a single day.

WRITER

N O DESCRIPTION OF RICH FIELDER would be
complete without mentioning his enjoyment of


the written word. (That's not to say he doesn't
like the spoken one, too.)
Although the 45 publications mentioned earlier
and the textbook Elementary Principles of Chemi-
cal Processes may be indicative of the quality of
Rich's writings, they are not true indicators of the
quantity. He is prolific. It is common knowledge
among graduate students that any question may
result in being given a handout specially prepared
for such occasions. A look around his office will
reveal stacks of documents he has written on
everything from "What is Chemical Engineering"
to "Radiotracer Applicators in System Analysis."
Writing a paper or a book with him can be both
excrutiatingly painful and exhilirating. It can be
painful because Rich's search for just the right
word or phrase can result in numerous rewritings.
None of his students or colleagues can escape his
trusty scissors, tape and stapler. His saving grace
in this regard is that he is just as likely as not to
rewrite one of his own drafts. And the exhilirating
part is that the document always sounds and reads
superbly.
It seems only fitting that I say a few words
about Rich's unique contribution to our joint
authorship of Elementary Principles of Chemical
Processes. This textbook was published in 1978
and has been adopted for use at approximately 80
Departments of Chemical Engineering in the
United States, several European universities, and
will be translated into Spanish and Chinese. Two
characteristics of the book which have been a
factor in its widespread adoption are its pedogogi-
cal approach and style of writing. Quoting from
a review of the book that appears in the AIChE
Journal, 25, 382 (1979), "... the style and level of
presentation of the content is excellent, and the
subject matter represents the ideal body of
knowledge which should be imparted to students
in the first year of a chemical engineering curricu-
lum." These features are primarily the result of
Rich Felder's insight into what students need to
facilitate learning and his very special gift with
the written word. In addition, the exploits of
Sebastian Goniff, Johann Sebastian Farblunget,


It is not unusual to see him charging out of his class on chemical kinetics
and into a meeting with a third grade class from one of Raleigh's magnet schools for
extraordinarily gifted and talented kids. He will have volunteered to discuss something
like coal gasification with these children and will do so with the same clarity
and enthusiasm he has for his senior class in reactor design.


CHEMICAL ENGINEERING EDUCATION


I -








Edd Seddera and other seedy but colorful charac-
ters sprinkled throughout the text, are illustrations
of his sense of humor and his ability to couple wit
with the illustration of chemical engineering
principles.

LIFE AND TIMES

A AFTER A CHILDHOOD IN Manhattan, Queens,
Buffalo and North Miami, Rich settled down
to make good grades and enter the City College of
New York to study chemical engineering. Why
Chemical Engineering? (a) Everyone who knew
anything in 1957 was going into engineering and
(b) he was intrigued by the idea of mixing color-
less liquids to produce a bright orange (his favor-
ite color and the reason for his subsequent


Felder posing (i.e. acting like he's doing something)
in front of coal gasification/gas cleaning pilot plant
control panel.

matriculation at Princeton) fluid. Why CCNY?
He didn't like the letter MIT wrote to him, and
think of all the carfare he saved.
He graduated from City College No. 2 in engi-
neering and entered graduate school at Princeton.
His interests became chemical physics, Barbara
Cowl (whom he married), and hopeless liberal
causes, not necessarily in that order. He was
Morton Kostin's first graduate student, but he
claims his major achievement was a catch in a
softball game for which he is still revered by old
timers on the Princeton faculty like Ernie Johnson
and Bob Axtmann. He also tried Electrical Engi-
neering at Princeton but, on falling through the
ceiling at 224B Halsey Street while installing air
conditioner wiring, he decided his future remained
in Chemical Engineering.


He enjoys music ranging
from Mozart to McCartney and is
especially fond of playing classical guitar,
but he likes to play in groups so that
his mistakes are less obvious ... he also
memorizes Gilbert and Sullivan patter
songs, believing that someday
they will come in handy.


Following his Ph.D., he spent a year at Har-
well, England as a NATO postdoctoral Fellow,
and two years at Brookhaven National Laboratory.
His research interests had now shifted to photo-
reactor design and analysis, and mixing effects
in reactors. Letting it become known that he was
interested in an academic career, some enlightened
soul recommended he interview for a vacant posi-
tion at North Carolina State University. With his
interest in United States geography confined to the
blighted land mass east of the Hudson River and
the hedonistic environment surrounding the San
Francisco Bay, he is reported to have uttered the
famous quote for which many New Yorkers later
claimed credit: "North Carolina??? Get serious,
wouldja!!". Nevertheless, being basically curious,
he came, he saw, he stayed. Why? He fell in love
with the school, faculty, and (you guessed it)
North Carolina. He claims never to have regretted
the decision, except when he finds himself almost
enjoying eating grits with red eye gravy.
He maintains his passion for hopeless liberal
causes, bialys with whipped cream cheese and
Chivers Olde English Marmalade. He enjoys music
ranging from Mozart to McCartney and is es-
pecially fond of playing classical guitar, but he
likes to play in groups so that his mistakes are less
obvious. He is often awed by our friend and
colleague Jim Ferrell, who makes and plays classi-
cal guitars. You're not going to believe this, but
he also memorizes Gilbert and Sullivan patter
songs, believing that some day they will come in
handy.
Rich is also the devoted father of Kenneth,
Elena and Gary, ages 14, 12 and 10. Despite his
tireless professional efforts, he always seems to
have enough energy left over to spend time with
his children. One of his passions that he indulges
in frequently is being beaten in chess by these
budding Bobby Fishers. As a father, he exhibits
a degree of patience and concern which reflects his
feelings about children and, in fact, all people. EI


WINTER 1981









stirred pots


UNIVERSITATIS MINNESOTENSIS
COLLEGIUM FABRORUM CHYMICORUM
SODALES PRINCETONIENSES,
NUNC ANNUM EORUM QUINQUAGESIMUM
FELICITER AGENTS,
GRATULATUR,
MAGNO CUM GAUDIO,
GRATUITO CUM CONSILIO,
VENIAMQUE W. S. GILBERT POSCENS

EDITOR'S NOTE: We are grateful to Prof. John Seinfeld
(California Institute of Technology) for bringing our
attention to the following poem, written by Prof. Ruther-
ford Aris of the University of Minnesota to congratulate
Princeton University's Chemical Engineering Department
on their fiftieth anniversary.

When you're taking a whack,
in your orange & black,
at a problem defying solution
In kinetics or flow,
or the ways that bugs grow,
or just how to get rid of pollution.
When you're wracking your brain
& you cannot obtain
a result that fulfills your intentions
Remember that Chem.E.s
do nothing by semis,*
and always get rid of dimensions
Recollect that p'raps Schmidt's
is the number that fits
and that Peclet is Reynolds times Prandtl.
Just remember your D's,
it'll come out with ease
when it's wrapped up in Damkdhler's mantel.
If you wish you could borrow
relief from your sorrow,
the Ohnesorge number we'll mention,
Into Reynolds you shoot
the good Weber's square root-
it accounts for the surface's tension.
For tubes in the boiler,
use t'number of Euler
and for drag use the factor of Fanning,
Which in matters of fiction
was used for the friction
twixtt Newman and Cardinal Manning.
But it's really quite rude
to rhyme Froude with St. Jude
or to mess up a grave patronymic,


To dress up in gingham
the number of Bingham,
or regard Boussinesq's as a gimmick,
While to think that Biot
has to do with the glow
that both heat and hard work often foster,
Or that Deborah's song
has the permanent pong
of an overly ripe double Gloucester.
To madden a Hatta
or exchange for the latter
the group that's been named Svant Arrhenius,
To mock at the balding
of Sherwood or Spalding;
these are all of 'em crimes hyperhein (i)ous.
If none of these fit,
just reflect for a bit,
devise one of your own-
it's a sine qua non-
for there's many a name
that has brought Princeton fame.
For size of reactor,
use great Wilhelm's factor;
for hard computation,
'tis Leon's equation;
and if that don't fit well
the number of Whitwell.
If you've pulled a slight boner,
be absolved by Dick Toner;
your problem's all garbled?
Why, Dean Elgin's not marbled;
While, if biking's your goal,
use the Johnson Control.
You've got Schowalter (Bill),
and there's Dudley Saville,
Andres, Russel and Hall,
Prud'homme, Ollis et al.**,
for from such you can scoop
a dimensionless group
and you'll out of your fix be
with some help from Ms. Bixby.
But away cerebration.
Now 'tis your celebration
and we all think it's nifty
that you flourish at 50.
So we wish you good cheer
for full many a year.

RUTHERFORD ARIS


*Except Centenaries, of course.
**With due apologies to those not mentioned.


CHEMICAL ENGINEERING EDUCATION







Chevron


Chevron Oil Field


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PhD Chemical Engineers e
For Research And Development
In Enhanced Oil Recovery


Chevron's laboratory in La Habra, California is
engaged in research directed toward Increased
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business of recovering petroleum from known
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discovered and in quantities large enough to
make a real difference in the United States'
domestic energy supply. That is, if we can find
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The research, the development and the field
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Our chemical engineers are also
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If you want to learn more about
research in the more complex
applications of chemical engineering,
send your resume to:

J.C. Benjamin
Chevron Oil Field Research Company
P.O. Box 446
La Habra, CA. 90631


Iff~


-
- -


I


~~g "' 0


Z2


--


b


;1P, ZJ0 C/7










4wawd 2ecW e


A NEW LOOK AT AN OLD FOSSIL:

KINETICS OF COAL PROCESSING


The 1979 ASEE ChE Division Lecturer was
Dr. Daniel Perlmutter of the University of
Pennsylvania. The 3M Company supports this
annual award.
Dan Perlmutter earned his Bachelor's Degree
(Magna Cum Laude) from New York Univ. and
his Doctorate in ChE from Yale Univ. From 1955
to 1958 he worked for the Exxon (then Esso)
Standard Oil Company. His academic career
began in 1958 at the U. of Illinois, Urbana, and
moved to the U. of Pennsylvania in 1964. Follow-
ing a reorganization of the College of Engineer-
ing and Applied Science, he became the first Chair-
man of the department of Chemical and Biochemi-
cal Engineering, a position he held from 1972 to
1977. He has been a visiting Professor at Harvard
U., the U. of Manchester, the U. of Zagreb, and
the Hebrew U. of Jerusalem, in the capacity of a
Fulbright Professor in England and Yugoslavia
and as a Guggenheim Fellow in Cambridge.
He has developed new course materials in
chemical reactor control, optimization, and
stability problems. His textbook, Introduction to
Chemical Process Control, was one of the first
available in its field, and was widely adopted in
the U.S. and abroad. His monograph on Stability
of Chemical Reactors provided a unified view of
a wide range of questions by combining some
original work with an integrated survey of ma-
terial only available in scattered journal articles.
His most recent research has been on the kinetics
of gas-solid reactions, prompted especially by
their connections with energy-related problems in
coal drying, oxidation, and gasification, as well
as reversible storage in the form of heat of re-
action.


D. D. PERLMUTTER
University of Pennsylvania
Philadelphia, PA 19104

T HE WIDELY PROCLAIMED energy crisis that so
profoundly affects world affairs should be
understood to be caused not by a lack of fossil fuel
resources, as much as by a shortage of fuel in the
highly desirable gaseous and liquid forms. It is
accepted in all quarters that proved coal reserves
are ample to supply anticipated world energy
needs for at least several hundred years and
further that no geographic monopoly is possible,
since the deposits are very widely distributed over
virtually every continent. It is evident in this
context that the technology of the so-called gasi-
fication and liquefaction processes are central to
handling the crisis: techniques for coal conver-
sion are being sought that will supply transporta-
tion, space heating, chemical feedstocks, and in-
dustrial needs at prices comparable to petroleum
sources. The objective moves closer as OPEC
prices continue to rise.
It is convenient to think of gasification as com-
posed of three steps: (i) coal pretreatment, (ii)
pyrolysis, and (iii) char reaction, even though a
particular process may circumvent one or more
of these, or may be designed to accomplish several
objectives in a single reactor. The step-wise view-

Copyright ChE Division, ASEE, 1981


CHEMICAL ENGINEERING EDUCATION









point leads most smoothly into an examination of
the appropriate chemical and physical properties
of coal, and of the changes that need to be sought
and monitored.

PRETREATMENT
T HE PRIMARY MOTIVATION for a study of coal
pretreatment is a practical processing diffi-
culty. When common bituminous coals are sub-
jected to high temperature gasification conditions
they tend to soften and swell, and can plug re-
actors and transport lines before ultimately re-
solidifying as a porous char or coke. This process
is commonly referred to as caking; it must be con-
trolled if the solid fuel is to be successfully gasi-
fied. A mild oxidative pretreatment is commonly
used to reduce or eliminate this coal caking pro-
pensity, providing two steps in one: drying to re-


7000


360 400 440 480 020 640
TEST TEMPERATURE. "C (AT 2C/MIN. RISE)
FIGURE 1. Caking test results for feed coal samples.

move naturally occurring water on the coal
surfaces, and the chemical oxidation.
Many laboratory test methods have been used
to study the plastic properties of coals, all em-
pirical in nature and devised to characterize the
plastic behavior of coal by means of numerical
indices. Comprehensive summaries and reviews of
the methods have been given by Brewer (1945)
and Loison et al. (1963). One common test is the
Gas Flow test (Foxwell, 1924; Coffman and
Layng, 1927, 1928), chosen for its simplicity in
apparatus design and operation and for its close
resemblance to the caking of coal in a packed bed


... techniques for coal
conversion are being sought that
will supply transportation, space heating,
chemical feedstocks, and industrial
needs at prices comparable
to petroleum sources.


reactor. In this test, a sample of the coal is heated
at a constant rate of temperature rise (2C/min)
inside a tube with a constant flow of nitrogen
through the coal sample. The differential pressure
drop across the sample is monitored, as the sample
goes through its plastic range. Pressure drop vs.
temperature readings are taken as data, as shown
in Figure 1. After the oxidizing pretreatment the
same test shows a sharp reduction in pressure
drop as in Figure 2, reflecting a lesser degree of
softening, swelling, and "caking."
Changes recorded as mechanical properties
need to be matched to chemical effects, if one is
to understand the details of the preoxidation. For
this purpose, a HVA bituminous coal was oxidized
in a packed-bed reactor with a once-through mix-
ture of N2 and 0,, monitored by analyzing the
composition of the feed and product gases with a
dual-column Gas Chromatograph.
Typical results on overall reaction rates are
shown in Figures 3 to 7, emphasizing the effects of
flow rate, particle size, oxygen concentration, pres-
sure, and temperature, respectively. In addition,
the chromatographic analysis run on each sample
of reactor effluent provided a record of carbon
dioxide and carbon monoxide production to match


s0 o400 440 480 520 540
TEST TEMPERATURE, *C (AT 2- C/MIN. RISE)
FIGURE 2. Caking test results for -18 to +50 mesh
oxidized coal samples.


WINTER 1981










the rates of oxidation. Cross plots are presented
as Figures 8 and 9 to illustrate the linearity and
to demonstrate that the correlations for the
various coals do indeed persist as flow rate,
particle size, and conversion vary. Evidently, the
two carbonic gases are formed in a constant ratio,
presumably by the same mechanism.
Correlation of all these findings by means of a
comprehensive argument requires formulation of
a model that includes several steps. The two car-
bonic gases appear to form together by a direct
burnoff reaction. Simultaneously, oxygen is ad-
sorbed by the coal to form any of a series of oxy-


0 2 4 6
REACTION TIME, HRS.

FIGURE 3. Effect of feed gas flow rate
rate.


on 0, reaction


functional groups, and hydrogen is removed in a
direct water formation reaction. Superimposed on
this complex chemistry are possible transport
limitations outside and inside the coal particles.
Quantitative tests have been used to demonstrate
consistency between the data and such models
(Kam et al., 1976; Karsner and Perlmutter,
1980).
Turning to more immediately practical results,
it is of interest to relate oxidation rates to the
geologic history of various coals. In Figure 10
comparable rates are presented as a function of

16


S 0 22 -18 +50
S/ A 21 -14 +18
4
016



4
o 16'8 E]23 -6 +14



I

c 14 -






z
w


0




6


0 2 4 6 a
REACTION TIME, HRS.
FIGURE 4. Effect of particle size on 02 reaction rate.
50
T 225 C
RUN VOL.% 0O
0 47 286
40 -
< 44 20-2
S45 13.9

S[] 46 9-7
2 30 C)




s0
I-
w

o o

o



0 2 4 6 8
REACTION TIME, HRS.
FIGURE 5. Effect of feed 02 concentration on oxygen
reaction rate.


CHEMICAL ENGINEERING EDUCATION



































REACTION TIME, HRS.
FIGURE 6. Effect of pressure on oxgen reaction rate.


S 2 4 6 8
REACTION TIME, HRS.
FIGURE 7. Effect of temperature on oxygen reaction
rate.


carbon content, a commonly used index of a coal's
rank. As shown, by the duplicate runs, the cross-
hatched band is primarily a reflection of vari-
ability among coals and only in minor part caused
by experimental scatter. A balanced evaluation of
pretreatment must also consider the economic
losses that accompany any reduction in heating
values. The data show a strong correlation with
the carbon content of a sample. Regardless of
particle size, the heating value of a material
changed upon oxidation primarily as the carbon
changed for a wide range of coals of different
types. There is also a suggestion in the data that


Regardless of particle size, the
heating value of a material changed
upon oxidation primarily as the carbon
changed for a wide range of
coals of different types.


4.0


3.0 -


/






/A


Run No. Mesh Size
o 10A -6+16
o 11 A -16+18
, 12 A -18+50
* 23W -6 +16
* 22 W -16+18


1.0 /


//
//


CO Production Rate, g/KG Coal/Hour
FIGURE 8. Relative carbon dioxide and carbon
monoxide production rates. Coal: MV
bituminous, PSOC 135.


WINTER 1981


2.0 r-










generalizations regarding the fixation of oxygen
that occurred for all the various bituminous coals
do not apply to the lignite (PSOC 87) and the
anthracite (PSOC 80) coals.

CHAR REACTION

T URNING ATTENTION TO the downstream side of
a coal gasification process, models are needed
to describe kinetics of the several gas-solid re-


20 -


10 l-


CO Production Rate, g/KG Coal/Hour
FIGURE 9. Relative carbon dioxide and carbon
monoxide production rates. Coal: HVC
bituminous, PSOC 190.

actions involving porous chars. The experimental
reports of Hashimoto et al. (1979) provide a good
point of departure, since any model to be de-
veloped must be consistent with the features of re-
action such as are presented in Figure 11.
Above all a viable model must permit the de-
velopment of a maximum in rate (or reactive
surface) as a function of conversion. A promising


KEY

RUN PSOC NO.
0 8W 4
A12W 197
V27W 127
024W 135
K ---
V 9A 127
*12A 135


0 I I I I I
65 70 75 80 85 90
Carbon Content, Wt. :' (ultimate)
FIGURE 10. Effect of coal carbon content on initial
oxidation rate for -18 + 50 mesh particles
at 2250C, 100 SCCM.

candidate in this direction has been developed by
Bhatia and Perlmutter (1980), who considered
the isothermal chemical reaction of particles of
the solid B with a fluid A according to the stoi-
chiometry

aA(g) + bB(s) -> pP(g) + qQ(s) (1)

The reaction is initiated on the surfaces of pores
in the solid B. As further reaction occurs, a layer
of product Q is formed around each pore, which
separates the growing reaction surface of the
solid B from the fluid reactant A within the pores.

Continued on page 49.



6001 CS 850 t
1:0 c. \ "C
IIC(slom)
,-, f tx4260mesh
E 40 -0 14.16mesh
S 8.9 2h \ \
300 *

200



O0 02 0' 06 01 10
Burnof. Xc [-3
FIGURE 11. Effect of char conversion on surface area,
after Hashimoto et al. (1979).


CHEMICAL ENGINEERING EDUCATION


I i









Monsanto Drive.
It takes you a very long way.


VK'I h 40 q
t4


This sign marks the
into our International
St. Louis.


road that leads
Headquarters in


These words, "Monsanto Drive"
have another and more significant mean-
ing at Monsanto. It's a way of expressing
the special qualities of Monsanto people,
who have the will to meet challenges
head-on-to accomplish and succeed.
We offer bright and energetic people
with this drive the opportunity to help
solve some of the world's major problems
concerning food, energy, the environment
and others.
Challenging assignments exist for
engineers, scientists, accountants and


marketing majors at locations throughout
the U.S.
We offer you opportunities, training
and career paths that are geared for
upward mobility. If you are a person
who has set high goals and has an
achievement record, and who wants to
advance and succeed, be sure to talk
with the Monsanto representative when
he visits your campus or write to:
Buck Fetters, University Relations and
Professional Employment Director,
Monsanto Company, 800 North Lind-
bergh, St. Louis, MO 63166.

Monsanto
An equal opportunity employer


WINTER 1981


Aq~r, 7W,











lecture


INFINITE POSSIBILITIES FOR THE FINITE ELEMENT*


BRUCE A. FINLAYSON
University of Washington
Seattle, WA 98195

F INITE ELEMENT METHODS are being used in-
creasingly for engineering studies of struc-
tures, heat transfer, fluid flows, design of dams
and flow of water in aquifers. Because of this
widespread use the well-educated engineer should
have some experience applying the finite element
method.
Finite elements are most effective for solving
two-dimensional problems on irregular domains,
but their use is sometimes warranted in one-
dimensional problems. Chemical engineers have
used finite element methods in 1-D, without calling
it a finite element method. Sometimes finite ele-
ments are not needed, and an analyst should know
when to use finite elements and when not. This


Bruce Finlayson has extensive experience modelling chemical
engineering systems. He is well known for developing the orthogonal
collocation method as an efficient computational tool for modelling
chemical reactors with both radial and axial dispersion and monolith,
wall catalyzed reactors. More recently he is known for work in finite
element methods solving heat transfer and flow problems, particularly
viscoelastic polymeric fluids and flow in porous media. He is the
author of two books: The Method of Weighted Residuals and Varia-
tional Principles, Academic Press, 1972, and Non-Linear Analysis in
Chemical Engineering, McGraw-Hill, 1980.

*This paper was presented at the ASEE meeting in
Baton Rouge, LA, on June 24, 1979.


(
J, x / J
'7/7,.., r1771/1, 1/ 77 / 77/71'//.'/ / V- 7/-

FIGURE 1. Flow Past a Flat Plate.

distinction is less important for the practicing
engineer who may use an available program.

ONE-DIMENSIONAL PROBLEMS

P PROBABLY THE OLDEST USE of finite element
methods is for flow past a flat plate (see
Figure 1). In the integral method (1, p. 142) we
divide the region of space into two elements: a
small element near the plate and a larger element
away from the plate. We represent the velocity in
these two regions by two functions:
outer element: u = U.
inner element: u = U~. (71),
S= y / 8(x)
The boundary layer thickness is 8(x). It is this
division of the region into two, with expansions of
velocity in each region, that makes this a finite
element method. We must still determine 4 (7)
and 8(x).
These expansions are substituted into the
boundary-layer equations (see 1, p.142; 2, 4.2 for
the details) and the result is called a residual. We
would like the residual to be zero since then the
differential equation is satisfied. That may not be
possible, particularly if the expansions for 4)())
or 8(x) are simple. In the integral method we
integrate the differential equation over the
domain-in this case over the inner element-and
set the result to zero, thereby making the
differential equation zero "on the average." The
result is an equation for the boundary layer
thickness.
Copyright ChE Division, ASEE. 1981


CHEMICAL ENGINEERING EDUCATION









(B A) 8 -- C (1)
dx y.
The numbers A, B, and C can be calculated once
)(7) is known, and Eq. (1) is easily solved.
The expansion for 4 (q) is made as simple as
possible: a polynomial. There are certain condi-
tions it must satisfy: The velocity should be zero
at y = 0 (on the wall) or at ) = 0: ((0) = 0.
The velocity should match at the node between
the inner and outer element, which occurs at y =
8(x) or -q = 1: 0 (1) = 1. Likewise it is con-
venient to have the slopes match at i- = 1: (1)
= 0. Applying these conditions to a quadratic
function, 4 = a + bq + ci2, gives the expansion
for ()7).
4 = 2r7 q2
Ref. (1) uses

2 2
S- 2. 2 -<(2)

which is derived by using a cubic polynomial and
adding the condition )" (0) = 0, which is obtained
by making the differential equation be satisfied at
the point 71 = 0 on the wall. Eq. (2) gives a
slightly better result. With this function we have
a representation for the velocity field in the whole
domain. By satisfying the equation "on the aver-
age" we are using the integral method, and by
representing the velocity by piecewise polynomials
in different regions we are using finite elements.
The finite elements are necessary because of the
sharp changes of velocity near the wall.
For the next example we turn to diffusion and
reaction in a spherical catalyst pellet. Consider the
reaction of carbon monoxide with oxygen in an
alumina catalyst coated with small amounts of
platinum. The rate of reaction has been measured
to be
kc*
Rate =
(1 + Kac*)2
where k and Ka depend on temperature (see 3,
p. 461). The equations to be solved are


1 d dc
r2 dr dr


R2 k(T)c
D, (1 + ac)2


de
Bim(c-l) atr=l

where we have written the non-dimensional r =
r' / R, with r' the dimensional radial position in
the catalyst and R the radius. c = c* '/ co, where
co is the external concentration of CO, taken here


Finite elements are most
effective for solving two-dimensional
problems on irregular domains, but their
use is sometimes warranted in
one-dimensional problems.

as 4%, and a = Kaco = 5 at 58C. For purposes
of illustration we solve this for Bim = 20 and a
variety of R2k (T) / De = 42, the Thiele modulus
squared. A quantity of interest is the average rate
of reaction, compared to the rate of reaction if
there were no diffusion limitation. The effective-
ness factor is
1 1
S Rate (c(r))r2 dr / Rate (c = 1)r dr
0 0
Now we know the concentration profile depends
strongly on 02, which is the ratio of diffusion
time to reaction time. If the diffusion time is very
small (i.e. diffusion is very rapid) then the con-
centration profile is as indicated in Figure 2a.
Under these conditions the concentration can be
easily represented by a polynomial in r, and finite
elements are not indicated. By contrast, if 02 is
large then the reactants are rapidly depleted in
the pellet, and concentration profiles such as Fig.
(2b) are possible. Then finite elements are indi-
cated-express the solution as one function in the
inner core and another in the outer boundary
layer.
For low 0 we can use the orthogonal collocation
method to solve the problem. The concentration is
expanded in a quadratic polynomial.
c(r) = c2+ a(l-r2)
Higher order polynomials are possible but are not
needed except for high accuracy. We find it more
convenient to solve in terms of c2 = c(1) and c, =
c (rj), where r, is the collocation point = 0.65465.
The orthogonal collocation equations are given
here (for details see 2, 5.3 and 4).


sk,141 d


FIGURE 2. Concentration in Catalyst Pellet.


WINTER 1981









Bilc + B12c2 = R2k(T)cl /1 De(1 + ac,

-(A21 1 + A22c2) = Bi(C2-1)
7 = 3(wR (cl) + wR(c2)) / R(c = 1)
Bil = -B12 = -10.5, A21 = -A22 = -3.5
wt = 0.2333, w2 = 0.1, rl = 0.65465
T, = 1 + 8 + p(1 8)c, 3c
8 = Bi / Bi = kke / (hpDe)
/ = (-AHa) CoDe / keTo)
The equation for Ti is exact. (4, pp. 96-97). 1
we solve for / = 0 isothermall case) and Bi,
20. This solution is not valid for any )2, but i
a good approximation provided c(r = 0)
(see Figure 2a). Since

ce = c2 + a(1-r 2)

a = C C2
a -
1 r2

the approximation is valid for
c2 + a> 0
or c1 r12c2 > 0.
The 0 curve is shown in Figure 3 and is
distinguishable from the exact solution w
b < 10. This curve is easily calculated, witl
iteration, simply by choosing a c2, finding c, f
Eq. (4), T1 from (5) (if non-isothermal),
R2k(T,) / ci from (3), with a evaluated at'
For large 0 we must use the Patern
Cresswell (5) approach using finite elements
the inner element of Figure 2b we take c = 0
we let the inner element have length b < 1. In
outer element we use the trial function


4(
FIGURE 3. Effectiveness Factor Thiele Modulus for
Carbon Monoxide Reaction, Bim = 20,
a = 5. ---exact, approximate.


)2
(3) The advantage of the finite
(4) element method is that the elements
can easily be deformed, small elements
can be used in important regions, and
irregular domains are easily handled.


(5) T 100
h 3 h=3
To= To= O


lere =3 h -s
To=O To = 0
n =
it is (b) DOMAIN WITH SYMMETRY
ST= 100
- lh =3


h 3 h = q=0
T= 100
(a)HEAT TRANSFER IN A STRUT
q=O
(c) BOUNDARY CONDITIONS
FIGURE 4. Heat Transfer Problem.

c = u23,,
u= (r-b) / (-b)
which satisfies c = 0 and dc/du = 0 at the node
between elements. The collocation equations are
now (see 4), for planar geometry,
1
1-b2 (B21 + B22C2 + B23c3)

= R k(T,)c2 / (De(1 + aC2)2) (6)
1
1- b (Ai1ci + A32CZ + A33c3)

= Bi (c 1). (7)
Now c = c(u = 0), c2 = c(u = 1/2), at the mid-
point of the outer element, and c3 = c(u = 1)
= c(r=1). We have c3 = 0 and c2 = c3 / 4, so we
can solve (7) for c,.

(1-b) Bim
c 2 + (1 b) Bi ()
For various b from 0 to 1 it is easy to see the
influence of external diffusion resistance. When
cs = 1 there is no concentration drop across the
boundary layer surrounding the pellet, and this
condition depends on (1 b)Bim. For large Bim,
we have cs = 1. These equations are solved with-
out iteration by choosing b, finding c. by (8),
C2 = C3 / 4, and then using (6) to get 0,2 =
Rk (T2) / De. Choosing b = 0 gives the dividing


CHEMICAL ENGINEERING EDUCATION








changing, Figure 2b, whereas non-finite element
methods are suitable for smooth solutions; Figure
2a.

TWO-DIMENSIONAL PROBLEMS

A MORE IMPORTANT USE of finite element methods
is for two-dimensional problems. Consider
heat transfer in the region shown in Figure 4.
The boundaries are maintained at temperature =
100 and the interior is cooled with a heat transfer
coefficient h = 3, To = 0. We wish to solve kV2T
= Q in strut, T = 100 on top and bottom boundary,
-kn-VT = h(T To) on side boundaries. Space
does not permit a complete discussion of all
aspects of the finite element method but the high-
lights can be given.
We first discretize the space, as shown in
Figure 5. We can divide the region into triangles,


iV---J
FIGURE 5. Mesh for Heat Transfer Problem.
line between the orthogonal collocation solution
and the finite element solution. Here we have
solved the finite element solution for planar
geometry (it is easier than spherical geometry),
and we use

A =-
3
to get the results for spherical geometry. The
7) 0 curve is shown in Figure 3. Over the whole
range of 0 we get a reasonable solution; compared
to much more difficult numerical solutions.
Certainly the solution exhibits all the important
phenomena, usually within experimental accuracy.
This example clearly shows the importance of
using finite elements when the solution is sharply



fl F_


FIGURE 6. Element Deformation.


FIGURE 7. Trial Function, Linear on Triangle.
rectangles or quadrilaterals. Because of the way
finite element programs are written it is very easy
to use deformed elements, as shown in Figure 6.
The actual calculations are made on the square
element, with appropriate account taken of the
transformation properties. Within each element
we expand the unknown function in a polynomial
-either linear or quadratic, usually (see Figure
7). Having decided on the trial function (here
linear functions on triangles) we number the
nodes and elements (see Figure 5). Now in two
adjacent elements the equations are similar when
written in terms of the local coordinates (see
Figure 8). The appropriate equations must be
assembled properly. The equations are solved with


Since finite methods are being used increasingly by industry
for design of structures, heat transfer, fluid flow, design of nuclear reactors,
etc., it is important that the modern student be exposed to them. It is not necessary that
the engineer be familiar with the details ... but (he) should know the general idea.


WINTER 1981:









an LU-decomposition or a Gaussian elimination
(6). These techniques are beyond the scope of
this article.
The user then specifies the thermal conductivity
and heat generation rate in each element. Here we
have
ke = 1, Qe = 0.
Finally the boundary conditions are specified as
Ti = 100
nodes i = 7, 14, 17, 20, 23
hi = 3, To, = 0
nodes i = 8, 9, 10, 11, 12, 15, 18, 21, 22, 23.
For a boundary node at which temperatures are
not specified by the user the boundary condition
is automatically the natural boundary condition
ZT / an = 0
nodes i = 1, 2, 3, 4, 5, 6, 7, 8
with n the outward pointing normal.
This problem is solved using the program in
Huebner's book (7). The solution is shown in


122


(a) GLOBAL NUMBERING SYSTEM


3




I 2


3




I 2


(b) LOCAL NUMBERING SYSTEM
FIGURE t. Finite Element Numbering System.

Figure 9. Naturally more elements are needed
for good accuracy, but the essential elements are
clear in Figure 9.
The advantage of the finite element method is
that the elements can easily be deformed, small
elements can be used in important regions, and
irregular domains are easily handled. The reason
for these features is that the computer programs
are written on an element-by-element basis, since
each element is similar. The user, then, has
complete freedom in how the elements are to be
arranged.


FIGURE 9. Solution to Heat Transfer Problem. Contours
are for each 10 degree increment.


COMPARISON TO FINITE DIFFERENCE

THERE ARE BOTH SIMILARITIES and differences
between finite element and finite difference
methods. For the heat conduction problem

32T +aT
+ -0
Ex2 ry2
a finite difference grid is shown in Figure 10a.
The finite difference method uses the following
equation representing the differential equation at
node 5.

V2T = (T + T T + T 4T- ) / h2.

The same equation results from application of the
finite element methods, provided linear trial
functions are used on the triangles shown in
Figure 10b. (Other types of terms in an equation
may be different, however). If we use quadratic

7_ _8 9 B

4 5 6 4 5 6
/

I 2 3 1 1 .2 3
(a) FINITE DIFFERENCE (b)FINITE ELEMENT, (c)FINITE ELEMENT.
LINEAR OUADRATIr.
FIGURE 10. Comparison of Finite Difference and Finite
Element Methods.


CHEMICAL ENGINEERING EDUCATION









polynomials in the finite element method, then we
have more nodes and the equation at node 5 in-
volves terms at each node represented by in
Figure 10c. Because the equations are derived in
different ways the finite element method is, how-
ever, easy to apply with the irregular geometries
shown in earlier figures. In addition, certain types
of boundary conditions are easily handled in finite
element methods, particularly boundary conditions
involving derivatives and/or free surfaces, whose
location is to be determined.
SUMMARY

SINCE FINITE ELEMENT methods are being used
increasingly by industry for design of struc-
tures, heat transfer, fluid flow, design of nuclear
reactors, etc., it is important that modern students
be exposed to them. It is not necessary that the
engineer be familiar with the details of the method,
but the engineer should know the general idea and
be able to apply the method. The author has found
students are quick to learn how to use finite ele-
ment programs, and once experienced will always
know what someone means when they say Finite
Element Methods.
FURTHER INFORMATION

COMPARISONS OF finite element, collocation, and
finite difference methods are given in Ref. (8).
One-dimensional cases are emphasized since that
allows the easiest description of the methods and
details of applications. Two-dimensional problems
are treated there as well as books by Huebner (7)
and Chung (9). Huebner's book contains a simple
finite element program for heat transfer problems.
More elaborate programs are available (10). Ap-
plications to engineering design are widespread,
and one concentrated source is the International
Journal of Numerical Methods in Engineering.
Probably there are published accounts of research
applications of the finite element method in the
journals related to your area of interest. O
REFERENCES
1. Bird, R. B., W. E. Stewart and E. N. Lightfoot,
"Transport Phenomena," Wiley (1960).
2. Finlayson, B. A., "The Method of Weighted Residuals
and Variational Principles," Academic Press (1972).
3. Carberry, J. J., "Chemical and Catalytic Reaction
Engineering," McGraw-Hill (1976).
4. Finlayson, B. A., "Orthogonal Collocating in Chemical
Reaction Engineering," Cat. Rev.-Sci. Eng. 10, 69-138
(1974).
5. Paterson, W. R. and D. L. Cresswell, "A simple method
for the calculation of effectiveness factors," Chem.
Eng. Sci. 26, 605-616 (1971).


6. Hood, P., "Frontal Solution Program for Unsym-
metric Matrices," Int. J. Num. Methods. Eng. 10, 379-
399 (1976); 11, 1055, 1202 (1977).
7. Huebner, K. H., "The Finite Element Method for
Engineers," Wiley (1975).
8. Finlayson, B. A., "Nonlinear Analysis in Chemical
Engineering," McGraw-Hill (1980).
9. Chung, T. J., "Finite Element Analysis in Fluid
Dynamics," McGraw-Hill (1978).
10. Program DOT available from Professor E. L. Wilson,
Department of Civil Engineering, University of Cali-
fornia, Berkeley, California 94720.




Letters

FOREIGN STUDY PROGRAM
Dear Sir:
We read with interest about the successful Study-
Travel Program at Virginia Tech (Summer 1980 issue).
I would like to briefly mention two intensive foreign
study programs which are open to selected Chemical
Engineering undergraduates at Case Western Reserve.
They may also serve as examples for other Departments
who wish to initiate such programs.
Each year since 1978, three of our undergraduates
have spent their junior year at the University of Edin-
burgh. There they are regular full time students in the
third year Chemical Engineering program. The students
normally live in university student housing and can par-
ticipate in the usual range of student activities. Full
academic transfer credit for a years work is granted upon
successful completion of the third year course at Edin-
burgh. This arrangement has been extremely successful,
primarily due to the excellent and continued cooperation
of the Edinburgh faculty. The experiences of the students
have been uniformly good and there have been minimal
academic re-entry problems after returning to Case for
their senior year.
We also participate, with Iowa State University and
Georgia Tech, in a summer laboratory course at Uni-
versity College London. This very well run program
lasts for approximately one month and, in addition to the
intensive laboratory course, includes a one week bus tour
of various British chemical industries. Credit for our
Unit Operations Lab is given upon completion of the
course. Part of the reason for the success of the pro-
gram is the dedicated work of the faculty representatives
from Iowa State and Georgia Tech that accompany the
students.
Overseas study has been an area in which we in engi-
neering education have lagged behind our colleagues in
the liberal arts. Part of the reason has been the necessity
of meshing requirements from two highly structured
curricula. Despite these difficulties, the remarkable benefits
to the students involved make the effort worthwhile. More
programs of this type should surely be offered.
Sincerely yours,
John C. Angus
Case Western Reserve University


WINTER 1981










laboratory


A SIMPLE TUBULAR REACTOR EXPERIMENT


ROBERT R. HUDGINS
University of Waterloo
Waterloo, Ontario, Canada

BERTRAND CAYROL
University de Sherbrooke
Sherbrooke, Qu6bec, Canada


USING AS A REACTION system the hydrolysis of
acetic anhydride, Anderson [1] developed a
laboratory demonstration of tubular reactor be-
haviour. In this article, another such demonstra-
tion is presented with two novel additions: (i) a
color change is added as a visual reinforcement
of the measured results and (ii) the temperature
constraint is removed in order to provide an ex-
periment operable at room temperature. The


Robert R. (Bob) Hudgins, born in Toronto, Canada, obtained all
his degrees in Chemical Engineering; B.A.Sc. and M.A.Sc. at the Uni-
versity of Toronto and the Ph.D. degree at Princeton University. He
came to the University of Waterloo in 1964 where he has remained
except for study leaves at Polysar, Sarnia, Ontario, Universite de
Sherbrooke, Sherbrooke, Quebec, and most recently (1979) at the
Swiss Federal Institute of Technology (EPF), Lausanne. His research
studies have focused upon the influence of inert diluent gases in
heterogeneous catalytic reactions, and on the behavior of chemical
reactors under forced cycling. (L)
Bertrand Cayrol received his Ph.D. from McGill University, Canada,
in 1972. He has been a Research Visitor at Chalmers University of
Technology, Sweden, and a Research Assistant at the Universite
d'Orsay, France. Presently he is Assistant Professor at the Universite
de Sherbrooke, Canada, with special interest and work on the visco-
elastic properties of polymers synthesized by micro-organisms. (R)


latter innovation reduces the complexity and thus
the cost of the apparatus.
Corsaro [2] described the hydrolysis of crystal
violet dye by sodium hydroxide. Reaction is first
order in the concentrations of each of the reacting
species. If the base is in great excess, the kinetics
of reaction become pseudo-first order,

-rdye = k' [dye]
where k' = k[NaOH]. The dye concentrations
needed for this experiment are of the order of
10-5 mol/L. Thus, a 0.01 mol/L solution of NaOH
is in 1000-fold excess and in a concentration
readily achieved at low cost. Also, NaOH con-
centrations can be varied considerably in order to
achieve a desired pseudo-first order rate constant
k' at room temperature. This feature of the experi-
ment eliminates the expensive temperature control
equipment of the sort used by Anderson [1].
Another advantage of this system over that
using acetic anhydride hydrolysis is that the
system remains isothermal during reaction. The
fact that the reagents are also very dilute means
that there is little safety hazard if the reagents
are spilled, though safety glasses are recom-
mended.
The results of this experiment may be ap-
proximated by idealized models, such as the plug
flow tubular reactor (PFTR) and laminar flow
tubular reactor (LFTR).

THEORY
The PFTR model is widely used, (see Leven-
spiel [3] for example) and is related to the inlet
and outlet dye concentrations as follows.
V 1 dye]i __ 1
S Vo k' dye]. k x)
The LFTR model has been developed by Cle-
land and Wilhelm [4]. The radial mean conversion
at the exit from the tube is given by the expres-
sion.

Copyright ChE Division, ASEE. 1981


CHEMICAL ENGINEERING EDUCATION


--~-~-









S00
dy
i-= l- 2 dy
1
= 1-v2Ei(v) +e-' (v-1)
where v = k'ro, y = t/To
and ro = L7 r2/(2vo)
Ei is the exponential integral, available in mathe-
matical handbooks.

APPARATUS
The principal components required for this ex-
periment are listed below; code letters refer to
the schematic in Figure 1.
Tanks: (T1) 200-L polyethylene tank bottle with 3/4-in
spigot for draw-off. (T2) 10-L Nalgene aspirator
bottle with spigot.
Pumps: (P1) Century type SPS (1/4 HP); available from
Flotec Inc., Norwalk, California. (P2) Magnetic-
drive variable speed micropump; Cole-Parmer Cat.
No. 7004-92.
Mixer: (M) Graphite impeller pump (whose impellers have
been removed for use as a mixer); Eastern Pumps,
LFE Fluids Control Div., Hamden, Conn.
Rotameters: (R1) Brooks type R-6-15-A. (R2) Brooks
type R-2-15-B.
Reactor: 40 m of 3/8-in I.D. Tygon tubing, wound on a
spool 28 cm in diameter and 55 cm in length.
Valves: (V) any adjustable valve to adjust flow in the
recycle lines.
Spectrometer: Spectronic 20 (Bausch & Lomb) fitted with
a "Flow-Thru Accessory" for rapid sampling.



TI
T2
V
V
P2
PI


7 | RI i R2


SI S2
.I Q.0.9JQ L 0 I
TUBULAR
REACTOR
FIGURE 1: Schematic Diagram of Apparatus. T1, T2 -
tanks for NaOH solution, dye solution re-
spectively; P1, P2 pumps; R1, R2 -
rotameters; V adjustable valves; M -
mixer; Sl, S2 sample points.


A 200-L reservoir (T1) is used for the caustic
solution and a 10-L reservoir (T2) for the crystal
violet dye solution. These are metered into a mixer
(M) at the entrance to the tubular reactor.
Samples may be withdrawn from the entrance
(S1) to the reactor and from the exit (S2) from
it at tee-junctions. These tees are fashioned by
welding short lengths of 1/8 in O.D. stainless
tubing to 3/8 in O.D. stainless tubes used as
connectors at the entrance to and exit from the
reactor tube.
For convenience, the reactor tube itself takes
the form of a helical coil, although there is no
reason in principle why it could not be straight
or folded (a comparison between the conversions
using helical coils vs. straight tubes might make
an interesting variation of this experiment, to in-
vestigate the importance of secondary flow in the
helical reactor). During operation, a strong change
in color may be observed along the reactor tube
between inlet and outlet.
The analysis of crystal dye at both the inlet to
and outlet from the reactor is readily done with
a spectrometer, and the method is given by
Corsaro [2]. The Flow-Thru Accessory of the
Spectronic 20 consists of a vacuum system to draw
small samples through a fine tube into cuvette,
and then to empty into a waste jar. Since the
sampling time is brief, and reproducible, errors in
measuring the concentration of the reacting
sample are kept to a minimum. The concentration
is readily obtained by calibration with known
concentrations of the dye. Occasional sampling of
methanol or ethanol will prevent the build-up of
adsorbed crystal violet dye on the walls of the
cuvette.

EXPERIMENTAL PROCEDURE

T HE MAXIMUM FLOWRATES of crystal violet dye
solution and caustic soda solution are 50 mL/
min and 1000 mL/min respectively. Thus, in the
reactor volume, the holding time is just a few
minutes, and since plug flow is approximated, little
more than a single filling of the reactor is needed
to obtain steady state conditions after a change is
made in the input flows and/or concentrations.
For purposes of illustration of the behavior of
this reactor, several points may be obtained at
different space velocities. This is done by deciding
on the range of flowrates available and then keep-
ing the two feed pumps in the same ratio. Con-
centrations are measured at a sample point just at


WINTER 1981









1.0-- -- -----------------




S0.9




0.8




07 6 0
3.0 40 50 60
r (min )
FIGURE 2: Comparison of Experimental Conversions
with those Predicted from PFTR and LFTR
Models.

the entry to the reactor, and just at the exit. Some
student data are presented in Table 1, for the
experiment at Universit6 de Sherbrooke. Note that
the volume of the reactor was 2780 mL, and the
concentration of NaOH (from the titration tests)
was 0.04 mol/L. In addition, batch tests of dye
with caustic soda solution of this concentration
provided a pseudo-first order rate constant k' =
0.54 min-1.
Using this information in the reactor models
provided, the model conversions of Table 1 were
calculated and the graphs in Figure 2 prepared
for both PFTR and LFTR. The conversion data
from Table 1 are also plotted in Figure 2. It ap-
pears that the behavior of the reactor lies between
the LFTR and the PFTR. No particular signifi-
cance is attached to the fact that the conversion
curve crosses the LFTR curve at short holding
times; the conversion data of most student groups
appear to lie between the two theoretical curves.
A wider range of flows might be used in order to


discern trends in the behavior of the real reactor
with holding time.
Finally, we offer a comment or two on student
reaction to the experiment. The change in color of
the reactants across the reactor is quite a novelty
in a chemical engineering laboratory experiment.
This visual effect helps to reinforce what is learned
from both the measurements and the theory. The
measurements are readily made, and the theoreti-
cal models used to bracket the expected per-
formance of the reactor are inherently interesting.
This happy combination of factors has meant that
the experiment has always been well received
by students working on it. El

REFERENCES
1. J. B. Anderson, "A Chemical Reactor Laboratory for
Undergraduate Instruction," Princeton University,
1968.
2. G. Corsaro, Chem. Educ., 41, 48 (1964).
3. 0. Levenspiel, "Chemical Reaction Engineering," 2nd.
ed., Wiley New York, 1972.
4. F. A. Cleland, and R. H. Wilhelm, AIChE J 2, 489
(1956).
5. H. Kramers and K. R. Westerterp, "Elements of
Chemical Reactor Design and Operation," Nether-
lands University Press, 1963, p. 93.

NOTATION
e,i = subscript symbols for exit, inlet
k = rate constant L/molmin
k' = k[NaOH]; pseudo-first order rate
constant (min-1)
L = length of reactor tube (m)
-r = reaction rate mol/L.min
t = time (min)
Vo = volumetric flow rate (L/min)
V = volume (m3)
X = conversion
y = t/7o
v = k'ro
S = V/vo (min-1)
To = Lr / (2vo) (min-1)


TABLE 1
Experimental Results

Flow of Flow of Dye Concentration Holding Fractional Conversion
dye NaOH Inlet Outlet Time PFTR LFTR
Run No. (mL/min) (mL/min) (mol/L x 105) (min) Exp'tl Model Model

1 15 450 1.1 0.08 5.98 0.93 0.96 0.90
2 20 600 1.05 0.15 4.48 0.86 0.91 0.84
3 25 750 1.05 0.22 3.59 0.79 0.86 0.77
4 30 900 1.05 0.30 2.99 0.71 0.80 0.72


CHEMICAL ENGINEERING EDUCATION









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WINTER 1981









curriculum


IMPRESSIONS OF

CHEMICAL PROCESS CONTROL EDUCATION

AND RESEARCH IN THE USA*


KURT V. WALLER
Abo Akademi
SF-20500 Abo Finland

T HE FIELD OF CHEMICAL process control was
heavily criticized in 1973. Foss [1] wrote a
much cited critique of the theory research. Athans'
critique[2] pointed in a different direction when
he stated: "It is indeed unfortunate that the
process control engineers have disassociated them-
selves from the mainstream of modern control
theory. In this manner, the tremendous ad-
vances during the past three years in system
identification, adaptive control, sensor location,
and accuracy tradeoffs have probably gone un-
noticed by the very profession that stands the
benefit most."
Athans was aware of the difficulties: "I do
believe that far greater care and finesse is re-
quired to apply modern control theory to process
control problems than missile autopilotes," but
his opinion about what action should be taken is
clear: "Everybody knows that chemical process
control systems are inherently less understood in
their dynamic behaviour than Newtonian systems.
But it seems to me that this should be viewed as
a challenge, rather than an outcry that the theory
is no good."
It is easy to criticize. This is especially true
of process control research, which is in the

In design of control systems
there are two basic approaches. The
first, in this paper referred to as the forward
approach ... The second here called
the backward approach, starts
from the process operator.


*This is a condensed version of Prof. Waller's original
paper published in the Finnish journal Kemia-Kemi, Vol, 7
(1980), page 85.


Kurt V. Waller was born in Mariehamn, Finland, in 1940. After
studying in Finland and West Germany he got the degrees M.Sc., Tech.
Lic. and Tech.Dr from Abo Akademi, Finland, in 1966, 1970, and
1972. A member of the faculty of Chemical Engineering at Abo
Akademi since 1970, Dr. Waller was appointed full Professor in 1975.
Professor Waller has written about 50 scientific papers, mainly on
process dynamics, optimization, and control.

difficult position that it [3] "must compete for
funds with such endeavors as process de-bottle-
necking, process improvements, new plant con-
struction, and other undertakings. Returns from
these latter efforts are usually more easily proven
or at least more readily believed."
Still, has the critique from 1973 been seriously
considered by the chemical engineering profes-
sion? Is the field of chemical process control in
USA today a vital field, or does it lack enthusiasm
and perspectives?

STATE OF THE ART
Education
A good picture of how established process
control has become in chemical engineering educa-
tion in the United States and Canada is obtained
from Seborg's recent survey [4]. It shows that the
basics of process control is now taught at practi-

0 Copyright ChE Division. ASEE, 1981


CHEMICAL ENGINEERING EDUCATION


--~-~-~-~








cally all chemical engineering departments. The
main part of the teaching is, however, concentrat-
ing on very basic facts only and using surprisingly
old textbooks, the clearly dominating one (by
Coughanowr and Koppel [5]) written over 15 years
ago.
The vast majority of departments have only
one faculty member in process control. There are
some departments, however, which put more
emphasis on control and which can offer quite
advanced programs. One example of a two-person
process control program was recently described
in [6].

Research and Development
In design of control systems there are two basic
approaches. The first, in this paper referred to as
the forward approach, is to take a theory with
potential for the specific process in question and
apply it after a possible adaptation to the class
of problems at hand.
The second, here called the backward approach,
starts from the process operator. In this approach
the goal is more or less to imitate a skillful and
experienced operator by the automatic control
system. In many respects the automatic system
can perform better than the manual, since it is
not influenced by the many sources for human
errors, it won't get tired, etc. It is natural to im-
prove the system continuously by extending it to
include more and-more new and abnormal situa-
tions, making the reasons for the operator to
switch to manual less frequent.
It seems natural that a sound design includes
elements from both the forward and the backward
approach. The impression obtained is that applica-
tions in the U.S. industry have a stronger emphasis
on the backward approach than is the case in
Finland (and Scandinavia).
One explanation for such a difference is easily
found. The connections between the universities
and industry seem to be much closer in Finland
than in U.S.A., as also indicated by Foss and
Denn [7] in summing up the 1976 Asilomar
Conference on Process Control: "The ties between
industry and the university appear closer in
Europe than in North America, and the closeness
seems to have afforded European university re-
searchers opportunities to implement and test their
control methods on industrially significant pro-
cesses." There are, however, a few university
groups in the U.S. sponsored by and working in


The connections between
the universities and industry seem
to be much closer in Finland than the U.S.A.

close cooperation with industry. One is the group
at the Case Western Reserve University directed
by I. Lefkowitz.
If there is a gap between industry and the
university on the one hand, there also seems to be
quite a gap between the control researchers in
U.S. electrical and chemical engineering depart-
ments. The electrical engineers are often very
theoretical while their chemical colleagues are
quite oriented towards applications, often even to
that extent that they rather work on specific
problems than on concepts. Thus there seems to
be a certain vacuum in the study of the applic-
ability of the more advanced theory, seemingly
the most natural process control field for activity
in chemical engineering departments. However,
there seems to exist a strong controversy concern-
ing this latter statement.
There are some workers in the field though.
At the University of California, to provide just
one example, Foss at the Berkeley campus has
for many years studied a packed bed chemical
reactor, the studies including state space modeling
by orthogonal collocation [8] and recently [9] [10]
the applicability of LQG-theory to the reactor,
which exhibits inverse response. At the Santa
Barbara campus Seborg and Mellichamp are work-
ing both on reactor and distillation control, two
of the applications in chemical process control
which seem to have a large potential for modern
multivariable estimation and control theory.
There is also quite an interest in exploring the
potential of the frequency response methods for
multivariable systems developed in Great Britain
by Rosenbrock, MacFarlane and coworkers.
Indeed, such an interest was already expressed by
Fisher [11] in 1973. The largest advantage is
generally considered to be the insight into and feel-
ing for the system obtained by the methods. Recent
applications treat Foss' reactor [12] and Wood's
distillation column [13] in Alberta, Canada.
Among new approaches being studied can be
mentioned "Inferential Control," studied by
Brosilow and coworkers [14]. The goal is to infer
unmeasurable product qualities from secondary
measurements, and here e.g. standard least squares
estimates are used. The novelty is how the second-
ary measurements are selected so as to minimize


WINTER 1981








the number of such measurements required to
obtain an accurate estimate which is insensitive
to modeling errors. A compensator, which is a
process model, compensates for the effect of the
control effort on the secondary measurements. This
leads to the appealing feature of the approach
that the control effort is not fed back in the
system, only the disturbances and the model mis-
matching. This fact is said to give the system
excellent stability properties. One interesting task
would be to exploit the approach systematically
for the model mismatching problem, which is of
such a central importance in process control. A
first step in this direction is taken in [15].
At present there does not seem to be much
active interest among chemical engineers to try
to apply and explore the self-tuning regulator
(STR) of Astrom and coworkers [16] [17] or
Zadeh's fuzzy control concepts [18] [19]. The


Another use of the interaction analysis is
for design of decoupling schemes.

common attitude is to wait and see until convincing
application studies are presented in which these
approaches have turned out to result in something
that more familiar and commonly accepted
methods have not. Previous studies in North
America of the STR and of Fuzzy Control have
mainly been done on the north side of the Canadian
border.
One of the subjects of great research activity
in chemical process control in the U.S. today is
interaction analysis, in which coupling between
inputs and outputs in multi-input multi-output
systems is studied. Interestingly enough the topic
is studied by consults and industrial researchers
as well as by university people.
The analysis starts in many cases from
Bristol's Relative Gain Array [20] [21] or similar
interaction indices suggested by Rijnsdorp [22] or
Nisenfelt and Schultz [23]. One of the main uses
for the technique is to pair variables, resulting in
(interacting) single-input single-output control
systems. It should be emphasized that one is not
restricted to basic manipulators but can use
various combinations of manipulative variables.
Interesting examples are given by McAvoy [24]
in exploring two-composition control in distilla-
tion. Conventional control, in which reflux and
boilup are manipulated, is compared to Shinskey's
material balance control (with either reflux and


bottoms flow rate or boilup and distillate flow rate
as manipulators), and also to Rijnsdorp's sug-
gestion to use the ratio reflux to boilup as one
control variable in addition to boilup. The least
amount of interaction is found for a hybrid
between Shinskey's and Rijnsdorp's suggestions.
While the interaction analysis usually uses
only steady-state data, extensions to include
dynamics in the interaction analysis in a rational
way have been treated in several papers. Witcher
and McAvoy [25] as well as Tung and Edgar [26]
show by including dynamics in the analysis that
it can lead to wrong pairing to take only steady-
state properties of the process into account.
While Witcher and McAvoy, Tung and Edgar,
and recently Gagnepain and Seborg [27] work in
the time domain, Kominek and Smith [28] work
with polar plots in the frequency domain. The
screening of a dual composition control scheme
from 12 potential candidates for an ethylene
column is used by Kominek and Smith to illustrate
the use of the theory. Use of only steady-state
interaction index is shown to result in systems un-
suitable for implementation.
Another use of the interaction analysis is for
design of decoupling schemes. The discussion is
largely concerned with decoupling in two-composi-
tion control in distillation. At present the dis-
cussion is highly concerned with the question of
whether one-way (also called partial) decoupling,
advocated e.g. by Shinskey [29], or two-way (com-
plete) decoupling, which is the approach pre-
viously investigated, is to be preferred. Strongly
related to this question in distillation is the
question of degeneracy in decoupling, recently
studied by McAvoy and coworkers [30] [31].
Additional papers on the topics of interaction
and decoupling analysis are [32] to [34].
Some further research objects of present and/
or planned activity are mentioned below in the
discussion of trends.

THE FUTURE: TRENDS AND SPECULATIONS
Education
Since no major changes concerning process
control can be foreseen in chemical engineering
departments in U.S.A. in the near future, most
departments will continue to have one faculty
member who teaches the basics of process control
and systems engineering. Advanced teaching pro-
grams in process control will probably be given
only in the very few departments (the order of 5


CHEMICAL ENGINEERING EDUCATION









Since no major changes concerning process control can be foreseen in ChE
departments in the U.S.A. in the near future, most departments will continue to have one
faculty member who teaches the basics of process control and systems engineering.


schools in the whole U.S.A.) where there is
more than one faculty member in the control field.
This scarcity of more advanced programs in
process control seems to be very unfortunate, be-
cause the correct interpretation and intelligent ap-
plication of modern control concepts is a task that
takes quite a lot of understanding of and famili-
arity with the theory as well as it demands engi-
neering skill. There are several examples where
the application has failed solely because of unsuit-
able interpretation of the theory. A perspicious
example of the importance of a correct interpreta-
tion of the theory is given in [35] and [36] concern-
ing the way of treating the integrals in optimal
PI-control of systems with time delay.
What will be taught? There probably won't
be much enthusiasm in the teaching of only the
basic process control courses, so for that matter
the text by Coughanowr and Koppel could be used
for another 15 years. It seems likely, however,
that it will be replaced by a text which has a much
stronger emphasis on computers and digital
systems. The text may very well start the treat-
ment directly in discrete time and skip much of
the old material used for continuous time treat-
ments. The same goes for the future teaching of
process control, which is likely to put less
emphasis on equations and more on algorithms
than has been done in the past.
What will be taught in the more advanced
courses will usually reflect the research.

Research and Development
Largely the industry is likely to continue to
go its own way. Then the "backward approach,"
i.e. the one in which the operator is translated into
the computer system, may be one of the main
approaches for design of industrial control
systems.
Undoubtedly the approach has its merits. One
rationale for it is that things are almost never
"normal" in process operation: "the normal state
is the abnormal one." Therefore one should start
from the process at hand, (and why not) as viewed
by the experienced operator.
Important university research in this area
will be concerned with plant diagnosis, fault detec-


tion, control under failure, and system reliability.
Also, the emphasis will shift towards treating
more difficult processes and to be more "devilish"
in testing the control systems. The important
subject of man-machine communication, however,
is probably best studied in industrial environment.
There is, however, also in industry an aware-
ness of the serious drawbacks inherent in the back-
ward approach. It conserves bad habits of the
operators and retards the progress. A catalytic
reformer is a good example: The operator tends
to recycle much hydrogen because the operation is
then very stable and safe. However, less hydrogen
recycled generally means less energy consumed and
more economic operation. Another example [37]:
In distillation it is common practice for operators
to increase the reflux rate above the design value.
Then disturbances in the feed composition seldom
cause the top product to fall below specifications,
but this advantage is balanced by the excess steam
supply needed to overreflux the column.
Today we are faced with a lot of double con-
servatism in the process industries. Firstly, pro-
cesses and plants are designed to be conservative
meaning a lot of capacity for decoupling and dis-
turbance attenuation. And secondly, the processes
are operated in such a conservative way so that
most of the disturbances left by the design dis-
appear into the conservative operation. And this
usually means a waste in energy and equipment.
However, it seems quite clear, that industry
has to cut down the waste of resources by means
of more sophisticated technology. Processes will
have to be designed as well as operated in a sig-
nificantly more integrated way, closer to con-
straints, than today. It probably won't be possible,
and certainly not economic, to operate such plants
manually. Or as seen by Evans [38]: ". new
processes are bigger, more integrated and more
highly automated. Operators are at the same time
becoming further divorced from the process, re-
moved from the operation of the process, so when
it comes time to start up or shutdown, or
emergency situations occur, the operator does not
have the intimate familiarity with the process
which his counterpart in the less automated
facility once had."
Closer ties between industry and universities


WINTER 1981








would, of course, decrease the gap. The industry
would get competent help to apply more advanced
control concepts and the university people could
more easily ask the right questions and attack the
relevant problems.
The gap can be illustrated by some views on
process modeling [39].
Much of the university research in modeling
for process control has been concerned with the
small perturbation, linear approach. The tendency
has been to include more and more smaller and
smaller effects into the model. An industrial re-
sponse is: These complicated models can never
take everything into account anyway, the operator
does not understand them since they are so compli-
cated, so they are not used.
Or to put it another way: University people
usually suppose a "normal" state for the process.
An industrial conception of what is "normal" was
expressed as: Things are never normal-or per-
haps 2% of the time.
Models will have to become simpler and more
robust. (Signs of steps in this direction are already
visible [40]). In many cases a simple model struc-
ture only will be determined from first principles.
In operation there will be a strong shift towards
experimental modeling, i.e. towards on-line
identification and estimation, with a subsequent
reduction in importance of modeling from first
principles.
It seems likely that the concept Fuzzy Control
will find increased use in the backward approach,
since the most important property of a system
designed by the backward approach is that it is
kept on automatic and not switched over to
manual. System performance comes only second
in importance. The natural language flavor of
fuzzy control seems ideal to prevent the operator
from feeling unfamiliar with the concepts used
in the computer system. Another rationale for
the use of fuzzy logic is that much of the control
work going on in industry is done, and will
continue to be done, almost without any control
theory in the sense of "hard" systems theory. So
far, however, use of fuzzy logic has been reported
mainly from Europe [41] [42].
For a long time it has been recognized that
there is a large potential in an integration between
process and plant design and control. Indeed [43],
"it is important to consider process control in
general-the development and the application of
its theory-as an integrated part of the plant
design and the process operation." There is quite


a lot of interest in the subject among chemical
engineers in the U.S.A. today, and increased re-
search activity can be expected. In this integration
the potential of the chemical engineer can be
utilized at its very best.
The increased integration of processes and
complexity of plants, will make the control aspects
more critical. There will be a greater need for,
and emphasis on, multivariable control methods.
Analysis of plants will to an increased extent rely
on efficient simulation methods for large systems.
More work in these areas is needed and is likely
to be done [44].
What about adaptive control methods? Will, for
example, the self-tuner see an increased number of
applications? The answer is most likely yes. One
of the reasons was formulated, somewhat
cynically, by an industrial control system design-
er: These methods will be used more because
university people like to play around with them.
Starting from the single process unit rather
than from the concept point of view, no significant
changes are visible. Thus the large interest in
distillation control of the last decades continues.
Today research in distillation control in U.S.A.
is concerned with such questions as pressure
control, coupling and decoupling in two-composi-
tion control, multivariable control in general, and
nonlinear control of high-purity columns.
The other "large" process will probably
continue to be the chemical reactor, which offers
a wealth of challenging design, optimization,
identification, estimation, and control problems.
It is also felt by several workers, both in uni-
versities and industry, that these two processes,
the chemical reactor and the distillation process,
have the greatest potential for use of modern
control theory.

DISCUSSION
H ow HAS THE CHEMICAL process control com-
munity responded to the critique expressed in
1973?
Athans' opinion 5 years later is not less critical,
when he comments on the-in his opinion sad-
state of applications of advanced control in the
process industries. He states [45] that the chemi-
cal engineers are so conservative that they have
only got what they deserve. Shinnar [46] (1977)
laconically states: "the state of process control is
rather sad."
Continued on page 51.


CHEMICAL ENGINEERING EDUCATION


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SEnews


CHEMICAL ENGINEERING SYMPOSIUM

AT CARNEGIE-MELLON


MICHAEL LOCKE
Carnegie-Mellon University
Pittsburgh, PA 15217
ON NOVEMBER 15th and 16th, 1979, Carnegie-
Mellon University held its first annual Chemi-
cal Engineering Symposium. It was a chance for
graduate students in the department to present
their work before an audience of interested pro-
fessors and students. The symposium was intended
to serve several purposes. It would give students
experience in speaking before an audience. This
experience would be helpful in the future, making
it easier to speak at technical meetings, and, for
those who desire to teach, in the classroom. The
symposium was also a good way for research
groups in the department and in other depart-
ments in the university to examine each others'
work. Here was a chance for the left hand to at
last find out what the right hand is doing. It was
hoped that the symposium would lead to co-opera-
tion and an exchange of ideas between research
groups. Also, the symposium was a good time for
new graduate students to check out the work
that the professors in the department are doing.
This exposure helped the new students to decide


Mike Locke received his B.S.Ch.E. from the University of Massa-
chusetts in 1976, his M.S.Ch.E. from Carnegie-Mellon in 1978 and is
presently working on his Ph.D. at Carnegie-Mellon. His areas of interest
include Optimization, Computer Aided Design, and Equation Solving.
He presently serves as a consultant to NTP Corporation of Pittsburgh.


Westerman-Clark presenting his winning paper .

which faculty members they would choose as their
advisors.
The idea for a symposium was first brought
up in September during a meeting between depart-
ment chairman Tomlinson Fort and the officers of
Carnegie-Mellon's Chemical Engineering Graduate
Student Association (ChEGSA). Arrangements
for the symposium began with a call for papers.
Prospective speakers were required to turn in the
titles of their talks. It was at this point that the
organizers realized that they were on to something.
The response from students and faculty was over-
whelming. Twenty-seven students responded
positively, with 29 papers to present. This was
twice the number that had been anticipated.
One month before the symposium, speakers
submitted abstracts of their talks. The abstracts
were collected in a booklet, along with the agenda
of talks. Copies of the booklet were distributed to
all faculty members and graduate students in CMU
Chemical Engineering, and also to the heads of the
departments in the School of Engineering. Each
student was given 20 minutes to talk, with 5 addi-
tional minutes for questions. Topics ranged from
separation of polymer wastes to synthesis of heat
exchange networks. Other interesting topics were
Copyright ChE Division, ASEE, 1981


CHEMICAL ENGINEERING EDUCATION








trace metal levels in Pittsburgh air (there's more
than just a trace), and the velocity of blood flow
in a rabbit's ear. Interesting discussions started
during the symposium, and are continuing.
As an incentive for the students, a prize was
awarded for the best paper. It consisted of an
expense paid trip to the next AIChE convention, to
deliver the winning paper, and a check for $100
from Tomlinson Fort. The judging committee was
made up of 5 faculty members, headed by Dr.
Robert Rothfus, the senior member of the depart-
ment. Speakers were judged on content, presenta-
tion, and a written copy of the talk.
After much deliberation, the judging commit-
tee chose Jerry Westermann-Clark as the prize
winner. The title of his talk was "Coion Exclusion
Potential in Charged Membranes." Jerry entered


S. .and receiving his award and the congratulations
of Professor Fort.

CMU in September, 1976, with a B.S. from the
University of Pennsylvania. He has a Masters
Degree from Carnegie-Mellon and his Ph.D. in
September, 1980. His work was supervised
by Dr. John Anderson. Jerry is now an Assistant
Professor at the University of Florida.
The judges also named three runners up. They
were Greg Townsend, for his talk "Pharmaco-
kinetics of Adriamycin in Normal and Neoplastic
Tissues" with Dr. Rakesh Jain supervising; Lewis
Grimes, with a talk entitled "The Synthesis and
Evaluation of Networks of Heat Exchangers that
Feature the Minimum Number of Units," super-
vised by Dr. Arthur Westerberg; and Michael
Reilly for his talk "Ambient Trace Metal Levels
in Pittsburgh Air," supervised by Dr. Eric Suu-
berg. O


i POSITIONS AVAILABLE
Use CEE's reasonable rates to advertise. Minimum rate
% page $50; each additional column inch $20.

OKLAHOMA STATE UNIVERSITY
Chemical Engineering. Two Assistant or Associate Pro-
fessor Positions. These are tenure-track positions and will
be approximately half-time teaching and half-time re-
search. We will help successful candidates establish re-
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search. Candidates must possess an earned Ph.D. degree
from an accredited Department or School of Chemical
Engineering or have a Ph.D. degree in related areas and
have strongly related qualifications. We welcome applica-
tions from candidates with competencies and interests in
any field of chemical engineering, but especially seek those
with strengths in material sciences or controls. The posi-
tions are available as early as July, 1981. Applications
will be received thru June, 1981. Salary and rank are
commensurate with qualifications and experience. Please
send your resume and list of three references to: Dr.
Billy L. Crynes, Head, School of Chemical Engineering,
423 Engineering North, Oklahoma State University, Still-
water, Oklahoma 74078, 405-624-5280. (Calls for addi-
tional information invited.) OSU is an equal opportunity/
affirmative action employer.






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WINTER 1981









problems for teachers


PRAIRIE DOG APPENDIX*
R. L. KABEL
Pennsylvania State University
University Park, PA 16802

SOLUTION:
We see that the wind velocity increases as a
logarithmic function of the height above the
earth's surface. Because of the higher velocity at
2.5 m than at 0.5 m there will be a lower pressure
at the top of the tube than at the bottom. This
pressure difference will induce an upward flow in
the tube.
A Reynolds Number can be calculated for flow
through the tube:

Re = Dp
/-L
0.01m(lms-1) (1.2 kg m-3)
1.8 (10-5 kg m-1 s-1)
which indicates laminar flow.
Thus the Hagen-Poiseuille equation can be used
to find the pressure drop. Eq. 2.3-19 Bird, et. al.
(or the Prairie Dog problem) gives


r Ap R4
8,L


Q8cL
or Ap Q/L
7irR4


Q = A = 7rR2
= 1ms-1 (r) (0.0052 m2) = 7.85 (10-5 m3 s-1)
= 1.8 (10-5 kg m-1 s-1)
L = 2m
R = 0.005 m
Substituting, we obtain
Ap = 11.52 kg m- s-1
This pressure drop can be related to horizontal
wind velocity by the Bernoulli equation:
P2
1 V3> ^A 1 A +
1 + b) + I-dp + W + E = 0
2
Pi
A A
Neglecting friction and work, E, and W are zero.
If the air can be assumed to be incompressible
under these conditions, p is constant and


*The problem statement was presented in CEE Vol.
14, No. 4 (Fall 1980).


z = 3m
z= 2 m

z= 1m
z = oM


-1
U 0 ms
d = 0.01 m
z = 2.5 m

= 1 ms-

z= 0.5 m
7 7 / 77 / / / / 7/ / 7 /7


FIGURE 1

P2
fdp P2 P1
jP P
pi

The potential energy difference A 4 between
points is negligible and for turbulent flow of air,
/ a 2, and
S 2 (p, p2)
2- 2 =
P
Taking point (1) at the bottom and point (2)
at the top, both terms are positive. Thus we have
one equation and two unknowns. The logarithmic
velocity profile
U(z) 1 z U. z
U(z) = I In or U(z) = 0.4n
U. k zo 0.4 01.04
provides two more equations but only one more
unknown, U.. Since U in the log velocity profile
and in the Bernoulli equation are the same
thing (i.e. the horizontal wind velocity) we can
combine these equations.

<> n [.5 ]= 10.34 U.
<.4 0.0 4

_U In f 0.5 = 6.31 U.
S-0.4 [L 0.04 J

(10.34 U.)2 (6.31U.)2 = 2(pl -P2)
P
2 (11.52 kg m-' s-2)
67.10 U," -
1.2 kg m-3
= 19.20 m2 -2

U. / 19.20 = 0.535 ms-1
S= 67.10
This value of U. can now be used in the velocity
profile to get velocity at 3 m.
U. z 0.535 3
U (z) =- In = In
k 0.04 0.4 0.04
= 5.77 ms-1
O


CHEMICAL ENGINEERING EDUCATION























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classroom


TEACHING MARKET ANALYSIS


J. T. RYAN
University of Alberta
Alberta, Edmonton, Canada

BRETT HAUGRUD
Sherritt Gordon Mines
Fort Saskatchewan, Alberta, Canada

MARKETING OF CHEMICAL PRODUCTS is a subject
which is almost completely ignored in a
chemical engineer's university education. This
omission is unfortunate since marketing is usually
the crucial constraint on the commercial viability
of many projects. In spite of its obvious im-
portance, market analysis is not taught to under-
graduates; the undergraduate is not trained to

,ABLE I

Capital Costs(1)
ALBERTA GULF COAST


Capacity 1
7
Direct Fixed Cost 6
(excluding working
capital)
Debt(2) 2
Equity 4
Interest rate on debt (

Term on debt 1
Yearly debt charge(4) $
Interest rate on equity (

Term on equity 1
Yearly charge: equity
recovery, return on invest-
ment (5) 5
Total Yearly Capital
Charges on D.F.C. 7
Unit Capital Charges
on D.F.C. I


.000 T/D
'20 mm lb/yr
i6 mm $Can


2000 T/D
1440 mm lb/yr
80 mm $US


!0.5 mm $Can 25 mm $US
45.5 mm $Can 55 mm $US
Canadian prime US prime
t I/Vz% (3) + 1%
5 years 15 years
;2.2 mm $Can $3.1 mm $US
Canadian prime US prime
- 4% + 3%


5 years


15 years


.6 mm $Can 7.65 mm $US


'.8 mm $Can

.09 tCan/lb


(1)Unless stated otherwise, costs are
currency of the home country.
(2)Debt-equity ratio of 0.45.


10.75 mm $US

0.747 SUS/lb
expressed in the


(3)Canadian prime interest rate = 8%%, U.S. prime in-
terest rate = 8%.
(4)Both debt and equity charges taken as uniform payment
retirement.
(5)Working capital and salvage neglected.

Copyright ChE Division, ASEE, 1981


Brett Haugrud graduated from the University of Alberta with a
B.Sc. in Chemical Engineering in 1973 and a MSc in Chemical Engi-
neering from the same school in 1978. He worked for several years
as an engineer in the Research Department of a Canadian Potash
Company before accepting his present position as process engineer
for Sherritt Gordon Mines, Fort Saskatchewan, Alberta. (L)
Jim Ryan received his Ph.D. from the University of Missouri
(Columbia) in 1966. He has taught at the University of Alberta since
that time. Primary teaching duties include the senior design project,
undergraduate fluid mechanics and introductory thermodynamics. He
serves as a consultant to the petroleum industry, mainly in the area
of pipeline design and explosions. Occasionally serves as a writer
and researcher for CBC-TV and Radio. (R)

analyze a market problem even in a rudimentary
fashion. The neglect of the marketing process by
the students' professors is understandable since
their training emphasizes the scientific aspects of
the chemical production process, such as research,
development and design. From an academic's view,
the estimation of a market size and its location is
regarded as a black art best left to someone else.
This paper presents a technique which hope-
fully transforms market estimation from a black
art into a dark gray one. Its objective is a quanti-
tative means of estimating a potential market area
at a given time for an undifferentiated chemical.
An undifferentiated product is one which does not
have any unique property that can be attributed
to its manufacturer. The manufacturer cannot
claim that his product is better than his competi-
tor's since both products are identical within
normal engineering specifications. Methanol,
fertilizer-grade ammonia and polymer-grade ethy-
lene are examples of undifferentiated products,
while almost anything that is advertised as unique


CHEMICAL ENGINEERING EDUCATION








or better is a differentiated product. Consequently,
the major factor which will govern the sale of this
type of chemical is its price, not its quality.
The potential market area for an undifferenti-
ated chemical, produced by a given plant, is defined
as that region where the delivered cost of the
chemical is equal to or less than other competing
producers. The delivered cost of a chemical com-
modity to a customer is the sum of the produc-
tion costs, transportation charges, tariffs and
currency exchange. The last two expenses are ap-
plicable only if the commodity is traded inter-
nationally. Rather than analyzing the position of
all potential competitors for a market, the tech-
nique of estimating a market area can be il-
lustrated more simply by considering only two
competitors.
As an example, assume that two hypothetical
methanol producers, one located in southern Al-
berta and the other on the Texas Gulf Coast, are


in competition with each other. In recognition of
historical precedence, the capacity of the Canadian
plant is taken initially as one half that of the
Gulf Coast plant. Table I gives the illustrative
capital costs and financial charges for each of the
two plants. The financial arrangements are simpli-
fied in order to make the presentation of the results
concise. Unit prices of inputs and associated unit
manufacturing costs are shown in Table II. The
cost figures in both tables are given in the
currency of the home country.
Until recently, the plant gate cost of Gulf
Coast methanol was significantly below that of
methanol produced in Alberta. In fact, at one
time the cost of methanol delivered from the Gulf
Coast to Alberta was less than the plant gate cost
of Alberta methanol. That situation was due
primarily to the economics of scale typical of the
American plants and the generally low level of
natural gas prices. As is obvious from Table II,


TABLE II


Capacity


Direct Fixed Capital
Working Capital
VARIABLE COSTS


Manufacturing Costs

ALBERTA
720 mm lb/yr
1000 T/D
54 mm $Can
4.9 mm $Can


Natural Gas as Feedstock and Fuel (32 mm Btu/ton)
Power
Catalyst
Water, misc.


FIXED COSTS
Labour & Admin.-80 people
Maintenance & Local Taxes
Sales


$1.25/mm Btu
30/KW-hr





$22,000/yr
5% of DFC
2% of Plant
._Gate Cost


CAPITAL COSTS
Unit debt on D.F.C.
Unit equity on DFC
Interest on W.C.


SUMMARY


Variable Costs
Fixed Costs
Capital Costs



WINTER 1981


Unit Cost
tCan/lb
2.05
.02
.15
.03
2.25


.244
.375
.078

.69


.307
.779
.03
1.11


2.25
.69
1.11
4.05


GULF COAST
1440 mm lb/yr
2000 T/D
80 mm $US
5.8 mm $US



$1.95/mm Btu
3.5S/KW-hr





$20,000


Unit Cost
OUS/lb
3.28
.02
.15
.03
3.48


.111
.278
.09

.479


.215
.531
.036
.782


3.48
.48
.78
4.74











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The potential market area for
an undifferentiated chemical, produced by
a given plant, is defined as that region where the
delivered cost of the chemical is equal to or
less than other competing producers.


the situation is now reversed. The plant gate cost
of Alberta methanol is below that of the Gulf Coast
even though there is a considerable size advantage
in favour of the American plant. The reason for
the reversal is that the Alberta plant now has a
large advantage in natural gas prices. It should
be noted these are new gas prices (as of January,
1978) and do not apply to older plants which have
long term contracts at lower natural gas prices
or to plants that can blend the old and new gas
prices.
To estimate the delivered cost at any point, the
transportation costs, tariffs and currency ex-
changes must be added to the average plant gate
production costs. The effect of these factors can
be illustrated in a simple example. Suppose the
two plants attempt to sell methanol in the San
Francisco area. The Gulf Coast producer can
transport methanol by ship through the Panama
Canal while the Canadian producer is restricted
to more expensive rail transportation. In addition
the American producer will not have to pay a tariff
while the Alberta plant must. All of these factors
favour the American plant and tend to erode the
plant gate cost advantage enjoyed by the Canadian
plant. On the other hand, the devaluation of the
Canadian dollar relative to the U.S. dollar in
effect lowers the plant gate cost of Alberta
methanol by about 10%. Table III summarizes all
of these effects and shows that the U. S. producer
is able to deliver methanol into San Francisco
more cheaply than his Canadian competitor. As a
consequence, San Francisco is regarded as a po-
tential market area for the U. S. producer.
TABLE III
Cost of Methanol Delivered to San Francisco


Plant Gate Cost

Rail to San Francisco
1,324 miles at 20/ton-mile
Ship to San Francisco
4000 at .5/ton-mile
Tariff-7.6 O/US gal
Delivered cost


ALBERTA
4.05 Can/lb
(3.65) CUS/lb
1.32 OUS/lb


1.15 OUS/lb
6.12 OUS/lb


GULF COAST
4.74


5.74 OUS/lb


The technique used to calculate the delivered
costs of the two competitors in the San Francisco
area can be generalized to any point of sale. The
results of this generalization are best presented on
a map as a series of curves of constant delivered
costs. These lines will be circles with their centers
located at each plant. When a commodity shipment
encounters an international border, the "iso-cost"
lines will have a discontinuity as a result of tariffs
and exchange rates. In general, the magnitude of
the discontinuities will not be the same for both
competitors.
A further complication arises where there is
a possibility of change in mode of transportation.
For instance, to market methanol in the U.S. Mid-
west, the Gulf Coast producer might ship his
product via barge to Chicago, then distribute from
Chicago either by rail or by truck. The base cost
in Chicago would then be the Gulf Coast plant gate
cost plus the barge charges to Chicago. Local Mid-
west costs would be the Chicago cost plus rail or


FIGURE 1. Iso-Cost Lines and Market Line for Base
Case.
truck transportation charges to the market area.
Consequently, the iso-cost lines in the Midwest are
again circles, but their origin is at Chicago instead
of the plant site. In addition to Chicago, San Fran-
cisco and Montreal were chosen as distribution
centers.
The technical exercise is to construct the lines
of constant cost for each distribution center. A
set of these curves is shown in Figure 1. Each of
them is labelled with the delivered cost in the
currency of the consuming country. These circles
are idealizations since the railroads do not run in
straight lines. The actual iso-cost lines would be
severely distorted, particularly in the west. At this
stage of the analysis, this is viewed as a second
order effect and is neglected. The potential market


WINTER 1981










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engineering mean
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Kerr-McGee Corporation
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Oklahoma City, Oklahoma 73125


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An Equal Opportunity Employer M/F/H/V





















FIGURE 2. Approximate Yearly Consumption and
Growth Rate of Methanol by Region.

area for each competitor is found by drawing a line
connecting the intersections of the lines of equal
constant costs. This, the market line, is also shown
in Figure 1. The market area for Alberta methanol
is north of the line and the Gulf Coast market is
to the south.
As can be seen from the figure, Alberta's
market area is all of Canada west of Quebec City
and a large portion of the northwest and west
central United States. The Gulf Coast producer
has a lower delivered cost everywhere else. Once
the geographical areas which represent potential
markets for the two competitors are established,
the objective is to locate customers within those
areas. Figure 2 shows the approximate demand for
methanol by region. The upper number is the 1977
capacity of chemical plants which use methanol as
a chemical feedstock, expressed in mm lb/yr.
Below this number is one in parentheses which is
the six year net growth in demand for feedstock
methanol. The data used to construct this figure
were taken from the Chemical Economics Hand-
book [2] and include only specific plants listed in
that publication. These values are somewhat low
because they do not take into account demand for
methanol as a solvent, gas line antifreeze, etc.
Since a large fraction of methanol is used in manu-
facturing resins for plywood and other wood
products, the markets are concentrated in those
regions which have a significant harvestable
forest. The pacific northwest and southeastern
states are examples of this concentration.
By superimposing the market line on the con-
sumption patterns, it is possible to compare the
production of the two plants with the require-
ments of customers potentially available to each.
It is clear from Table 2 that the price paid for


natural gas is the most significant component of
methanol manufacturing costs. The base case
natural gas prices were taken as the prevailing
new gas prices (1978). Actual prices could be
significantly different if old gas was under
contract. A number of cases were studied to show
the effect of gas prices on the market line. The
cases examined are designated on Figure 3 as one
through four with line 2 being the base case. When
the Alberta producer has a price advantage of
$1.00/mm Btu, the change in the market size is
fairly small. The only new market penetrated is
San Francisco where about 100 mm lb/yr are con-
sumed. Case 3 occurs when both competitors have
the same natural gas costs. The Gulf Coast pro-
ducer can now capture most of the Pacific north-
west market as well as the eastern Canadian
market. This situation would force the Alberta
producer to operate at less than full capacity,
further improving the position of the U. S. com-
petitor. Since a small change in any economic or
technical variable could cause a large change in
market size, competition in the PNW would be
intense. Price discounting by both parties would
be a definite possibility. Finally, if the Gulf Coast
operator enjoys old prices and the Alberta pro-
ducer pays new gas prices, the Texas plant would
capture all of the PNW. The Alberta producer
would be left with only the three western Cana-
dian provinces, whose total market is less than
his breakeven production rate. The problem is


FIGURE 3. Effect of Natural Gas Price on Market Area.

solved since he must then shut down if actually
operating or decide not to build a new plant.
Operating under the base case conditions, the
Gulf Coast producer has access to a market of
approximately 6000 mm lb/yr, while the Alberta
manufacturer has a maximum market of 970 mm


WINTER 1981









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lb/yr. With the indicated growth rates, these
markets will have expanded to 7050 and 1220 mm
lbs/yr respectively during the three years taken
for planning and construction. To operate at full
capacity, the new American producer must cap-
ture 20% of the market available to him, whereas
the equivalent number for the Alberta plant is
60%. The potential market available to the Al-
berta producer at start-up is about twice the
capacity specified in the base case, i.e. 1000 T/D.
As a first step, he might consider doubling the
plant capacity to 2000 T/D in order to capture
the entire base case market area plus any other
market that becomes available as a result of the
economics of scale. Figure 4 shows the market


FIGURE 4. Effect of Plant Size and Duty Draw Back on
Market Area.
lines for the 1000 and 2000 T/D plants. All other
factors were held constant. The interesting
feature of the increase in plant size is that, in spite
of the reduced unit cost of methanol, not one more
major customer was added to the Alberta market.
The only effect of the increase was to add sufficient
capacity to satisfy the demand of the customers
that a 1000 T/D plant could not. It is obvious that
the next plant size that should be tried is about
1200 T/D. However, this is too precise a refinement
in view of the potential effects of changes in other
variables.
On occasion, a commodity is imported into a
country, processed, then exported in a different
form. When this occurs, the duty or tariff origin-
ally imposed on the imported good is forgiven.
This is called a duty drawback. In the PNW up
to one-third of imported methanol is exported in
the form of resin. In effect, the cost of the Alberta
produced methanol is reduced by an amount equal
to the duty drawback, which improves the com-
petitive position of Alberta methanol in a con-


tested area. The sensitivity of the market line to a
change in duty drawback is also shown on Figure
4 for the case of equal natural gas prices of $1.25/
mm Btu. With no duty drawback, the Alberta pro-
ducer should be able to capture virtually all of
Washington and half of the Idaho market area.
With one-third of the tariff forgiven, he will be
able to penetrate one-half of the Oregon market in
addition to the states of Idaho and Washington.
The incremental increase in geographical area due
to the change is relatively small; however, the
amount of increased sales should be significant
because of the concentration of users located in
the area. It should be noted that the line repre-
senting the one-third duty drawback is mislead-
ing. The line is for drawback based on the average,
whereas in reality the drawback is specific for only
those plants which exported the processed
methanol.
So far it has been assumed that the determina-
tion of the market size was undertaken so that
both potential competitors can make the capital in-
vestment decision of whether to build a plant or
not. A more interesting situation occurs when one
of the plants is already in production, while the
decision to construct the other has yet to be made.
For the sake of argument, suppose the Texas plant
exists and that the Alberta plant has yet to be
built. The Alberta plant must use the average cost
of production which includes return on equity to
determine its market. On the other hand, the
Gulf producer makes his decisions based on the
marginal cost of production.
In the short term, the existing plant can sell
its production at a cost equal to the variable pro-
duction cost or breakeven. In the midterm, the
producer can sell at a price which includes all
manufacturing and debt repayment costs, but ex-
cludes equity capital recovery or return on equity.
Operating for an extended period under this
condition will have adverse effects on either the
value of the company's stock or the plant liquida-
tion value. Figure 5 shows the market lines for
the Texas plant selling its product under several
pricing options. The Alberta producer is assumed
to have full equity recovery and return. On this
figure, four market lines are shown. The three
most southern lines are parametric in the fraction
of original anticipated return and recapture of
equity. The line designated as 100% corresponds
to the original base case and that line marked
as 0 % is the case where only production and debt
costs are met. Finally, the market area outlined


WINTER 1981























FIGURE 5. Effect on Percent Capital Recovery for Gulf
Coast Plant on Western Market Area.
by the breakeven line is the situation where only
the variable costs of production are achieved. In
the last case there is no allowance made for equity
or debt repayment. By selling its product at the
marginal cost of production, the northernmost
line, the Gulf Coast producer is able to capture
most of the PNW market. However, this situation
can only be a short-lived phenomenon, since this
market is equal to about one-third of the Texas
plant's production. Usually, selling at the margin
is resorted to when a small fraction of the plant's
capacity is under-utilized. In the long run, the
Alberta producer does not need to worry about
this single competitor capturing a large share of
the PNW methanol market. This is certainly not
the case if a large number of U. S. producers are
operating at less than their capacity. The market
line in Eastern Canada was shown only for the
base case. The Gulf Coast producer selling into
Eastern Canada at breakeven or at the margin
would be in violation of Canadian dumping laws,
so these lines were not drawn. Dumping occurs
when a company sells internationally at a price
below its domestic price.
Thus far, the analysis has been used to find the
respective market areas for two competitors under
a variety of conditions using the concept of de-
livered cost as the sole criterion. By interpreting
the technique in a slightly different manner, the
two competitor price can be estimated. Here, a
two competitor price at a given point is defined as
the higher of the two delivered costs at that point.
The concept of this price is best illustrated by a
simple example. Suppose the two methanol pro-
ducers are attempting to sell methanol to hypo-
thetical customers in Pendleton, Washington and
Vancouver, B.C. As shown on Figure 6, the cost
of Gulf Coast produced methanol in Pendleton is


6.5 U.S. //lb, whereas the Alberta plant cost de-
livered at the same point is 5.34 U.S. 0/lb. Given
that there are no other suppliers, the Alberta
producer can charge slightly less than 6.5 U.S.
/lb and still capture the Pendleton market.
By subtracting transportation, tariff and
currency conversions from the Pendleton price,
the FOB plant gate price of methanol in Calgary
is approximately 5.2 Can. 0/lb. This is shown on
the figure as a dashed line. Since the plant gate
cost was only 4.05 Can. /lb, the sales into Pendle-
ton will yield a profit of 1.15 Can. /lb in addi-
tion to the required profit embedded in the cost
calculation. On the other hand, the American plant
can set the price in San Francisco at the Alberta
delivered cost of about 6.1 U.S. 0/lb. The basic
principle is that in a given market area, the price
is set equal to the competitor's delivered cost at
any point in that area. The situation can be more
complicated, as illustrated by an analysis of the
Vancouver market. The Gulf Coast plant could
transport methanol via ship from San Francisco
and land it in Vancouver at 6.8 Can. $/lb. This
delivered cost would fix the FOB plant gate price
available to the Alberta producer at 6.2 Can. I/lb.
6.8
Vanec
\ \a
6.4


e= "..... '. \
60
.... ,, 5.6 |
,I 52.


4.8
Vanc*-...
4.4

I .e I 4.0
San Base Case Pendleton INTL Calgary
Francisco Market Line Border
FIGURE 6. Two Competitor Pricing in PNW.
However, the Canadian plant might then be violat-
ing American anti-dumping laws by selling to the
U.S. at 5.2 Can. /lb FOB plant gate and in the
Canadian market at 6.2 Can. //lb. Because the
PNW market size is much larger than that in
Vancouver, the delivered price of methanol in Van-
couver should be set at 5.8 Can. /lb instead of
the 6.8 Can. /lb calculated in the absence of anti-
dumping laws. Oddly enough, the U.S. anti-dump-
ing law has had the effect of lowering the price to


CHEMICAL ENGINEERING EDUCATION







the Canadian methanol consumer while benefitting
neither the American methanol producer nor
American consumers.
A word of caution is necessary to warn the
reader that the actual price will probably not be
equal to the one calculated above. Obviously the
two competitor model is much too simple to be
applicable in the commercial world. The extension
of the technique to a multi-competitor one is
straightforward in principle and a natural appli-
cation for a computer simulation. However, even
the more complicated model would probably not
arrive at a realistic price because of the un-
availability of accurate input data. The model
would be useful in the commercial world in the
hands of someone familiar with the industry. The
technique has proven to be a very useful tool in
showing students how the technical, economic and
regulatory factors influence the potential markets
for a chemical commodity. E

REFERENCES
1. Various industry sources.
2. Chemical Economics Handbook, Standford Research
Institute, Menlo Park, California, Vol. II, 1977.
3. Brett Haugrud, M.Sc. Thesis, University of Alberta,
1978.


AWARD LECTURE
Kinetics of Coal Processing
Continued from page 18.
Reactant A diffuses through the product layer to
the reaction surface where chemical change occurs.
As reaction progresses, each pore of the particle
has associated with it a growing reaction surface
which initially corresponds to the inner surface
of the pore. As the various reaction surfaces in
the particle grow, it is inevitable that neighboring
surfaces will intersect one another as the solid B
separating them is consumed and replaced by the
product Q.
The growth of the total reaction surface may be
followed in terms of the radial growth of a given
set of overlapping cylinders, as shown in Figure
12. If the rate of reaction on the actual surface is
proportional to the total surface area


I -
S1-X2
/ 1-/ln 1X
( i-

(2)


and the conversion is

X=1- (1- ) exp [-r(1+ )] (3)

The surface development predicted by Equation
(2) is shown in Figure 13, exhibiting the antici-
pated maximum, but only for pore structures that

OVERLAP OF
CYLINDERS


PORE CROSS-
SECTION

UNREACTED
SOLID




FIGURE 12. Overlapping of cylindrical surfaces. The
hatched area shows the overlapped
portion. The blackened area represents un-
reacted solid B. The reaction surface is the
interface between the nonoverlapped
portion of the cylindrical surface and the
unreacted solid. The product layer that is
deposited as the reaction surface moves is
not shown in this figure. (After Avrami).


provide 9 > 2. In this regard the model is more
flexible than those based on an order of reaction
or a grain model. The Petersen model (1957) can
also describe either kind of behavior; but it makes
no provision for further pore wall intersections
and neglects the distribution of pore sizes. As an
example of the use of the above technique, it is
worthwhile to return to the data of Hashimoto et
al. (1979) on the surface areas produced by steam
activation of chars. As a- -- oo, Equation (2) pre-
dicts a linear semilog relationship between the
group [S/(1 X)]2 and (1 X). This expectation
is supported by the data within the limits of ex-
perimental error, as shown in Figure 14.
That the subject of coal processing is a com-
plex matter with multiple branches is a common-
place. The emphasis of this paper has been
to demonstrate that the newer techniques of ex-
perimentation and modeling can shed new light
on the old fossil, if the broad problems of practice
are directed into manageable parts, each to be
digested in its turn. O


WINTER 1981


S 1-X
S1-
S. 1 T











280


240
E
u
200


160


S120

0
0
U .


FIGURE 13. Development of the reaction surface with
conversion according to the random pore
model, compared with grain model for
m = 2/3 and Petersen model for co =
0.26, Lo = 3.14 x 106 cm/cm3, So = 2,425
cm2/cm3.


NOTATION


stoichiometric coefficients
concentration of gaseous reactant A
rate constant for surface reaction
length of overlapped system
reaction order with respect to gas A
stoichiometric coefficients
initial particle radius
reaction surface area per unit
volume
Sat t = 0
time
conversion


GREEK LETTERS

E = porosity
Eo = initial value of e
r = 4,Lo (1 o) /So2, structural
parameter
o- = R.So/ (1-E.), particle size parameter
T = k,CnSot/ (1 o), dimensionless time


VC CHAR
o


CS CHAR



/


0 02 01 06 08 10 1.2 1.4


FIGURE 14. Correlation of the data of Hashimoto et al.
(1979) with random pore model.

LITERATURE CITED

Bhatia, S. K. and D. D. Perlmutter, "A Random Pore Model
For Fluid-Solid Reactions," AIChE Journal, 26, 385
(1980).
Brewer, R. E., "Chemistry of Coal Utilization," Vol. 1,
H. H. Lowry, Ed., p. 160, Wiley, New York, N.Y., 1945.
Coffman, A. W., Layng, T. E., Ind. Eng. Chem., 19 (8)
924-925 (1927).
Coffman, A. W., Layng, T. E., Ind. Eng. Chem., 20 (2),
165-170 (1928).
Foxwell, G. E., Fuel, 3, 122-128 (1924).
Hashimoto, K., K. Miura, F. Yoshikawa, and I. Imai,
"Change in Pore Structure of Carbonaceous Materials
During Activation and Adsorption Performance of Ac-
tivated Carbon," Ind. Eng. Chem. Process Design De-
velop., 18, 73 (1979).
Kam, A. Y., A. N. Hixson, and D. D. Perlmutter, "The
Oxidation of Bituminous Coal, Part 1: Development
of a Mathematical Model," Chem. Eng. Sci., 81, 815
(1976a).
Kam, A. Y., A. N. Hixson, and D. D. Perlmutter, "The
Oxidation of Bituminous Coal, Part 2: Experimental
Kinetics and Interpretation," Chem. Eng. Sci., 31, 821
(1976b).
Kam, A. Y., A. N. Hixson, and D. D. Perlmutter, "The
Oxidation of Bituminous Coal, Part 3: Effect on Caking
Properties," Ind. Eng. Chem. Process Design Develop.,
15, No. 3, 416 (1976c).
Karsner, G. G. and D. D. Perlmutter, AIChE Journal
(1981).
Loison, R., Peytavy, A., Boyer, A. F., Grillot, R., "Chemis-
try of Coal Utilization," Suppl. Vol., H. H. Lowry, Ed.,
p. 150, Wiley, New York, New York, 1963.


CHEMICAL ENGINEERING EDUCATION


a, b
C
k,
L
n
p, q
Ro
S

So
t
X









PROCESS CONTROL EDUCATION
Continued from page 34.
Then, if the field has not been able to respond
in the way the critics had hoped, what explana-
tion can be found?
Process control seems to have been unable
to successfully compete for research and develop-
ment funding with other fields, which have been
able to be more convincing concerning return of
investment, especially short term. Indeed, Shinnar
[46] states that "the total expense of any major oil
company on research in process control in any
given year is less than for one major television
commercial."
Changes can be expected, however. The in-
creased emphasis on energy utilization will, as
mentioned above, put increased demands on a less
conservative and more tightly and carefully
controlled operation of existing processes. One
of the most efficient means to meet the increased
cost of energy is and will be a more efficient
energy utilization. Actually, one of the reasons
for the receptivity of European industry to more
sophisticated control approaches has been the high
cost of energy in Europe. Now when the U.S.A. is
experiencing higher energy costs-which will un-
doubtedly continue to climb-much more in-
dustrial interest in advanced control can be an-
ticipated.
The rise of the energy costs will force process
design in the same direction as process operation.
The processes and plants will become more inte-
grated, more sensitive, and more difficult to
control. Thus, both from the design and the
operational point of view more emphasis will
have to be put on advanced control in the future.
Another circumstance which might have re-
tarded the progress in process control research,
is the structure of U.S. faculties. The American
professor, be he assistant, associate or full, often
has no other research assistance than his (gradu-
ate) students. And when students have learned
enough to be fast and efficient workers they are
ready to leave. This system is not very efficient
in an applied field like process control, in which
such a large amount of knowledge and technics
from various fields have to combined in every
single non-trivial application. As expressed by
Wallman et al. [10] in a LQG-application to the
Foss chemical reactor: "It is undoubtedly evident
from the account given here that the approach
taken exacts a high price in engineering effort


and expertise. To recount, effort is required in
process modeling, parameter estimation, variable
reconstruction, and control system design. On top
of all this rests an overhead in approximation and
numerical methods."
The hierarchical European faculty system, in
which research groups form naturally, almost by
themselves, seems to be more efficient in this field.
The difference may become larger in the future as
the systems and problems to be treated are be-
coming more complex.
This organizational drawback in U.S. faculties
is pronounced by the fact that most faculties have.
not gone in for process control whole-heartedly
enough. One faculty member (the usual situa-
tion) is below the critical mass and no chain re-
action, so important for creative work, is
possible.
During the keynote address at the 1973 Joint
Automatic Control Conference Richard Bellman,
recently recipient of the IEEE Medal of Honor,
the highest honor that can be given by the world's
largest professional society, predicted that control
science will be the most influential discipline for
solving pressing national problems for the next
two to three decades. Athans has agreed [2], "with
no reservations whatsoever."
Even if Bellman and Athans turn out to be ex-
cessively optimistic, it is easy to agree with Athans
when he continues: "Modern control science will
continue to flourish with or without the support
of the process control community."
It seems to me that the question of whether the
chemical engineering community will be the one
that bears the burden and wins the victories in
chemical process control is still open. The potential
is there, but so are the obstacles. El


ACKNOWLEDGMENTS

The material providing the background for the
present review was gathered during a 9-month
stay as a Senior Fulbright Fellow 1978-79 at the
Chem. Eng. Department at the University of Cali-
fornia at Berkeley. The stay was made possible by
grants from the United States Educational
Foundation in Finland and the Foundation of
Neste Oy. Visits to a number of other universities
and to an AIChE meeting were made possible by
a special travelers grant from the Research
Institute of the Abo Akademi Foundation. These
grants are acknowledged with sincere gratitude.


WINTER 1981









Most stimulating and valuable discussions with
a number of scientists and designers concerning
the topic of this paper as well as comments on and
criticism of the first draft of the paper are greatly
appreciated. Above all Alan Foss, so perfect a host
in Berkeley, as well as M. Athans, E. H. Bristol,
C. B. Brosilow, P. S. Buckley, J. M. Douglas, T. F.
Edgar, L. A. Gould, W. L. Luyben, T. J. McAvoy,
D. E. Seborg, F. G. Shinskey, R. M. Tong, R. K.
Wood, and L. A. Zadeh.



REFERENCES

1. Foss, A. S., AIChEJ 19 (1973) 209.
2. Athans, M. in Weaver, R.E.C. (Coordinator), Pro-
ceedings of the Workshop on priorities in process
control research, Tulane-Univ. 1973.
3. Smith, C. L., Ibid.
4. Seborg, D. E., A survey of process control education
in the United States and Canada, Paper presented at
the 71st Annual AIChE Meeting, Miami, Nov. 1978.
5. Coughanowr, D. R., Koppel, L. B., Process Systems
Analysis and Control, McGraw-Hill 1965.
6. Morari, M., Ray, W. H., The Integration of Real-Time
Computing into Process Control Teaching at Wis-
consin, Paper presented at the 71 Annual AIChE
Meeting, Miami, November 1978. The first part of
the paper has been published in Chem. Eng. Education
13 No. 4 (1979) 160. The second part is in Chem. Eng.
Education 14, No. 1 (1980) 32.
7. Foss, A. S., Denn, M. M. (Eds), Chemical Process
Control, AIChE Symposium Series, 159 Vol. 72, 1976.
8. Vakil, H. B., Michelsen, M. L., Foss, A. S., Ind. Eng.
Chem. Fund. 12 (1973) 323.
9. Silva, J. M., Wallman, P. H., Foss, A. S., Ibid. 18
(1979) 383.
10. Wallman, P. H., Silva, J. M., Foss, A. S., Ibid. 18
(1979) 392.
11. Fisher, D. G. in Weaver, R.E.C. (Coordinator), Pro-
ceedings of the Workshop on priorities in process
control research, Tulane Univ. 1973.
12. Foss, A. S., Edmunds, J. M., Kouvaritakis, B., Ind.
Eng. Chem. Fund. 19 (1980) 109.
13. Bilec, R., Wood, R. K., Multivariable Frequency
Domain Controller Design for a Binary Distillation
Column, Paper presented at the 86th National AIChE
Meeting, Houston, April 1979.
14. Joseph, B., Brosilow, C. B., Tong, M., AIChEJ 24
(1978) 485.
15. Brosilow, C. B., The structure and design of Smith
predictors from the viewpoint of Inferential control,
Paper presented at JACC 1979.
16. Astrim, K. J., Wittenmark, B., Automatica 9 (1973)
185.
17. Astr6m, K. J., Borison, U., Ljung, L., Wittenmark, B.,
Ibid. 18 (1977) 457.
18. Zadeh, L. A., Trans. ASME, J. Dyn. Syst. Meas.
Control 94 Ser. G (1972) 3.
19. Zadeh, L. A., IEEE Trans. Systems, Man, Cyber-
netics SMC-3 (1973) 28.


20. Bristol, E. H., IEEE Trans. Auto. Contr. AC-11
(1966) 133.
21. Shinskey, F. G., Process-Control Systems, McGraw-
Hill 1967, Second Edition 1979.
22. Rijnsdorp, J. E., Automatica 1 (1965) pp. 15, 29.
23. Nisenfelt, A. E., Schultz, H. M., Instr. Technology 18
No. 4 April (1971) 52.
24. McAvoy, T. J., ISA Trans. 16 (1977) No. 4, p. 83.
25. Witcher, M. F., McAvoy, T. J., Ibid. 16 (1977) No. 3,
p. 35.
26. Tung, L. S., Edgar, T. F., Analysis of Control-Output
Interaction in Dynamic Systems, Paper presented at
the 71 Annual AIChE Meeting, Miami, Nov. 1978.
27. Gagnepain, J. P., Seborg, D. E., An analysis of process
interactions with applications to multiloop control
system design, Paper presented at the 72nd Annual
AIChE Meeting, San Francisco, November 1979.
28. Kominek, K. W., Smith, C. L., Analysis of System
Interaction, Paper presented at the 86th National
AIChE Meeting, Houston, April 1979.
29. Shinskey, F. G., The Stability of Interacting Control
Loops with and without Decoupling, Proc. IFAC
Multivariable Technological Systems Conf. 4th Inter-
national Symposium, Univ. of New Brunswick (1977)
p. 21.
30. Jafarey, A., McAvoy, T. J., Ind. Eng. Chem. Proc. Des.
Dev. 17 (1978) 485.
31. Jafarey, A., McAvoy, T. J., Douglas, J. M., Ibid. 49
(1980) 114.
32. McAvoy, T. J., Ind. Eng. Chem. Fund. 18 (1979) 269.
33. Jafarey, A., McAvoy, T. J., Douglas, J. M., Ibid. 18
(1979) 269.
34. Bristol, E. H., Recent Results in Interaction in Multi-
variable Process Control, Paper presented at the 71st
Annual AIChE Meeting, Miami, Nov. 1978.
35. Donoghue, J. F., IEEE Trans. Ind. Elect. Contr.
Instr. IECI-24 (1977) 109.
36. Hammarstr6m, L. G., Waller, K. V., IEEE Trans.
Ind. Elect. Contr. Instr. IECI-27 (1980) 301.
37. Jafarey, A., Douglas, J. M., McAvoy, T. J., Ind. Eng.
Chem. Proc. Des. Develop. 18 (1979) 197.
38. Evans, L. B. in Weaver, R. E. C. (Coordinator), Pro-
ceedings of the Workshop on priorities in process
control research, Tulane Univ. 1973.
39. Waller, K. V., Paper and Timber, 62 (1980) 128.
40. Chen, F. T., Douglas, J. M., Georgakis, C., Ind. Eng.
Chem. Fund. 18 (1979) 321.
41. Mamdani, E. H., Applications of Fuzzy Set Theory
to Control Systems: A Survey, in Gupta, M. M.,
Saridis, G. N., Gaines, B. R. (Eds), Fuzzy Automata
and Decision Processes, Elsevier North-Holland 1977.
42. Tong, R. M., Automatica 13 (1977) 559.
43. Asbjornsen, 0. A., Survey Paper, Symposium on use
of process computers, European Federation of Chemi-
cal Engineering, 166th Event, Firenze, Italy, Sept.
1976.
44. Ballard, D., Brosilow, C. B., Dynamic Simulation of
Multicomponent Distillation Columns, Paper pre-
sented at the 71st Annual AIChE Meeting, Miami,
45. Athans, M., Discussion remark in round table dis-
cussion on "The next decade in control theory and
applications," IFAC VII Triennial World Congress,
Helsinki, June 1978.
46. Shinnar, R., Chem. Eng. Education 11 (1977) 150.


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"This kind of decision-
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PROCTER & GAMBLE is looking for in R&D / Product Development This organization is responsible for the creation and improvement of new and existing products, together with developing the associated technology advances and solving technical problems. While this organization encompasses the full range of scientific and engineering backgrounds, the primary need at the BS/ MS level is for Chemical Engineers and MBAs with a chemical or engineering undergraduate degree. Your initial responsibilities in the organization would be primarily technical, with varying degrees of interactions with P&G's Engineering, Manufacturing and Marketing divisions. As you advance, your career could evolve along technical and/or management routes. This evolution will include progressive assignments, exposure to other divisions, and in many cases a transfer to another R&D/Product Development division, or where appropriate to an Engineering, Manufacturing or Marketing division. The R&D/Product Development organization is headquartered in Cincinnati, consists of over 20 divisions, focuses on U S. consumer and industrial products, conducts P&G's basic research, and provides technical support for our international operations and technical centers. (This technical support includes international travel by certain of our U.S.-based division personnel.) RESPONSIBILITY NOW! If you are Interested In this area, please send a resume to: The Procter & Gamble Company R&D BS/ MS Recruiting Coordination Office lvorydale Technlcal Center Spring Grove and June Avenues Cincinnati, Ohio 45217 PROCTER & GAMBLE AN EQUAL OPPORTUNITY EMPLOYER

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EDITORIAL AND BUSINESS ADDRESS Department of Chemical Engineering University of Florida Gainesville, Florida 32611 Editor: Ray Fahien (904) 392-0857 Associate Editor: Mack Tyner Editorial & Business Assistant: Carole C. Yocum (904) 392-0861 Publications Board and Regional Advertising Representatives: Chairman: Lee C. Eagleton Pennsylvania State University Past Chairman: Klaus D. Timmerhaus University of Colorado SOUTH: Home1 F. Johnson University of Tennessee Ralph W. Pike Louisiana State University James Fair Univers ity of Texas Gary Poehlein Georgia Tech CENTRAL: Darsh T. Wasan Illinois Institute of Technology J. J. Martin University of Michigan Lowell B. Koppel Purdue University WEST: William H. Corcoran California Institute of Technology William B. Krantz University of Colorado C. Judson King University of California Berkeley NORTHEAST: Angelo J. Perna New Jersey Institute of Technology Stuart W. Churchill University of Pennsylvania Raymond Baddour M.I.T. A W. Westerberg Carnegie-Mellon University NORTHWEST: Charles Sleicher University of Washington CANADA: Leslie W. Shemilt McMaster University LIBRARY REPRESENTATIVE Thomas W. Weber State University of New York WINTER 1981 Chemfoal Engineering Educa tion VOLUME XV NUMBER l WINTER 1981 14 .,(/u,ca11,r/, .eectw,,e A New Look at an Old Fossil: Kinetics of Coal Processing, D. D. Perlmutter 2 Departments of Chemical Engineering ChE at Notre Dame, Faculty 8 The Educator Richard M. Felder, R. W. Rousseau 20 ChE Lecture Infinite Possibilities for the Finite Element, Bruce A. Finlayson 26 ChE Laboratory A Simple Tubular Reactor Experiment, Robert R. Hudgins, Bertrand Cayrol 30 ChE Curriculum Impressions of Process Control Education and Research in the U.S., Kurt V. Waller 12 Stirred Pots Sodales Princetonienses, Rutherford Aris 36 ChE News Chemical Engineering Symposium at Carnegie-Mellon, Michael Locke 38 Problems for Teachers Solution: Prarie Dog Appendix, R. L. Kabel 40 Classroom Teaching Market Analysis, J. T. Ryan, Bret Haugrud 25 Letter to the Editor 37 Positions Available CHEMICAL ENGINEERING EDUCATION is published quarterly by Chemical Engineering Di v ision American Society for En g ineering Education. The publication is ed ited at the Chemical Engineering D epartme nt, University of Florida. Second-class postage is paid at Gainesville, Florida, and at DeLeon Spr in gs, 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 ot h er advertising material may be sent dir ec tly to the printer: E. 0. Painter Printing Co., P. 0. Box 877, DeLeon Sprin gs, Florida 32028. Sub sc ription rate U.S., Canada, and Mexico is $16 per year, $10 per year mailed to members of AIC hE and of the ChE Di vision of ASEE. Bulk subscription rates to ChE faculty on request Write for prices on individual back cop i es. Copyright 1981 Chemical Engineering Division of American Society for Engineerin g Education. 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 day s, The International Or ga nization for Standardization has assigned the code US ISSN 0009 2479 for the identification of this periodical. 1

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The ChE department i s l ocated i n t he n ew Fitzpatrick Hall of Engineering complete d i n J uly 1 979 [i) ;j :I department I CHE AT NOTRE DAME PREPARED BY THE FACULTY Uni v ersity of Notre Dame Notre Dame, IN 46556 T HE CHEMICAL ENGINEERING PROGRAM at Notre Dame began in 19 0 9. The 19 08 -9 B ulletin published in July 1909 noted that "chemical manu facture has developed so rapidly and grown so exacting that there has arisen a demand for men who not only can create and improve chemical processes strictly so called, but who can deal with the problems of construction and maintenance as far as they are related to chemical industries. To prepare yom ; 1g men for such work, the course in Chemical Engineering has been design e d." There were no specific courses in chemical engineering per se; of the total 167 semester credit hours in Copyright C h E D ivision ASEE. 19 8 1 2 the curriculum there were various courses in chemistry ( 58 er hrs) mechanical engineering (30 er hrs), drawing (15 er hrs) and shopwork (14 er hrs). By today's standards, the university was small then, with all students numb e ring 995, and only 42 faculty of which two were in chemis try. (Current total enrollment is 8500 and faculty number about 700). The first undergraduate "de gree of chemical engineer" was awarded in June 1911 at the 67th annual commencement to Guillermo Patterson, Jr. of New York City. (Inci dentally, ours is the only Chemical Engineering Department in the world which can boast of an alumnus named Jacques Rousseau. He did not minor in philosophy.) It was in the 1920 21 academic year that the university was reorganized in a form that exists to this date, with four undergraduate colleges in Arts CHEMICAL ENGINEERING EDUCATION

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The early chemical engineers at Notre Dame were taught chemistry by the brilliant chemist J. A. Nieuwiand, CSC-who with H. H. Carothers of du Pont is credited with inventing the first synthetic rubber "neoprene" ... -and by Knute Rockne, who was on the chemistry faculty during 1916-22 before moving on fulltime to some other activity. and Letters, Science, Engineering, and Business Administration (then Commerce)-each with its own Dean-and a separate Committee on Gradu ate Study, which preceded formal establishment of the Graduate School in 1932. A department of Law, now the Law School, was established in 1869. The heads of various departments were also ap pointed in 1920-21, and the first Head of Chemical Engineering (1920-41) was Henry B. Froning. Froning was a distinguished chemist who joined Notre Dame in 1920, and also served as Head of Chemistry (1920-41) before becoming Dean of Science (1940-43). The course "Principles of Chemical Engineering" based on the pioneering devote fulltime as Dean of Science. Rich had joined the faculty in 1933, and was a Notre Dame alumnus (B.S. Ch.E. '28, M.S. Chem. '36) ; he guided the department until 1959 when Julius T. Banchero arrived from Michigan as Head. Other Chemical Engineering faculty during this period were P. J. Byrne, Jr. (1920-22), H. Wenzke (192239), E.G. Mahin (1926-33), H. Hinton (1929-38), A. Boyle (1929-39), G. Hennion (1933-40) and E. J. Wilhelm (1938-71). The Chemical Engineer ing Department also moved to a then new building in 1941. GRADUATE PROGRAM book of the same name by Walker, Lewis and p RIOR TO 1945, THERE WERE NO graduate courses McAdams (1923) was added to the curriculum in offered within the Chemical Engineering De1921, replacing its predecessor course in Industrial partment. Several graduate courses including lecChemistry. The early chemical engineers at Notre tures and a laboratory in Applied ElectrochemisDame were taught chemistry by the brilliant try, Advanced Thermodynamics, Advanced Unit chemist Rev. Julius A. Nieuwland, CSC-who with Operations lectures and laboratory, and Advanced W. H. Carothers of du Pont is credited with inPlant and Equipment Design were initiated in venting the first synthetic rubber "neoprene" in 1945-46 to accommodate the returning WWII the late 20's-and by Knute Rockne, who was on veterans who were anxious to renew their engithe chemistry faculty during 1916-22 before neering background. Allen S. Smith (Ph.D. Michimoving on fulltime to some other activity. gan, '40), who joined the Chemical Engineering By 1920, there were only 11 graduates of the faculty in 1946 and remained here till his death department. The present undergraduate degree in 1967, was a major factor in this development. "bachelor of science in chemical engineering" was He introduced additional graduate level courses in instituted in 1925. The number of graduates rose 1946 on analysis of Distillation and Extraction, steadily; 59 degrees in the 20's and 156 in the and Applied Chemical Kinetics; these along with a 30's. The headship of the department passed to Heat Transmission course by Rich and Corrosion Ronald E. Rich in 1941 when Froning left to of Metals and Alloys offered by Wilhelm, plus Henry B. Froning 1920-41 WINTER 1981 CHAIRMEN OF ChE AT NOTRE DAME Ronald E. Rich 1941-59 Julius T. Banchero 1959-79 Roger A. Schmitz 19793

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those initiated the previous year provided sufficient offerings to begin a formal master's program with required thesis research. Other engineering departments were also beginning their master's programs at this time. The very first master of science in engineering was awarded to a mechani cal engineer in June 1947; the first wave of ten masters of science in Chemical Engineering gradu ated in August 1947. Other than Rich, it was Wilhelm and Smith, F. L .Benton (1940-56), M. T. Howerton (194956), J. Treacy (1950-56), G. Parravano (195659) and J. P. Kohn (1955-present) who taught Chemical Engineering at Notre Dame during the 40's and 50's. A total of 212 bachelors degrees in Chemical Engineering were awarded during the 40's, and 336 in the 50's. By 1959, 77 master's degrees had also been awarded. Due to Rich's failing health, J. T. Banchero was acquired as Head in 1959. He came with assurance from the administration that a doctoral program in Chemical Engineering could be started. By this time, G. S. John (1958-63) had already joined the faculty, but the major addition was that of E. W. Thiele-well known for his pioneering contributions to two major areas of Chemical Engineering science ; the McCabe Thiele method for graphical design of distillation columns for binary separations and the Thiele modulus in the problem of simultaneous diffusion and reaction in porous catalyst pellets. Thiele had just retired after a long and productive research career with American Oil Company in 1960, and was persuaded to take on a second career at Notre Dame. Thiele retired from active teaching in 1970 at age 75, and was awarded an honorary doctorKinetics and reactor studies are conducted in the Catalysis and Reaction Engineering laboratory. 4 ate in 1971 in recognition of his contributions to Chemical Engineering and Notre Dame. The next addition to the faculty was J. J. Car berry in 1961, a former Notre Dame undergradu ate, who had been with du Pont after receiving his Ph.D. at Yale in 1957. Along with Banchero, Kohn, Smith, Thiele and Wilhelm already present then, his addition provided a major thrust towards the growth of the graduate program. A total of 55 Ph.D. degrees in Chemical Engineering have been awarded since the first one in June 1963 to Joosup Shim who did his thesis research with Jim Kohn. During the sixties and much of the seventies, undergraduate enrollments were about 30 in each class, and fulltime graduate students in residence averaged 22 per year. The graduate program was considerably strengthened during this period. Several other faculty members, A. H. P. Skelland (1963-69), E. D. Crandall (1965-69), T. G. Smith (1969-75), N. D. Sylvester (1969-73), F. H. Ver hoff (1969-74) and K. D. Luks (1967-79) played a major role in this development. Various new graduate courses were added to the program. Three other present faculty members, W. Strieder (1969), A. Varma (1975) and E. E. Wolf (1975) also joined during this period. The department moved to its present location in the new Fitzpatrick Hall of Engineering in July 1979. Our clas$room and laboratory facilities are now among the best and most modern available anywhere. THE PRESENT w ITH THE RETIREMENT and elevation to emeritus status of Julius Banchero in 1979, the de partment was very fortunate to attract Roger A. Schmitz as Keating-Crawford Professor and Chairman. Schmitz had taught at the University of Illinois-Urbana since 1962, and is widely known for his pioneering experimental research on dy namics and control of chemical reactors. As with other Chemical Engineering depart ments, we are also experiencing a large growth in our undergraduate enrollments. We had 30 bachelor's degree graduates in 1978-the average per year for the preceding twenty years-and 50 in 1979. Our current senior class is 70, and we have 87 sophomores! F emale students were first admitted to Notre Dame at the undergraduate level in 1972; our first batch of female bachelor's degree holders graduated in 1975. Today 22% of our CHEMICAL ENGINEERING EDUCATION

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undergraduate students are female, which almost equals the university figures and is significantly higher than the rest of the College of Engineering. Three new tenure-track faculty, all fresh Ph.Ds, have been hired this year; C. F. Ivory and J. C. Kantor from Princeton, and M. A. McHugh from Delaware. We have 31 fulltime graduate students in residence this year-which with the present faculty strength permits excellent student faculty interaction. CURRICULA THE B.S. DEGREE IN CHEMICAL Engineering is a four year program requiring 128 semester hours. The 24 hours of liberal arts required, are well in excess of ECPD requirements. We hope to increase that number as Notre Dame deems a Professor James J Carberry providing valuable tips on reactor design. liberal education to be of paramount importance whatever be the students professional calling. In addition to the usual Chemical Engineering and allied chemical and physical sciences, there is an engineering core including a course in the Fresh man year, Introduction to Engineering in which engineering methodology is taught along with computer training, including use of FORTRAN. The remaining core engineering courses are in probability, engineering mechanics, electrical engi neering science, thermodynamics, materials science, and applied mathematics. Chemical Engi neering courses include mass and energy balances, stagewise operations, transport phenomena, chemi cal reaction engineering, thermodynamics, process design, process modeling and control, transport processes laboratory and unit operations labora tory. The graduate curriculum includes courses in WINTER 1981 advanced thermodynamics, statistical thermo dynamics, mathematical methods (2 courses), transport phenomena (2 courses), advanced re action engineering, heterogeneous catalysis, poly mer engineering, numerical methods, ,_ process control and modeling, dynamics of reaction. pro cesses (2 courses), heterogeneous phase eqilibria, and equilibrium state operations. In a:dd ~ tion to the formal courses, there is a Chemical ~ n gineer ing seminar, advanced topics in Chemica f Engi neering, advanced studies projects, and re ~ arch projects leading to M.S. and Ph.D. degrees : '}:'here is a research M.S. degree which requires 24)10urs of course work and a thesis. However most students elect to pursue the non-research M.S. degree which requires 30 hours of course work. Graduate students are encouraged to take gradu ate level courses from outside the department, particularly in chemistry, physics, mathematics, or engineering. First year graduate students are required to take a 3 credit special topics course in which they choose an advisor and devote them selves to solution of an original problem. The Ph.D. degree requires the course work for the M.S. degree plus additional courses in Chemi~ cal Engineering and science deemed important to the candidate's research area. The progress of each Ph.D. student is reviewed periodically by his or her research committee. Normally the M.S. degree can be obtained in one calendar year of fulltime study, while the Ph.D. degree ordinarily takes from three to four years of fulltime study beyond the undergraduate degree. A casual discussion of important issues among faculty members, from left: Arvind Varma, James Kohn and William Strieder 5

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Graduate research in the Thermodynamics and Phase E q ui l ibria laboratory. FACULTY AND RESEARCH INTERESTS J. T. Banchero, Professor Emeritus, Ph.D. University of Michigan, 1950. Co-author of text book "Introduction to Chemic a l Engineering" with W. L. Badger, McGraw-Hill Compan y (1955), and "Unit Operations" with G. G Brown et al., J. Wiley Company (1950). Dr. Banchero has interests in liquid-phase epoxide reactions, design of chemical reactors, and thermodynamic s of solutions. J. J. Carberry, Professor Dr. Eng., Yale Uni versity, 1957. Author of textbook "Chemical and Catalytic Reaction Engineering," McGraw-Hill Book Company (1976), and co-editor of the journal "Catalysis Reviews." Dr. Carberr y has con centrated his research intere s ts in chemical re action engineering and heterogeneous catalysis, and in 1976 was recipient of the Wilhelm Award in Chemical Reaction Engineering (AIChE). C F. Ivory, Assistant Professor, Ph.D., Prince ton University, 1980. Dr Ivory has wide-based interests in transport phenom,ena and biosepara~ tions. J.C. Kantor, Assistant Professor Ph.D. Prince ton University, 1980. Dr. Kantor is interested in process analysis, dynamics and control, and applied mathematics. J. P. Kohn, Professor, Ph.D. University of Kansas, 1955. Dr. Kohn has interests in applied thermodynamics, heterogeneous phase equilibria, 6 transport phenomena, and solar energy. M. A. McHugh, As s istant Professor, Ph.D. Universit y of Delaware, 1980. Dr. McHugh has interests in high pressure phase equilibria, super critical solvent extraction, and application to coal utilization. R. A. Schmitz, Keating-Crawford Professor and Chairman, Ph.D. University of Minnesota, 1962. Dr. Schmitz has interests in dynamics and control of chemical reactors; instabilities and o s cillator y phenomena in chemically reacting s ys tem s and in kinetics of gas-liquid reactions. He won the Colburn Award of AIChE in 1970, and the Westinghouse Award of ASEE in 1977. W. C. Strieder, Associate Professor, Ph.D., Case Institute of Technology, 1963. Co-author with Rutherford Aris of the monograph "Varia tional Methods Applied to Problems of Diffusion and Reaction," Springer-Verlag, (1973). Dr. Strieder ha s interests in diffusion in porous media, kineti c theory, surface phenomena and molecular theor y of transport processes. A. Varma, Professor, Ph.D., University of Minnesota, 1972. Dr. Varma has interests in chemi cal and catalytic reaction engineering, modeling and simulation and applied mathematics. Varma, with Aris, recently co-edited "Mathematical Underst a nding of Chemical Engineering Systems -Selected Papers of Neal R. Amundson," Perga mon Press (1980). E. E. Wolf, Associate Professor, Ph.D., Uni versity of California, Berkeley, 1975. Dr. Wolf has interests in heterogeneous catalysis, chroma tographic separations, and chemical reactor engi neering. Wolf recently translated Carberry's text into Spanish. In sum, the Chemical Engineering program at Notre Dame has evolved through three stages: An exclusively undergraduate program, 1909-1946. A n undergraduate and master 's program, 1946-1960. A B.S., M.S. and Ph D. program since 1960. With the appointment of Roger Schmitz as Chairman in 1979, and the addition of three as sist a nt professors in 1980, a fourth stage of ad vancement is manifest insofar as our research strength has been broadened : chemical and c a tal y tic reaction engineering, heterogeneous catalysis applied mathematics, thermodynamics and phase equilibria, transport phenomena, and process dynamics and control. We are happily charged by our administration in the spirit of Verdi's Falstaff: "Continua!" CHEMICAL ENGINEERING EDUCATION

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INNOVATION ... Sometimes it's not all it's cracked up to be. an equal opportunity employer However, at Union Carbide innovation continues to improve peoples lives. Union Carbide pioneered the petrochemicals industry Today the Corporation s many hun dreds of chemicals are used in everything from automobile bumpers to shampoos. A leader in the field of industrial gases our cryogenic technology led to the development of the Oxygen Walker System which allows mobility for patients with respiratory diseases Union Carbiders are working on the frontiers of energy research-from fission to geothermal-at the world renowned Oak Ridge National Laboratory in Tennessee. Our revolutionary Unipol process produces polyethylene, the world s most widely used plastic at one half the cost and one quarter the energy of standard converting processes From sausage casings to miniature power cells the Union Carbide tradition of innovation extends beyond research and development activities to our engineering groups, manufactur ing operations, and sales forces Continued innovation will largely spring from the talents of the engineers and scientists who join us in the 1980's We invite you to encourage qualified students to see our representatives on campusor write to: Coordinator Professional Placement Union Carbide Corporation 270 Park Avenue New York NY 10017

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[! ;j a educator R. W. ROUSSEAU North Carolina State University Raleigh,, NC 27650 R ICH FELDER JOINED the Department of Chemical Engineering at North Carolina State Uni versity in July 1969. He holds the rank of Pro fessor and has established himself as a leader in chemical engineering education. His contributions in teaching, research and administration reflect commitment to the profession and engender ap preciation and admiration from his colleagues. TEACHING RICH TEACHES UNDERGRADUATE courses in Reaction Kinetics and Reactor Design, Thermo dynamics, Chemical Process Systems and Chemi cal Process Principles, which is the first course in chemical engineering. In addition he teaches graduate courses in Chemical Kinetics, Reactor Design, Optimization, Process Modeling and Special Topics in Coal Gasification. His ability to establish rapport with students makes him one of the most popular faculty mem bers in the Department. Undergraduate and gradu ate students have consistently evaluated his courses as being among the best they have taken. In recognition of his teaching performance he has received a School of Engineering Outstanding Teacher Award and has been named to the NCSU Academy of Outstanding Teachers. :.-Students particularly compliment the clarity with which Rich can present a lecture. Course evaluation forms describe him as "always pre :Rared," "clear and easy to follow" and a "great teacher.'; More than any other faculty member, he is responsible for glowing compliments con sistently used by students to describe the intro ductory course in chemical engineering. The de manding nature of this course makes such atti tudes remarkable. Rich has a classroom style centered about what might be called a present-and-probe approach. The "present" part always consists of a routine in which the class is told first what is going to be covered and why it is important. The concept is subsequently presented clearly and concisely and, finally, an example is used to illustrate its application to a practical problem. The "probe" part actually occurs during his presentation; he sprinkles an oversupply of "okay"? and other rhetorical questions throughout the lecture, some how sensing which points have been grasped by students and which need additional coverage. His ability to establish rapport with students makes him one of the most popular faculty members in the Department . In recognition of his teaching performance he has received a School of Engineering Outstanding Teacher Award and has been named to the NCSU Academy of Outstanding Teachers. Co p yright ChE Di vi s i on, ASEE, 1981 8 CHEMICAL ENGINEERING EDUCATION

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The reorganization of the Ph.D. qualifying exam is one of Rich's most significant administrative accomplishments. His work with students outside the classroom is also exemplary, both in his official capacity as Graduate Administrator and in his unofficial role of confidant and consultant. His concern for the development of the complete person fosters state ments on student evaluations like "he is always willing to discuss a problem, even if it is a personal one." In recent years Rich has given numerous in dustrial short courses in Basic Principles of Chemical Engineering, Process Maximization, Polymer Reactor Technology and Separation Pro cess Technology. In participant critiques of these courses he draws raves for his clarity, style and quantity of material covered. Finally, no description of Rich's teaching would be complete without mentioning his work with countless elementary and junior high school students. It is not unusual to see him charging out of his class on chemical kinetics and into a meeting with a third grade class from one of Raleigh's magnet schools for extraordinarily gifted and talented kids. He will have volunteered to discuss something like coal gasification with these children, and will do so with the same clarity and enthusiasm he has for his senior class in re actor design. It is believed that he could, given a little notice, walk into a class on almost any subject and present a lecture that would result in students learning the material he presented. ADMINISTRATOR As GRADUATE ADMINISTRATOR, Rich coordinates all graduate student activities in the Depart ment, including applications for admission, ad mission of new students, selection of a research advisor and graduate committee, selection of a minor, administration of the Ph D. qualifying examination and scheduling of final oral examina tions. Graduate students recognize him as their most important contact, outside of their thesis supervisor, during their stay at North Carolina State University. The reorganization of the Ph.D. qualifying exam is one of Rich's most significant administrative accomplishments. It has been given in its present format for almost 10 years without significant complaint WINTER 1981 RESEARCHER RICH'S RESEARCH IS BASED on his interests in modeling chemical processes and the effects of chemical processing on the environment. These broad concerns have led to a variety of research programs, including radioisotope applications to proce s s anal y sis, photochemical reactions, use of polymeric interfaces for stack sampling, modeling of electrostatic precipitators and, most recently, environmental effects associated with coal gasifica tion. He has published forty-five articles in refereed journals as a result of research in these fields and he was recently awarded a patent for the novel use of polymeric interfaces in stack gas monitoring. The Environmental Protection Agency sup ports his research on the development of a collec tion tube for use as an interface in stack sampling, modeling the performance of electrostatic precipi tators and the environmental effects of coal gasi fication. His research on the evaluation of trace metals and sulfur gases from coal is supported by the Department of Energy. The NCSU Faculty Professor Felder giving impromptu lecture on CSTR's. Research and Professional Development Fund has supported the const r uction of a batch photoreactor, measurement of beta spectra emitted by a slab source, and dynamic simulation of a pulp chlorina tion tower. The research efforts described above have been marked by the same thoroughness and quality as Rich' s teaching. He was given the 1974 NCSU Sigma Xi Research Award for superior ac complishments in the field of scientific research. Rich has unselfishly contributed to other re search programs in the Department. His library of computer programs is extensive and he makes 9

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Felder with colleagues, Hal Hopfenberg (Depart ment Head) and Ron Rousseau. them available to colleagues and students. Further more, he can generally be counted on to have the latest information on analytical instrumentation. When the coal gasification research project got underway, there was a need for someone to learn capabilities of various instruments available for analyses of coal and char, waste water and gases found in the gasification/gas cleaning pilot plant. Rich accepted the responsibility and maintains an experti se in the use of an array of instruments, including atomic absorption spectrometer, ion chromatograph, gas chromatographs, sulfur ana lyzer, nitrogen analyzer, etc. Despite the enthusiasm Rich has for these re search efforts, he never loses sight of the proper relationship between university research and graduate students. He is concerned with their total professional and personal development, as well as their accomplishment of short range goals like ac cumulating data points and, ultimately, a degree. None of Rich's students has the slightest re luctance to take their "problem of the day" to him. His mortality and temper have been ob served, however, when a student has just broken the third calibrated rotameter in a single day. WRITER N O DESCRIPTION OF RICH FELDER would be complete without mentioning his enjoyment of the written word. (That's not to say he doesn't like the spoken one, too.) Although the 45 publications mentioned earlier and the textbook Elementary Principles of Chemi cal Processes may be indicative of the quality of Rich's writings, they are not true indicators of the quantity He is prolific. It is common knowledge among graduate students that any question may result in being given a handout specially prepared for such occasions. A look around his office will reveal stacks of documents he has written on everything from "What i s Chemical Engineering" to "Radiotracer Applicators in System Analysis." Writing a paper or a book with him can be both excrutiatingly painful and exhilirating. It can be painful because Rich's search for just the right word or phrase can result in numerous rewritings. None of his students or colleagues can escape his trusty scissors, tape and stapler. His saving grace in this regard is that he is just as likely as not to rewrite one of his own drafts. And the exhilirating part is that the document always sounds and reads superbly. It seems only fitting that I say a few words about Rich's unique contribution to our joint authorship of Elementary Principles of Chemical Processes. This textbook was published in 1978 and has been adopted for use at approximately 80 Departments of Chemical Engineering in the United States, several European universities, and will be translated into Spanish and Chinese. Two characteristics of the book which have been a factor in its widespread adoption are its pedogogi cal approach and style of writing Quoting from a review of the book that appears in the AIChE Journal, 25, 382 (1979), ... the style and level of presentation of the content is excellent, and the subject matter represents the ideal body of knowledge which should be imparted to students in the first year of a chemical engineering curricu lum." These features are primarily the result of Rich Felder' s insight into what students need to facilitate learning and his very special gift with the written word. In addition, the exploits of Sebastian Goniff, Johann Sebastian Farblunget, It is not unusual to see him charging out of his class on chemical kinetics and into a meeting with a third grade class from one of Raleigh's magnet schools for extraordinarily gifted and talented kids. He will have volunteered to discuss something like coal gasification with these children and will do so with the same clarity and enthusiasm he has for his senior class in reactor design. 10 CHEMICAL ENGINEERING EDUCATION

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Edd Seddera and other seedy but colorful charac ters sprinkled throughout the text, are illustrations of his sense of humor and his ability to couple wit with the illustration of chemical engineering principles. LIFE AND TIMES A FTER A CHILDHOOD IN Manhattan, Queens, Buffalo and North Miami, Rich settled down to make good grades and enter the City College of New York to study chemical engineering. Why Chemical Engineering? (a) Everyone who knew anything in 1957 was going into engineering and (b) he was intrigued by the idea of mixing color less liquids to produce a bright orange (his favor ite color and the reason for his subsequent Felder posing (i.e. acting like he's doing something) in front of coal gasification/gas cleaning pilot plant control panel. matriculation at Princeton) fluid. Why CCNY? He didn't like the letter MIT wrote to him, and think of all the carfare he saved. He graduated from City College No. 2 in engi neering and entered graduate school at Princeton. His interests became chemical physics, Barbara Cowl (whom he married), and hopeless liberal causes, not necessarily in that order. He was Morton Kostin's first graduate student, but he claims his major achievement was a catch in a softball game for which he is still revered by old timers on the Princeton faculty like Ernie Johnson and Bob Axtmann. He also tried Electrical Engi neering at Princeton but, on falling through the ceiling at 224B Halsey Street while installing air conditioner wiring, he decided his future remained in Chemical Engineering. .WINTER 1981 He enjoys music ranging from Mozart to McCartney and is especially fond of playing classical guitar, but he likes to play in groups so that his mistakes are less obvious .. he also memorizes Gilbert and Sullivan patter songs, believing that someday they will come in handy. Following his Ph.D., he spent a year at Har well, England as a NATO postdoctoral Fellow, and two years at Brookhaven National Laboratory. His research interests had now shifted to photo reactor design and analysis, and mixing effects in reactors. Letting it become known that he was interested in an academic career, some enlightened soul recommended he interview for a vacant posi tion at North Carolina State University. With his interest in United States geography confined to the blighted land mass east of the Hudson River and the hedonistic environment surrounding the San Francisco Bay, he is reported to have uttered the famous quote for which many New Yorkers later claimed credit: "North Carolina??? Get serious, wouldja !". Nevertheless, being basically curious, he came, he saw, he stayed. Why? He fell in love with the school, faculty, and (you guessed it) North Carolina. He claims never to have regretted the decision, except when he finds himself almost enjoying eating grits with red eye gravy. He maintains his passion for hopeless liberal causes, bialys with whipped cream cheese and Chivers Olde English Marmalade. He enjoys music ranging from Mozart to McCartney and is es pecially fond of playing classical guitar, but he likes to play in groups so that his mistakes are less obvious. He is often awed by our friend and colleague Jim Ferrell, who makes and plays classi cal guitars. You're not going to believe this, but he also memorizes Gilbert and Sullivan patter songs, believing that some day they will come in handy. Rich is also the devoted father of Kenneth, Elena and Gary, ages 14, 12 and 10. Despite his tireless professional efforts, he always seems to have enough energy left over to spend time with his children. One of his passions that he indulges in frequently is being beaten in chess by these budding Bobby Fishers. As a father, he exhibits a degree of patience and concern which reflects his feelings about children and, in fact, ,all people. ll

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[9;jpl stirred pots UNIVERSITATIS MINNESOTENSIS COLLEGIUM FABRORUM CHYMICORUM SODALES PRINCETONIENSES, NUNC ANNUM EORUM QUINQUAGESIMUM FELICITER AGENTES, GRATULATUR, MAGNO CUM GAUDIO, GRATUITO CUM CONSILIO, VENIAMQUiE W. S. GILBERTI POSCENS EDITOR'S NOTE: We are grateful to Prof. John Seinfeld (California Institute of Technology) for bringing our attention to the following poem, written by Prof. Ruther ford Aris of the University of Minnesota to congratulate Princeton University's Chemical Engineering Department on their fiftieth anniversary. When you're taking a whack, in your orange & black, at a problem defying solution In kinetics or flow, or the ways that bugs grow, or just how to get rid of pollution. When you're wracking your brain & you cannot obtain a result that fulfills your intentions Remember that Chem.E.s do nothing by semis and always get rid of dimensions Recollect that p' raps Schmidt's is the number that fits and that Peclet is Reynolds times Prandtl. Just remember your D's, it'll come out with ease when it's wrapped up in Damkohler's mantel. If you wish you could borrow relief from your sorrow, the Ohnesorge number we'll mention, Into Reynolds you shoot the good Weber's square root-it accounts for the surface's tension. For tubes in the boiler, use t'number of Euler and for drag use the factor of Fanning, Which in matters of fiction was used for the friction 'twixt Newman and Cardinal Manning. But it's really quite rude to rhyme Froude with St. Jude or to mess up a grave patronymic, 12 To dress up in gingham the number of Bingham, or regard Boussinesq's as a gimmick, While to think that Biot has to do with the glow that both heat and hard work often foster, Or that Deborah's song has the permanent pong of an overly ripe double Gloucester. To madden a Hatta or exchange for the latter the group that's been named Svant Arrhenius, To mock at the balding of Sherwood or Spalding; these are all of 'em crimes hyperhein(i)ous. If none of these fit, just reflect for a bit, devise one of your own it's a sine qua non for there's many a name that has brought Princeton fame. For size of reactor, use great Wilhelm's factor; for hard computation, 'tis Leon's equation; and if that don't fit well the number of Whitwell. If you've pulled a slight boner, be, absolved by Dick Toner; your problem's all garbled? Why, Dean Elgin' s not marbled; While, if biking's your goal, use the Johnson Control. You've got Schowalter (Bill), and there's Dudley Saville, Andres, Russel and Hall, Prud'homme, Ollis et al.**, for from such you can scoop a dimensionless group and you'll out of your fix be with some help from Ms. Bixby. But away cerebration. Now 'tis your celebration and we all think it's nifty that you flourish a~ 50. So we wish you good cheer for full many a year. RUTHERFORD ARIS Except Centenaries, of course. ** With due apologies to those not mentioned. CHEMICAL ENGINEERING EDUCATION

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Chevron Chevron O ii Field Research Company PhD Chemical Engineers For Research And Development In Enhanced Oil Recovery Chevron s laboratory In La Habra, California Is engaged In research directed towartl Increased recovery of oil and gas from known subsurface reservoirs Chemical engineering technology Is extremely Important In the very complicated business of recovering petroleum from known reservoirs-reservoirs of oil and gas already discovered and In quantities large enough to make a real difference In the United States domestic energy supply That Is, If we can find more effective processes for breaking it free from the rocks and bringing It to the surface The research, the development and the field trials of new ideas for recovering oil carry high risks and high costs But the stakes are high too! When you realize that typically twice as much oil Is left behind as Is produced by conventlonal methods It Is easy to understand how large these stakes really are and the energy resources that will be available If we can find the unlocking processes Our chemical engineers are also working on the problems of In situ recovery of heavy oils and oil from tar sands and shale. If you want to learn more about research in the more complex applications of chemical engineering send your resume to : J C. Benfamln Chevron 011 Field Research Company P O. Box446 La Habra CA 90631

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---------------------A NEW LOOK AT AN OLD FOSSI L: KINETICS OF COAL PROCESSING The 1979 ASEE ChE Division Lecturer was Dr Daniel Perlmutter of the University of Pennsyl v ania The 3M Company supports this annual award. Dan Perlmutter earned his Bachelor's Degree (Magna Cum Laudei) from New York Univ. and his Doctorate in ChE from Yale Univ. From 1955 to 1958 he worked for the Exxon (then Esso) Standard Oil Company His academic career began in 1958 at the U of Ill i nois, Urbana, and mo v ed to the U. of Pennsylvania in 1964. Follow ing a reorgani z ation of the College of Engineer ing and Applied Science, he became the first Chair man of the department of Chemical and Biochemi cal Engineering, a position he held from 1972 to 1977. He has been a v isiting Professor at Harvard U., the U. of Manchester, the U. of Zagreb, and the Hebrew U. of Jerusalem, in the capacity of a Fulbright Professor in England and Yugoslavia and as a Guggenheim Fellow in Cambridge. He has developed new c ourse materials in chemical reactor control, optimi z ation, and stability problems. His textbook, Introduction to Chemical Process Control, was one of the first available in its field, and was widely adopted in the U.S and ab r oad. His monograph on Stability of Chemical Reactors provided a unified view of a wid~ range of questions by combining some original work with an integrated survey of ma terial only a v ailable in scattered journal articles. His most recent research has been on the kinetics of gas solid reactions, prompted especially by their connections w i th energy related problems in coal drying, oxidation, and gasification, as well as reversible storage in the form of heat of re action. 14 D. D. PERLMUTTER University of Pennsyl v ania Philadelphia, PA 19104 T HE WIDELY PROCLAIMED energy crisis that so profoundly affects world affairs should be understood to be caused not by a lack of fossil fuel resources, as much as by a shortage of fuel in the highly desirable gaseous and liquid forms. It is accepted in all quarters that proved coal reserves are ample to supply anticipated world energy needs for at least several hundred years and further that no geographic monopoly is possible, since the deposits are very widely distributed over virtually every continent. It is evident in this context that the technology of the so-called gasi fication and liquefaction processes are central to handling the crisis : techniques for coal conver sion are being sought that will supply transporta tion, space heating, chemical feedstocks, and in dustrial needs at prices comparable to petroleum sources. The objective moves closer as OPEC prices continue to rise. It is convenient to think of gasification as com posed of three steps: (i) coal pretreatment, (ii) pyrolysis, and (iii) char reaction, even though a particular process may circumvent one or more of these, or may be designed to accomplish several objectives in a single reactor. The step-wise viewCopy ri ght ChE D ivisi on, ASEE, 1 981 CHEMICAL ENGINEERING EDUCATION

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point leads most smoothly into an examination of the appropriate chemical and physical properties of coal, and of the changes that need to be sought and monitored. PRETREATMENT THE PRIMARY MOTIVATION for a study of coal pretreatment is a practical processing diffi culty. When common bituminous coals are sub jected to high temperature gasification conditions they tend to soften and swell, and can plug re actors and transport lines before ultimately re solidifying as a porous char or coke. This process is commonly referred to as caking; it must be con trolled if the solid fuel is to be successfully gasi fied. A mild oxidative pretreatment is commonly used to reduce or eliminate this coal caking pro pensity, providing two steps in one: drying to re7000 7 1000 I T.J +14 WE.SM } 2 2 ;5000 => I 1_ 1 4 +II J ::: I .. E ooo I ., I ., 1 I 0, e +oo : 3000 0 1:: \\ ., I "' : 2000 I I ., .. ;:~ .. 1000 I \ : \ C ....... _-!__ uo 400 40 520 &40 TEST TEM.PERAT !J JIE, c (AT 2c/MIN. JI ISE) FIGURE 1. Caking test results for feed coal samples. move naturally occuring water on the coal surfaces, and the chemical oxidation. Many laboratory test methods have been used to study the plastic properties of coals, all em pirical in nature and devised to characterize the plastic behavior of coal by means of numerical indices. Comprehensive summaries and reviews of the methods have been given by Brewer (1945) and Loison et al. (1963). One common test is the Gas Flow test (Foxwell, 1924; Coffman and Layng, 1927, 1928), chosen for its simplicity in apparatus design and operation and for its close resemblance to the caking of coal in a packed bed WINTER 1981 ... techniques for coal conversion are being sought that will supply transportation, space heating, chemical feedstocks, and industrial needs at prices comparable to petroleum sources. reactor. In this test, a sample of the coal is heated at a constant rate of temperature rise (2C/min) inside a tube with a constant flow of nitrogen through the coal sample. The differential pressure drop across the sample is monitored, as the sample goes through its plastic range. Pressure drop vs. temperature readings are taken as data, as shown in Figure 1. After the oxidizing pretreatment the same test shows a sharp reduction in pressure drop as in Figure 2, reflecting a lesser degree of softening, swelling, and "caking." Changes recorded as mechanical properties need to be matched to chemical effects, if one is to understand the details of the preoxidation. For this purpose, a HV A bituminous coal was oxidized in a packed-bed reactor with a once-through mix ture of N 2 and 0 2 monitored by analyzing the composition of the feed and product gases with a dual-column Gas Chromatograph. Typical results on overall reaction rates are shown in Figures 3 to 7, emphasizing the effects of flow rate, particle size, oxygen concentration, pres sure, and temperature, respectively. In addition, the chromatographic analysis run on each sample of reactor effluent provided a record of carbon dioxide and carbon monoxide production to match o~---------~ ; 110 3 e .. .. 120 .. 0 C 0 .. 1 0 ;;: 4 ., .. .. .. o .. o ,Ill[[FLOW I NG 400 440 48 0 520 540 TEST TEMPERAT UR E c (AT z C/MIN A ISE) FIGURE 2. Caking test results for -18 to + 50 mesh oxidized coal samples.

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the rates of oxidation. Cross plots are presented as Figures 8 and 9 to illustrate the linearity and to demonstrate that the correlations for the various coals do indeed persist as flow rate, particle size, and conversion vary. Evidently, the two carbonic gases are formed in a constant ratio, presumably by the same mechanism. Correlation of all these findings by means of a comprehensive argument requires formulation of a model that includes several steps. The two car bonic gases appear to form together by a direct burnoff reaction. Simultaneously, oxygen is ad sorbed by the coal to form any of a series of oxy20 T = 2 00 C RUN G AS FLOW a: 0 20 142 SCCM :J: 28 98 ..J C( 0 0 8 21 70 ::E (!) 0 19 42 >< 15 ::E (!) ... IC( a: z I~10 ... a: z ... (!) X 0 5 L...........I.-....L.-.I..---L--'-__;:1-_.,___ 0 2 4 6 8 REACTION Tl ME, HRS FIGURE 3. Effect of feed gas flow rate on 0 2 reaction rate. functional groups, and hydrogen is removed in a direct water formation reaction. Superimposed on this complex chemistry are possible transport limitations outside and inside the coal particles. Quantitative tests have been used to demonstrate consistency between the data and such models (Kam et al., 1976; Karsner and Perlmutter, 1980). Turning to more immediately practical results, it is of interest to relate oxidation rates to the geologic history of various coals. In Figure 1 10 comparable rates are presented as a function of 16 20 T = 200c 18 RUN COAL SIZE 1 MESH oi 0 22 -18 +~o :J: 8 -14 +18 ..J 21 C( 18 0 [:] 23 -6 +14 0 :I: (!) "' ..... :I: 14 (!) ... IC( a: z 12 0 j:: 0 C( ... a: 10 z ... (!) X 0 8 6 2 4 6 8 REACTION TIME I HRS FIGURE 4. Effect of particle size on 0 2 reaction rate 50 a: :J: ::}40 C( 0 u ::E "' "' 30 "' ... C( a: 20 lo C( UJ a: z "'10 "' X 0 RUN VOL.% 0 2 047 28 20 8 45 13 0 46 9 0 ~.....L--'--1----'--...1----'--'-o 2 4 6 8 REA CTI ON TIME, HRS. FIGURE 5. Effect of feed 0 2 concentration on oxygen reaction rate. CHEMICAL ENGINEERING EDUCATION

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a:: :I: .J c( 30 fl 25 ::E
PAGE 20

generalizations regarding the fixation of oxygen that occurred for all the various bituminous coals do not apply to the lignite (PSOC 87) and the anthracite (PSOC 80) coals. CHAR REACTION T URNING ATTENTION TO the downstream side of a coal gasification process, models are needed t o describe kinetics of the several gas-solid re2 0 I iSfiD f p 15 .... ::::i 0 :::c ..; C, u <.!) :><'. C'l ~10 "' 0:: I C 0 B ::::i -0 0 .... c.. A "' ,. 0 u A I 5 I I fil Run No. Flow, SCCM I I I o 13 A 100 A 18 A 50 I I I 0 0 5 10 C O P rodu cti o n Ra t e, g I KG C oal / Hour FIGURE 9 Rela ti v e carb o n d i o xi d e a n d carbon mo n o xi d e p r odu ct io n rat e s. C oa l: HVC bitumi n o u s PSOC 1 90 acti o ns involving p o rous chars. The experimental rep o rts of Hashimoto et al. (1979) provide a good p o int of departure, since any model to be de vel o ped must be consistent with the features of re action such as are presented in Figure 11. Ab o ve all a viable m o del must permit the de vel o pment of a maximum in rate ( or reactive surface) as a function of conversion. A promising K EY R UN !_Qf~ 0 SW 4 6, 121,1 197 .c 'v 2 7W 127 --'"" 80 .. 24W 135 0 u K .. 70 -"' 9A 127 --.. 60 12A 135 0 50 QI u 40 .. C 0 30 ... u .. .., 20 ... X 0 1 0 0 65 70 75 80 85 90 Ca r bo~ Co nte11t, W t i (ultimate) F IGURE 10. Effect of coal carbon content on initial oxidation rate for -18 + 50 mesh particles at 225 C, 100 SCCM. candidate in this direction has been developed by Bhatia and Perlmutter (1980) who considered the isothermal chemical reaction of particles of the solid B with a fluid A a ccording to the stoi chiometry aA (g) + bB (s) pP (g) + qQ (s) (1) The reaction is initiated on the surfaces of pores in the solid B. As further reaction occurs, a layer of product Q is formed around each pore, which separates the growing reaction surface of the solid B from the fluid reactant A within the pores. Continued on page 49. 0 o 02 04 06 08 10 B urnoff Xe[-] F I G U R E 11. Effect of char conversion on surface area, after Hashimoto et al. (1979). CHEMICAL ENGINEERING EDUCATION

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Monsanto Drive. It takes you a very long way. This sign marks the road that leads marketing majors at locations throughout into our International Headquarters in the U.S. St. Louis. We offer you opportunities, training These words, "Monsanto Drive" and career paths that are geared for have another and more significant meanupward mobility. If you are a person ing at Monsanto. It's a way of expressing who has set high goals and has an the special qualities of Monsanto people achievement record, and who wants to who have the will to meet challenges advance and s ucceed, be sure to talk head-on-to accomplish and succeed. with the Monsanto representative when We offer bright and energetic people he visits your campus or write to: with this drive the opportunity to help Buck Fetters, University Relations and solve some of the world's major problems Professional Employment Director, concerning food, energy, the environment Monsanto Company, 800 Nmth Lindand others. bergh, St. Louis, MO 63166 Challenging assignments exist for engineers, scientists, accountants and Monsanto A n e qual o pp o 1 tu11it y e mp l oy e r WINTER 1981 ,19

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INFINITE POSSIBILITIES FOR THE FINITE ELEMENT* BRUCE A. FINLAYSON University of Washington Seattle, 'WA 98195 FINITE ELEMENT METHODS are being used increasingly for engineering studies of struc tures, heat transfer, fluid flows, design of dams and flow of water in aquifers. Because of this widespread use the well-educated engineer should have some experience applying the finite element method. Finite elements are most effective for solving two-dimensional problems on irregular domains, but their use is sometimes warranted in one dimensional problems. Chemical engineers have used finite element methods in 1-D, without calling it a finite element method. Sometimes finite ele ments are not needed, and an analyst should know when to use finite elements and when not. This Bruce Finlayson has extensive experience modelling chemical engineering systems He is well known for developing the orthogonal collocation method as an efficient computational tool for modelling chemical reactors with both radial and axial dispersion and monolith, wall catalyzed reactors More recently he is known for work in finite element methods solving heat transfer and flow problems, particularly viscoelastic polymeric fluids and flow in porous media. He is the author of two books: The Method of Weighted Residuals and Vari tional Principles, Academic Press, 1972, and Non-linear Analysis in Chemical Engineering, McGraw-Hill 1980. This paper was presented at the ASEE meeting in Baton Rouge, LA, on June 24, 1979. 20 FIGURE 1. Flow Past a Flat Plate. distinction is less important for the practicing engineer who may use an available program. ONE-DIMENSIONAL PROBLEMS p ROBABL y THE OLDEST USE of finite element methods is for flow past a flat plate (see Figure 1). In the integral method (1, p. 142) we divide the region of space into two elements: a small element near the plate and a larger element away from the plate. We represent the velocity in these two regions by two functions : outer element: u = Uoo inner element : u = U"' cf> ( '>7) 11=y/8(x) The boundary layer thickness is a (x). It is this division of the region into two, with expansions of velocity in each region, that makes this a finite element method. We must still determine cf> ( '>7) and 8(x). These expansions are substituted into the boundary-layer equations (see 1, p.142; 2, .2 for the details) and the result is called a residual. We would like the residual to be zero since then the differential equation is satisfied. That may not be possible, particularly if the expansions for cf,(11) or a (x) are simple In the integral method we integrate the differential equation over the domain-in this case over the inner element--and set the result to zero, thereby making the differential equation zero "on the average." The result is an equation for the boundary layer thickness. Copyright ChE D ivision, ABEE, 1981 CHEMICAL ENGINEERING EDUCATION

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(B-A) a da = ~c dx U "' (1) The numbers A, B, and C can be calculated once q,(71) is known, and Eq. (1) is easily solved. The expansion for q, ( 71) is made as simple as possible: a polynomial. There are certain condi tions it must satisfy: The velocity should be zero at y = 0 (on the wall) or at 71 = 0: q,(0) = 0. The velocity should match at the node between the inner and outer element, which occurs at y = 8(x) or 71 = 1: q,(1) = 1. Likewise it is con venient to have the slopes match at 71 = 1: q,' (1) = 0. Applying these conditions to a quadratic function, q, = a + b71 + c71 2 gives the expansion for q, ( 71). q, = 271 7] 2 Ref. (1) uses (2) which is derived by using a cubic polynomial and adding the condition q," (0) = 0, which is obtained by making the differential equation be satisfied at the point 71 = 0 on the wall. Eq. (2) gives a slightly better result. With this function we have a representation for the velocity field in the whole domain. By satisfying the equation "on the aver age" we are using the integral method, and by representing the velocity by piecewise polynomials in different regions we are using finite elements. The finite elements are necessary because of the sharp changes of velocity near the wall. For the next example we turn to diffusion and reaction in a spherical catalyst pellet. Consider the reaction of carbon monoxide with oxygen in an alumina catalyst coated with small amounts of platinum. The rate of reaction has been measured to be Rate= kc where k and Ka depend on temperature (see 3, p. 461). The equations to be solved are 1 d 2 de R 2 k(T)c r 2 dr (r dr ) = De (1 + ac) 2 ~= Bi (c-1) atr = 1 dr m where we have written the non-dimensional r = r' / R, with r' the dimensional radial position in the catalyst and R the radius. c = c* i; co, where c 0 is the external concentration of CO, taken here WINTER 1981 Finite elements are most effective for solving two-dimensional problems on irregular domains, but their use is sometimes warranted in one-dimensional problems. as 4 % and a = K a e o = 5 at 58 C. For purposes of illustration we solve this for Bi m = 20 and a variety of R 2 k (T) / D 0 =
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B11C1 + B1 2 C 2 = R 2 k (T1) C1 / D e (1 + ac 1 ) 2 (3) -(A 21 C1 + A 22 C 2 ) = Bi m (C 2 -1) (4) '1J = 3(w 1 R(c 1 ) + W 2 R(c 2 )) / R(c = 1) B 11 =-B u = -10.5, A 21 = A 22 = 3.5 W1 = 0 2333, W 2 = 0.1, r 1 = 0.65465 T 1 = 1 + [38 + {3(18)C 2 /3C1 (5) 8 = Bi m / Bi = k g k e / (h p D e ) /3 = (-AHR) CoDe / keTo) The equation for T 1 is exact ( 4, pp. 96-97) Here we solve for f3 = 0 (isothermal case) and Bi m = 20. This solution is not valid for any cf, 2 but it is a good approximation provided c(r = 0) 0 (see Figure 2a). Since the approximation is valid for C 2 +a ~ 0 orc 1 -r / c 2 0. The '1J cp curve is shown in Figure 3 and is in distinguishable from the exact solution when cp < 10. This curve is easily calculated, without iteration, simply by choosing a C 2 finding C 1 from Eq. (4), T1 from (5) (if non-isothermal), and R 2 k(T 1 ) / c 1 from (3), with a evaluated at T 1, For large cp w e must use the Paterson Cres s well (5) approach using finite elements. In the inner element of Figure 2b we take c = 0 and we let the inner element have length b s 1. In the outer element we use the trial function 1.0 ~-----1.0 10 1 00 FIGURE 3. Effectiveness Factor Thiele Modulus for Carbon Monoxide Reaction, Bi m = 20, a = 5 ..;.-exact, approximate. 22 The advantage of the finite element method is that the elements can easily be deformed, small elements can be used in important regions, and irregular domains are easily handled. h 3 T 0 =0 T h ~-~ T 0 =o h 3 To = 0 I (bl DOMAI N WITH SYMMETRY TIOO TI O O (al HEAT T RAN S FER IN A STRUT q O ( cl BOU N DARY CO N D ITI O N S FIGURE 4. Heat Transfer Problem. u = (r b) / (1 b) w hich satisfies c = 0 and de/du = 0 at the node between elements. The collocation equations are now (see 4), for planar geometry, 1 (1-b) 2 (B 2~ C 1 + B 22 C 2 + B 2 3 C 3 ) = R 2 k(T 2 )c 2 / (D (1 + ac 2 ) 2 ) (6) 1 1 b (A 31 C 1 + A s 2 C 2 + A 33 C 3 ) (7) Nowc 1 = c(u = 0),c 2 = c(u = 1/2),atthemid point of the outer element, and c 3 = c(u = 1) = c( r =l). We have c 1 = 0 and C 2 = C 3 / 4, so we can sol v e (7) for C 3 (1-b) Bi m C a = 2 + ( 1 b) Bi m (8) For various b from 0 to 1 it is easy to see the influence of external diffusion resistance. When C a = 1 there is no concentration drop across the boundary layer su r rounding the' pellet, and this condition depends on ( 1 b) Bi ;,, For large Bim, w e ha v e c 3 = 1. These equations are solved with out iteration b y choosing b, finding C s by (8), C 2 = C 3 / 4, and then using ( 6) to get / = R 2 k (T 2 ) / D e Choosing b = 0 gives the dividing CHEMICAL ENGINEERING EDUCATION

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__ ____,8 FIGURE 5. Mesh for Heat Transfer Problem. line between the orthogonal collocation solution and the finite element solution. Here we have solved the finite element solution for planar geometry (it is easier than spherical geometry), and we use cf> cf>p = 3 to get the results for spherical geometry. The 7J cf> curve is shown in Figure 3. Over the whole range of cf> we get a reasonable solution; compared to much more difficult numerical solutions. Certainly the solution exhibits all the important phenomena, usually within experimental accuracy. This example clearly shows the importance of using finite elements when the solution is sharply cJ D FIGURE 6. Element Deformation. changing, Figure 2b, whereas non-finite element methods are suitable for smooth solutions; Figure 2a. TWO-DIMENSIONAL PROBLEMS A MORE IMPORTANT USE of finite element methods is for two-dimensional problems. Consider heat transfer in the region shown in Figure 4. The boundaries are maintained at temperature = 100 and the interior is cooled with a heat transfer coefficient h = 3, To = 0. We wish to solve k'v 2 T = Q in strut, T = 100 on top and bottom boundary, -lm.'vT = h(T To) on side boundaries. Space does not permit a complete discussion of all aspects of the finite element method but the high lights can be given. We first discretize the space, as shown in Figure 5. We can divide the region into triangles, FIGURE 7. Trial Function, Linear on Triangle. rectangles or quadrilaterals. Because of the way finite element programs are written it is very easy to use deformed elements, as shown in Figure 6. The actual calculations are made on the square element, with appropriate account taken of the transformation properties. Within each element we expand the unknown function in a polynomial -either linear or quadratic, usually (see Figure 7) Having decided on the trial function (here linear functions on triangles) we number the nodes and elements (see Figure 5). Now in two adjacent elements the equations are similar when written in terms of the local coordinates (see Figure 8). The appropriate equations must be assembled properly. The equations are solved with Since finite methods are being used increasingly by i~dustry for design of structures, heat transfer, fluid flow, design of nuclear reactors, etc., it is important that the modern student be exposed to them. It is not necessary that the engineet< be familiar with the details ... but (he) should know the general idea. WINTER 1981 : ___ :._ _ : :._ .: ~

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an LU-decomposition or a Gaussian elimination ( 6) These techniques are beyond the scope of this article. The user then specifies the thermal conductivity and heat generation rate in each element Here we have k e = 1, Q e = 0 Finally the bounda r y conditions are specified as T i = 100 nodes i = 7, 14, 17, 20, 23 h 1 = 3, T oi = 0 nodes i = 8 9, 10 11, 12, 15, 18, 21, 22, 23. For a boundary node at which temperatures are not specified by the user the boundary condition is automatically the natural boundary condition oT / c)n = 0 nodes i = 1, 2, 3, 4, 5, 6, 7, 8 with n the outward pointing normal. This problem is solved using the program in Huebner's book (7) The solution is shown in 121 122 AA 95 96 97 (al GLOBAL NUMBERING SYSTEM 3 0 2 (bl LOCAL NUMBERING S Y STEM FIGURE -8. Finite Element Numbering System. 3 2 Figure 9. Natu r ally more elements are needed for good accuracy, but the essential elements are clear in Figure 9. The advantage of the finite element method is that the elements can easily be deformed, small elements can be used in important regions, and irregular domains are easily handled. The reason for these features is that the computer programs are written on an element-by-element basis, since each element is similar. The user, then has complete freedom in how the elements are to be arranged. 24 100 90 80 70 60 50 40 30 20 10 FIGURE 9. Solution to Heat Transfer Problem. Contours are for each 10 degree increment. COMPARISON TO FINITE DIFFERENCE T HERE ARE BOTH SIMILARITIES and differences between finite element and finite difference methods. For the heat conduction problem 0 2 T 0 2 T 'c) x 2 + 'oY 2 = 0 a finite difference grid is shown in Figure 10a. The finite difference method uses the following equation representing the differential equation at node 5. 'v 2 T 15 = (T a + T + T 2 + T s 4T 11 ) / h 2 The same equation results from application of the finite element methods, provided linear trial functions are used on the triangles shown in Figure 10b. ( Other types of terms in an equation may be different, however) If we use quadratic h 1 n7 : ITJ3 lo) FINIT E D IFFEREN CE lb)FINITE ELEMENT LINEAR ( c l FI NIT E E L E M ENT O UAORATl l' FIGURE 10. Comparison of Finite Difference and Finite Element Methods. C HEMICAL ENGINEERING EDUCATION

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polynomials in the finite element method, then we have more nodes and the equation at node 5 in volves terms at each node represented by in Figure 10c. Because the equations are derived in different ways the finite element method is, how ever, easy to apply with the irregular geometries shown in earlier figures. In addition, certain types of boundary conditions are easily handled in finite element methods, particularly boundary conditions involving derivatives and/or free surfaces, whose location is to be determined. SUMMARY s INCE FINITE ELEMENT methods are being used increasingly by industry for design of struc tures, heat transfer, fluid flow, design of nuclear reactors, etc., it is important that modern students be exposed to them. It is not necessary that the engineer be familiar with the details of the method, but the engineer should know the general idea and be able to apply the method. The author has found students are quick to learn how to use finite ele ment programs, and once experienced will always know what someone means when they say Finite Element Methods. FURTHER INFORMATION COMPARISONS OF finite element, collocation, and finite difference methods are given in Ref. (8). One-dimensional cases are emphasized since that allows the easiest description of the methods and details of applications. Two-dimensional problems are treated there as well as books by Huebner (7) and Chung (9). Huebner's book contains a simple finite element program for heat transfer problems. More elaborate programs are available (10). Ap plications to engineering design are widespread, and one concentrated source is the International Journal of Numerical Methods in Engineering. Probably there are published accounts of research applications of the finite element method in the journals related to your area of interest. REFERENCES 1. Bird, R. B., W. E. Stewart and E. N. Lightfoot, "Transport Phenomena," Wiley (1960). 2. Finlayson, B. A., "The Method of Weighted Residuals and Variational Principles," Academic Press (1972). 3. Carberry, J. J., "Chemical and Catalytic Reaction Engineering," McGraw-Hill (1976). 4. Finlayson, B. A., "Orthogonal Collocating in Chemical Reaction Engineering," Cat. Rev.-Sci. Eng. 10, 69-138 (1974). 5. Paterson, W. R. and D. L. Cresswell, "A simple method for the calculation of effectiveness factors," Chem. Eng. Sci. 26, 605-616 (1971). WINTER 1981 6. Hood, P., "Frontal Solution Program for Unsym metric Matrices," Int. J. Num. Methods. Eng. 10, 379399 (1976); 11, 1055, 1202 (1977). 7. Huebner, K. H., "The Finite Element Method for Engineers," Wiley (1975). 8. Finlayson, B. A., "Nonlinear Analysis in Chemical Engineering," McGraw-Hill (1980). 9. Chung, T. J., "Finite Element Analysis in Fluid Dynamics," McGraw-Hill (1978). 10. Program DOT available from Professor E. L. Wilson, Department of Civil Engineering, University of Cali fornia, Berkeley, California 94720. (ejn:,I letters FOREIGN STUDY PROGRAM Dear Sir: We read with interest about the successful Study Travel Program at Virginia Tech (Summer 1980 issue). I would like to briefly mention two intensive foreign study programs which are open to selected Chemical Engineering undergraduates at Case Western Reserve. They may also serve as examples for other Departments who wish to initiate such programs. Each year since 1978, three of our undergraduates have spent their junior year at the University of Edin burgh. There they are regular full time students in the third year Chemical Engineering program. The students normally live in university student housing and can par ticipate in the usual range of student activities. Full academic transfer credit for a years work is granted upon successful completion of the third year course at Edin burgh. This arrangement has been extremely successful, primarily due to the excellent and continued cooperation of the Edinburgh faculty. The experiences of the students have been uniformly good and there have been minimal academic re-entry problems after returning to Case for their senior year. We also participate, with Iowa State University and Georgia Tech, in a summer laboratory course at Uni versity College London. This very well run program lasts for approximately one month and, in addition to the intensive laboratory course, includes a one week bus tour of various British chemical industries. Credit for our Unit Operations Lab is given upon completion of the course. Part of the reason for the success of the pro gram is the dedicated work of the faculty representatives from Iowa State and Georgia Tech that accompany the students. Overseas study has been an area in which we in engi neering education have lagged behind our colleagues in the liberal arts. Part of the reason has been the necessity of meshing requirements from two highly structured curricula. Despite these difficulties, the remarkable benefits to the students involved make the effort worthwhile. More programs of this type should surely be offered. Sincerely yours, John C. Angus Case Western Reserve University 25

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[eJ ;j I laboratory A SIMPLE TUBULAR REACTOR EXPERIMENT ROBERT R. HUDGINS University of Waterloo Waterloo, Ontario, Canada BERTRAND CAYROL Universite de Sherbrooke Sherbrooke, Quebec, Canada U SING AS A REACTION system the hydrolysis of acetic anhydride, Anderson [1] developed a laboratory demonstration of tubular reactor be haviour. In this article, another such demonstra tion is presented with two novel additions: (i) a color change is added as a visual reinforcement of the measured results and (ii) the temperature constraint is removed in order to provide an ex perim ent operable at room temperature The Robert R (Bob). H~dgins born in Toronto, Canada, obtained all hjs degrees in Chemic~! Engineering; B.A.Sc. and M.A.Sc at the Uni ve_rsity o i Toronto a n cl the Ph.D. degree at Princeton University. He c 0 ame t o the University. of Waterloo in 1964 where he has remained exa~pt for study leaves at Polysar, Sarnia, Ontario, Universite de Sherbrooke, Sherbrooke, Quebec, and most recently (1979) at the Swiss Federal Institute of Technology (EPF), Lausan ne His research studies have focused upcm the influence of .inert diluent gasf;ls in heterogeneous catalytic reactions, and on the behavior of chemical reactors under forced cycling. (L) Bertrand Cayrol received his Ph.D from McGill University, Cal')ada, in 1972 He has been a Research Visitor at Chalmers University of Technology Sweden, and a Research Assistant a~ the Universite d'Orsay, France. Presently he is Assistant Professor at the Universite de Sherbrooke, Canada, with special interest and work on the visco elastic properties of polymers synthesized by micro-organisms. (R} 26 latter innovation reduces the complexity and thus the cost of the apparatus. Corsaro [2] described the hydrolysis of crystal violet dye by sodium hydroxide. Reaction is first order in the concentrations of each of the reacting species. If the base is in great excess, the kinetics of reaction become pseudo-first order, -rdye = k' [dye] where k' = k[NaOHJ. The dye concentrations needed for this experiment are of the order of 105 mol/L. Thus, a 0.01 mol/L solution of NaOH is in 1000-fold excess and in a concentration readily achieved at low cost. Also, NaOH con centrations can be varied considerably in order to achieve a desired pseudo-first order rate constant k' at room temperature. This feature of the experi ment eliminates the expensive temperature control equipment of the sort used by Anderson [1]. Another advantage of this system over that using acetic anhydride hydrolysis is that the system remains isothermal during reaction. The fact that the reagents are also very dilute means that there is little safety hazard if the reagents are spilled, though safety glasses are recom mended. The results of this experiment may be ap proximated by idealized models, such as the plug flow tubular reactor (PFTR) and laminar flow tubular reactor (LFTR). THEORY The PFTR model is widely used, (see Leven spiel [3] for example) and is related to the inlet and outlet dye concentrations as follows. -r = .:!.._ = 1 Zn fldye]i = _!_zn(l-x) Vo k' [dye]e k' The LFTR model has been developed by Cle land and Wilhelm [4]. The radial mean conversion at the exit from the tube is given by the expres sion. Copyright ChE D ivision A SEE, 1981 CHEMICAL ENGINEERING EDUCATION

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GO 1-2 -dy X f e'VY ys 1 l-v 2 Ei(v) + e v (v-1) where V = k'T o y = t/To and To = L71"r 2 /(2vo) Ei is the exponential integral, available in mathe matical handbooks. APPARATUS The principal components required for this ex periment are listed below; code letters ref er to the schematic in Figure 1. Tanks: (Tl) 200-L polyethylene tank bottle with 3/4-in spigot for draw-off. (T2) 10-L Nalgene aspirator bottle with spigot. Pumps: (Pl) Century type SPS (1/4 HP); available from Flotec Inc., Norwalk, California. (P2) Magnetic drive variable speed micropump; Cole-Parmer Cat. No; 7004-9~ . Mixer: (M) Graphite impeller pump (whose impellers have been removed for use as a mixer); Eastern Pumps, LFE Fluids Control Div., Hamden, Conn. Rotameters: (Rl) Brooks type R-6-15-A. (R2) Brooks type R-2-15-B. Reactor: 40 m of 3/8-in I.D. Tygon tubing, wound on a spool 28 cm in diameter and 55 cm in length. Valves: (V) any adjustable valve to adjust flow in the recycle lines. Spectrometer: Spectronic 20 (Bausch & Lomb) fitted with a "Flow-Thru Accessory" for rapid sampling. Tl Pl FIGURE 1: V RI M S2 QQQOooo I TUBULAR REACTOR V R2 .. Schematic Diagram of Apparatus. Tl, T2 tanks for NaOH solution, dye solution re spectively; Pl, P2 pumps; Rl, R2 rotameters; V adiustable valves; M mixer; 51, 52 sample points. WINTER 1981 A 200-L reservoir (Tl) is used for the caustic solution and a 10-L reservoir (T2) for the crystal violet dye solution. These are metered into a mixer (M) at the entrance to the tubular reactor. Samples may be withdrawn from the entrance (S1) to the reactor and from the exit (S2) from it at tee-junctions. These tees are fashioned by welding short lengths of 1/8 in O.D. stainless tubing to 3/8 in O.D. stainless tubes used as connectors at the entrance to and exit from the reactor tube. For convenience, the reactor tube itself takes the form of a helical coil, although there is no reason in principle why it could not be straight or folded (a comparison between the conversions using helical coils vs. straight tubes might make an interesting variation of this experiment, to in vestigate the importance of secondary flow in the helical reactor). During operation, a strong change in color may be observed along the reactor tube between inlet and outlet. The analysis of crystal dye at both the inlet to and outlet from the reactor is readily done with a spectrometer, and the method is given by Corsaro [2]. The Flow-Thru Accessory of the Spectronic 20 consists of a vacuum system to draw small samples through a fine tube into cuvette, and then to empty into a waste jar. Since the sampling time is brief, and reproducible, errors in measuring the concentration of the reacting sample are kept to a minimum. The concentration is readily obtained by calibration with known concentrations of the dye. Occasional sampling of methanol or ethanol will prevent the build-up of adsorbed crystal violet dye on the walls of the cuvette. EXPERIMENTAL PROCEDURE THE MAXIMUM FLOWRATES of crystal violet dye solution and caustic soda solution are 50 mL/ min and 1000 mL/min respectively. Thus, in the reactor volume, the holding time is just a few minutes, and since plug flow is approximated, little more than a single filling of the reactor is needed to obtain steady state conditions after a change is made in the input flows and/or concentrations. For purposes of illustration of the behavior of this reactor, several points may be obtained at different space velocities. This is done by deciding on the range of flowrates available and then keep ing the two feed pumps in the same ratio. Con centrations are measured at a sample point just at 27

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1.0.--------------, 0 9 iii ffi > z 0 u ...J z 0 E o e a: .... 0 7 ~~-~-~--~---~3 0 4 0 T (m i n) 5 0 6 0 FIGURE 2: Comparison of Experimental Conversions with those Predicted from PFTR and LFTR Models. the entry to the reactor, and just at the exit. Some student data are presented in Table 1, for the experiment at Universite de Sherbrooke. Note that the volume of the reactor was 2780 mL, and the concentration of NaOH (from the titration tests) was 0.04 mol/L. In addition, batch tests of dye with caustic soda solution of this concentration provided a pseudo-first order rate constant k' = 0.54 min1 Using this information in the reactor models provided, the model conversions of Table 1 were calculated and the graphs in Figure 2 prepared for both PFTR and LFTR. The conversion data from Table 1 are also plotted in Figure 2. It ap pears that the behavior of the reactor lies between the LFTR and the PFTR. No particular signifi cance is attached to the fact that the conversion curve crosses the LFTR curve at short holding times; the conversion data of most student groups appear to lie between the two theoretical curves. A wider range of flows might be used in order to discern trends in the behavior of the real reactor with holding time. Finally, we offer a comment or two on student reaction to the experiment. The change in color of the reactants across the reactor is quite a novelty in a chemical engineering laboratory experiment. This visual effect helps to reinforce what is learned from both the measurements and the theory. The measurements are readily made, and the theoreti cal models used to bracket the expected per formance of the reactor are inherently interesting. This happy combination of factors has meant that the experiment has always been well received by students working on it. REFERENCES 1. J. B. Anderson, "A Chemical Reactor Laboratory for Undergraduate Instruction," Princeton University, 1968. 2. G. Corsaro, Chem. Educ., 41, 48 (1964). 3. 0. Levenspiel, "Chemical Reaction Engineering," 2nd. ed., Wiley New York, 1972. 4. F. A. Cleland, and R. H. Wilhelm, AIChE J 2, 489 (1956). 5. H. Kramers and K. R. W esterterp, "Elements of Chemical Reactor Design and Operation," Nether lands University Press, 1963, p. 93. NOTATION e,i k k' L -r t Vo V X y V T 'To subscript symbols for exit, inlet rate constant L / molmin k[NaOH]; pseudo-first order rate constant (min 1 ) length of reactor tube (m) reaction rate mol/Lmin time (min) volumetric flow rate (L/min) volume (m 3 ) conversion t/T 0 k'T 0 V /V o (min1 ) L1rr 2 /(2v o ) (min 1 ) TABLE I Experimental Results Run No. 28 1 2 3 4 Flow of dye (mL/min) 15 20 25 30 Flow of Dye Concentration NaOH Inlet Outlet (mL/min) (mol/L x 105) 450 1.1 0.08 600 1.05 0.15 750 1.05 0.22 900 1.05 0.30 Holding Fractional Conversion Time PFTR LFTR (min) Exp'tl Model Model 5.98 0.93 0.96 0.90 4.48 0.86 0.91 0.84 3.59 0.79 0.86 0.77 2.99 0.71 0.80 0.72 CHEMICAL ENGINEERING EDUCATION

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T SPORTATIONfS FUTUREf AN ENGINEERING cHALLENGE. WINTER 1981 One of the biggest engineering challenges facing the world today is the future of transportation. And at M ic helin we re doing our best to contribute some answers We ve been anticipating the transportation needs of an ever changing world since 1889 when Michel i n invented the detach able bicycle tire and then again in 1948 when we introduced the radial tire Now as the world 's leader in radial tire technology M i chelin has openings for chemists and chemical engineers Dedicated to ma in taining its leadership role through innovation Michelin is e x pand i ng its United States manufacturing and research capabilities to meet the fast growing demand for gas -s aving radial tires To take advantage of these opportunities with Michelin a background in organic chemistry polymers and te x tile fibers is very desirable Michelin relies heavily on research and development to keep the Michelin radial tire the best in the world Facilities are new and fully equipped Living conditions are ideal. Find out how you can be a part of this professional challenge by sending your resume with salary history to Michelin Tire Corporation Manufacturing Division Department SPM-JH-91 Box 2846 Greenville SC 29602 or to Michelin Americas Research & Development Corporation Dept. SP Box 1987 Greenville SC 29602 MICHELIN An equal opportunity employer M / F 29

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(!) ;j I curriculum IMPRESSIONS OF CHEMICAL PROCESS CONTROL EDUCATION AND RESEARCH IN THE USA* KURT V. WALLER .J.bo Akademi SF-20500 .J.bo Finland T HE FIELD OF CHEMICAL process control was heavily criticized in 1973. Foss [1] wrote a much cited critique of the theory research. Athans' critique[2] pointed in a different direction when he stated: "It is indeed unfortunate that the process control engineers have disassociated them selves from the mainstream of modern control theory ... In this manner, the tremendous ad vances during the past three years in system identification, adaptive control, sensor location, and accuracy tradeoffs have probably ,gone un noticed by the very profession that stands the benefit most." Athans was aware of the difficulties: "I do believe that far greater care and finesse is re quired to apply modern control theory to process control problems than missile autopilotes," but his opinion about what action should be taken is clear: "Everybody knows that chemical process control systems are inherently less understood in their dynamic behaviour than Newtonian systems. But it seems to me that this should be viewed as a challenge, rather than an outcry that the theory is no good." It is easy to criticize. This is especially true of process control research, which is in the In design of control systems there are two basic approaches. The first, in this paper referred to as the forward approach ... The second here called the backward approach, starts from the process operator This is a condensed version of Prof. Waller's original paper published in the Finnish journal Kemia-Kemi, Vol, 7 (1980), page 85. 30 Kurt V. Waller was born in Mariehamn, Finland, in 1940. After studying in Finland and West Germany he got the degrees M.Sc., Tech. lie. and Tech Dr from Abo Akademi, Finland, in 1966, 1970, and 1972. A member of the faculty of Chemical Engineering at Abo Akademi since 1970 Dr. Waller was appointed full Professor in 1975. Professor Waller has written about 50 scientific papers, mainly on process dynamics, optim izati on and control. difficult position that it [3] "must compete for funds with such endeavors as process de-bottle necking, process improvements, new plant con struction, and other undertakings. Returns from these latter efforts are usually more easily proven or at least more readily believed." Still, has the critique from 1973 been seriously considered by the chemical engineering prof es sion? Is the field of chemical process control in USA today a vital field, or does it lack enthusiasm and perspectives? STATE OF THE ART Education A good picture of how established process control has become in chemical engineering educa tion in the United States and Canada is obtained from Seborg's recent survey [4]. It shows that the basics of process control is now taught at practiCopyright ChE Di vision, ASEE, 1981 CHEMICAL ENGINEERING EDUCATION

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cally all chemical engineering departments. The main part of the teaching is, however, concentrat ing on very basic facts only and using surprisingly old textbooks, the clearly dominating one (by Coughanowr and Koppel [5]) written over 15 years ago. The vast majority of departments have only one faculty member in process control. There are some departments, however, which put more emphasis on control and which can off er quite advanced programs. One example of a two-person process control program was recently described in [6]. Research and Development In design of control systems there are two basic approaches. The first, in this paper referred to as the forward wpproach, is to take a theory with potential for the specific process in question and apply it after a possible adaptation to the class of problems at hand. The second, here called the backward approach, starts from the process operator. In this approach the goal is more or less to imitate a skillful and experienced operator by the automatic control system. In many respects the automatic system can perform better than the manual, since it is not influenced by the many sources for human errors, it won't get tired, etc. It is natural to im prove the system continuously by extending it to include more and more new and abnormal situa tions, making the reasons for the operator to switch to manual less frequent. It seems natural that a sound design includes elements from both the forward and the backward approach. The impression obtained is that applica tions in the U.S. industry have a stronger emphasis on the backward approach than is the case in Finland (and Scandinavia). One explanation for such a difference is easily found. The connections between the universities and industry seem to be much closer in Finland than in U.S.A., as also indicated by Foss and Denn [7] in summing up the 1976 Asilomar Conference on Process Control : "The ties between industry and the university appear closer in Europe than in North America, and the closeness seems to have afforded European university re searchers opportunities to implement and test their control methods on industrially significant pro cesses." There are, however, a few university groups in the U.S. sponsored by and working in WINTER 1981 The connections between the universities and industry seem to be much closer in Finland than the U.S.A. close cooperation with industry. One is the group at the Case Western Reserve University directed by I. Lefkowitz. If there is a gap between industry and the university on the one hand, there also seems to be quite a gap between the control researchers in U.S. electrical and chemical engineering depart ments. The electrical engineers are often very theoretical while their chemical colleagues are quite oriented towards applications, often even to that extent that they rather work on specific problems than on concepts. Thus there seems to be a certain vacuum in the study of the applic ability of the more advanced theory, seemingly the most natural process control field for activity in chemical engineering departments. However, there seems to exist a strong controversy concern ing this latter statement. There are some workers in the field though. At the University of California, to provide just one example, Foss at the Berkeley campus has for many years studied a packed bed chemical reactor, the studies including state space modeling by orthogonal collocation [8] and recently [9] [10] the applicability of LQG-theory to the reactor, which exhibits inverse response. At the Santa Barbara campus Seborg and Mellichamp are work ing both on reactor and distillation control, two of the applications in chemical process control which seem to have a large potential for modern multivariable estimation and control theory. There is also quite an interest in exploring the potential of the frequency response methods for multivariable systems developed in Great Britain by Rosenbrock, MacFarlane and coworkers. Indeed, such an interest was already expressed by Fisher [11] in 1973. The largest advantage is generally considered to be the insight into and feel ing for the system obtained by the methods. Recent applications treat Foss' reactor [12] and Wood's distillation column [13] in Alberta, Canada Among new approaches being studied can be mentioned "Inferential Control," studied by Brosilow and coworkers [14]. The goal is to infer unmeasurable product qualities from secondary measurements, and here e.g. standard least squares estimates are used. The novelty is how the second ary measurements are selected so as to minimize 31

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the number of such measurements required to obtain an accurate estimate which is insensitive to modeling errors. A compensator, which is a process model, compensates for the effect of the control effort on the secondary measurements. This leads to the appealing feature of the approach that the control effort is not fed back in the system, only the disturbances and the model mis matching. This fact is said to give the system excellent stability properties. One interesting task would be to exploit the approach systematically for the model mismatching problem, which is of such a central importance in process control. A first step in this direction is taken in [15]. At present there does not seem to be much active interest among chemical engineers to try to apply and explore the self-tuning regulator (STR) of Astrom and coworkers [16] [17] or Zadeh's fuzzy control concepts [18] [19]. The Another use of the interaction analysis is for design of decoupling schemes. common attitude is to wait and see until convincing application studies are presented in which these approaches have turned out to result in something that more familiar and commonly accepted methods have not. Previous studies in North America of the STR and of Fuzzy Control have mainly been done on the north side of the Canadian border. One of the subjects of great research activity in chemical process control in the U.S. today is interaction analysis, in which coupling between inputs and outputs in multi-input multi-output systems is studied. Interestingly enough the topic is studied by consults and industrial researchers as well as by university people. The analysis starts in many cases from Bristol's Relative Gain Array [20] [21] or similar interaction indices suggested by Rijnsdorp [22] or Nisenfelt and Schultz [23]. One of the main uses for the technique is to pair variables, resulting in (interacting) single-input single-output control systems. It should be emphasized that one is not restricted to basic manipulators but can use various combinations of manipulative variables. Interesting examples are given by McA voy [24] in exploring two-composition control in distilla tion. Conventional control, in which reflux and boilup are manipulated, is compared to Shinskey's material balance control (with either reflux and 32 bottoms flow rate or boilup and distillate flow rate as manipulators), and also to Rijnsdorp's sug gestion to use the ratio reflux to boilup as one control variable in addition to boilup. The least amount of interaction is found for a hybrid between Shinskey's and Rijnsdorp's suggestions. While the interaction analysis usually uses only steady-state data, extensions to include dynamics in the interaction analysis in a rational way have been treated in several papers. Witcher and McA voy [25] as well as Tung and Edgar [26] show by including dynamics in the analysis that it can lead to wrong pairing to take only steady state properties of the process into account. While Witcher and McAvoy, Tung and Edgar, and recently Gagnepain and Seborg [27] work in the time domain, Kominek and Smith [28] work with polar plots in the frequency domain. The screening of a dual composition control scheme from 12 potential candidates for an ethylene column is used by Kominek and Smith to illustrate the use of the theory. Use of only steady-state interaction index is shown to result in systems un suitable for implementation. Another use of the interaction analysis is for design of decoupling schemes. The discussion is largely concerned with decoupling in two-composi tion control in distillation. At present the dis cussion is highly concerned with the question of whether one-way (also called partial) decoupling, advocated e.g. by Shinskey [29], or two-way (com plete) decoupling, which is the approach pre viously investigated, is to be preferred. Strongly related to this question in distillation is the question of degeneracy in decoupling, recently studied by McAvoy and coworkers [30] [31]. Additional papers on the topics of interaction and decoupling analysis are [32] to [34]. Some further research objects of present and/ or planned activity are mentioned below in the discussion of trends. THE FUTURE: TRENDS AND SPECULATIONS Education Since no major changes concerning process control can be foreseen in chemical engineering de partments in U.S.A. in the near future, most departments will continue to have one faculty member who teaches the basics of process control and systems engineering. Advanced teaching pro grams in process control will probably be given only in the very few departments (the order of 5 CHEMICAL ENGINEERING EDUCATION

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Since no major changes concerning process control can be foreseen in ChE departments in the U.S.A. in the near future, most departments will continue to have one faculty member who teaches the basics of process control and systems engineering. schools in the whole U.S.A.) where there is more than one faculty member in the control field. This scarcity of more advanced programs in process control seems to be very unfortunate, be cause the correct interpretation and intelligent ap plication of modern control concepts is a task that takes quite a lot of understanding of and famili arity with the theory as well as it demands engi neering skill. There are several examples where the application has failed solely because of unsuit able interpretation of the theory. A perspicious example of the importance of a correct interpreta tion of the theory is given in [35] and [36] concern ing the way of treating the integrals in optimal PI-control of systems with time delay. What will be taught? There probably won't be much enthusiasm in the teaching of only the basic process control courses, so for that matter the text by Coughanowr and Koppel could be used for another 15 years. It seems likely, however, that it will be replaced by a text which has a much stronger emphasis on computers and digital systems. The text may very well start the treat ment directly in discrete time and skip much of the old material used for continuous time treat ments. The same goes for the future teaching of process control, which is likely to put less emphasis on equations and more on algorithms than has been done in the past. What will be taught in the more advanced courses will usually reflect the research. Research and Development Largely the industry is likely to continue to go its own way. Then the "backward approach," i.e. the one in which the operator is translated into the computer system, may be one of the main approaches for design of industrial control systems. Undoubtedly the approach has its merits. One rationale for it is that things are almost never "normal" in process operation: "the normal state is the abnormal one." Therefore one should start from the process at hand, ( and why not) as viewed by the experienced operator. Important university research in this area will be concerned with plant diagnosis, fault detecWINTER 1981 tion, control under failure, and system reliability. Also, the emphasis will shift towards treating more difficult processes and to be more "devilish" in testing the control systems. The important subject of man-machine communication, however, is probably best studied in industrial environment. There is, however, also in industry an aware ness of the serious drawbacks inherent in the back ward approach. It conserves bad habits of the operators and retards the progress. A catalytic reformer is a good example : The operator tends to recycle much hydrogen because the operation is then very stable and safe. However, less hydrogen recycled generally means less energy consumed and more economic operation. Another example [37] : In distillation it is common practice for operators to increase the reflux rate above the design value. Then disturbances in the feed composition seldom cause the top product to fall below specifications, but this advantage is balanced by the excess steam supply needed to overreflux the column. Today we are faced with a lot of double con servatism in the process industries. Firstly, pro cesses and plants are designed to be conservative meaning a lot of capacity for decoupling and dis turbance attenuation. And secondly, the processes are operated in such a conservative way so that most of the disturbances left by the design dis appear into the conservative operation. And this usually means a waste in energy and equipment. However, it seems quite clear, that industry has to cut down the waste of resources by means of more sophisticated technology. Processes will have to be designed as well as operated in a sig nificantly more integrated way, closer to con straints, than today. It probably won't be possible, and certainly not economic, to operate such plants manually. Or as seen by Evans [38]: ... new processes are bigger, more integrated and more highly automated. Operators are at the same time becoming further divorced from the process, re moved from the operation of the process, so when it comes time to start up or shutdown, or emergency situations occur, the operator does not have the intimate familiarity with the process which his counterpart in the less automated facility once had." Closer ties between industry and universities 33

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would, of course, decrease the gap. The industry would get competent help to apply more advanced control concepts and the university people could more easily ask the right questions and attack the relevant problems. The gap can be illustrated by some views on process modeling [39]. Much of the university research in modeling for process control has been concerned with the small perturbation, linear approach. The tendency has been to include more and more smaller and smaller effects into the model. An industrial re sponse is : These complicated models can never take everything into account anyway, the operator does not understand them since they are so compli cated, so they are not used. Or to put it another way: University people usually suppose a "normal" state for the process. An industrial conception of what is "normal" was expressed as : Things are never normal-or per haps 2 % of the time. Models will have to become simpler and more robust. (Signs of steps in this direction are already visible [ 40]) In many cases a simple model struc ture only will be determined from first principles. In operation there will be a strong shift towards experimental modeling, i.e. towards on-line identification and estimation, with a subsequent reduction in importance of modeling from first principles. It seems likely that the concept Fuzzy Control will find increased use in the backward approach, since the most important property of a system designed by the backward approach is that it is kept on automatic and not switched over to manual. System performance comes only second in importance. The natural language flavor of fuzzy control seems ideal to prevent the operator from feeling unfamiliar with the concepts used in the computer system. Another rationale for the use of fuzzy logic is that much of the control work going on in industry is done, and will continue to be done, almost without any control theory in the sense of "hard" systems theory. So far, however, use of fuzzy logic has been reported mainly from Europe [ 41] [ 42]. For a long time it has been recognized that there is a large potential in an integration between process and plant design and control. Indeed [43], "it is important to consider process control in general-the development and the application of its theory-as an integrated part of the plant design and the process operation." There is quite 34 a lot of interest in the subject among chemical engineers in the U.S.A. today, and increased re search activity can be expected. In this integration the potential of the chemical engineer can be utilized at its very best. The increased integration of processes and complexity of plants, will make the control aspects more critical. There will be a greater need for, and emphasis on, multivariable control methods. Analysis of plants will to an increased extent rely on efficient simulation methods for large systems. More work in these areas is needed and is likely to be done [44]. What about adaptive control methods? Will, for example, the self-tuner see an increased number of applications? The answer is most likely yes. One of the reasons was formulated, somewhat cynically, by an industrial control system design er: These methods will be used more because university people like to play around with them. Starting from the single process unit rather than from the concept point of view, no significant changes are visible. Thus the large interest in distillation control of the last decades continues. Today research in distillation control in U.S.A. is concerned with such questions as pressure control, coupling and decoupling in two-composi tion control, multivariable control in general, and nonlinear control of high-purity columns. The other "large" process will probably continue to be the chemical reactor, which offers a wealth of challenging design, optimization, identification, estimation, and control problems. It is also felt by several workers, both in uni versities and industry, that these two processes, the chemical reactor and the distillation process, have the greatest potential for use of modern control theory. DISCUSSION How HAS THE CHEMICAL process control com munity responded to the critique expressed in 1973? Athans' opinion 5 years later is not less critical, when he comments on the--in his opinion sad state of applications of advanced control in the process industries. He states [ 45] that the chemi cal engineers are so conservative that they have only got what they deserve. Shinnar [46] (1977) laconically states: "the state of process control is rather sad." Continued on page 51. CHEMICAL ENGINEERING EDUCATION

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[eJ;j?I news CHEMICAL ENGINEERING SYMPOSIUM AT CARNEGIEMELLON MICHAEL LOCKE Carnegie-Mellon Uni v ersity Pittsburgh, PA 15217 0 N NOVEMBER 15th and 16th, 1979, CarnegieMellon University held its first annual Chemi cal Engineering Symposium. It was a chance for graduate students in the department to present their work before an audience of interested pro fessors and students. The symposium was intended to serve several purposes. It would give students experience in speaking before an audience. This experience would be helpful in the future, making it easier to speak at technical meetings, and, for those who desire to teach, in the classroom. The symposium was also a good way for research groups in the department and in other depart ments in the university to examine each others' work. Here was a chance for the left hand to at last find out what the right hand is doing. It was hoped that the symposium would lead to co-opera tion and an exchange of ideas between research groups. Also, the symposium was a good time for new graduate students to, check out the work that the professors in the department are doing. This exposure helped the new students to decide Mike Locke received his B.S.Ch E from the University of Massa chusetts in 1976, his M S.Ch.E. from Carnegie-Mellon in 1978 and is presently working on his Ph D at Carnegie-Mellon. His areas of interest include Optimization, Computer Aided Design, and Equation Solving. He presently serves as a consultant to NTP Corporation of Pittsburgh 36 Westerman-Clark presenting his winning paper which faculty members they would choose as their advisors. The idea for a symposium was first brought up in September during a meeting between depart ment chairman Tomlinson Fort and the officers of Carnegie-Mellon's Chemical Engineering Graduate Student Association (ChEGSA). Arrangements for the symposium began with a call for papers. Prospective speakers were required to turn in the titles of their talks. It was at this point that the organizers realized that they were on to something. The response from students and faculty was over whelming. Twenty-seven students responded positively, with 29 papers to present. This was twice the number that had been anticipated. One month before the symposium, speakers submitted abstracts of their talks. The abstracts were collected in a booklet, along with the agenda of talks. Copies of the booklet were distributed to all faculty members and graduate students in CMU Chemical Engineering, and also to the heads of the departments in the School of Engineering. Each student was given 20 minutes to talk, with 5 addi tional minutes for questions. Topics ranged from separation of polymer wastes to synthesis of heat exchange networks. Other interesting topics were Copyright ChE Division, ASEE, 1981 CHEMICAL ENGINEERING EDUCATION

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trace metal levels in Pittsburgh air (there's more than just a trace), and the velocity of blood flow in a rabbit's ear. Interesting discussions started during the symposium, and are continuing. As an incentive for the students, a prize was awarded for the best paper. It consisted of an expense paid trip to the next AIChE convention, to deliver the winning paper, and a check for $100 from Tomlinson Fort. The judging committee was made up of 5 faculty members, headed by Dr. Robert Rothfus, the senior member of the depart ment. Speakers were judged on content, presenta tion, and a written copy of the talk. After much deliberation, the judging commit tee chose Jerry Westermann-Clark as the prize winner. The title of his talk was "Coion Exclusion Potential in Charged Membranes." Jerry entered ... and receiving his award and the congratulations of Professor Fort. CMU in September, 1976, with a B.S. from the University of Pennsylvania. He has a Masters Degree from Carnegie-Mellon and his Ph.D. in September, 1980. His work was supervised by Dr. John Anderson. Jerry is now an Assistant Professor at the University of Florida. The judges also named three runners up. They were Greg Townsend, for his talk "Pharmaco kinetics of Adriamycin in Normal and Neoplastic Tissues" with Dr. Rakesh Jain supervising; Lewis Grimes, with a talk entitled "The Synthesis and Evaluation of Networks of Heat Exchangers that Feature the Minimum Number of Units," super vised by Dr. Arthur Westerberg; and Michael Reilly for his talk "Ambient Trace Metal Levels in Pittsburgh Air," supervised by Dr. Eric Suu berg. WINTER 1981 POSITIONS AVAILABLE Use CEE's reasonable rates to advertise. Minimum rate page $50; each additional column inch $20. OKLAHOMA STATE UNIVERSITY Chemical Engineering. Two Assistant or Associate Pro fessor Positions. These are tenure-track positions and will be approximately half-time teaching and half-time re search. We will help successful candidates establish re search by providing initiation funds, co-investigation op portunities with senior faculty, and proposal preparation processing assistance from our Office of Engineering Re search. Candidates must possess an earned Ph.D. degree from an accredited Department or School of Chemical Engineering or have a Ph.D. degree in related areas and have strongly related qualifications. We welcome applica tions from candidates with competencies and interests in any field of chemical engineering, but especially seek those with strengths in material sciences or controls. The posi tions are available as early as July, 1981. Applications will be received thru June, 1981. Salary and rank are commensurate with qualifications and experience. Please send your resume and list of three references to: Dr. Billy L. Crynes, Head, School of Chemical Engineering, 423 Engineering North, Oklahoma State University, Still water, Oklahoma 74078, 405-624-5280. (Calls for addi tional information invited.) OSU is an equal opportunity/ affirmative action employer. MEET THE TECHNOLOGICAL CHALLENGES Of THE '8O's with U.S. PATENTS AND PATENT PUBLICATIONS on microfilm from RESEARCH PUBLICATIONS INC. 1980 PRODUCT OF THE YEAR INFORMATION INDUSTRY ASSOCIATION For complete details and specifications write or call collect: Research Publications Inc 12 Lunar Drive Woodbridge Connecticut 06525 (203) 397-2600 37

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[;) ;j Ii problems for teachers I PRAIRIE DOG APPENDIX* R.L.KABEL Pennsyl vania State University Uni v ersity Park, PA 16802 SOLUTION: We see that the wind velocity increases as a logarithmic function of the height above the earth's surface. Because of the higher velocity at 2.5 m than at 0.5 m there will be a lower pressure at the top of the tube than at the bottom. This pressure difference will induce an upward flow in the tube. A Reynolds Number can be calculated for flow through the tube : Re Dp = /J, 0.0lm(lms 1 ) (l.2kgm3 ) 1.8 ( 10 -s kg m 1 s1 ) which indicates laminar flow. 667 Thus the Hagen-Poiseuille equation can be used to find the pressure drop. Eq. 2.3-19 Bird, et. al. (or the Prairie Dog problem) gives Q (11' .6.p R4 8,L or Q A 7r R 2 Q8.L 7r R4 1 ms 1 ( 7r) (0.005 2 m 2 ) = 7.85 (l05 m 3 s 1 ) /J, l.8(l05 kgm 1 s1 ) L 2m R 0.005m Substituting, we obtain Ap = 11.52 kg m 1 s 1 This pressure drop can be related to horizontal wind velocity by the Bernoulli equation: P 2 A ( :~; + $) + I dp + + fu. ~ 0 P 1 I\ /\ Neglecting friction and work, E v and Ware zero If the air can be assumed to be incompressible under these conditions, p is constant and The problem statement was presented in GEE Vol. 14, No. 4 (Fall 1980). 38 -1 U = 0 ms z = 3 m 1 ---Z = 2 ID FIGURE 1 ~ dt 0 01 m z = 2 Sm < v > = 1 ms-l z = 0.5 m A The potential energy difference A cf> between points is negligible and for turbulent flow of air, / ::::: 2, and 2 2 = 2 (P 1 P 2 ) p Taking point (1) at the bottom and point (2) at the top, both terms are positive. Thus we have one equation and two unknowns. The logarithmic velocity profile U (z) 1 z u. [ z } 71:= k ln z;;or U (z) = 0.4 ln 0 04 provides two more equations but only one more unknown, U . Since U in the log velocity profile and in the Bernoulli equation are the same thing (i.e. the horizontal wind velocity) we can combine these equations. = U ln 0.4 [ 2.5 ] 0.04 = 10.34 u. = u ln [~] = 6.31 u. 0.4 0.04 (10.34 U ) 2 (6.31 U ) 2 61.10 u 2 u 2 (11.52 kg m1 s 2 ) 1.2 kg m 3 19.20 m 2 s 2 I 19.20 --...; 67.10 0.535 ms1 This value of U can now be used in the velocity profile to get velocity at 3 m. U(z) = Uk ln O.z04 = 0.535 ln _3_ 0.4 0.04 = 5.77 ms 1 D CHEMICAL ENGINEERING EDUCATlON

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[iJ n a classroom TEACHING MARKET ANALYSIS J. T. RYAN University of Alberta Alberta, Edmonton, Canada BRETT HAUGRUD Sherritt Gordon Mines Fort Saskatchewan, Alberta, Canada MARKETING OF CHEMICAL PRODUCTS is a subject which is almost completely ignored in a chemical engineer's university education. This omission is unfortunate since marketing is usually the crucial constraint on the commercial viability of many projects. In spite of its obvious im portance, market analysis is not taught to under graduates; the undergraduate is not trained to fABLE I Capacity Capital Costs < 1 > ALBERTA 1000 T/D GULF COAST 2000 T/D Direct Fixed Cost (excluding working capital) Debt< 2 > Equity Interest rate on debt Term on debt Yearly debt charge( 4 l Interest rate on equity Term on equity Yearly charge: equity recovery, return on invest720 mm lb/yr 66 mm $Can 1440 mm lb/yr 80 mm $US 20.5 mm $Can 25 mm $US 45.5 mm $Can 55 mm $US Canadian prime US prime + % ( a ) + 1 % 15 years 15 years $2.2 mm $Can $3.1 mm $US Canadian prime US prime + 4% + 3 % 15 years 15 years ment (5) 5.6 mm $Can 7.65 mm $US 10.75 mm $US 0.747 US/lb Total Yearly Capital Charges on D.F.C. Unit Capital Charges on D.F.C. 7.8 mm $Can 1.09 Can/lb < 1 >Unless stated otherwise, costs are expressed in the currency of the home country. < 2 > Debt-equity ratio of 0.45. < 8 >Canadian prime interest rate = % U.S. prime in terest rate = 8 % C 4 > Both debt and equity charges taken as uniform payment retirement. ( 5 l Working capital and salvage neglected. Co p y right ChE D ivi s i on, ASEE. 1981 40 Brett Haugrud graduated from the University of Alberta with a B Sc in Chemical Engineering in 1973 and a MSc in Chemical Engi n e ering from the same school in 1978 He worked for several years as an engineer in the Research Department of a Canadian Potash Company before accepting his present position as process engineer for Sherritt Gordon Mines, Fort Saskatchewan Alberta (L) Jim Ryan received his Ph.D. from the University of Missouri (Columbia) in 1966. He has taught at the University of Alberta since that time. Primary teaching duties include the sen i or design project, undergraduate fluid mechanics and introductory thermodynamics. He serves as a consultant to the petroleum industry, mainly in the area of pipeline design and explosions Occasionally serves as a writer and researcher for CBC TV and Radio (R) analyze a market problem even in a rudimentary fashion. The neglect of the marketing process by the students' professors is understandable since their training emphasizes the scientific aspects of the chemical production process, such as research, development and design. From an academic's view, the estimation of a market size and its location is regarded as a black art best left to someone else. This paper presents a technique which hope fully transforms market estimation from a black art into a dark gray one. Its objective is a quanti tative means of estimating a potential market area at a given time for an undifferentiated chemical. An undifferentiated product is one which does not have any unique property that can be attributed to its manufacturer. The manufacturer cannot claim that his product is better than his competi tor's since both products a re identical within normal engineering specifications. Methanol, fertilizer-grade ammonia and polymer-grade ethy lene are examples of undifferentiated products, while almost anything that is advertised as unique CHEMICAL ENGINEERING EDUCATION

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or better is a differentiated product. Consequently, the major factor which will govern the sale of this type of chemical is its price, not its quality. The potential market area for an undifferenti ated chemical, produced by a given plant, is defined as that region where the delivered cost of the chemical is equal to or less than other competing producers. The delivered cost of a chemical com modity to a customer is the sum of the produc tion costs, transportation charges, tariffs and currency exchange. The last two expenses are ap plicable only if the commodity is traded inter nationally. Rather than analyzing the position of all potential competitors for a market, the tech nique of estimating a market area can be il lustrated more simply by considering only two competitors. As an example, assume that two hypothetical methanol producers, one located in southern Al berta and the other on the Texas Gulf Coast, are in competition with each other. In recognition of historical precedence, the capacity of the Canadian plant is taken initially as one half that of the Gulf Coast plant. Table I gives the illustrative capital costs and financial charges for each of the two plants. The financial arrangements are simpli fied in order to make the presentation of the results concise. Unit prices of inputs and associated unit manufacturing costs are shown in Table II. The cost figures in both tables are given in the currency of the home country. Until recently, the plant gate cost of Gulf Coast methanol was significantly below that of methanol produced in Alberta. In fact, at one time the cost of methanol delivered from the Gulf Coast to Alberta was less than the plant gate cost of Alberta methanol. That situation was due primarily to the economics of scale typical of the American plants and the generally low level of natural gas prices. As is obvious from Table II, TABLE II Manuf a cturing Costs Capacity Direct Fixed. Capital Working Capital VARIABLE COSTS Natural Gas as Feedstock and Fuel (32 mm Btu/ton) Power Catalyst Water, misc. FIXED COSTS Labour & Admin.-80 people Maintenance & Local Taxes Sales CAPITAL COSTS Unit debt on D.F.C. Unit equity on DFC Interest on W.C. Variable Costs Fixed Costs Capital Costs WINTER 1981 ALBERTA 720 mm lb/yr 1000 TJD 54 mm $Can 4.<9 mm $Can $1.25/mm Btu 3/KW-hr $22,000/yr 5 % of DFC 2 % of Plant ._Gate Cost SUMMARY Unit Cost Can/lb 2.05 .02 .15 .03 2.25 .244 .375 .078 .69 .307 .779 .03 1.11 2.25 .69 1.11 4.05 GULF COAST 1440 mm lb/yr 2000 TJD 80 mm $US 5.8 mm $US Unit Cost US/lb $1.95/mm Btu 3.28 3.5/KW-hr .02 .15 .03 3.48 $20,000 .111 .278 .09 .479 .215 .531 .036 .782 3.48 .48 .78 4.74 41

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The potential market area for an undifferentiated chemical, produced by a given plant, is defined as that region where the delivered cost of the chemical is equal to or less than other competing producers. the situation is now reversed. The plant gate cost of Alberta methanol is below that of the Gulf Coast even though there is a considerable size advantage in favour of the American plant. The reason for the reversal is that the Alberta plant now has a large advantage in natural gas prices. It should be noted these are new gas prices (as of January, 1978) and do not apply to older plants which have long term contracts at lower natural gas prices or to plants that can blend the old and new gas prices. To estimate the delivered cost at any point, the transportation costs, tariffs and currency ex changes must be added to the average plant gate production costs. The effect of these factors can be illustrated in a simple example. Suppose the two plants attempt to sell methanol in the San Francisco area. The Gulf Coast producer can transport methanol by ship through the Panama Canal while the Canadian producer is restricted to more expensive rail transportation. In addition the American producer will not have to pay a tariff while the Alberta plant must. All of these factors favour the American plant and tend to erode the plant gate cost advantage enjoyed by the Canadian plant. On the other hand, the devaluation of the Canadian dollar relative to the U.S. dollar in effect lowers the plant gate cost of Alberta methanol by about 10 % Table III summarizes all of these effects and shows that the U. S. producer is able to deliver methanol into San Francisco more cheaply than his Canadian competitor. As a consequence, San Francisco is regarded as a po tential market area for the U. S. producer. TABLE 1H Cost of Methanol Delivered to San Francisco Plant Gate Cost Rail to San Francisco 1,324 miles at 2/ton-mile Ship to San Francisco 4000 at .5/ton-mile Tariff-7.6 /US gal Delivered cost WINTER 1981 ALBERTA 4.05 Can/lb (3.65) US/lb 1.32 US/lb 1.15 US/lb 6.12 US/lb GULF COAST 4-.74 1.0 5.74 US/lb The technique used to calculate the delivered costs of the two competitors in the San Francisco area can be generalized to any point of sale. The results of this generalization are best presented on a map as a series of curves of constant delivered costs. These lines will be circles with their centers located at each plant. When a commodity shipment encounters an international border, the "iso-cost" lines will have a discontinuity as a result of tariffs and exchange rates. In general, the magnitude of the discontinuities will not be the same for both competitors. A further complication arises where there is a possibility of change in mode of transportation. For instance, to market methanol in the U.S. Mid west, the Gulf Coast producer might ship his product via barge to Chicago, then distribute from Chicago either by rail or by truck. The base cost in Chicago would then be the Gulf Coast plant gate cost plus the barge charges to Chicago. Local Mid west costs would be the Chicago cost plus rail or FIGURE 1. lso-Cost Lines and Market Line for Base Case. truck transportation charges to the market area. Consequently, the iso-cost lines in the Midwest are again circles, but their origin is at Chicago instead of the plant site. In addition to Chicago, San Fran cisco and Montreal were chosen as distribution centers The technical exercise is to construct the lines of constant cost for each distribution center. A set of these curves is shown in Figure 1. Each of them is labelled with the delivered cost in the currency of the consuming country. These circles are idealizations since the railroads do not run in straight lines. The actual iso-cost lines would be severely distorted, particularly in the west. At this stage of the analysis, this is viewed as a second order effect and is neglected. The potential market 43

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------------FIGURE 2. Approximate Yearly Consumption and Growth Rate of Methanol by Region. area for each competitor is found by drawing a line connecting the intersections of the lines of equal constant costs. This, the market line, is also shown in Figure 1. The market area for Alberta methanol is north of the line and the Gulf Coast market is to the south. As can be seen from the figure, Alberta's market area is all of Canada west of Quebec City and a large portion of the northwest and west central United States. The Gulf Coast producer has a lower delivered cost everywhere else. Once the geographical areas which represent potential markets for the two competitors are established, the objective is to locate customers within those areas. Figure 2 shows the approximate demand for methanol by region. The upper number is the 1977 capacity of chemical plants which use methanol as a chemical feedstock, expressed in mm lb/yr. Below this number is one in parentheses which is the six year net growth in demand for feedstock methanol. The data used to construct this figure were taken from the Chemical Economics Hand book [2] and include only specific plants listed in that publication. These values are somewhat low because they do not take into account demand for methanol as a solvent, gas line antifreeze, etc. Since a large fraction of methanol is used in manu facturing resins for plywood and other wood products, the markets are concentrated in those region~ which have a significant harvestable forest. The pacific northwest and southeastern states are examples of this concentration. By superimposing the market line on the con sumption patterns, it is possible to compare the production of the two plants with the require ments of customers potentially available to each. It is clear from Table 2 that the price paid for WINTER 1981 natural gas is the most significant component of methanol manufacturing costs. The base case natural gas prices were taken as the prevailing new gas prices (1978). Actual prices could be significantly different if old gas was under contract. A number of cases were studied to show the effect of gas prices on the market line. The cases examined are designated on Figure 3 as one through four with line 2 being the base case. When the Alberta producer has a price advantage of $1.00 / mm Btu, the change in the market size is fairly small. The only new market penetrated is San Francisco where about 100 mm lb/yr are con sumed. Case 3 occurs when both competitors have the same natural gas costs. The Gulf Coast pro ducer can now capture most of the Pacific north west market as well as the eastern Canadian market. This situation would force the Alberta producer to operate at less than full capacity, further improving the position of the U. S. com petitor. Since a small change in any economic or technical variable could cause a large change in market size, competition in the PNW would be intense. Price discounting by both parties would be a definite possibility. Finally, if the Gulf Coast operator enjoys old prices and the Alberta pro ducer pays new gas prices, the Texas plant would capture all of the PNW. The Alberta producer would be left with only the three western Cana dian provinces, whose total market is less than his breakeven production rate. The problem is FIGURE 3. Effect of Natural Gas Price on Market Area. solved since he must then shut down if actually operating or decide not to build a new plant. Operating under the base case conditions, the Gulf Coast producer has access to a market of approximately 6000 mm lb/ yr, while the Alberta manufacturer has a maximum market of 970 mm 45

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D esigned as a working tool that enables engineers to save time b y avoiding extensive sea r ches for pe rti nent info r mation Di vided into four sections-Ammon i a Synthesis, Syngas Genera t ion, Carbon Dioxide Removal and Final Purification-each containing descriptions with data in tables and charts approx. 220 pp. (1-02722-7) April 1981 $22.00 (tent.) FERMENTATION AND ENZYME TECHNOLOGY Dan i el I C. Wang Charles L. Cooney Arnold L. Demain Peter Dunnill Arthur E. Humphrey & Malcolm D. Lilly A practical, up-to-date introduction to fermentation and enzyme technology outlining the fundamen tal microbiological, biochemical, genetic, and engineering aspects of fermentation and p r esen t ing ad v anced me th ods of f e r mentation and contro l. Covers the isolation of enzymes, espec i al l y th ose f ound in intrace l lula r contents of mic r oo rgani sms. 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Flexibility Analys is by the General Analytical M e thod Flexibility Analysis by M odel Test. Approaches for Reducing Expansion Effects: Expansion Joints. Supporting, Restraining and Bracing th e Piping System Vibration: Prevention and Control Appendixes 385 pp ( 1-467952 ) 1964 $37.50 HANDLING RADIOACTIVITY: A PRACTICAL APPROACH FOR SCIENTISTS AND ENGINEERS D.C Stewart A broad overview of all of the many factors invo lved in the s afe handling of rad i oactive materials on the bench scale A dministrators of nuclear orien t ed programs, archi t ect engineers, nuclear facility managers and those r esponsible for training of pe r sonnel will find many practical matters o f i n te r est. The more highly t echnica l a r eas (dosimetry shielding, nuclear critica l i ty) ar e su rveyed and s ummarie s presented in straig htf orward non-mathematical language app r ox. 336 pp. (1-04557-8) Jan 1981 $35.00 TRANSPORT THEORY James J Duderstadt & William R Mart i n P r esen t s a gene r a l unified theo r y, surveying methods used to analyze the transport of such microscopic particles as neutrons, pho t ons, electrons and molecule s through matter. Covers numerous fields inc l uding nuclear r eacto r physics, astrop h ysics, gas and plasma dy namics and statistical mechanics. In c lude s fr e quent r e fe rences to lea d in g rev iew articles 613 pp. (1 -044 92-X) 1979 $39.95 INDUSTRIAL SEALING TECHNOLOGY H. Hugo Buchter Demons tr a t es how to identify and solve all kinds of sealing problems conso lidating data previously sca tt e r ed throughout th e li t erature Discusses ba sic principles of how seals work, what different kinds of se als ca n accomplish and what range of environmental and mechanical specifications each seal type is suited for 441 pp. (1-03184-4) 1979 $34 50 CHEMODYNAMICS Environmental Movement of Chemicals in Air Water and Soil Louis J Thibodeaux This advanced text covers the general topic of movement within the exch ange of man-made chemica l s between the three phases of the env ironment-air, soi l, and water. Th e topic o f chemodynamics in the exterior environment is organized and developed to provide students wi th a unified a pproa ch. 501 pp. (1-04720-1) 1979 $36 00 ENGINEERING FUNDAMENTALS, 2nd Ed. Examination Review Donald G Newnan & Bruce E. Larock A systema ti c, comprehensive review of basic engineering principle s, together wit h a pra c tical guide to s u ccessful preparation f o r s t ate Engineer-in-Training (E IT) examina t ions Covers all importan t con c epts in nine major areas: mathematics, statics, dynamics, mechanics of ma t e r ials, fluid mechan i cs, thermodynam ics, chemistry, elect r icity and eco n omic ana l ysis. 503 pp. (1-01900-3) 1978 $27 50 PULP AND PAPER Chemistry and Chemical Technology, 3rd Ed., Vols. 1, 2, & 3 James P. Casey Here's an in-depth look a t the chemis t ry and chemical technology i nvolved in the manufacture o f pulp and pape r the p r operties of paper, and the uses for paper The new edi t ion contains contributions by forty recognized authori t ies in th e fie ld Emphasi zing the underlying science and t echno l ogy, thi s edi ti on r ev iews in detail, chemical and engi n ee rin g principles Vol. 1 : 820 pp (1-03175-5) 1980 Vol. 2: 625 pp. (1-03176-3) 1980 Vol. 3: approx. 700 pp. (1-03177-1) $55 00 $50 .00 April 1981 $48.50 (tent.) Books under consideration as classroom texts are available f o r a 60-day free examinat i on. Write to Ju l es Kazimir O rd er through your bookstore or write to Nat Bod i an Dept. 74 36 TO ORDER BY PHONE call toll t ree 800 526-5368 In New Jerse y ca ll co ll ec t (2 0 1 ) 7977 809 WILEY INTERSCIENCE a d i v ision of John W i l ey & Sons Inc. 6 0 5 T hir d A v enu e New Yo rk N. 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lb / yr. With the indicated growth rates, these markets will have expanded to 7050 and 1220 mm lbs/yr respectively during the three years taken for planning and construction. To operate at full capacity, the new American producer must cap ture 20 % of the market available to him, whereas the equi valent number for the Alberta plant is 60 % The potential market available to the Al berta producer at start-up is about twice the capacity specified in the base case, i.e. 1000 T /D. As a first step, he might consider doubling the plant capacity to 2000 T / D in order to capture the entire base case market area plus any other market that becomes available as a result of the economics of scale. Figure 4 shows the market Note : Base Case Data Expect for Natural Gas Prices (Alberta & Gulf Coast $1 25 / mm Btu) Du l y Draw Back Only FIGURE 4. Effect of Plant Size and Duty Draw Back on Market Area. lines for the 1000 and 2000 T /D plants. All other factors were held constant. The interesting feature of the increase in plant size is that, in spite of the reduced unit cost of methanol, not one more major customer was added to the Alberta market. The only effect of the increase was to add sufficient capacity to satisfy the demand of the customers that a 1000 T /D plant could not. It is obvious that the next plant size that should be tried is about 1200 T /D. However, this is too precise a refinement in view of the potential effects of changes in other variables. On occasion, a commodity is imported into a country, processed, then exported in a different form. When this occurs, the duty or tariff origin ally imposed on the imported good is forgiven. This is called a duty drawback. In the PNW up to one-third of imported methanol is exported in the form of resin. In effect, the cost of the Alberta produced methanol is reduced by an amount equal to the duty drawback, which improves the com petitive position of Alberta methanol in a conWINTER 1981 tested area. The sensitivity of the market line to a change in duty drawback is also shown on Figure 4 for the case of equal natural gas prices of $1.25 / mm Btu. )Vith no duty drawback, the Alberta pro ducer should be able to capture virtually all of Washington and half of the Idaho market area. With one-third of the tariff forgiven, he will be able to penetrate one-half of the Oregon market in addition to the states of Idaho and Washington. The incremental increase in geographical area due to the change is relatively small; however, the amount of increased sales should be significant because of the concentration of users located in the area. It should be noted that the line repre senting the one-third duty drawback is mislead ing. The line is for drawback based on the average, whereas in reality the drawback is specific for only those plants which exported the processed methanol. So far it has been assumed that the determina tion of the market size was undertaken so that both potential competitors can make the capital in vestment decision of whether to build a plant or not. A more interesting situation occurs when one of the plants is already in production, while the decision to construct the other has yet to be made. For the sake of argument, suppose the Texas plant exists anq. that the Alberta plant has yet to be built. The Alberta plant must use the average cost of production which includes return on equity to determine its market. On the other hand, the Gulf producer makes his decisions based on the marginal cost of production. In the short term, the existing plant can sell its production at a cost equal to the variable pro duction cost or breakeven. In the midterm, the producer can sell at a price which includes all manufacturing and debt repayment costs, but ex cludes eq-q.ity capital recovery or return on equity. Operating for an extended period under this condition will have adverse effects on either the value of the company's stock or the plant liquida tion value. Figure 5 shows the market lines for the Texas plant selling its product under several pricing options. The Alberta producer is assumed to have full equity recovery and return. On this figure, four market lines are shown. The three most southern lines are parametric in the fraction of original anticipated return and recapture of equity. The line designated as 100 % corresponds to the original base case and that line marked as O % is the case where only production and debt costs are met. Finally, the market area outlined 47

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FIGURE 5. Effect on Percent Capital Recovery for Gulf Coast Plant on Western Market Area. by the breakeven line is the situation where only the variable costs of production are achieved. In the last case there is no allowance made for equity or debt repayment. By selling its product at the :marginal cost of production, the northernmost line, the Gulf Coast producer is able to capture most of the PNW market. However, this situation can only be a short-lived phenomenon, since this market is equal to about one-third of the Texas plant's production. Usually, selling at the margin is resorted to when a small fraction of the plant's capacity is under-utilized. In the long run, the Alberta producer does not need to worry about this single competitor capturing a large share of the PNW methanol market. This is certainly not the case if a large number of U. S. producers are operating at less than their capacity. The market line in Eastern Canada was shown only for the base case. The Gulf Coast producer selling into Eastern Canada at breakeven or at the margin would be in violation of Canadian dumping laws, so these lines were not drawn. Dumping occurs when a company sells internationally at a price below its domestic price. Thus far, the analysis has been used to find the respective market areas for two competitors under a variety of conditions using the concept of de livered cost as the sole criterion. By interpreting the technique in a slightly different manner, the two competitor price can be estimated. Here, a two competitor price at a given point is defined as the higher of the two delivered costs at that point. The concept of this price is best illustrated by a simple example. Suppose the two methanol pro ducers are attempting to sell methanol to hypo thetical customers in Pendleton, Washington and Vancouver, B.C. As shown on Figure 6, the cost of Gulf Coast produced methanol in Pendleton is 48 6.5 U.S. /lb, whereas the Alberta plant cost de livered at the same point is 5.34 U.S. /lb Given that there are no other suppliers, the Alberta producer can charge slightly less than 6.5 U.S. /lb and still capture the Pendleton market. By subtracting transportation, tariff and currency conversions from the Pendleton price, the FOB plant gate price of methanol in Calgary is approximately 5.2 Can. / lb. This is shown on the figure as a dashed line. Since the plant gate cost was only 4.05 Can. / lb, the sales into Pendle ton will yield a profit of 1.15 Can. /lb in addi tion to the required profit embedded in the cost calculation. On the other hand, the American plant can set the price in San Ftancisco at the Alberta delivered cost of about 6.1 U.S. lb. The basic principle is that in a given market area, the price is set equal to the competitor's delivered cost at any point in that area. The situation can be more complicated, as illustrated by an analysis of the Vancouver market. The Gulf Coast plant could transport methanol via ship from San Francisco and land it in Vancouver at 6.8 Can. /lb. This delivered cost would fix the FOB plant gate price available to the Alberta producer at 6.2 Can. /lb. \ \ 6 8 \ 6 4 6 0 -0 5 6 0 c.. "' 5 2 c 4 8 Q) (.) __ ___l__ _____ ---+___ _L_ ___J 4 0 Sa n B ase C a se P endle t on INT L Calgary Francisco M a r ket L ine Borde r FIGURE 6. Two Competitor Pricing in PNW. However, the Canadian plant might then be violat ing American anti-dumping laws by selling to the U.S. at 5.2 Can. / lb FOB plant gate and in the Canadian market at 6.2 Can. / lb. Because the PNW market size is much larger than that in Vancouver, the delivered price of methanol in Van couver should be set at 5.8 Can. / lb instead of the 6.8 Can. / lb calculated in the absence of anti dumping laws. Oddly enough, the U.S. anti-dump ing law has had the effect of lowering the price to CHEMICAL ENGINEERING EDUCATION

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the Canadian methanol consumer while benefitting neither the American methanol producer nor American consumers. A word of caution is necessary to warn the reader that the actual price will probably not be equal to the one calculated above. Obviously the two competitor model is much too simple to be applicable in the commercial world. The extension of the technique to a multi-competitor one is straightforward in principle and a natural appli cation for a computer simulation. However, even the more complicated model would probably not arrive at a realistic price because of the un availability of accurate input data. The model would be useful in the commercial world in the hands of someone familiar with the industry. The technique has proven to be a very useful tool in showing students how the technical, economic and regulatory factors influence the potential markets for a chemical commodity. REFERENCES 1. Various industry sources. 2. Chemical Economics Handbook, Standford Research Institute, Menlo Park, California, Vol. II, 1977 3. :Srett Haugrud, M.Sc. Thesis, University of Alberta, 1978. AWARD LECTURE Kinetics of Coal Processing Continued from page 18. Reactant A diffuses through the product layer to the reaction surface where chemical change occurs. As reaction progresses, each pore of the particle has associated with it a growing reaction surface which initially corresponds to the inner surface of the pore. As the various reaction surfaces in the particle grow, it is inevitable that neighboring surfaces will intersect one another as the solid B separating them is consumed and replaced by the product Q. The growth of the total reaction surface may be followed in terms of the radial growth of a given set of overlapping cylinders, as shown in Figure 12. If the rate of reaction on the actual surface is proportional to the total surface area I S 1-X s,:-=( ,..)s 1--i:/ 1-wln l-X ,/ (1 :r (2) WINTER 1981 and the conversion is X=l-(1 : ) 3 exp[-'1'(1+ ~T)] (3) The surface development predicted by Equation (2) is shown in Figure 13, exhibiting the antici pated maximum, but only for pore structures that OVERLAP OF CYLINDERS PORE CROSS SECTION UNREACTED SOLID FIGURE 12. Overlapping of cylindrical surfaces. The hatched area shows the overlapped portion. The blackened area represents un reacted solid B. The reaction surface is the interface between the nonoverlapped portion of the cylindrical surface and the unreacted solid. The product layer that is deposited as the reaction surface moves is not shown in this figure. (After Avrami). provide \JI :2: 2. In this regard the model is more flexible than those based on an order of reaction or a grain model. The Petersen model ( 1957) can also describe either kind of behavior; but it makes no provision for further pore wall intersections and neglects the distribution of pore sizes. As an example of the use of the above technique, it is worthwhile to return to the data of Hashimolo et al. (1979) on the surface areas produced by steam activation of chars As aoo, Equation (2) pre dicts a linear semilog relationship between the group [S / (1X)] 2 and (1 X). This expectation is supported by the data within the limits of ex perimental error, as shown in Figure 14. That the subject of coal processing is a com plex matter with multiple branches is a common place. The emphasis of this paper has been to demonstrate that the newer techniques of ex perimentation and modeling can shed new light on the old fossil, if the broad problems of practice are disected into manageable parts, each to be digested in its turn. 49

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1.6 1 .4 \.2 0 (/) ;;; UJ u 1.0
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--------------------------. PROCES S CONTROL EDUCATION Continued from page 34. Then, if the field has not been able to respond in the way the critics had hoped, what explana tion can be found? Process control seems to have been unable to successfully compete for research and develop ment funding with other fields, which have been able to be more convincing concerning return of investment, especially short term. Indeed, Shinnar [46] states that "the total expense of any major oil company on research in process control in any given year is less than for one major television commercial." Changes can be expected, however. The in creased emphasis on energy utilization will, as mentioned above, put increased demands on a less conservative and more tightly and carefully controlled ope r ation of existing processes. One of the most efficient means to meet the increased cost of energy is and will be a more efficient energy utilization. Actually, one of the reasons for the receptivity of European industry to more sophisticated control approaches has been the high cost of energy in Europe. Now when the U.S.A. is experiencing higher energy costs-which will un doubtedly continue to climb-much more in dustrial interest in advanced control can be an ticipated. The rise of the energy costs will force process design in the same direction as process operation. The processes and plants will become more inte grated, more sensitive, and more difficult to control. Thus, both from the design and the operational point of view more emphasis will have to be put on advanced control in the future. Another circumstance which might have re tarded the progress in process control research, is the structure of U.S. faculties. The American professor, be he assistant, associate or full, often has no other research assistance than his (gradu ate) students. And when students have learned enough to be fast and efficient workers they are ready to leave. This system is not very efficient in an applied field like process control, in which such a large amount of knowledge and technics from various fields have to combined in every single non-trivial application. As expressed by Wallman et al. [10] in a LQG-application to the Foss chemical reactor: "It is undoubtedly evident from the account given here that the approach taken exacts a high price in engineering effort WINTER 1981 and expertise. To recount, effort is required in process modeling, parameter estimation, variable reconstruction, and control system design. On top of all this rests an overhead in approximation and numerical methods." The hierarchical European faculty system, in which research groups form naturally, almost by themselves, seems to be more efficient in this field. The difference may become larger in the future as the s y stems and problems to be treated are be coming more complex. This o r ganizational drawback in U.S. faculties is pronounced by the fact that most faculties have not gone in for process control whole-heartedly enough. One faculty member (the usual situa tion) is below the critical mass and no chairi re action, so important for creative work, is possible. During the keynote address at the 1973 Joint Automatic Control Conference Richard Bellman, recently recipient of the IEEE Medal of Honor, the highest honor that can be given by the world's largest professional society, predicted that control s c ience will be the most influential discipline for solving pressing national problems for the next t w o to three decades. Athans has agreed [2], "with no reservations whatsoever." Even if Bellman and Athans turn out to be ex cessively optimistic, it is easy to agree with Athans when he continues: "Modern control science will continue to flourish with or without the support of the process control community." It seems to me that the question of whether the chemical engineering community will be the one that bears the burden and wins the victories in chemical process control is still open. The potential is there, but so are the obstacles. ACKN O WLEDGMENTS The material providing the background for the present Teview was gathered dUTing a 9-month stay as a Senior Fulbright Fellow 1978-79 at the Chem. Eng. Department at the University of Cali fornia at Berkeley. The stay was made possible by grants from the United States Educational Foundation in Finland and the Foundation of Neste Oy. Visits to a number of other universities and to an AIChE meeting were made possible by a special travelers grant from the Research Institute of the Abo Akademi Foundation. These grants aTe acknowledged with sincere gratitude. 51

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Most stimulating and valuable discussions with a number of scientists and designers concerning the topic of this paper as well as comments on and criticism of the first draft of the paper are greatly appreciated. Above all Alan Foss, so perfect a host in Berkeley, as well as M. Athans, E. H. Bristol, C. B. Brosilow, P. S. Buckley J.M. Douglas, T. F. Edgar, L.A. Gould, W. L. Luyben, T. J. McAvoy, D. E. Seborg, F. G. Shinskey, R. M. Tong, R. K. Wood, and L. A. Zadeh. REFERENCES 1. Foss, A. S., AIChEJ 19 (1973) 209. 2. Athans, M. in Weaver, R.E.C. (Coordinator), Pro ceedings of the Workshop on priorities in process control research, Tulane-Univ. 1973. 3. Smith, C. L., Ibid. 4. Seborg, D. E., A survey of process control education in the United States and Canada, Paper presented at the 71st Annual AIChE Meeting, Miami, Nov. 1978. 5. Coughanowr, D. R., Koppel, L. B., Process Systems Analysis and Control, McGraw-Hill 1965. 6. Morari, M., Ray, W. H., The Integration of Real-Time Computing into Process Control Teaching at Wis consin, Paper presented at the 71 Annual AIChE Meeting, Miami, November 1978. The first part of the paper has been published in Chem. Eng. Education 13 No. 4 (1979) 160. The second part is in Chem. Eng. Education 14, No. 1 (1980) 32. 7. Foss, A. S., Denn, M. M. (Eds), Chemical Process Contro l, AIChE Symposium Series, 159 Vol. 72, 1976. 8. Vakil, H.B., Michelsen, M. L., Foss, A. S., Ind. Eng. Chem Fund. ;12 (1973) 323. 9 Silva, J. M., Wallman, P. H., Foss, A. S., Ibid. 18 (1979) 383. 10. Wallman, P. H., Silva, J. M., Foss, A. S., Ibid. 1 ; 8 (1979) 392. 11. Fisher, D. G. in Weaver, R.E.C. (Coordinator), Pro ceedings of the Workshop on priorities in process control research, Tulane Univ. 1973. 12. Foss, A. S., Edmunds, J. M., Kouvaritakis, B., Ind. Eng. Chem. Fund. 19 (1980) 109. 13. Bilec, R., Wood, R. K., Multivariable Frequency Domain Controller Design for a Binary Distillation Co lumn Paper presented at the 86t h National AIChE Meeting, Houston, April 1979. 14. Joseph, B., Brosilow, C. B., Tong, M., AIChEJ 24 (1978) 485. 15. Brosilow, C. B., The structure and design of Smith predictors from the viewpoint of Inferential control, Paper presented at JACC 1979. 16. Astrom, K. J., Wittenmark, B., Automatica 9 (1973) 185. 17. Astrom, K. J., Borison, U., Ljung, L., Wittenmark, B., Ibid. 13 (1977) 457. 18. Zadeh, L. A., Trans. ASME, J. Dyn. Syst. Meas. Control 94 Ser. G (1972) 3 19. Zadeh, L. A., IEEE Trans. Systems, Man, Cyber netics SMC-3 (1973) 28. 52 20. Bristol, E. H., IEEE Trans. Auto. Contr. AC-11 (1966) 133 21. Shinskey, F. G., Proce ss Contr ol Systems, McGraw Hill 1967, Second Edition 1979. 22. Rijnsdorp, J. E., Automatica 1 (1965) pp. 15, 29. 23. Nisenfelt, A. E., Schultz, H. M., Instr. Technology 18 No. 4 April (1971) 52. 24. McAvoy, T J. IS A Trans. 16 (1977) No. 4, p. 83. 25. Witcher, M. F., McAvoy, T. J., Ibid. 16 (1977) No. 3, p. 35. 26. Tung, L. S., Edgar, T F., Analysis of Control-Output Interaction in Dynamic Systems, Paper presented at the 71 Annual AIChE Meeting, Miami, Nov. 1978. 27 Gagnepain, J.P., Seborg, D. E An analysis of process interactions with applications to multiloop control system design, Paper presented at the 72nd Annual AIChE Meeting, San Francisco, November 1979. 28 Kominek, K. W., Smith, C L., Analysis of System Interaction, Paper presented at the 86th National AIChE Meeting, Houston, April 1979. 29. Shinskey, F. G., The Stability of Interacting Control Loops with and without Decoupling, Proc. IF AC Multivariable Technological Systems Conf 4th Inter national Symposium, Univ. of New Brunswick (1977) p 21. 3 0. Jafarey, A., McAvoy, T. J., Ind Eng. Chem. Proc. Des. Dev. 17 (1978) 485. 3 1. Jafarey, A., McAvoy, T. J., Douglas, J. M., Ibid. il-9 (1980) 114. 32 McAvoy, T. J., Ind. Eng. Chem. Fund. 18 (1979) 269. 33. Jafarey, A., McAvoy, T. J., Douglas, J M., Ibid. 18 (1979) 269. 34 Bristol, E. H., Recent Results in !nteraction in Multi variab l e Process Control, Paper presented at the 71st Annual AIChE Meeting, Miami, Nov. 1978. 35. Donoghue, J. F., IEEE Trans Ind. Elect. Contr. Instr. IECI24 (1977) 109. 36 Hammarstrom, L. G., Waller, K. V., IEEE Trans. Ind. Elect. Contr. Instr. IECI-27 (1980) 301. 3 7. Jafarey, A., Douglas, J. M., McAvoy, T. J., Ind. Eng. Chem Proc. Des. Develop. 18 (1979) 197. 38. Evans, L. B. in Weaver, R. E. C. (Coordinator), Pro ceedings of the Workshop on priorities in process control research, Tulane Univ. 1973. 39. Waller, K. V., Paper and Timber, 62 (1980) 128. 40. Chen, F. T., Douglas, ,T. l'vI., Georgakis, C ., Ind. Eng. Chem. Fund. 18 (1979) 321. 41. Mamdani, E. H., Applications of Fuzzy Set Theory to Control Systems: A Survey, in Gupta, M. M., Saridis, G. N., Gaines, B. R. (Eds), Fuzzy Automata and Decision Processes, Elsevier North-Holland 1977. 42. Tong, R. M., Automatica 13 (1977) 559. 43 Asbjornsen, 0. A., Survey Paper, Symposium on use of process computers, European Federation of Chemi cal Engineering, 166th Event, Firenze, Italy, Sept. 1976. 44 Ballard, D., Brosilow, C. B., Dynamic Simulation of Multicomponent Distillation Columns, Paper pre sented at the 71st Annual AIChE Meeting, Miami, 45. Athans, M., Discussion remark in round table dis cussion on "The next decade in control theory and applications," IF AC VII Triennial World Congress, H e lsinki, June 1978. 46 Shinnar, R.; Chem. Eng Education 11 (1977) 150. CHEMICAL ENGINEERING EDUCATION

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ACl{NOWLEDGMENTS Departmental Sponsors: The following 140 departments contributed to the support of CHEMICAL ENGINEERING EDUCATION in 1981 with bulk subscriptions. University of Akron University of Alabama University of Alberta Arizona State University University of Arizona University of Arkansas Auburn University Brigham Young University University of British Columbia Bucknell Uni v ersity University of Calgary California State Polytechnic California Institute of Technology University of California (Berkeley) University of California (Davis) University of California (Santa Barbara) Carnegie-Mellon University Case-Western Reserve University University of Cincinnati Clarkson College of Technology Clemson University Cleve : and State University University of Colorado Colorado School of Mines Columbia University University of Connecticut Cooper Union Cornell University University of Dayton University of Delaware U. of Detroit Drexel University Ecole Polytechnique (Canada) University of Florida Georgia Technical In s titute University of Houston Howard University University of Idaho University of Illinois (Urbana) Illinois Institute of Technology Institute of Gas Technology Institute of Paper Chemistry University of Iowa Iowa State University Kansas State University University of Kentucky Lafayette College Lamar University Lehigh University Loughborough University Loui s iana State University Loui s iana Tech. Uni v ersity University of Louisville University of Maine University of Maryland University of Massachusetts Massachusetts Institute of Technology McMaster Uni v ersity McNeese State University University of Michigan Michigan State University Michigan Tech University University of Minnesota University of Mississippi University of Missouri (Columbia) University of Missouri (Rolla) Monash Univer s ity Montana State University University of Nebraska University of New Brunswick New Jersey Inst. of Tech. University of New Hampshire New Mexico State University University of New Mexico City University of New York Polytechnic In s titute of New York State University of N.Y. at Bulfalo North Carolina State University University of North Dakota Northwestern University University of Notre Dame Nova Scotia Tech. College Ohio State University Ohio University University of Oklahoma Oklahoma State University Oregon State University University of Ottawa University of Pennsylvania Pennsylvania State University University of Pittsburgh Princeton University University of Puerto Rico Purdue University Queen's University Rensselaer Polytechnic Institut University of Rhode Island Rice University University of Rochester Rose-Bulman In s titute Rutgers U. University of South Carolina University of Saskatchewan South Dakota School of Mines University of South Florida University of Southern California Stanford University Stevens Institute of Technology Syracuse University Tennessee Technological University University of Tennessee Texas A&M University Texas A&I University University of Texas at Austin Texas Technological University University of Toledo University of Toronto Tri-State University Tufts University Tulane University University of Tulsa University of Utah Vanderbilt University Villanova University Virginia Polytechnic Institute University of Virginia Washington State University Uni,ersity of Washington Washmgton University University of Waterloo Wayne State University We s t Virginia In s t. Technology West Virginia University University of Western Ontario University of Windsor University of Wisconsin (Madison) Worcester Polytechnic Institute University of Wyoming Yale University Youngstown State University TO OUR READERS: If your department is not a contributor, please ask your department chairman to write CHEMICAL ENGINEERING EDUCATION, c/o Chemical Engineering Department, University of Florida, Gainesville, Florida 32611.

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11 Can a new plastic be produced efficiently? It$ up to me to decide:' Mark Carlson BS, Chemical Engineering This kind of decision making is a great responsibility. At Du Pont I have the freedom to do whatever testing is necessary to make accurate judgements. Working with plastics was my chief interest at the South Dakota School of Mines and Technology. I interviewed with Du Pont because its strength in the field matched my interests. I started work at the Parkersburg, West Virginia site on process development for DELRIN Then I worked on the engineering of a color develop ment facility. My present assign ment is compounding glass mineral and rubber reinforced plastics. All this calls for initiative and gets me into design activities with the marketing people That's the great thing about Du Pont. You use a lot more than just your engineering ." If you want to develop all your talents-whether you're a ChE ME or EE-see the Du Pont Representative when he's on cam pus. Or write Du Pont Company Room 37798, Wilmington DE 19898. At DuPont ... there's a world of things you can do something about. "E C. US P JI.T 8 T M o F f An Equal O pp o rtunity Empl o y e r M F