Citation

## 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:
periodical ( marcgt )
serial ( sobekcm )

## Notes

Citation/Reference:
Chemical abstracts
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

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Chemical Engineering Documents

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Chemical Engineering Education
Department of Chemical Engineering
University of Florida
Gainesville, FL 32611

EDITOR: Ray W. Fahien (904) 392-0857
ASSOCIATE EDITOR: T. J. Anderson
CONSULTING EDITOR: Mack Tyner
MANAGING EDITOR: Carole Yocum (904) 392-0861

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*PAST CHAIRMEN
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Library Representative
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SUMMER 1989

Chemical Engineering Education
VOLUME XXIII NUMBER 3 SUMMER 1989

DEPARTMENT
130 New Jersey Institute of Technology, Gordon Lewandowski

VIEWS AND OPINIONS
134 Extrinsic Versus Intrinsic Motivation in Faculty
Development, E. Dendy Sloan

REPORT
138 Content and Gaps in BSChE Training: Value and Mystique
in Engineering Economics, James B. Weaver

188 Chemical Engineering Curricula for the Future: Synopsis of
Proceedings of a U.S.-India Conference, January, 1988,
D. Ramkrishna, P.B. Deshpande, R. Kumar, M.M. Sharma

RANDOM THOUGHTS
166 The View Through the Door, Richard M. Felder

LABORATORY
144 Using the Laboratory to Develop Engineering Awareness,
R. England, R.W. Field

150 The Coffee Pot Experiment: A Better Cup of Coffee via
Factorial Design, R.J. McCluskey, S.L. Harris

182 Biotechnology Laboratory Methods,
Robert H. Davis, Dhinakar S. Kompala

CLASSROOM
154 Another Way of Looking at Entropy: Entropy and Aging,
Evolving Systems, Daniel Hershey

168 Generalized Saturation Properties of Pure Fluids via Cubic
Equations of State, Maria A. Barrufet, Philip T. Eubank

CURRICULUM
176 Triangular Diagrams Teach Steady and Dynamic
Behaviour of Catalytic Reactions,
K. Klusacek, R.R. Hudgins, P.L. Silveston

194 A Chemical Plant Safety and Hazard Analysis Course,
J.P. Gupta

CLASS AND HOME PROBLEMS
163 A Practical Application of Mass Balances,
William F. Furter, Michael J. Pegg, Paul R. Amyotte

143 LettertotheEditor
149,161,175 181 Book Reviews

CHEMICAL ENGINEERING EDUCATION (ISSN 0009-2479) is published quarterly by Chemical
Engineering Division, American Society for Engineering Education and is edited at the University of
Florida. Correspondence regarding editorial matter, circulation, and changes of address should be sent to
CEE, Chemical Engineering Department, University of Florida, Gainesville, FL 32611. Advertising mate-
rial may be sent directly to E. O. Painter Printing Co., P. 0. Box 877, DeLeon Springs, FL 32028. Copyright
1989 by the Chemical Engineering Division, American Society for Engineering Education. The statements
and opinions expressed in this perodical are those of the writers and not necessarily those of the ChE
Division, ASEE, which body assumes no responsibility for them. Defective copies replaced if notified with
120 days of publication. Write for information on subscription costs and for back copy cost and availability.
POSMASTER: Send address changes to CEE, Chemical Engineering Department, University ofFlorida,
Gainesville, FL 32611.

Department

NEW

JERSEY

INSTITUTE

OF

TECHNOLOGY

GORDON LEWANDOWSKI
New Jersey Institute of Technology
Newark, NJ 07102

UNTIL ABOUT 1980, NJIT was largely an under-
graduate teaching institute producing high qual-
ity bachelor's degree engineers. The focus of the un-
dergraduate curriculum was (and still remains) a prag-
matic program of study for the 95% of our students
who go to work immediately after graduation.
More than 90% of our undergraduates commute to
attending a university with a very definite vocational
objective in mind, namely to enter a well-paying pro-
fession. One out of every four engineers in New Jer-
graduate enrollment is black and another 11% is his-
panic. In fact, NJIT ranks 12th nationwide in the
number of engineering degrees awarded annually to
minorities (black and hispanic) [1].
Over the years we have been fortunate in attract-
ing bright, well-motivated students. Their leadership
skills are reflected in the fact that our AIChE Student
Chapter has received the Award of Excellence for
eighteen consecutive years, which is far and away an
AIChE record.

Photo by Bill Wittkop

Although we continue to recognize the importance
of our undergraduate program, over the past few
years there has been a dramatic change in faculty em-
phasis on research (as shown in Figure 1). Research
funding in the department has increased six-fold (ap-
proximately three-fold in uninflated dollars) over the
past ten years, to a current level of $2.2 million. The increasing research effort has paralleled the 2,400 2,200 .I 2,000 - 1,800 -. 1,600 - S1,400 - 1,200 - 1,000oo - 800 - 600 4I I I I IOL ARS 00 -''-- lASSU'MI'N 6.5% 400 - 200 -m INFLATION/YR) 79-80 80-81 81-82 82-83 83-84 84-85 85-86 86-87 87-88 88-89 89-90 YEAR FIGURE 1. Research Funding, Department of Chemical Engineering, Chemistry, and Environmental Science E Division ASEE 1989 CHEMICAL ENGINEERING EDUCATION Although we continue to recognize the importance of our undergraduate program, over the past few years there has been a dramatic change in faculty emphasis on research funding in the department had increased six-fold over the past ten years, to a current level of$2.2 million.

growth in our graduate program. In fact, we now have
a higher enrollment in the graduate program (240
total) than in the undergraduate program (140 total).
Approximately half of our graduate students are en-
rolled in the MS program in Environmental Science.
A negative factor has been the low enrollments in our
doctoral program; of the 240 full and part-time
graduate students, only fifteen are doctoral students.
This is clearly inconsistent with the level of research
funding and as a result, we have embarked on a vigor-
ous campaign to publicize our graduate program in
order to recruit more qualified doctoral students.

A BRIEF HISTORY
NJIT began in 1881 as the Newark Technical
School, which later evolved into the Newark College
of Engineering. In 1975, with the incorporation of a
School of Architechture, the name was changed to
New Jersey Institute of Technology. NJIT now oc-
cupies a thirty-six acre campus in Newark, and has an
annual budget of approximately $85 million. About half of that amount comes from the State. Total enroll- ment includes about 4000 full-time (2700 under- graduate and 1300 graduate) and 3400 part-time stu- dents. BS degrees in chemical engineering were first awarded in 1919, and the program has been accredited since 1950. The first female graduate was in 1930, making our department a pioneer in that regard (cur- rently, about 20% of our undergraduates are female). The MS program has been in existence since 1948 and the DEngSc since 1961. The department also awards BS and MS in Applied Chemistry, and an MS in En- vironmental Science. INTERDISCIPLINARY NATURE The department combines faculty in chemical en- gineering and chemistry, and this affords many oppor- tunities for interdisciplinary projects-both educa- tional and research. In that respect, as well as in others, we have been old-fashioned enough to become modern. We began as an industrial chemistry depart- ment more than 100 years ago and have always main- tained close ties between the two disciplines. The re- cent report on "Frontiers in Chemical Engineering Education" [2] has given renewed vigor to the thesis that chemical engineers need to be well-grounded in Photo by Bill Wittkop Students at work in the senior chemical engineering lab. chemistry (as well as other sciences). Although we do not have a biology department at NJIT, the Newark campus of Rutgers University (lo- cated across the street from NJIT) has an excellent Department of Biological Sciences. We currently have joint research projects with faculty in that department and have students enrolled there in an introductory course on microbiology. We also maintain close ties to the University of Medicine and Dentistry of New Jer- sey (UMDNJ) through both our biomedical engineer- ing (MS) and environmental science (MS) programs. FACILITIES The department is principally located in Tiernan Hall, which was built in 1972. Departmental resources include two dedicated computer rooms containing a total of twenty-five terminals which are connected to a VAX 11/785 and a VAX 8800. We are also linked to the supercomputer facility at the John von Neumann National Supercomputer Center in Princeton, NJ. In addition, all freshmen at NJIT are provided with their SUMMER 1989 own personal computer. Our undergraduate instructional facilities include an outstanding unit operations laboratory (comprised of about 6,500 ft2 on three levels) with a multi-story high-head area, pilot-scale equipment, and a number of computer-driven process control experiments. We also occupy about 20,000 ft2 of research space in Tiernan Hall. Research labs include the analytical equipment normally expected of a serious research ef- fort (GCs, GC/MS, HPLCs, AAS, NMR, etc.) as well as specialized research equipment (continuous and batch fermentors, a laser doppler velocimeter, a fully instrumented pilot-scale scrubber, UV/ozone reac- tors, etc.). In 1988, an$11 million building dedicated to
hazardous waste research was built on campus. More

Photo by Bill Wittkop
The process control lab at NJIT.

than $2 million of research equipment is being pur- chased for the new building, and many of our faculty have research labs and offices there. RESEARCH FOCUS A principal research focus is hazardous waste treatment. In 1984, NJIT became the lead institute in an NSF Industry/University Cooperative Research Center in Hazardous and Toxic Substances. The Center was then designated an Advanced Technology Center by the State of New Jersey, and is now known as the Hazardous Substance Management Research Center (HSMRC). The other universities represented in the center are Rutgers University, Princeton Uni- versity, Stevens Institute of Technology, and UMDNJ. HSMRC support comes from the State of New Jersey ($3 million), NSF, the U.S. Army, and
twenty-eight major corporations (each of which con-

tributes $30,000/year and appoints a representative to the Industrial Advisory Board). In addition, the HSMRC, in conjunction with Tufts University and MIT, has been designated a regional center for hazardous waste research by the U.S.EPA, which provides an additional$1 million in annual support.
About 25% of the HSMRC research budget involves
faculty from our department (Drs. Armenante,
Baltzis, Bozzelli, Dauerman, Huang, Knox, Lei,
Lewandowski, Shaw, and Sofer). Richard Magee (pro-
fessor of chemical and mechanical engineering) is
Executive Director of HSMRC, and Gordon Lewan-
dowski is Director of the Biological/Chemical Treat-
ment Division.
Through the efforts of the HSMRC, we have re-
cently developed ties to the Institut National des Sci-
ences Appliquees (INSA), in Lyon, France. We cur-
rently have both a graduate student and a post-doc-
toral student from that university in our MS program
in environmental science.
Another important departmental resource as-
sociated with environmental research has been the Air
Pollution Research Laboratory, directed by Drs. Boz-
zelli, Greenberg, and Kebbekus. They have received
substantial funding for more than a decade from the
N.J.DEP and U.S.EPA for the purpose of monitoring
the concentration of air pollutants in the region.
A different research focus involves structural or-
ganic chemistry. Arthur Greenberg has a strong re-
search program in strained organic molecules and is
co-editor of the journal Structural Chemistry, pub-
lished by VCH (New York). Drs. Venanzi and Gund
direct the state-of-the-art molecular modeling com-
puter graphics laboratory which examines the interac-
tions between substrates and enzymes (or between
drugs and receptors).
The biotechnology program is also supported by
the engineering research of Drs. Armenante, Baltzis,
and Sofer. Although geared primarily toward biodeg-
radation of hazardous waste, their research also in-
volves multiphase mixing phenomena, microbial com-
petition, and conversion of biomass.
In addition, David Kristol (professor of chemistry)
program (which awards an MS in that field). As a
result of that program, faculty in our department are
involved in joint research projects with faculty at the
nearby medical school (UMDNJ). Additional areas of
research interest are given in Table 1.

CURRICULUM
The undergraduate curriculum includes 139 cred-
its: 41 in chemical engineering, 27 in chemistry, 16 in

CHEMICAL ENGINEERING EDUCATION

TABLE 1
NJIT Faculty and Research Interests

Piero Armenante (University of Virginia) biodegradation of
hazardous waste; mixing phenomena
Basil Baltzis (University of Minnesota) mathematical modeling
of microbial systems
Joseph Bozzelli (Princeton University) gas phase reaction ki-
netics; air pollution analysis
Leonard Dauerman (Rutgers University) treatment of solid
waste using microwaves
Arthur Greenberg (Princeton University) strained organic
molecules; air pollution analysis
Teddy Greenstein (New York University) biochemical pro-
cesses; fluid mechanics
James Grow (Oregon State University) production of thin films;
surface analysis
Tamara Gund (Princeton University) molecular modeling of
drug/receptor interactions
Deran Hanesian (Cornell University) reaction kinetics; plastics
processing
Ching Huang (University of Michigan) photochemical oxidation
of waste; transport phenomena
Barbara Kebbekus (Pennsylvania State University) air pollu-
tion analysis
Dana Knox (Rensselaer Polytechnic Institute) stabilization of
solid waste; thermodynamic modeling
George Lei (Polytechnic University) polymers
Gordon Lewandowski (Columbia University ) biodegradation
of hazardous waste
Howard Perlmutter (New York University) organic synthesis
Angelo Perna (University of Connecticut) solid waste disposal
Edward Roche (Stevens Institute of Technology) computer
modeling of chemical processes and distillation
Henry Shaw (Rutgers University) control of air pollutants
Sam Sofer (University of Texas) biochemical and biomedical
processes
Lawrence Suchow (Polytechnic University) superconductivity;
solid state materials
Reginald Tomkins (University of London) electrochemical
processes
Richard Trattner (City University of New York) control of
gaseous pollutants
Carol Venanzi (University of California, Santa Barbara) molecu-
lar modeling of enzyme/substrate interactions

TEACHING FACULTY
Ernest Bart (NYU) Vincent Cagnati (MS-Stevens)
Robert Conley (Brown) Donald Getzin (Columbia)
Donald Lambert (VPI) Avner Shilman (Polytechnic U.)

Howard Kimmel (CUNY) Assistant Vice President for Academic
Affairs; Director, Center for Precollege Programs
David Kristol (NYU) Director, Biomedical Engineering and En-
gineering Science Programs
Richard Magee (Stevens Institute) Executive Director, HSMRC
Richard Parker (U. Washington) Associate Dean, Engineering

mathematics, 12 in physics, 24 in liberal arts, and 19
in miscellaneous subjects and electives. The chemical
engineering courses include: material and energy bal-
ances, a unit operations/transport sequence (fluid
mechanics, heat transfer, mass transfer and stage sep-
arations), reactor design, thermodynamics, process
control, process and plant design, and unit operations
laboratory. Computer projects are required in all
junior- and senior-level courses.
For many years now we have also been encourag-
ing undergraduates to become involved in research.

More than 90% of our undergraduates commute
are attending a university with a very definite
vocational objective in mind, namely to
enter a well-paying profession.

Qualified students can satisfy two of their electives by
working on a research project under faculty guidance.
We also want to make sure that we continue to
produce professionals. This means educating our stu-
dents to be more aware of the world around them and
their place in that world. In this regard, we are fortu-
nate in having an excellent program in Science,
Technology, and Society (STS) at NJIT. Course mate-
rials have been developed in conjunction with STS and
Humanities faculty that expand the educational base
of our students into areas such as public policy, com-
munication, and ethics.
NJIT also has a very strong co-operative education
program with industry. This program involves both
we are currently developing a co-op program with a
local waste treatment company which would enable
our environmental science students to gain practical
experience before receiving their MS degrees.
At the graduate level, we have a required core
curriculum which includes: mathematical methods,
kinetics, thermodynamics, and transport phenomena.
MS students receiving financial support are required
to complete a thesis and eight courses (including the
core and four electives). Students not receiving an
assistantship are not required to complete a thesis and
dents take eight courses beyond the MS, in addition
to a thesis. Qualified students may also be admitted
directly into the doctoral program with a bachelor's
degree.
We are very interested in receiving more applica-
tions to our doctoral program. We have the research
program to support a much larger doctoral population
Continued on page 165.

SUMMER 1989

views and opinions

EXTRINSIC VERSUS INTRINSIC

MOTIVATION IN FACULTY DEVELOPMENT*

Higher education succeeds or fails in terms of motivation, not cogni-
tive transfer of information. To teach implies a transfer of information,
and that is not the main purpose of higher education. To profess means
to confess one's faith in, or allegiance to, some idea or goal. An effective
professor is one who is intrinsically motivated to learn, because he/she
will have the best chance to educate others.
Csikszentmihalyi (1982)

E. DENDY SLOAN
Golden, CO 80401

F WE WISH TO address the question of faculty mo-
tivation and vitality we must follow the findings of
Wergin, Mason, and Munson [1] who suggest that the
factor most predictive of success in faculty motivation
and development is depth of knowledge about the fac-
ulty members themselves and their personal charac-
teristics. Bess [2] also indicates that the best effects
of such motivation will be realized by accounting for
individual differences. However, there appears to be
a paucity of data concerning the select sample of en-
gineering faculty on which we wish to concentrate. In
addition, there are many components affecting faculty
motivation which are too diverse to discuss, e.g.,
health, family situation, etc. This need for data on the
faculty sample leads to the initial conclusion of this
paper; we would be much more comfortable with any
of the following tentative conclusions if we had
thorough research information on the faculty of in-
terest. We initially suspect, however, that the means
of motivating faculty may be radically different from

Engineers draw upon sciences such as chemistry,
physics, and mathematics for tools in application to
technical problem solving, but here we must turn to
softer sciences, i.e., psychology and sociology, for
tools in determining faculty characteristics.

*Modified from a portion of a paper "Enriching the Undergraduate
Engineering Experience," originally presented at a workshop of
the American Society for Engineering Education, sponsored by the
National Science Foundation.

E. Dendy Sloan is a professor of
School of Mines, where he has depended
upon the magnanimity of students and
colleagues for twelve years. He has served
as Chairman of both the Chemical Engi-
neering Division and the Educational Re-
search and Methods Division of ASEE. He
does research in natural gas hydrates, fluid
properties, and pedagogical methods.

the means of motivating industrial workers.
But as engineers we typically have to make heuris-
tic decisions based on incomplete data, accepting the
risks involved and with the expectation that sequen-
tial heuristics, based upon more data, will be much
better. Therefore we must make some inferences from
the small data base on the collection of both engineer-
ing and science faculty, and hope to paint the
silhouette of the faculty with a broad brush.
Engineers draw upon sciences such as chemistry,
physics, and mathematics for tools in application to
technical problem solving, but here we must turn to
softer sciences, i.e., psychology and sociology, for
tools in determining faculty characteristics. Since the
author has no formal training in either field, the
examination should be considered somewhat cursory.
In particular, I hope to show how the concept of stages
in faculty growth and development are related to the
motivation of faculty for effective professing.

STAGES IN FACULTY GROWTH AND DEVELOPMENT
The mathematician/philosopher Alfred North
Whitehead [3] postulated three stages of education.

CHEMICAL ENGINEERING EDUCATION

JM I

The initial stage is the Romance stage in which the
learner becomes enthralled with the potential of the
subject area, but has only a fragmentary knowledge
of what is involved in reaching that potential. The
second stage is one of Precision, in which the learner
fills in the detailed learning required to achieve the
potential. Finally comes the stage of Generalization,
when both the precise principles and romance are in-
corporated and connected to other areas of the learn-
er's knowledge and life. While Whitehead's model of
education was intended to describe optimal learning
stages through the college years, similar learning
stages may be postulated for other learners, such as
faculty who encounter the field of teaching (for which
they have had no formal training.)
Levinson, et al. [4] were somewhat more specific
years), using a longitudinal study. It is worth noting
that 20% of the Levinson group's sample was univer-
sity faculty. That original work was supported and
popularized by Gould [5] and Sheehy [6]. In their
analysis, growth and development occur through a
series of stable and transitional periods. During stable
periods the adult pursues fairly clear goals. During
transitional periods, however, individuals reorder
priorities and change behavior in order to compensate
for neglected dimensions.
There is a growing body of evidence that there are
faculty career phases, especially in teaching and re-
search components. Research phases appear to be
bimodal in terms of productivity according to
Blackburn, Behymer, and Hall [7] in their study of a
large cross-sectional sample of 1,216 faculty. Produc-
tivity appears to increase from the entry level until
the ages between 35 and 39, during which time faculty
normally strive to obtain tenure and full professor
status. There is a slight decline in productivity be-
tween the ages of 35-39 and 40-44 while faculty go
through Levinson's mid-life transitional period. Pro-
ductivity increases again with the resolution of the
mid-life transition until the early fifties, and then
there is a slow decline until retirement. Senior faculty
still produce significantly more writings than junior
faculty, even with this last decline. These findings are
supported by Cole [8] who determined that roughly
the same proportion of scientists in different age
groups makes important discoveries. This is a direct
refutation of the theory by Lehman [9] (brought about
by questionable sampling) that most of the important
discoveries are made by those faculty under thirty
years of age.
Teaching development also appears to be bimodal
(Baldwin and Blackburn [10]), although Blackburn

Difficult times generally arise twice during
[teachers' careers] ... during the early years when they
are first learning how to teach, [and during] periods of
new or added responsiblility which involve new

[11] appeals for more data before coming to conclu-
sions on the initial, somewhat anecdotal evidence.
Their findings of the characteristics of teacher devel-
opment are summarized in Table 1. There is an ap-
proximate parallel of teaching development to the
above research development. Difficult times generally
arise twice during a career. Teachers have difficulty
during the early years when they are first learning
how to teach (Stage I of Table 1); in this respect the
increase in teaching productivity lags the research
productivity by 2-3 years. The second difficult period
occurs with periods of new or added responsibility
(Stages II to IV) which involve new coursework, addi-
tional committee work, administrative duties, etc.
Normally, career reassessment also occurs twice.
The first period of reassessment is in the late assistant
professor period (Stage II) when the faculty must
explore contingency options in case tenure is not
achieved. In the full professor period (Stage IV) there
is also a time when he/she must decide whether to
remain a classroom teacher or to try to diversify as a
means of maintaining professional vitality.
The two periods of difficulty in teaching, the period
of decline in research productivity, and the periods of
career reassessment all provide clues for strategies to
approach the problem of motivation, as discussed
below.

FACTORS IN FACULTY MOTIVATION
While there is a sizeable amount of data on other
motivational theories, i.e., expectancy theory and be-
havior modification theory, one of the clearest and
most applicable motivational theories is the so-called
"Needs Theory" derived from the work of Maslow [(12,
13]. In this concept, Maslow proposed a hierarchy of
needs of the individual, shown below in successive de-
grees of fundamental needs:

1. Self-Actualization Needs
2. Esteem Needs
3. Belongingness Needs
4. Safety Needs
5. Physiological Needs

The Needs Theory suggests that the lower needs
on the hierarchy (levels 4 and 5) are the first ones

SUMMER 1989

encountered, and the higher needs are realized only
after the lower needs are gratified. The stronger the
deprivation of a need, the more it dominates; the more
a need is gratified, the less important it is and the
more important the next higher need becomes.
Schneider and Zalesny [14] suggest that faculty, by
their autonomous nature, appear to have the needs
which are the most mature. The academic environ-
ment attracts people who tend to be oriented to self-
initiated behavior. Aldefer [15] indicates that frustra-
tion of growth (self-actualization) needs increases the
desires of relatedness satisfaction, and frustration of
relatedness leads to the desire for existence gratifica-
tion. In other words, frustrated researchers might
turn to affiliation available through teaching; frus-
trated teachers might move to another institution, ex-
tend their education, or participate more in adminis-
tration.
McKeachie [16], Csikszentmihalyi [17] and Deci
and Ryan [18] all indicate that faculty are intrinsically
motivated and have limited positive extrinsic motiva-
tion possibilities. Intrinsic motivation is coincident
with the highest levels of Maslow's need hierarchy,
while extrinsic motivators are appropriate for those
on the lower levels of the hierarchy. Organizational

structure, external rewards (such as promotion and
pay), and feedback are examples of extrinsic reward
systems-which are seen as somewhat self-defeating
when used in a controlling manner. If extrinsic re-
wards are used, then faculty may slacken their efforts
once full professorship and tenure have been obtained;
such administration may build in a never-ending spiral
of salary increases in hopes of continuing faculty moti-
vation.
Centra [19] suggests that when self-actualized
people encounter a discrepancy between one's self-
theory and other evidence, there is motivation to take
action. Csikszentmihalyi [17], McClelland, et al. [20],
and Litwin and Stringer [21] all suggest that intrinsic
motivation is reinforced by slightly imbalancing (a) the
challenges to the faculty, with (b) the skills the faculty
have to meet the challenge. If the challenge severely
outweighs the skills, then frustration occurs; if the
challenge (such as teaching a course multiple times)
does not require stretching the skills, then boredom
occurs. Optimally, challenges are addressed which
allow concerted efforts to lead to success.
Deci and Ryan [18] indicate that intrinsic motiva-
tion appears to work equally well for both teachers
and learners. A teacher who is intrinsically motivated

TABLE 1
Faculty Characteristics and Experiences at Five Stages of the Academic Career
I n I Iv V
Assistant Professors
Assistant Professors with more than Full Professors
in the first three three years of more than five Full Professors
years of full-time college teaching Associate years from within five years of
college teaching experience Professors retirement retirement
* Idealistic (sometimes unrealistic) More confident of their skills than Enigmatic At a career turning point Generally content with their career
career ambitions are novice professors achievements
* Enthusiastic about the job More politically sophisticated Enjoy peer recognition associated Reduced enthusiasm for teaching Quite limited goals for the remainder
with tenure and promotion and research of their professional career
Know how their institution works
and how to get things done
* Adjusting to novel Apprehensive about up- Becoming integral part of their Sometimes question the value of Gradually withdrawing from
occupational demands coming tenure evaluation institution, academic career various responsibilities
Actively involved in college activ-
ities, especially major committees
* Concerned about succeeding as Seeking recognition and advance- Generally satisfied with career Must decide to continue same career Fear their knowledge is out-of-date
teacher ment (confirmed by receipt of progress to dale activities or move in different direc-
tenure) tions (choice between stagnation and
diversification
* Eager to engage in scholarship Experience disappointment if career Sometimes nagged by fear that Seek to extend career (influence) be- Somewhat isolated from younger
does not measure up to original career has plateaued, that there yond own campus through consultation, colleagues
expectations is little room left to advance professional organizations
professionally
* Unfamiliar with informal opera- Question their future in higher ed- Limited opportunities for change; ad- Try to cope with problems
tions and governance (power) ucation and occasionally consider vancement can lead to disillusinment independently
structure in their higher education career alternatives at this stage
institution
* Receptive to assistance from more Only half will take advantage of for-
experienced colleagues mal professional growth opportunities
Particularly comfortable with service
to department or college
Alter Baldwin & Blackburn [3

CHEMICAL ENGINEERING EDUCATION

seems to enjoy the activity for its own sake and has a
good chance to get the student to seek the intrinsic
rewards of learning. If a teacher is extrinsically moti-
vated, students might conclude that learning is worth-
less in and of itself, and lacks inherent value.
Whitehead [3] says that the ideal of a technical educa-
tion is to be ". a commonwealth in which work is
play and play is life." Two action systems are cited to
yield intrinsic rewards in teaching: (1) changes in stu-
dent performance attributable to teacher actions, and
(2) the continuing integration of new information on
the teacher's part.
The implicit assumption in this application of
Needs Theory is that those attracted to engineering
education are gratified by the relatively unstructured
academic world, have strong self-actualization needs,
and enjoy a moderate challenge and risk. Thus these
individuals would take advantage of an opportunity to
grow and develop, if that opportunity were made
available, with some encouragement and no stigma.

IMPLICATIONS OF CAREER PHASES
The recognition of the clues provided by the phases
in a career allows administrators to capitalize on a
professor's knowledge, expertise, and interests in
order to increase intrinsic motivation. There is also a
severe caution against the use of extrinsic motivation
such as occurs on an industrial scale; extrinsic motiva-
tional techniques appear to be hazardous to the long-
term health of faculty.
For younger faculty, one might capitalize on up-to-
date research knowledge by having novice faculty
members teach advanced courses rather than intro-
ductory ones. Some of the responsibilities of younger
faculty might be relieved while they are learning the
art of teaching during the first difficult years.
Younger faculty typically appreciate formal work-
shops and seminars on the state-of-the-art, both in
research and in teaching methodology. .
Funding, facilities, and release time reserved for
mid-career faculty could generate new enthusiasm and
could provide a challenge, or even retraining, for
those faculty who have reached an easy, perhaps bor-
ing, part of a career. One could encourage career plan-
ning to assist in consciously and systematically exa-
mining the alternatives. In particular, a flexible leave
and internship policy would allow resolution of some
of the mid-life career uncertainty.
Senior faculty could play a major developmental
role as a mentor or teaching consultant to beginning
or adjunct faculty. Such mentorship has been indi-

cated to be a positive influence for both junior and
senior faculty, provided there is eventual growth
away by both parties (Levinson, et al., [4]). Senior
faculty, in particular, appear to like designing an indi-
vidual program, rather than (say) partaking in a work-
shop with others. Such faculty could undertake
"senior statesman" projects such as long range plan-
ning, studies of student attrition, or work with alumni
groups. Temporary administrative jobs might be of-
fered to those faculty. In some cases early retirement
and outplacement should be considered as alterna-
tives.

Senior faculty could play a major developmental
role as a mentor or teaching consultant to beginning
or adjunct faculty. Such mentorship has been indicated
to be a positive influence for both junior and senior
faculty provided there is eventual growth
away by both parties.

IMPLICATIONS OF MOTIVATIONAL STUDIES
Motivational factors indicate the need for an envi-
ronment which increases intrinsic motivation while
supplying extrinsic motivators as informational tools
only. Increasing amounts of administrative control
and increased concern about promotion and tenure are
both seen as counter-productive in the long run. Ex-
trinsic rewards appear to reinforce intrinsic motiva-
tion only when they are given in a positive, informa-
tional sense.
Intrinsic gratification/ is gained by encouraging
satisfying relationships with students and colleagues
such as is brought about by small classes, by continued
exposure to students beyond the normal single-term
class, and by networking with colleagues for teaching
discussions. Intrinsic satisfaction is also brought about
by providing a sense of autonomy, perhaps from a
sense of input to the curriculum, a choice concerning
courses to be taught, and more formative and less
summative evaluation procedures.
Intrinsic motivation also occurs when intellectual
stimulation occurs. This stimulation must meet the
criteria that it changes the way people think about the
subject area. For example, stimulation may be gained
by participation with industry, either in open-ended
problem-solving courses, in team-teaching normal
courses, or by consulting in ways which enrich the
faculty's intellect and put him on the frontier of knowl-
edge. Sabbaticals, summer work, workshops, and
short courses to do research/teaching development
can also provide such stimulation. Ultimately, elec-
Continued on page 187.

SUMMER 1989

Report

CONTENT AND GAPS IN BSChE TRAINING*

Value and Mystique in Engineering Economics

JAMES B. WEAVER
Venture Services
Sarasota, FL 34235-8233

ENGINEERING ECONOMICS is often taught to
chemical engineering students by other en-
gineering departments. Within ChE departments,
economics is usually introduced into a design course
as a major sub-topic and therefore receives student
attention only for part of a semester. AIChE is plan-
ning a survey to clarify the current extent of
economics training in BSChE curricula.
Thirty-eight texts on investment analysis from all
sources have been reviewed by the author, and cover-
age of these is compared. The books include engineer-
ing economics, chemical engineering design/
school sources. While coverage of many topics is con-
sistent and adequate, omissions are remarkable. Some
patterns seem related to differences among the four
sources above. For instance, many engineering
economics texts still omit proper coverage of working
capital and corporate income taxes-apparently for
historical reasons. Chemical engineering-sourced
texts are consistent on these important topics, but
rate lower on other important factors of investment
analysis. Finance/business texts rate better overall.
The author believes engineers should receive con-
sistent training in these topics, as a first step toward
improving the image of investment analysis by top
executives. (Now, investment analysis is often treated

Jim Weaver retired in 1980 as Vice-
President for Venture and Capital Appraisal
from ICI Americas, Inc. He earned his BS
and MS degrees in chemical engineering
from MIT. He has authored many articles on
investment appraisal, including coauthor-
ship of sections on "Cost and Profitability
Estimation" for two editions of Perry's
Chemical Engineers' Handbook. He is en-
joying retirement in Florida, but continues
\\. to write and speak.
*Paper presented at the AIChE meeting, Washington, DC, in De-
cember, 1988.

as a computer-dominated toy, or a sales tool for de-
sired projects.) Additional consistent training could
improve objectivity and appropriateness of invest-
ment analyses in corporations and the government.

DISCUSSION
Industry does not generally use objective en-
gineering techniques for investment appraisal. With
the availability of computers, executives ask for more
economic studies but usually use the many possible
scenarios on a project to further their own goals-to
fortify their intuition. Top management is playing
with economic analysis more, but they are using it
less. Unless curricula for analysts are improved, it
will be difficult to improve industry's attitude.
Current practice and education for investment
analysis has dominated much of my time since my 1980
retirement, because I feel that the available economics
courses for chemical (and other) engineers are
haphazard and inappropriate for what is one of the
most important and all-encompassing aspects of en-
gineering. Project evaluation is not an engineering
specialty-it is a topic in which all specialties need a
background, so that freshly-graduated engineers can
(promptly) assist industry or government decisions on
major investments. Few engineers now receive the
proper education for this activity. And those that are
trained get inconsistent training.
Between October 1987, and November 1988, I read
38 texts currently offered for courses dealing with in-
vestment analysis.* I looked for the topics [1] that I
found unsettled and continually debated during my
40-year career in investment appraisal. I also looked
for important topics which I felt texts and courses
were missing entirely-or, conversely, were overem-
phasizing. I was seeking useful discussion which might
clarify unsettled problems for the student, not uni-
formity. Many non-economic engineering problems re-
main unsettled, and current status of studies is dis-
cussed in current engineering texts. As I feared, that

*Texts published before 1980 are included only for highly-rated vol-
umes not revised in this decade.

CHEMICAL ENGINEERING EDUCATION

Project evaluation is not an engineering specialty-it is a topic in which all specialties need a
background, so that freshly-graduated engineers can (promptly) assist industry or government decisions
on major investments. Few engineers now receive the proper education for this activity.
And those that are trained get inconsistent training.

was not the case in project-appraisal texts; each au-
thor has his own point of view, and only a few discuss
other views or say that topics are unsettled.
Texts I reviewed were not all by chemical en-
gineers-or even all by engineers. Investment
analysis has recently become just as important a topic
for business school students (in finance, for instance),
and I wanted to compare their coverage of these top-
ics. My conclusions are more favorable for the finance-
oriented texts than for those by engineers! Their
courses would probably be useful for chemical en-
Chemical engineering (ChE) texts do rate higher
than most traditional "engineering economics" (EE)
texts, based on my criteria. That doesn't help ChE
students much, because most universities do not have
a full course on project analysis in the chemical en-
gineering department. In ChE, economics is consid-
ered part of design and is introduced into that
course-if it is taught at all. That means part of a
semester-usually less than half.
Many chemical engineering departments also offer
(or require) a course in 'Engineering Economics' for
another engineering department (usually civil or in-
dustrial engineering). That is why I claim that prob-
lems of 'EE' texts are problems for many chemical
Today, all we know about the current status of
requirements is that different universities may or may
not require any such courses. Others may require
either, or both. With the help of an AIChE survey we
expect to be more specific on current status in a year
or two. For over a decade, Ed Eisen of McNeese State
University has taken useful surveys on a wide range
of ChE unit operations (including design) for AIChE's
Education Division. The 1989 survey will focus specif-
ically on courses in investment analysis, and results
should be available some time in 1990. The intent is
to include courses (and texts) in the business schools
at the same universities.

METHOD OF ANALYSIS
This is only a partial report on my survey, em-
phasizing strengths and weaknesses of ChE texts.
The complexity of the survey (31 topics in 38 books)

TABLE 1
Chemical Engineering Texts

Author/Year
key Citation
A&R86 Axtell, 0., and J. Robertson, Economic Evaluation in
the Chemical Process Industries, Edn. 1, Wiley (1986)
C&R86 Couper, J.R., and W. H. Rader, Applied Finance and
Economic Analysis for Scientists & Engineers, Edn. 1,
Van Nostrand/Reinhold (1986)
HW&W83 Holland, F.A., F. A. Watson, and J. K. Wilkinson, Intro-
duction to Process Economics, Edn. 2, Wiley (1983)
PG&M84 Perry, R.H., and D.W. Green, Perrry's Chemical
Engineers' Handbook, (Sec. 25 by Holland, et al.,
"Process Economics"), Edn. 6, McGraw-Hill (1984)
P&T80 Peters, M.S., and K. Timmerhaus, Plant Design and
Economics for Chemical Engineers, Edn. 3, McGraw-
Hill (1980)
U84 Ulrich, G.D., Guide to Chemical Engineering Process
Design and Economics, A, Edn. 1, Wiley (1984)
V83 Valle-Riestra, F., Project Evaluation in the Chemical
Process Industries, Edn. 1, McGraw-Hill (1983)

means each journal article will be incomplete. I have
sent full draft reports to many authors. The American
Association of Cost Engineers has agreed to publish
complete results as a monograph.
Complete citations for the seven ChE texts are
shown in Table 1. The 'Author-Year Key' is used in
Tables 3-6 to identify each text. Tables 3-6 contain my
key judgments. Note that in these tables, minus [-] is
better than zero [0]. Table 2 discusses alphabetically
the 31 topics which I used in analyzing the texts; most
are covered in more detail in reference [1].
Unlike usual book reviews, my screening looked
only at the specific topics discussed in Table 2. I have
volunteered further specifics on my judgments to in-
terested authors and several have accepted.

SUMMARY OF RESULTS
Two of these seven ChE books were ranked high-
est in the survey. For extensive coverage, Peters &
Timmerhaus was best, although it is becoming out of
date. For good (brief) coverage, Axtell and Robertson
also ranked well. In fact, in spite of its brevity,
A&R86 only missed nine of my topics (fewer than any

SUMMER 1989

TABLE 2: Discussion of Topics Listed in Tables 3-6

Accounting Systems Engineers need background about financial accounting systems,
including product cost accounting and capital record-keeping. Accounting figures are
estimates, approximations of history within legal constraints for use by shareholders and
government authorities. However, approved systems permit wide variation in detail and
any set can be misused by newcomers, outsiders, or untrained engineers. Texts should
warn that such historical data is often not suitable as such for use in investment analyses.

Acquisition Analysis Mergers and acquisitions represent important and frequent in-
vestments by major corporations. Texts should discuss whether or not the same in-
vestment appraisal techniques apply to them. Lack of discussion permits the inference
that the same techniques are applicable. Authors should say they are not applicable to
merger and acquisitions studles-or else discuss the many special considerations.

After-Tax Analysis Because depreciation is tax deductible, capital investment alter-
natives must be compared after taxes. However, before-tax comparisons have not been
abandoned, nor clearly vetoed, in many texts. Even for preliminary screening, before-tax
comparisons may mislead. Many authors prefer the simplicity of deferring all
consideration of taxes until late in the text. If they do, eventual need for considering
taxes should be stressed in early oaes. Even then, the occasional user may di into the
text and be misled by problem "solutions" in early pages which ignore taxes.

Alternatives Investment appraisal must include alternative investments-not just a
single proposal. For instance, mutually-exclusive alternatives solve the same problem with
different capital investments. Choosing a process or the plant capacity represents this
type of alternative. Restricted funds may also require comparison of non-mutually-ex-
clusive altematives which compete only for funds. All project forecasts should also be
compared to an alternative set of forecasts for the "zero-investment" case.

Break-Even Analysis This accounting-based concept was widely used in project,
plant, and product studies before cash-flow investment analysis was widespread It still
may be useful if cash-flow breakeven is considered, but many texts discuss only
breakeven at zero accounting profit. Limited usefulness of breakeven does not seem to
warrant extensive coverage.

Computer Short-Cuts An early criticism of discounting procedures was the effort and
time consumed in calculation. Computers, large and small, and hand-held programmable
calculators reduce the problem tremendously.

Cost of Capital Average or Project? Should all investment projects be compared
to the same hurdle rate, or should the hurdle be lower where special financing is available
to an investment project? Journal articles differ. Texts should discuss at least the authors
view.

Cost of Capital vs. MARR The hurdle rate (or minimum acceptable rate of return,
MARR) is clearly related to cost of capital but is it equal or higher? Some companies
have higher hurdle rates (for some projects) to allow for risk. A higher hurdle rate might
also allow for some projects justified on bases other than profitability for instance,

Depreciation Several different concepts are included; the distinction may be par-
ticularly important for engineers who may think of the wrong meaning first. Estimates of
depreciation may refer to: physical life of the equipment, due to deterioration (often most
important to engineers); accounting allocations maintained in financial books for share-
holders; and, often, different tax-deductble allocations acceptable to IRS. All should be
discussed, including frequent IRS changes in the latter. Legality of separate tax and
shareholder books (in the U.S.) should be recognized. Few engineers seem aware of the
important distinction.

Documentation For historical and legal purposes, records are needed about
justification of major investments. Such records supply feedback for later proposals, both
specific cost forecasts and from general approach to the justification. How detailed
should such documentation be? Should records cover all stages if changes are made in
project scope? Or in justification forecasts?

Equity Basis for Analysis 100%? (This relates to Cost of Capital-MARR above.)
For comparability, most authorities believe all projects should be analyzed and compared
on the basis of 100% equity, the full investment base, and financing should be considered
separately. Others recommend including interest as a cost and reducing the investment
base if borrowing is Involved in the project or the company.

Feasibility Studies For any large project, justification is a many-step procedure. How
should early studies be handled? What data should be available before the first formal
profitability calculation? How often should it be repeated?

Forecasting Forecasts of key elements affect project profitability studies, and fore-
casts for 5 to 15 years are required. Are year-by-year forecasts useful? Are they
possible?

Handling Inflation Inflation affects some but not all aspects of project profitability
studies, so it should be considered. High inflation rates of the 1970s brought this factor
into almost every text; continuing attention is needed.

Incremental Expansion Often a minor bottleneck can be broken to expand existing
facilities, delaying major investment. Sometimes a minor investment will permit activation
of larger, idle facilities. However, such alternatives introduce special hazards. The in-
cremental investment may put the producer deeper in unprofitable businesses, unless

Learning Curves Correlations since World War II showed patterns of cost reduction
on wide ranges of products as producers gained cumulative experience in manufacturing.
This provided a means of cost and price forecasting which could hep project appraisal
studies in the 1950s and 1960s. However, cost reductions never approached high rates
of inflation in the 1970s, and the technique no longer seems useful.

Linear Programming of Rosters If suitable data on single best-estimate forecasts
were available simultaneously on a roster of all foreseeable projects, and the projects
are independent (or relationships are specified), linear programming could be used to
choose the best set of alternatives. Data requirements are extreme, perhaps unrealistic.

Multiple Rates of Return In DCF internal rate of return studies, unusual cash pat-
terns can cause multiple and meaningless solutions. Mathematics are understood, and
several means are available to avoid the problem.

Payout Time This quick-and-dirty analytical technique remains a favorite with manu-
disadvantage it ignores working capital. Discounted payout time is recognized as an
improvement and should be mentioned.

Plant Location Costs differ by locality, so location has important (on occasion domi-
nating) effects on investment appraisal studies. The nature of the effects and importance
of analysis should be mentioned.

Plant Sizing A key alternative (q.v.) is how big a plant to build, how much capacity,
presumably based on sales forecasts. Building in several stages may show a higher
profitability, even if total Investment cost is higher. Some patterns of problems and solu-
tions exist.

Preliminary Engineering Approval Major projects often involve millions of dollars of
engineering and design expenses more than many other projects cost in total. If new
markets or technology are involved, or unusual risk of any sort, some special man-
agement approval seems warranted before such expenditures, even if its only internal
engineering.

Presentation Formats Standardized forms for project proposals are shown in some
articles and books. Some may be obsolete, based on a single scenario which may not
represent a management consensus. Multple scenarios complicate the presentation but
seem necessary to permit a real decision at top company levels.

Project Audits Many companies prescribe formal review of some or all capital pro-
jects, after implementation. Feedback is said to justify the cost. There are problems;
nature and extent of such audits should be discussed.

Reinvestment Assumption (DCF) Although many feel the question has been re-
solved, some authors maintain that internal rate of return assumes that positive cash
flows during a project must be reinvested during the orotect life at the solving rate of
Lretur to achieve the calculated return. Ideally, both points of view should be discussed.

Replacement Special techniques were devised after World War II to assess re-
placement of existing facilities. Such problems can now be handled within more general
project appraisal techniques. Some texts still include excessive details of the older
special techniques.

Risk Analysis This topic receives wide (if variable) coverage in engineering economy
texts and articles. While of theoretical interest, industry has considered and rejected
complex techniques. Detailed text coverage impinges on more important topics.

Sensitivity Analysis Projects are often presented for corporate decisions based on a
single "best estimate" scenario. Simple graphical and tabular means were developed to
show project sensitivity to major variables. As a minimum, these should be discussed. With
the computer, other possible scenarios can be calculated in full for further investigation
of sensitivities.

Sunk Costs Past investments should not (in general) influence current decisions.
However, tax deductibility of depreciation means some past decisions affect timing and
amount of future cash flows.

Unequal Project Lives Most "alternatives" (q.v.) can be considered at equal project
lives, which simplifies comparisons. Some cases necessarily involve unequal project lives,
and several decision models have been developed.

Working Capital Lke a new company, almost every investment project requires initial
cash to get under way, until incoming cash flows are sufficient to pay current bills.
Inventories and accounts receivable are assets, but they require initial cash, too, partly
offset later by accounts payable to others.

CHEMICAL ENGINEERING EDUCATION

other), and rated a + on thirteen topics (better than
any other).
Two other ChE texts also had satisfactory cover-
age. Couper & Rader was quite acceptable, in spite of
a few gaps. It contains outstanding coverage of a
couple of topics, as discussed below. The section on
"Process Economics" in the 6th edition of Perry's
Chemical Engineers' Handbook also rates satisfac-
tory for handbook coverage.
The other three ChE texts have coverage which I
feel is unsatisfactory, but each text had some strong
points that I will mention later. And some non-en-
gineering texts had better coverage on several topics.
The most flagrant omission, in all 38 books, was a
lack of attention to working capital and to the impact
of income taxes. Table 3 presents those results along
with my over-all judgments. All the ChE texts had
some discussion of both topics, unlike most of the EE
texts (all fourteen omissions of working capital were
in EE texts). Four ChE texts covered each of the two
major topics adequately-but not the same four!
Three tended to introduce taxes late and to give it low
emphasis, even though taxes can have a dominating
impact on choices. This makes the early examples and
homework problems in those texts misleading. Delay
in discussing taxes also prevents full discussion of sev-
eral other key topics, including sunk costs, payout
time, break-even analysis, and cost of capital, because
of the impact of taxes on each of them.
Table 4 groups the topics most often omitted in
texts on investment analysis. None of the seven ChE
texts covered more than three of the ten topics.
I ranked C&R86 "outstanding" on coverage of
feasibility studies. The sequence of early decisions on
projects is ignored in the majority of texts reviewed.
However, P&T80, A&R86, and V83 also covered
feasibility studies well, so ChE texts ranked above
the other engineering and non-engineering texts in

this respect. Are feasibility studies more important,
for some reason, in chemical engineering? I think the
answer is that the other specialties just have not seen
ChE texts and forgot to mention the problem.
Another strong point in C&R86 is its coverage of
computer short-cuts, and A&R86 also included the
topic well. None of the other ChE texts discussed the
important help that computers can give. Timing of
publication cannot be given as an excuse for ignoring
this topic; non-ChE texts as old as 1980 got good rank-
ings, but many others, more recent, did not.
Documentation of major investment decisions is
important in industry, but does not seem important to
textbook authors. Only two of the ChE texts bring it
up at all, and only one of the EE texts gives it
adequate coverage. Likewise, presentation of propos-
als for decision is important. Both C&R86 and P&T80
ranked high in this respect, but none of the other ChE
texts and only a handful of the other types did.
Note that three topics I would like to see covered
were not mentioned by any of the seven ChE texts.
One is acquisition analysis, a very important topic
nowadays. The authors could at least say whether or
not they feel the same techniques are applicable for
appraising acquisitions!
Table 5 summarizes results for other important
topics I felt were often inadequately covered. The
ChE texts did not rate well here, either. Three of the
books mentioned ten of the fourteen topics, but only
two adequately covered more than three of the topics
When texts mention audits of investment project

TABLE 4
Topics Often Omitted
Author/Year Code *
A&R C&R HW&W PG&M P&T U V
86 86 83 84 80 84 83

TABLE 3
Dominating Topics and Overall Judgmei
(Chemical Engineering-sourced Texts Only)
Author/Year Code
A&R C&R HW&W PG&M P&T
WR A 84 83

Working Capital +
After Tax Analysis +
My Total Judgment OK- OK-
(All Topics) and some
brief gaps
+ coverage which is adequate or better

+ + +
+ + +
Weak OK- OK
for exten
handbk

s- V
sive

Acquisition Analysis 0
Computer Shortcuts +
nt
Documentation
Feasibility Studies +
S V Forecasting
U V
84 83 Incremental Expansion 0
Plant Location 0
+ Plant Sizing +
Preliminary Eng. Approval 0
Veak Weak Presentation Formats
+ coverage which is adequate or better
++ outstanding coverage
0 no coverage of important topics

SUMMER 1989

0 0
+ 0
- 0
++ 0
0 0
0 0
0 0
0 0
0 0
+ 0

performance after implementation, they all say such
audits are important. But C&R86 was the only ChE
text to bring it up, and all but three of the non-ChE
texts also gave it short shrift.
How does one choose plant size to meet a given
forecast? Few texts discuss this at all. A&R86 is the
only ChE text with satisfactory coverage, although
V83 gives it some coverage.
Table 6 groups another set of topics-those I felt
were overemphasized in many EE texts. They are
topics of considerable mathematical and research in-
terest (or were at one time)-but I found that none

TABLE 5
Other Topics Often Poorly Covered

SAuthor/Year Code
A&R C&R HW&W PG&M P&T U V
86 86 83 84 80 84 83

Acctg. System Analsis
Alternatives +
Cost of Capital Average? 0
Cost of Capital vs MARR
Depreciation +
Equity Basis for Analysis +
Handling Inflation +
Multiple Rates of Return
Payout Time +
Project Audits 0
Reinvestment Assumption +
Sensitivity Analysis +
Sunk Cost 0
Unequal Project Lives 0

+ coverage which is adequate or better
0 no coverage of important topics

+
0 0
0
+
o 0

0 0
+

0 0 0

TABLE 6
Topics Often Overemphasized

SAuthor/Year Code *
A&R C&R HW&W PG&M P&T U V
86 86 83 84 80 84 83

Break-Even Analysis + + + -
Learning Curves exag -
Linear Programming of Rosters* *
Replacement Analysis + 0 0 0 +
Risk Analysis 0 exag exag 0

+ coverage which is adequate or better
exag exaggerated coverage, superfluous for real use in industry even if accurate
0 no coverage of important topics
no coverage where topic is not important; no criticism intended

* -
* +
* *
0 +
- exag

were widely used in industry. And I felt industry had
good reason to ignore them. I don't believe academics
have made progress not recognized by industry. So,
for the first three items in this table, I feel that omis-
sion of any coverage is all right (an asterisk is used
At the other extreme, "exag" shows (for any of the
five topics) where I feel book space is wasted by ex-
tensive coverage. In all likelihood, valuable course
time is also wasted on these topics at the expense of
those topics in Tables 4 and 5.
ChE authors did better than the average from
other sources on the Table 6 topics-particularly on
break-even analysis. Nobody got carried away, and
coverage by three was adequate. Three other ChE
texts dealt only with accounting break-even concepts,

CONCLUSION

I hope this comprehensive review (admittedly, one
man's judgment) will permit universities to improve
their choice of books for courses being given in chem-
ical engineering design-and-economics. But I must

TABLE 7
Top Ranked Texts

Author/Year
key Citation

Engineering Economics Texts

B78 Bussey, Lynn E., The Economic Analysis of Industrial
Projects, Edn. 1, Prentice-Hall (1978)
GI&L82 Grant, E.L., G. Ireson, and R. Leavenworth, Principles of
Engineering Economy, Edn. 7, Wiley (1982)

S87 Smith, G.W., Engineering Economy: Analysis of Capital
Expenditures, Edn. 4, Iowa State University Press (1987)

S&W86 Sprague, J.C., and J. Whittaker, Economic Analysis for
Engineers and Managers, Edn. 1, Prentice-Hall (1986)
S&S87 Stermole, Frank, and John M. Stermole, Economic
Evaluation and Investment Decision Methods, Edn. 6,
Engineering Press, Inc., San Jose, CA (1987)
S83 Stevens, G.T., Economic Analysis of Capital Investments
for Managers and Engineers, Edn. 1, Reston Pub. Co.
(1983)

B&S88 Bierman, Harold, and Seymour Smidt, The Capital
Budgeting Decision Economic Analysis of Capital
Investment, Edn. 7, MacMillan (1988)

B&M84 Brealey, R., and S. Myers, Principles of Corporate
Finance, Edn. 2, McGraw-Hill (1984)
H82 Herbsl, A.F., Capital Budgeting: Theory, Quantitative
Methods, and Applications, Edn. 1, Harper & Row (1982)

CHEMICAL ENGINEERING EDUCATION

sadly add that even the best is none too good for teach-
ing a consistent picture of the important elements of
students. The best I can say is that the chemical en-
gineering authors have been more perceptive than
many of the other engineering authors. The best
group of texts is from the finance/business school sec-
tor. ChE undergraduates might benefit from wider
use of those texts.
This paper cannot be stretched to cover the advan-
tages and shortcomings of the 31 texts from non-ChE
sources.
As a substitute, Table 7 lists the top ranked books
(in my opinion) in each category. All the engineering-
sourced books published since 1980 were included in
my study. Therefore, if a book is not listed in the
table, I recommend your school should not be using
it. However, my coverage of finance/business tests is
probably not so complete.

D letters

FLORIDA STATE/FLORIDA A&M
ACCREDITATION ERROR NOTED
To The Editor:
With reference to our article, "General Education
Requirements and Chemical Engineering Curric-
ula," appearing in the Spring 1989 edition of Chemi-
cal Engineering Education, in Table 3 we referred to
Florida State/Florida A & M as having an unaccred-
ited Chemical Engineering program. This resulted
from using the 1986 Annual Report of The Accredita-
tion Board for Engineering and Technology, Inc.
(ABET).
After the article was submitted, the 1987 Annual
Report of ABET was released. Florida State/Florida A
& M now has an accredited Chemical Engineering
program. We humbly apologize for the mistake and
take full responsibility for the error in our article.

REFERENCES

1. Weaver, James B., "Persistent Problems in Investment Analysis,"
Industrial Engineers, Norcross, GA 30092 O

1989

Chemical

Engineering

Texts from

Wiley

Walden L. S. Laukhuf
C. A. Plank
James C. Watters
University of Louisville

CHEMICAL AND ENGINEERING THERMODYNAMICS, 2/E
Stanley I. Sandler, The University of Delaware
0-471-83050-X, 656pp., Cloth, AvailableJanuary 1989
A fully revised new edition of the well received sophomore/junior level thermo-
dynamics text, now incorporating microcomputer programs.

PROCESS DYNAMICS AND CONTROL
Dale E. Seborg, University of California, Santa Barbara,
Thomas R. Edgar, University of Texas, Austin,
and Duncan A. Mellichamp, University of California,
Santa Barbara
0-471-86389-0, 840pp., Cloth, Available February 1989
A balanced, in-depth treatment of the central issues in process control, including
numerous worked examples and exercises.

Contact your local Wiley representative or write on your school's stationery to
Angelica DiDia Dept 9-0264,John Wiley & Sons, Inc, 605 Third Avenue, New York,
Ltd, 22 Worcester Road Rexdale, Ontario, M9W1L1.

WILEY

JOHN WILEY & SONS, INC.
605 Third Avenue
New York, NY 10158

sah/k

SUMMER 1989

laboratory

USING THE LABORATORY TO

DEVELOP ENGINEERING AWARENESS

R. ENGLAND and R. W. FIELD
University of Bath
Claverton Down, Bath, BA2 7AY, England

The Professional Institutions Directorate of the En-
gineering Council (of the United Kingdom) issued
guidelines in 1983 for the training of all undergraduate
engineering students in Great Britain who wish to at-
tain chartered engineering status. These proposals
subsequently became mandatory in 1985 and included
the requirements that all courses accredited by the
Engineering Council contain a minimum level of En-
gineering Applications 1 (EA1) and Engineering Appli-
cations 2 (EA2) by the start of the 1988 academic year.
For chemical engineering these are defined as:

An introduction to the methods of fabrication, selection of
materials of construction, and operation of chemical pro-
cess plant hardware, giving due consideration to the in-
teraction of these factors on costs, safety, operability, and
reliability.
The application of engineering principles to the solution of
practical process engineering problems.

In the UK it has been common for most chemical
engineering courses to integrate the practice of process

chemical engineering at the University
College, Swansea, University of Wales. He
is a lecturer in the School of Chemical En-
~ f gineering at the University of Bath. Re-
search interests are in biotransformation,
downstream processing, and membrane
separations.

Robert Field obtained his BA and
PhD degrees from the University of Cam-
bridge. He is a lecturer in the School of
Chemical Engineering at the University of
Bath and is author of the book Chemical
Engineering: Introductory Aspects
(Macmillan Education). Research interests
center on heat, mass, and momentum
transfer

engineering and to seek real solutions to practical prob-
lems. Thus, few modifications were necessary to meet
the requirements of EA2. However all UK courses
needed enhancement in order to meet the EA1 propos-
als of the Engineering Council. The focus of this paper
tory progamme of the chemical engineering first de-
gree course at the University of Bath. These changes
have been introduced in order to meet the Engineering
Council requirements and to develop a greater student
awareness of engineering concepts.

BACKGROUND
Before moving on to the detail, a contextual intro-
duction is given. Most students entering the chemical
engineering course at Bath have specialized in three
sciences at the secondary school level and have attained
at least three General Certificate of Education qualifi-
cations at the advanced level (usually in chemistry,
physics, and mathematics). The student has little or
no knowledge of engineering subjects, and practical
experience is limited since the trend in recent years
has been to reduce the amount of laboratory work at
secondary schools (mainly because of financial consid-
erations). Although the student may have visited com-
panies or listened to talks from visiting engineers, his
concept of engineering is often flawed. They are often
unaware of the probability of multiple solutions to a
problem and have no idea of the technical difficulties
encountered in design and construction of processing
units.
The Chemical and Bio Process Engineering degree
course at Bath endeavours to provide a solution to
some of the problems and to instill engineering aware-
ness in the student. For most students, a year-long
industrial placement is an integral part of the degree
scheme. The placement is undertaken as the third year
of a four-year course, and a position as a trainee en-
gineer within a company or research establishment is
found by the University. Not only is the relevance of

CHEMICAL ENGINEERING EDUCATION

BBER

... a year-long industrial placement is an integral part of the degree scheme. It is undertaken as the third year of
a four-year course, and a position as a trainee engineer within a company or research establishment is found
by the University progress of the student is monitored both by the company and by his industrial tutor.

the academic course highlighted for the students, and
knowledge consolidated, but valuable practical experi-
ence is also gained. During this period progress of the
student is monitored both by the company and by his
industrial tutor. An improved appreciation of financial
constraints and the importance of communication skills
is obtained, and the student's subsequent development
during the final year of the degree scheme is enhanced.

THE BATH APPROACH
Engineering awareness is developed from the very
beginning. Students entering the department are
given a week-long course which introduces them to
the various core subjects of chemical engineering and
their relation to the "process dimension." The process
dimension is seen to be the main characteristic of
chemical engineering and can be defined as "the ability
to break down into its component parts a manufactur-
ing process in which matter is transformed or chemi-
cally changed to provide a specification for each sub-
division, and to recombine the whole into an econom-
ical, workable, and maintainable plant." This is
achieved by means of overview lectures, a preliminary
design assignment, and industrial visits.
In the third term of each year the students under-
take a design project which has been chosen to show
the relationship between chemical engineering funda-
mentals, engineering practice, and the enabling sci-
ence (mathematics, economics, chemistry, etc.) which
they have been taught during the year. The design
projects are chosen to complement the courses, to pro-
vide experience in teamwork, and to develop aware-
ness of the practice of chemical engineering.
The first year design project is usually a mass
and energy balance and flow sheeting exercise on a
well-documented process. The second year design is
used to draw comparisons between existing processes
and less conventional routes, e.g., the production of
n-butanol by chemical and biochemical routes. In the
final year, senior chemical engineers from industry
suggest the original problem specification, provide
technical input when information is not available in
the open literature, and lead discussion groups. This
work involves projects requiring the latest technol-
ogy, e.g., off-shore gas-oil separation, destruction of
toxic wastes, and microbial production of cis-1,4-
polyisoprene.

A major element in developing engineering aware-
ness during the first two years of the degree scheme
is the undergraduate laboratory programme. The rest
of this paper is devoted to those elements of the pro-
gramme which relate to EA1.

The experiments relating to the EA1 require-
ments, which comprise approximately 30% of the total
first and second year laboratory programme, can be
summarized as follows:

1st Year Experiments
The design and construction of a pumping circuit involving
leak testing, calibration of instruments, and characteriza-
tion of the pump
Start-up, operation, manual control, and monitoring of
pilot plant equipment, e.g., double effect evaporator and
batch packed distillation column
The problems of measurement and choice of transducer,
e.g., temperature, pressure, and viscosity measurements
using various measuring devices

The object of these experiments is to demonstrate
the difficulties that can be encountered in "simple"
measurements and relatively "straightforward" pro-
cessing equipment, and to establish the need for en-
gineering input.

2nd Year Experiments
Start-up and operation of a steam boiler (capacity 2000 lbs
per hour steam at 150 psig)
Hazard and operability study (HAZOP) of a batch distilla-
tion column
Disassembly and reassembly in a different configuration
of a plate heat exchanger and analysis of thermal perform-
ance
Work permit preparation for the modification of a number
of pieces of process equipment, e.g., cooling tower and
distillation unit

Process safety has deliberately been included in
the experimental programme to complement the lec-
ture courses on process design and development and
loss prevention, and to emphasize the need for chemical
engineers to be aware of, and to actively include, safety
in all aspects of their work.

SUMMER 1989

FIRST YEAR EA1 EXPERIMENTS
The experiment (see Table 1) requiring the calibra-
tion of certain devices for temperature measurement
and for viscosity measurement was introduced in 1982
ing of accuracy, particularly with reference to the cali-
bration of instruments.
The first part of this experiment requires the cali-
bration of a number of temperature measuring devices
against a standardized National Physics Laboratory
thermometer and, if possible, comparison of the values
obtained with theoretical values from the literature,
e.g., e.m.f's of thermocouples. The equipment consists
of a thermostatically controlled water bath, a multi-
meter, and various temperature measuring devices
which can all be purchased for approximately 1300.
The students invariably report the results in terms of
the accuracy of one device, i.e., deviation from a
straight line or a smooth curve when compared to the
others, without consideration of the sensitivity of the
device or the limits on reading the scales on the instru-
ment.
The second part of the experiment is the determi-
nation of the viscosity of carboxy-methyl-cellulose so-
lution using three different techniques. The only ex-
pensive item of equipment is the rotating cup viscom-
eter, which costs approximately 1000. Students are
given references for the different methods, but are not
told that the fluid is non-Newtonian. The apparatus
for the falling sphere method was chosen to give very
small fall times, thus making the main experimental
error the timing of the fall of the sphere. Typical con-
clusions drawn by the students were that only the
rotating cup method was "accurate" and that the other
techniques were not suitable for determining vis-
cosities, in spite of the fact that they were given the
literature references and informed that these are
standard methods for determining viscosity. Only
about 10% of the students concluded that the tech-
niques being used might not be suitable for the range
of viscosities being studied.
Oral presentation of results (in the presence of their
fellow students) is required for these experiments, and
it enables us to make students aware of the difference
between errors resulting from the calibration of an
instrument, the accuracy of an instrument based on
theory, and the method of calibration. It also illustrates
some of the pitfalls to be avoided when using results
from measurement devices and fosters discussion of
the limitations of the various measurement techniques
and the problems of departure from ideality.
The experiment dealing with the operation of a
double effect evaporator (see Table 2) was designed

to give experience in start-up, steady-state operation,
and shut-down of a pilot plant. The equipment, which
would have cost in the region of 40,000 to purchase,
was donated to the department. Only manual control
is provided on the equipment, and hence the students
experience difficulty in obtaining and controlling the
unit at steady-state. This experiment gives most stu-
dents their first hands-on experience with equipment
of a reasonable size, and their reactions have been
mixed. Generally they have found it enjoyable to oper-
ate a pilot scale unit. However, the difficulties already
referred to limit the amount of meaningful data on the
performance of the evaporator, and this has been frus-
trating. In reporting their results, nearly all the stu-
dents refer to the need for better control so that steady-
state operation can be obtained.
The operation of a packed, batch distillation col-
umn, 80mm diameter, with a packed height of 1.7m,
gives the students their first exposure to distillation
on any pilot or larger scale. Their experience has usu-

TABLE 1
Calibration of Temperature Measuring Devices and
Measurement of Viscosity

Time allowed for experimentation: 4 hours

Experiment requires:
Part A: Calibration of the following devices using a stan-
dardised National Physical Laboratory ther-
mometer:
Mercury-in-glass thermometer
Thermistor
Platinum resistance thermometer
Type T and type K thermocouples
Comparison of results with data from literature

Part B: Measurement of viscosity
Preparation of a carboxy-methyl-cellulose solution
(range 0.5 to 1.5 w/w%)
Determination of viscosity at 20"C and 35"C using
Falling sphere method
Rotating cup
Ostwald viscometer

TABLE 2
Operation of Double Effect Evaporator

Time allowed: 7 hours
(Capacity of evaporator nominal 800 kgh-1)

Experiment requires:
Start-up of evaporator
Mass and energy balances over evaporator
Shut-down of evaporator

CHEMICAL ENGINEERING EDUCATION

ally been limited to small scale bench distillations in
chemistry practical, using standard glassware. They
are asked to start-up the column and to operate at
total reflux to determine heat losses. Then they must
choose a reflux ratio and carry out a mass balance for
the time of operation. Their main reaction is surprise
at both the length of time required (= 3 hours) to reach
equilibrium at total reflux and the poor thermal effi-
ciency. The latter is mainly due to the large heat losses
from the unlagged reboiler.
Written reports in the form of a technical letter
giving a brief outline of the experiment, together with
the results, a brief discussion, conclusions, and recom-
mendations are required for the above two experi-
ments. The students are graded by evaluating the re-
port and by monitoring their approach during the ex-
perimentation.
The experiment in which the students design, con-
struct, and test a pumping circuit is detailed in Table
3. The equipment consists of standard "off the shelf"
items and costs approximately 1250 per rig. The items
provided enable a number of different circuit configura-
tions to be constructed.
The experiment has been invaluable in demonstrat-
ing the problems involved in the design of even simple

TABLE 3
Design and Construction of Pumping Circuit

Time allowed: 15 hours

Experiment requires:
Design of circuit
Construction of circuit
Leak testing
Determination of flow rate versus head characteristics
of pump
The following components are provided:
Rotameter
Pump (dismantled)
Bordon pressure gauge and pressure transducer and
indicator
'V-Reg' valve and globe valve
Two tanks and framework
Q.V.F. pipe sections, elbows, tees, hose connectors and
couplings
Various pipe fittings and flexible hose
The student must determine:
The circuit design for characterisation of pump and
leak testing
Calibrate one of the pressure measuring devices using
a 'dead weight tester' before inserting in circuit
Use calibrated pressure gauge to calibrate other gauge
in-situ
Calibrate in-situ the rotameter
Determine flow rate versus head characteristics of
pump

Since an engineer is effective through what he
does rather than through what he knows or could do, it
is important that engineering students acquire not only
understanding and practical experience, but also
speaking, writing, and calculation skills.

rigs. This is particularly true for students who have
little or no previous practical experience who make
mistakes in the design and construction of the pumping
circuit. We hold discussions with each student pair to
point out errors in their design construction and to
suggest improvements before they attempt to con-
struct the rig. After the rig is built, tests are carried
out to leak test, to characterize the pump, and to carry
out the other tasks detailed in Table 3.
The lessons learned by the students during their
first year laboratory sessions on EA1 can be sum-
marized as follows:

Instruments are only as accurate as their calibration
Instruments must be chosen with a particular task in mind
Effective control of a unit must be carefully thought out;
the effect of altering one parameter may have considerable
effect on other parameters and the overall operation of the
unit.
Manual control can be satisfactory but is limited to some
simple systems
The time for a system to reach steady-state conditions can
be long
Multiple solutions exist even for simple design problems
An appreciation is gained of the practical difficulties en-
countered in the construction of units consisting of a variety
of materials and components
The importance of effective communication skills is demon-
strated

SECOND YEAR EA1 EXPERIMENTS

Although it can reasonably be argued that students
have already acquired a good level of understanding
of safe working procedures, this key area is now em-
phasized, through both existing and new experiments.
The expediture for the following experiments was less
than 250 since most of the necessary equipment was
The batch distillation of an organic mixture in a
steam heated boiler is undertaken by all students,
(for example the calculation of the HTU of the packing),
a hazard and operability study is required [2, 3, 4].
The latter forms the main focus of the reports produced
by the students.

SUMMER 1989

The Work Permit assignment (Table 4) requires
the students to read four official Health and Safety
Executive (HSE) guidance notes [5, 6, 7, 8]. They must
then prepare a work programme and issue a work
permit for 1) the replacement of a condenser on a batch
distillation column and the repair of a weld fracture
on the vapour return line of the reboiler, and 2) entry
into an induced draught cooling tower to inspect the
fan.
Students are not required to produce a formal re-
port of this assignment, but they must submit material
which would reflect the way in which the information
could be presented at a preliminary meeting of the
plant supervisor, the plant engineer, the maintenance
supervisor, and the safety officer. In common with the
previous assignment this is undertaken, in turn, by all
of the second year students.
A third task, undertaken by some students, is to
witness the start-up of the department's package
steam boiler, to report on the start-up and shut-down
procedures currently used, to identify the hazards,
and to note key operating parameters (see Table 5).
By way of preparation, a HSE guidance note on the
operation of automatically controlled steam and hot
water boilers [9] is studied.
The fourth and last task relating to EA1 illustrates
how a traditional experiment can be modified to include
an EA1 component. In the past, students have used
a small plate heat exchanger to evaluate the depen-
dency of heat transfer coefficients and the pressure
drop on fluid flowrates. The practical exercise of chang-
ing the plates and leak testing was introduced two
years ago. The students complete the performance
analysis, devise and discuss a safe procedure for chang-
ing the plates, and then carry out the task. As with
the other EA1 assignments, it is relevant and is en-
joyed by the students, making them more receptive
to the lessons embodied in the experiment.

DISCUSSION
At Bath all EA1 learning is woven into the degree
scheme, and it is apparent that the students are recep-
tive to this approach. Not only are additional demands
on the students' time minimized, but also the relevance
of the EA1 and EA2 material to process engineering
is clear.
An alternative approach reported by others [10]
includes an EA1 module on the dismantling, inspection,
reassembly, adjustment, and testing of a safety valve.
However, most students see this as a task where the
principal objective is simply overhauling and testing
a safety valve as quickly as possible. The originators

the activity would be an appreciation of the construc-
tion and functioning of the valve, and not the manual
task itself. This problem indicates that if EA1 learning
is to be educational (as opposed to mere training), then
it must be an integral part of the course.
Since an engineer is effective through what he does
rather than through what he knows or could do, it is
important that engineering students acquire not only
understanding and practical experience, but also
speaking, writing, and calculation skills. The engineer-
ing application tasks outlined above have proved to be
efficient learning experiences. Through the setting of
education tasks it has been possible to assess students
in this area. Previously, the development of engineer-
ing awareness was a valued but unquantified by-
product of a traditional course of study. The students'
experimental and design reports now reflect a better
understanding of engineering practice (as well as en-
gineering principles), and they are more fully prepared
for their industrial placement and final year of study.
The inclusion and integration of EA1 and EA2 ma-
terial into the Chemical and Bio Process engineering
degree course at Bath has met the requirements of
the Engineering Council, and re-accreditation of the
course has recently been granted. Students graduating
with an Honours degree are exempt from educational
requirements for Chartered Engineer status and Cor-

TABLE 4
Work Permit

Time allowed: 4 hours

Assignment requires:
Study of Health and Safety Guidance Notes
Familiarisation with proposed maintenance work
Familiarisation with use and application of
flammable gas detectors
Production of report proposing work programme

TABLE 5
Steam Boiler Operation

Time allowed: 4 hours

Assignment requires:
Study of Health and Safety Guidance Notes
Study of manufacturer's instruction manual
Witnessing of boiler start-up
Production of report: start-up and shut-down pro-
cedures, identification of hazards, and record of
key operating parameters

CHEMICAL ENGINEERING EDUCATION

porate membership of the Institution of Chemical En-
gineers.

CONCLUSIONS

A number of Engineering Applications related ex-
periments have been introduced into the course by
modifying existing equipment and by provision of new
items at a cost of 6000. The changes have given
the students more hands-on experience in the labora-
tory and have encouraged an engineering approach to
problems. The pumping circuit equipment allows the
students to develop their own thinking on the construc-
tion and functioning of a simple rig, and it lets them
make their own mistakes under carefully controlled
and safe conditions.
Overall it has been found that the students are
responding to this approach and are more receptive to
the laboratory sessions. Their laboratory reports re-
flect both an increasing awareness of a practical en-
gineering approach and improved communication
skills.

ACKNOWLEDGEMENT

The authors acknowledge the support of other
members of the School of Chemical Engineering in the

book reviews

CHEMICAL REACTION AND REACTOR
ENGINEERING
edited by James J. Carberry and Arvind Varma
Marcel Dekker, Inc., New York, NY 10016; 1088 pages,
$150 (1987) Reviewed by Anthony G. Dixon Worcester Polytechnic Institute This book is made up of fifteen chapters on various topics in reaction engineering, by leading workers in the field. It is similar in concept to the Wilhelm memorial vol- ume of ten years ago (Chemical Reactor Theory. A Re- view, L. Lapidus and N. R. Amundson, eds., Prentice-Hall, 1977), but strikes a much more even balance between theory and application. The editors claim the book to be "hardly a textbook or a handbook," but most chapters have aspects of both functions. Practitioners will find it a useful reference, while teachers will want to assign particular chapters as collateral reading for graduate courses in reactor design and related areas. The produc- tion of the book is high quality, with uniform type and il- lustrations for all chapters, which has had some trade- development of the laboratory programme. REFERENCES 1. Levy, J. C., Standards and Routes to Registration (1985 Onwards), The Engineering Council, London (1983) 2. Kletz, T. A., HAZOP and HAZAN: Notes on the Identification and Assessment of Hazards, Institution of Chemical Engineers, London (1983) 3. Kletz, T. A., "Eliminating Potential Process Hazards," Chemical Engineering, 48, (April 1985) 4. Lees, F. P., Loss Prevention in the Process Industries, Butterworth, London (1980) 5. Health & Safety Executive, Entry into Confined Spaces, Guidance Note GS5, HMSO, London (October 1984) 6. Health & Safety Executive, Industrial Use of Flammable Gas Detectors, Guidance Note CS1, HMSO, London (September 1979) 7. Health & Safety Executive, Safety in Pressure Testing, Guidance Note GS4, HMSO, London (July 1977) 8. Health & Safety Executive, Electrical Apparatus for Use in Potentially Explosive Atmospheres, Series booklet HS(G)22, HMSO, London (1984) 9. Health & Safety Executive, Automatically Controlled Steam and Hot Water Boilers, Guidance Note PM5, HMSO, London (September 1985) 10. Mattews, A. T., A. N. Main, and G. S. G. Beveridge, "Getting Experience," Engineering Design Education, Design Council, 2-5 (Spring 1985) 0 offs in terms of the high price and the delay in publish- ing-the almost complete lack of references after 1983 belies the 1987 publishing date. General topics are covered first. Villadsen and Michelsen open with a chapter on numerical methods, beginning with a short review of basic techniques. Most of the chapter emphasizes collocation methods, especially newer developments. A section on parameter estimation is most welcome. Shinnar's chapter on residence-time distributions gives a clear exposition of the limitations of the method, marred only by the many typographical er- rors. The author eschews mathematical complexity in fa- vor of conceptual understanding and common sense. In their chapter on catalytic surfaces, Delgass and Wolf provide an excellent guide to the alphabet soup of surface analysis and catalyst characterization techniques. They explain what each technique is used for, basic prin- ciples, equipment, interpretation of data, and difficulties. Both surface and adsorbed species methods are covered. Diffusion and reaction in catalyst pellets is covered by Luss in a chapter that provides a comprehensive litera- ture survey. The emphasis is less on physical insight and more on the mathematical development. A good section on effectiveness factors is provided. Doraiswamy and Kulkarni cover gas-solid noncatalytic reactions, begin- ning with single pellet models and moving to reactor Continued on page 153 SUMMER 1989 laboratory THE COFFEE POT EXPERIMENT A Better Cup of Coffee Via Factorial Design R. J. McCLUSKEY, S. L. HARRIS Clarkson University Potsdam, NY 13676 Undergraduates have little exposure to statistical experimental design. For some time we had been searching for a means of introducing senior lab stu- dents to the concepts of this important topic. We needed a process with numerous variables on which many experiments could be run within a short time frame, yet which was safe, simple, and satisfied the space constraints of our laboratory setting. It was also important that any new experiment illustrate chemi- cal engineering principles beyond those of our existing unit operations facilities. This article describes an un- dergraduate experiment that has successfully met the above objectives and yielded several extra benefits- some totally unexpected. Experimental design involves the use of statistical methods in the planning and analysis of experiments so that valid results with known and generally smaller ranges of uncertainty are obtained in an efficient man- Richard McCluskey received his PhD in chemical engineering from the University of Minnesota in 1977 and has been a fac- ulty member in the chemical engineering department at Clarkson since that time, where he currently serves as its executive officer. For several years he has been involved with the senior unit operations laboratory and since 1985 he has taught a graduate level course in Design of Experiments and Analysis of Data Sandra Harris received her PhD from the University of California at Santa Barbara in 1978. Since that time she has been a member of the chemical engineering de- partment at Clarkson University. She has been director of the senior unit operations q laboratory several times and is active on the Curriculum Committee and on the Labora- tory Improvement Committee. Other inter- ests include process dynamics and control. ner. Adherents of experimental design often em- phasize its ability to reduce the number of required experiments, but its greatest value lies in forcing an experimenter to use more forethought in the schedul- ing of runs and greater rigor in interpretation of their results. The likelihood of an unhappy conclusion to an experimental program, i.e., uninterpretable or mean- ingless results, is thereby considerably reduced. Applications for experimental design range from the comparison of two treatments to more esoteric subjects such as model identification and time series analysis. Since the majority of our students have had no formal training in statistics, the goals of our exper- iment are quite limited. The aim is to expose students to useful references on applied statistics and to re- quire them to carry out simple two-level factorial and fractional factorial designs. These elementary designs illustrate key statistical concepts, are usually the first designs encountered in any sequential strategy of ex- perimentation, and serve as a foundation for various more specialized designs (e.g., surface response de- signs). Several texts offer explanations of factorial de- signs [1-3], and some recent articles [4, 5] extolling the merits of experimental design are listed with our references. A continuing series on experimental de- sign in Chemtech [6] is also recommended, particu- larly for those familiar with matrices. THE EXPERIMENTAL PROGRAM Our senior laboratory course is organized along the following lines. Students work together in three or four member teams. Each student receives a lab man- ual containing experiment descriptions and additional references. Experiments are outlined in a manner that encourages creative approaches; cookbook procedures are kept to a minimum. All experiments are per- formed during two weekly six-hour lab periods. Stu- dents turn in a pre-lab report a day before the start of any experiment; prior to the second week of lab, c Copyright ChE. Division ASEE 1989 CHEMICAL ENGINEERING EDUCATION rn CEI they make an oral progress report to the faculty member serving as experiment director; and a final report is due a week after completion of the experi- ment. The problem posed to the students is excerpted below: Consider your lab group as a team of engineers hired by the Peyton Hall Coffee Company to develop a pro- cess for making coffee. The prospective customers are a discriminating lot who are unwilling to pay more than$.20
per cup. The company has invested a considerable sum
in a Norelco Dial-A-Brew II coffee maker, so this pro-
duction unit must be used. Don't break it. Process op-
tions that should be considered are
1. The type of coffee:
Coffee C1 ($2/lb) and Coffee C2 ($4/lb)
2. The type of filter:
Filter F1 ($.01/sheet) and F2 ($.02/sheet)
3. The type of water:
W1, from the water fountain at no cost
W2, distilled water at $.01/cup 4. At least two other process changes or variables of your choice. In their final report students are asked to present a process cost summary, to discuss recommendations for further process development, and to explain any discrepancies in their mass and energy balances. The apparatus for the experiment consists princi- pally of the drip coffee maker, four pint-size thermos bottles, a household thermometer, a water jug, a dish- washing bucket, and many styrofoam cups. Other in- struments the students are expected to use include a spectrophotometer, an ammeter, balances, a magnify- ing glass, and a microscope. A week before starting the experiment, students are given the operating instructions for the coffee maker and a copy of a statistics text. We find the book by Box, Hunter, and Hunter to be highly readable, and pages 306-328 plus pages 374-386 are a sufficient reading assignment for our purposes. During the first lab session, students perform a 23 factorial experiment. This consists of eight runs (pots of coffee, 3 cups/pot) covering all possible combina- tions of three variables at two different settings. En- couragement is given to replicate at least one run. With each pot of coffee, students must do overall mass and energy balances, measure several characteristics of the product, and obtain samples for a taste test. Property measurements normally include spectro- photometric percent transmission on a sample diluted with three parts water and a residual weight obtained from a Mettler balance with an infrared dryer attach- ment. pH measurement is convenient, but usually shows only minor variation with type of coffee. To date, no groups have taken on the challenge of a We needed a process with numerous variables on which many experiments could be run within a short time frame, yet which was safe, simple, and satisfied the space constraints of our laboratory setting. chromatographic analysis. Students are forewarned that reliable taste test results are obtained only with difficulty. Taste test procedures are left entirely as their responsibility. After using the first lab period to refine their ex- perimental procedures and to acquaint themselves with factorial experiments, students have an opportu- nity to meet with the experiment director before at- tempting a 2-1 fractional factorial design during the second week of lab. The effects of five different vari- ables are now to be evaluated from the results of six- teen runs. The variables are chosen by the students. Some fairly obvious choices are the "brew control" setting on the coffee maker and the change of coffee grounds. Other parameters that have been investi- gated include: addition of salt to the coffee grounds, pre-wetting the bed of grounds, comparison of fine versus coarse ground coffee, and use of stainless steel versus glass carafe. SAFETY Normal precautions for use of any electrical appliance need to be followed. Students are also cautioned that the glass carafe is fragile and cannot withstand significant thermal shock. We have kept a stainless steel carafe on hand as a substitute, but have not had to use it. The foremost hazard that we guard against is chemical contamination. To that end, the apparatus is stored in a nearby faculty member's office rather than in the lab stockroom, we deal exclusively with black coffee, and the experiment is set up in an area re- moved from the rest of the lab. THEORY For a 28 factorial experiment involving three vari- ables each at two levels or settings (arbitrarily de- noted by + and -), the basic model for interpreting any product characteristic, Y, is Eq. (1). <+ A+B+C+ ab+ ac+ bc Y = < Y > + 2 + error "*+ 2 where Y.+ + is the value obtained in the experiment with the first, second and third variables at their + setting; is the average Y value for all experi- SUMMER 1989 ments; A,B, and C represent the "main effects" of the three variables; ab, ac, and be are the "two factor interaction effects" of the respective variable sets; and the error term is assumed to be an independent and normally distributed random variable. The main effect, A, is defined as - , where is the average result for all experiments with the first variable at a + setting. The interaction effect, ab, is defined as - , where is the average for all ex- periments in which the product of the first two vari- able settings is positive, i.e. < YAB+>= AB + ab is a measure of the non-additivity of the response to changes in the first and second variables. A much fuller discussion of factorial designs is pre- sented in applied statistics texts [1-3]. Eq. (1) is pre- sented to illustrate that the primary goal is determin- ing which variables give large main effects and which variables may strongly interact. Note the above con- cepts apply whether a variable is quantitative, such as the mass of coffee grounds, or qualitative, such as the type of coffee. Luckily, there is a convenient technique, known as Yates Algorithm [2, pp. 323-324], for computing each of the main and interaction effects. All of the terms in Eq. (1) can be easily calculated from a table of Y val- ues. Variables whose main and interaction effects are small can be eliminated from consideration, and pro- cess development efforts can focus on those variables giving large effects. Early identification of unantici- pated synergism (i.e., large interaction effects) can speed efforts of process optimization, or, even better, serve as a basis for obtaining a patent. Nonetheless, experimenters must always be cauti- ous in interpretation of their results. If unexplained interaction is encountered, it is wise to redo the analysis using a simple transformation of Y, e.g., In Y or 1/Y. It may be that a model strictly additive in main effects is adequate for the transformed data. The error term in Eq. (1), what statisticians call the residual, should also be examined to see if it is approximately normally distributed. An unusually large residual may indicate a flawed experiment that needs to be repeated. Also, if residuals vary in rela- tion to the magnitude of Y, there is a need for data transformation of the type mentioned above. In order to do such an analysis in a 23 design, some experiments must be repeated. If there are only eight experiments, the error has but one degree of freedom and is equal to ( )/2, where is the av- erage of all experiments in which the product of the variable settings is positive, i.e. < abc+> = (Y +Y_ + Y_+_ +Y__ ) PITFALLS Students are prone to concentrate on the taste testing and lose sight of their overall objective-de- velopment of a process for the Peyton Hall Coffee Co. Also, taste test results are apt to be indecisive for a number of reasons: taste bud fatigue, lack of contrast between samples, or simply too few examiners for such a subjective test. A positive aspect to this is that process decisions can then be made on the basis of economics and more reliable measurements of coffee strength. The taste test still serves as a safeguard against concocting an unpalatable product. Review of initial student reports disclosed their unfamiliarity with cost analysis, standard errors, and use of microscopes. It is now explicitly mentioned that labor costs must be included in their analyses. Follow- ing the oral progress report, a lengthy discourse is made on procedures for estimating standard errors and the advantages of visual comparison. DISCUSSION A motivating factor behind this experiment was the increasing number of our graduates finding em- ployment in the food processing or consumer products industries, where consumer preference testing and statistical analysis of data are commonplace. The ex- periment drives home the points that many chemical engineers work outside the chemical industry and that you need go no further than your own kitchen to do interesting chemical engineering research. The taste testing also introduces a social compo- nent absent in our other experiments. As expected, offering coffee samples to volunteers led to greater alertness at the end of our six-hour lab period, particu- larly when students had been up late the night before completing final reports on prior weeks' experiments. An unexpected plus was the willingness of faculty members, who had never before participated in lab, to throw open their office doors and take part in the taste testing. Computational burdens associated with analysis of factorial experiments are avoided by providing stu- dents with a Multiplan software file that calculates all main and interaction effects using Yates Algorithm. We have not considered espresso or gourmet cof- CHEMICAL ENGINEERING EDUCATION (Y++ +Y + Y__ +Y---) fees, and it has been difficult locating common brands that give substantial taste differences. We will be happy to share our knowledge of which brand is un- usually distasteful with anyone who writes. A copy of the write-up appearing in our lab notebook is also available. This experiment, like all good research projects, has numerous facets worthy of additional exploration. Fundamental modeling of the drip making process, scale-up considerations, and effects of aging are all topics of interest. Another possible extension would have students report on the commercial processing of coffee beans [7]. Furthermore, there remains a con- troversy over whether professors' taste buds differ significantly from those of undergraduates. In summary, our experience with this experiment has been quite positive. Almost all lab groups are able to sort through many process variables and make a reasonable recommendation to the Peyton Hall Coffee Co. Some students come away with an appreciation of factorial experiments and some do not. They all share the experience of utilizing dollar signs in the evalua- tion of their results. Operation of the experiment goes well, and, importantly, most students report they have fun. REFERENCES 1. Bethea, R. M., B. S. Duran, and T. L. Boullion, Statisti- cal Methods for Engineers and Scientists, Marcel Dekker, New York (1975) 2. Box, G. E. P., W. G. Hunter, and J. S. Hunter, Statistics for Experimenters, John Wiley & Sons, New York (1978) 3. Cheremisinoff, N. P., Practical Statistics for Engineers and Scientists, TECHNOMIC Publishing Co., Lancaster, PA (1987) 4. Hunter, J. S., "Applying Statistics to Solving Chemical Problems," Chemtech pp 167-169, March 1987 5. Jones, B. A., "Design Lab Experiments to Assure Product Quality," Research & Development, pp 54-58, December 1987 6. Deming, S.N., "Quality by Design," Chemtech, part 1, p. 56, September (1988); Part 2, p. 52, January (1989) 7. Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Ed., Vol. 6, p 511, John Wiley & Sons, New York (1979) 0 REVIEW: Reactor Engineering Continued from page 149 models, which somewhat anticipates the next two chap- ters. This chapter also covers the literature extensively, but the authors give good physical explanations of the models. The next few chapters deal with some old favorites. The task of covering fixed-bed gas-solid catalytic reactors falls to Froment and Hofmann, who present a range of models. This chapter is not as comprehensive as the cor- responding one in Froment and Bischoffs book (Chemical Reactor Analysis and Design, Wiley, 1979). The authors emphasize uncertainties in reaction kinetics and reactor transport parameters, and deal mainly with phenomena actually seen under industrial conditions. In a well-written chapter, Rowe and Yates give a very clear description of the bubbling bed model and bubble be- haviour in fluidized beds. They also emphasize the importance of the distributor and freeboard regions in reactor design. Denn and Shinnar cover the area of coal gasification with a strong emphasis on reactor efficiency and energy analysis. Some of their references may be difficult for students to find, and some familiarity with specialized terms is assumed. In the longest chapter, Carra and Morbidelli give an extensive catalog of correlations, model equations, and solutions for gas-liquid reactors. Some interesting com- ments on scale-up and reactor power requirements are made at the end. Shah and Sharma treat trickle bed and slurry reactors under the heading of gas-liquid-solid reactors. Again, many references and results are given. The part on slurry reactors contains many typographical errors, but also provides a useful worked example of slurry reactor design. Some newer and more specialized reactor types are the subject of the concluding chapters. Tyrell, Galvan, and Laurence provide a short chapter that tries to make clear the focus of polymer reaction engineering, rather than being comprehensive. They concentrate on model- ing the product distribution by step-growth and chain- growth mechanisms. There is relatively little on actual reactor design. Erickson and Stephanopoulos give an introduction to biological reactors that is reasonably accessible for non- specialists. A short introduction to microbial growth con- cepts and a review of mass transfer (02 supply) set the stage for an interesting chapter on reactors. In possibly the first treatment in a reaction engineering book, DeBarnardez, Claria, and Cassano give a necessarily ex- pository view of photochemical reactors. They stress the differences between these and more traditional reactor designs, especially the need for proper models of emis- sion and absorbance of radiation. Several examples of photoreactor design are presented. Trost, Edwards, and Newman give a very readable survey of electrochemical reactors, with strong emphasis on porous electrode systems, following a general intro- duction. There is unfortunately no chapter in this book on de- position reactors, such as are used in the semiconductor industry. Maybe next time! The final chapter is by Morbidelli, Varma, and Aris, and is somewhat different from the rest of the book in that it is completely theoretical, covering reactor steady- state multiplicity and stability. The two limiting cases of CSTR and plug-flow reactor are analyzed extensively. O SUMMER 1989 classroom ANOTHER WAY OF LOOKING AT ENTROPY Entropy and Aging, Evolving Systems DANIEL HERSHEY University of Cincinnati Cincinnati, OH 45221 I TEACH A DUAL-LEVEL thermodynamics course which reflects my non-traditional interest in the subject, i.e., I am fascinated with the concept of en- tropy, dissipative systems, stability through fluctua- tions, stationary states and equilibrium. I apply these ideas to my major preoccupation-aging, evolving systems, longevity analysis, and structural complex- ity. I examine living systems and so-called inanimate systems such as corporations. I find in the classroom that teaching this "new" thermodynamics engages student interest and enthusiasm to a degree which, amazingly, seems to match my own. I challenge the class to analyze the aging process in humans, in corpo- rations and cities, from an entropic point of view. We examine the structure of organizations, as to which are most entropically efficient. We extend the bound- aries of knowledge into regions where there are no apparent right and wrong answers, which means that sometimes I give the entire class an A grade to reflect my pleasure in their accomplishments. Entropy, of course, is not something tangible, not something capable of being seen or touched. Hence, entropy is a difficult concept to grasp. It is not a solid, it is not hot or cold and does not have a physical con- sequence, such as temperature. We can say that en- tropy is a measure of the disorder of a system and show that more disorder means higher entropy con- tent [3]. Real processes tend to go in the direction of increasing entropy. Aging can be envisioned as an ir- Daniel Hershey is a professor of chemical engineering at the University of Cincinnati. He is the author of eight books, including the recent Must We Grow Old: From Prigogine to Pauling to Toynbee. His major research publications and teaching interests involve aging, evolving systems (entropy analysis of human and so-called inanimate systems such as corporations). He also specializes in the measurement of basal metabolic rates of well-elderly per- sons, dieters, smokers, and athletes, with the aim of tracing the aging process. Copyight Ch Entropy... is not something tangible, not something capable of being seen or touched. Hence, entropy is a difficult concept to grasp We can say that entropy is a measure of the disorder of a system and show that more disorder means higher entropy content. reversible process of entropy accumulation. Getting older means having less control of body functions, being more disordered. Death is the ultimate disor- der, a state of maximum entropy. This point has been speculated upon by many scientists, including Jones [18] and Von Bertalanffy [35]. The second law of thermodynamics essentially says that systems will run down of their own volition if left to themselves. In other words, the entropy content tends towards a maximum. Thus, increasing entropy could be an indication of the direction in which the system is inclined to go. Unless there is outside inter- vention, the second law of thermodynamics codifies the one-sidedness of time, or time's arrow. We can only move forward; that is, time is irreversible. Everything we know is tending towards chaos (un- less there is outside intervention), towards an equilib- rium with the environment. To quote Von Bertalanffy [35]: The significance of the second law can be expressed in another way. It states that the general trend of events is directed toward states of maximum disorder, the higher forms of energy such as mechanical, chemical, and light energy being irreversibly degraded to heat, and heat gra- dients continually disappearing. Therefore, the universe ap- proaches entropy death when all energy is converted into heat of low temperature, and the world process comes to an end. AGING, EVOLVING LIVING SYSTEMS It was not until the 1950s that entropy started to seriously emerge in discussions of living phenomena. Complicated biological processes such as cell differen- E Division ASEE 1989 CHEMICAL ENGINEERING EDUCATION ImS1E tiation, growth, aging, etc., were now analyzed from the second law of thermodynamics and entropy calcu- lations made [6, 36]. Bailey [1] wrote: "Entropy is a very viable concept for the biological and social sci- ences. It applies to both open and closed systems. It can be discussed in terms of organization or order." Jones [18] said: "One common feature of biological pro- cesses is their unidirectionality in time, that is, they are not reversible, except under special cir- cumstances. Since entropy is the only physical vari- able in nature which generally seems to parallel the direction and irreversibility of time, these should be fertile areas for the effective use of entropic models." Much of the historical development of entropy has dealt with isolated or closed systems. A closed system is one which can exchange energy but not matter with the surrounding environment. The second law of ther- modynamics states that a closed system must evolve to a state in equilibrium with its environment-a con- dition of maximum entropy. Open systems are those which can exchange both matter and energy with the surroundings. Obviously we, the living, are examples of open systems. Open systems must maintain the ex- change of energy and matter in order to sustain them- selves, or slow the approach to the final state, death. We can say that entropy accumulation within the living system is composed of two parts, one being the internal entropy production based on the myriad of irreversible chemical reactions which constitute the chemistry of life. Secondly, there is the entropy flow through our boundaries, such as in the food consumed, air inhaled and exhaled, biological waste products, heat from the skin, etc. The internal entropy produc- tion derived from our chemical reactions always pro- ceeds in the direction of increasing our entropy con- tent, since the chemistry of life is inherently irrevers- ible. However, the food in, air in and out, waste prod- ucts out, and heat out may in total contribute positive or negative entropy flows through our boundaries, which then affect the rate of accumulation of entropy in our living body. Zotin [37] proposed that we evolve towards a final state, death, by a series of changes, each change called a stationary state. We settle into a stationary state and stay for a while until pushed to the next, and the next. This is clearly seen in the transformation of but- terfly larvae and pupae, dramatic physical changes. Balmer [2] applied entropy concepts to the study of an aging annual fish. This species displays all the characteristics of birth, growth, aging, and senile death, over a short twelve-month period. Balmer identified entropy flows into and out of the fish, such as food, excrement and body heat dissipation. Aging as an Entropy Driven Process We can consider the aging process as a series of steps, proceeding from one stationary state to the next and the next. We can talk of an entropy driving force, causing the evolution from one stationary state to the next. Each time we achieve a stationary state, we "rest" for a "moment" and then go on to the next. In each stationary state we hunker down, collect our- selves, minimize our entropy production, smooth out our chemistry, and await the next push. And so we age. Thus the stationary state can be characterized as an entropy (disorder) producing state, where this en- tropy production is drawn down to a minimum before going on to the next stationary state where a new minimum is established. The theorem of minimum en- tropy production is a fundamental concept of the sta- tionary state, first developed by Prigogine and Wiame I challenge the class to analyze the aging process in humans, in corporations and cities, from an entropic point of view ... We extend the boundaries of knowledge into regions where there are no apparent right and wrong answers . [30]. Death is the final state to which we are drawn, where there no longer exists a tension for life; the driving forces have been reduced to nothing or some minimum level, below which life cannot be supported. Excess Entropy (EE) and Excess Entropy Production (EEP) Driving Forces for Aging Having introduced the idea of longevity as an en- tropy driven process involving an evolution through innumerable stationary states, we can now explore the nature of the entropy driving force for life. If death represents the ultimate disorder (and our maximum entropy content) then we can characterize our longevity potential and vitality by the distance we are from the "black hole" of death. We can calculate a difference in entropy content, from the present (where we are) to where we're heading (towards death). This difference is called Excess Entropy (EE) and may be a driving force for life. By tracking EE versus age, we can see our life unfolding, or winding down, as EE approaches zero, the end of the journey. Not only is EE an important parameter in tracing our lifespan, but so too is the rate of change of EE. In other words, how quickly EE is diminishing with age is another key marker. We call this second parameter Excess Entropy Production (EEP). EEP is the rate of change of EE with time. From Prigogine's theory of minimum entropy production in SUMMER 1989 the stationary state, we can surmise that EEP should not only become a minimum in the vicinity of death (a stationary state) but EEP should indeed become zero since that final stationary state is also the final equilib- rium state where all thermodynamic forces and flows become zero. Thus we can trace life's course by EE and EEP tracks [11]. Our life's course is considered stable, so long as the positive-valued EEP is descending to zero and the negative-valued EE is ascending to zero. From the stability theory developed by Liapunov [19], we can say that if both EE and EEP are positive, the living system becomes unstable. Thus we have another criterion for death: that is, when the EE line passes into the positive-valued domain (it crosses the zero axis). In other words, instability in the life process prevents us from exercising the control required to maintain a proper tension of life. And so we die. Internal entropy production for a chemical reaction system is given by Prigogine and Wiame [30] dS_ Ar (1) dt T where S = internal entropy content A = chemical affinity, a chemical driving force r = reaction velocity, a chemical flow T = temperature t = time Eq. (1) can be more generally written as d(S)- J.X. (2) a(S)= d 3 dt J j=1 where a(S) = internal entropy production at any time, t Jj = a thermodynamic flow, for component, j Xj = a thermodynamic driving force, for component, j For a reference state, from Eq. (2), we can write n oo(s) = J X. (3) j=1 and o(S)= o(S)+ 65(S) (4) where 6o(S) = a small deviation of internal entropy production from the reference state. Prigogine has shown [28] that o0(S) in Eq. (3) is a minimum in the reference state (the equilibrium or stationary state). From Eq. (2), Lee [19] showed 2S) n d(2S= 2 5J& 5X. (5) dt 1 j=i where 5Jj 8Xj S 82S S- So = 1 S = Excess Entropy = EE 2 =Jj Jj0, the deviation of the flow from the reference state = Xj Xj0, the deviation of the force from the reference state = entropy of the system, in the reference state = second entropy deviation from the reference state It is this difference between the entropy content, S, at any time and that of the reference state, S, which is defined as Excess Entropy, i.e., EE = S - S, a thermodynamic driving force for the life process. If the reference state is an equilibrium or final station- ary state, SO is a maximum. Thus EE is always nega- tive and approaches zero in the negative domain as the system ages and evolves towards the final refer- ence state. From Eqs. (5) and (6), Excess Entropy Production (EEP) can be written [12] as EEP= dEE _=2 = s8x. dt dt j= Lee [19] demonstrated that EEP approaches a minimum, or zero, as the system approaches the final stationary state or equilibrium. EEP describes the rate of approach of EE to the final state. For a chemically reacting system Z+Y -C+D and with the definitions A = chemical affinity = log[ZY/CD] = chemical force, X and r = chemical reaction velocity = ZY = chemical flow, J we can obtain Eq. (9), using Eq. (7) and assuming Y, C, D are constants [19] (6Z)2 EEP (a (9) Z Although the influences of free radicals, vitamins, minerals, and other nutrients are essential in estab- lishing longevity, nevertheless in a living system the chemistry of life is basically the metabolism of car- bohydrates, fats, and protein. In general, in a homogeneous population the proportions of these food components in the diet tend to remain approximately CHEMICAL ENGINEERING EDUCATION fixed. Thus, it is useful to focus on only one of these, protein, for example. Eq. (8) now becomes: protein + oxygen -> carbon dioxide + water + urea + energy, and Eq. (9) is as follows: (8[Protein]) [Protein] where [Protein] 8[Protein) = Daily Protein Consumption = Daily Protein Consumption minus the Minimum Protein Required (in the reference, equilibrium or final stationary state ofmaximum disorder) Life and Death Aging may be the evolution towards a more prob- able state, the equilibrium state. As the body ages (returns to equilibrium) the EE driving force weakens or diminishes. Schrodinger [32] wrote, "Living sys- tems survive by avoiding the rapid decay into the inert state of equilibrium." Jones [18] proposed, "The approach to equilibrium is a sign of death. Death may also be thought of as the attaining of a critical, maximum state of entropy during our journey towards equilibrium." Schrodinger further stated, "Thus a liv- ing organism continually increases its entropy .. and tends to approach the dangerous state of maximum entropy, which is death." Death can be when a critical amount of randomness is attained, when a certain amount of disorganization is suffered. Thus aging is a randomizing process, a disorganizing process. In terms of stability theory, equilibrium is the point or region of attraction; we are drawn relentlessly towards equilibrium. Life may be considered analogous to the spring-wound watch, where the timepiece may stop by one of two possible mechanisms. It can simply wind down (approach equi- librium), or the internal mechanism can somehow fail and the watch "dies" prematurely. Thus we can de- scribe equilibrium deaths and instability or a cata- strophic deaths. Life may be considered a temporary upset from or perturbation of equilibrium. Equilibrium is absolutely stable, a universal attractor. Equilibrium always wins. Aging is a spontaneous process, where the body dissipates its EE. The various theories of aging (cross- linking, wear and tear, free radical, etc.) all imply a declining metabolic rate with age, and by extension, a diminishing EE and EEP. Evolution may be the natural process of prolonging the time that an or- ganism spends in the far-from-equilibrium state. Genetics still plays its role in determining longevity potential, but is not in conflict with the ideas pre- sented here. The tendency to return to equilibrium We can consider the aging process as a series of steps ... In each stationary state we hunker down, collect ourselves, minimize our entropy production, smooth out our chemistry, and await the next push. And so we age. will always apply. Death will always have a probabil- ity of absolute certainty. AGING, EVOLVING, INANIMATE, CORPORATE-STYLE SYSTEMS The concept of entropy has been widely discussed in many scientific and social arenas [4, 7, 14, 15, 20, 27, 33] and its application to organizational structure is a logical extension of the work done previously by Prigogine [24, 28], Georgescu-Roegen [5], Shannon [33], Quastler [31], Horowitz [15, 16, 17] and others [14, 24, 25]. One of the most famous uses of the entropic con- cepts in chemistry was by Ilya Prigogine [28, 29], re- cipient of the 1977 Nobel Prize in chemistry. He corre- lated non-equilibrium phenomena and disorder (en- tropy). He studied systems near equilibrium and sys- tems with minimum entropy production. However, beyond a certain critical distance from equilibrim, en- tirely new structures could emerge. These new sys- tems, far from equilibrium, Prigogine referred to as dissipative structures. In addition to his work in chemical thermodynamics, Prigogine has also been an innovator in the field of social thermodynamics [24]. He has adapted many of the principles of ther- modynamics to social organizations, recognizing that each organization is itself an open system. Another contributor to the interdisciplinary analysis of open systems was economist and thermodynamicist, Nicholas Georgescu-Roegen [5] who believed that the notion of entropy had great utility in economics, that the earth is an open system with irreversible pro- cesses occurring within it. Emerging States Driven by Nonequilibrium Conditions The behavior of nations and other human organiza- tions illustrates the recondite dynamics of the nonequilibrium open system [14]. States, living cells, economic processes, ecological systems, and even transportation networks demonstrate the bridges be- tween the physical and social sciences [9]. Prigogine studied self-organization under conditions of fluctua- tions and change, an evolutionary process in systems pushed far from equilibrium. Whether the fluctuations impinge on a household or a nation, the belief is that SUMMER 1989 they can be explained. He examined oscillating phenomena and sought a basis for predicting order from the perspective of entropy production (regarded by some as the reification of the arrow of time since entropy production describes in general the direction spontaneous processes must go). Use of the term, en- tropy, is derived from the Greek, meaning evolution [7]. Systems near equilibrium can be buffeted by small perturbations in energy and mass pressures, but no new organizations, no new structures, are formed. Imposing stronger gradients from the outside world could force the appearance of new, dissipative, nonequilibrium stationary states. Examples cited by Prigogine are a town and the living cell. Georgescu- Roegen wants economics, which ignores entropy, to begin to mark the existence and applicability of nonequilibrium dynamics and irreversibility. Econ- omists, he says, have a blind faith in reversibility (we can restore original conditions by invoking the same laws, backwards and forwards, and ignoring time). Georgescu-Roegen states that matter is subjected to entropy degradation, from higher order to lesser, and hence becomes less useful. What he is stressing is an evolutionary philosophy. If driven hard enough we see new structures developing, nurtured by energy and matter fluxes [24]. Entropy, applied to the economic process, adds important new perceptions to the in- teractions of humans, technology, the market system, and limited resources-ideas spawned by Georgescu- Roegen. He proposed we think in terms of irrever- sibilities, limits on resource availability, and a more parsimonious society. Most current economic policy tinkers with prices, taxes, or the market in some way. Until now, we have stressed economic balances of energy and matter-what comes in must equal what goes out-rather than an understanding that some- thing is lost in every transaction (in entropy terms). The real world dictates the transformation in one di- rection only: low entropy to high entropy. The con- sumer takes in high-grade, ordered energy and matter and exhausts low-grade, disordered wastes. The wastes must not injure or render inoperative the feed- back and control mechanisms which affect the stability of the open, temporary state. Consumers may be indi- viduals, cities, governments, corporations, or civiliza- tions [10, 12, 13, 26]. Informational Entropy: Shannon's Approach The mathematical definition of informational en- tropy was derived by C. E. Shannon [33] in 1949. With molecules in motion, colliding and rebounding, differ- ent molecules will occupy a given space at various times and hence many molecular arrangements, called microstates, are possible. We associate the concepts of greater freedom, uncertainty, and more configura- tional variety with an increased number of microstates and higher entropy. If one had to guess where a par- ticular molecule would be at a given time, the proba- bility of error would be greater in the higher entropy state. Thus ordering of a system implies a lower en- tropy, which carries with it a certain reliability and smaller probability of error. From the preceding discussion we know that as the number of microstates, W, increases, the state entropy, H, increases. Hence we can write [4], H= K log W (11) where a is the logarithmic base. If we assume that all the microstates are equiprob- able, then the probability of achieving each individual microstate, pi, is simply one out of the total number of the microstates, W, or 1 (12) p. =W or H=-Kloga (pi) (13) We can extend this idea to non-equiprobable sys- tems with the use of the Expectation Value, Ex [22], which is by definition the probability of each outcome, pi, multiplied by the value of that individual outcome, Xi, summed over all possible outcomes, as indicated in Eq. (14) E, = pi Xi (14) With the probability, pi, and the associated H value, -K loga pi, from Eq. (13), Ex (also called S, the entropy of the system) is S= K pi loga Pi (15) i Thus, Eq. (15) expresses the entropy of a system in terms of probabilities. It takes the concept of entropy from the thermodynamic setting to the domain of gen- eral probability theory. It can be shown that S in Eq. (15) achieves a maximum value if and only if all the pi's are equal [26]. If for convenience the constant K is taken to be unity, then Eq. (15) reduces to S=-, pi log. pi (16) i This is Shannon's formula for informational entropy. The Meaning of Stored Information As Weaver [33] states, ". .. the word 'information' in communication theory relates not so much to what CHEMICAL ENGINEERING EDUCATION you say, as to what you can say." Potential message variety, freedom of choice, and a large vocabulary are the desired ends of communication and information transmission. A library obviously contains stored in- formation. The information is stored in a linear se- quence of symbols organized to the constraints of a language. The sequences are organized into books and periodicals, and these are carefully ordered on shelves. Everywhere order and constraints are as- sociated with the information storage process. This is a state of low entropy. If we take each page of each book, cut it into single-letter pieces and mix them in one jumbled heap, the entropy would increase and stored information would decrease. In entropy terms, stored information is the divergence from the state of maximum disorder (when all pi terms are equal). In other words, stored information is the difference be- tween entropy content for the equally probable state, Smax (maximum disorder) and that for the unequally probable present, S, and is denoted by D. Therefore, stored information is D= Sx-S (17) Entropy and Corporate Structure Shannon's informational entropy formula [33] has in the past found application by Gatlin [4], who com- puted genetic stored information, by Horowitz and Horowitz [15, 16] and Herniter [8] in marketing, by Lev [21] in accounting, by Thiel [34] and Georgescu- Roegen [5] in economics, by Philipatos and Wilson [27] in securities analysis, and by Murphy and Hasen- jaeger [23] in organizational decentralization. These authors extended the definition of pi from the probability that a system will be in a particular microstate to such related considerations as: (1) the probability that a customer will purchase a product; (2) the degree of competition in the marketplace; (3) a measure of the dispersion in a securities portfolio; (4) the degree of market share; (5) the degree of or- ganizational decentralization; and (6) the bits of stored genetic information. One can generate a Power Index [10, 12, 26] to be used in Shannon's formula, analogous to pi, in order to characterize the overall structure of a corporation. Since each unit controls those beneath it, one can also define a Cumulative Power Index for each unit, Ci, where Ci = Pi + sum of all Pi controlled by this unit, i Finally, a Fractional Cumulative Power Index, fi, is introduced as the unit's Ci divided by the sum of all Ci in the organization. Thus Eq. (16) is transformed to S=- fi log2 fi (18) We can define an entropic distance from disaster, D, for the actual structure, by Eq. (19): D= Sma -S (19) and the distance from disaster for an ideal structure, Do, as D = Sma SO (20) and a structural efficiency, 9q, by Eq. (21): max = s -sX 100 Tl=-- xlOO max 0 S S (21) The distance from disaster, D, is also stored infor- mation, Eq. (17), as well as EE for the inanimate sys- tem, the corporate-style organization, EE=S-S where Smax = maximum entropy content for the or- ganization, if all the units have the same budget, are at the same level, and are completely independent. A prescription for disaster. (Sm" = log2n and disaster = 1/n, where n is the number of units in the organization [10].) From Eqs. (7), (18) and (22) and recognizing that EEP is expressed as the product of thermodynamic forces and flows, we can write [12] EEP= SS EE (23) where J =flow=S X =Force=EE and where previously, for the living system, flow = r and force = A. It can be shown [12, 26] that EE=S-S =S-log, n EEP= (f log2 fi i=l For each year of a corporation's history, fi can be computed for each unit and the summing process of Eq. (18) accomplished to produce S and then effi- ciency, -q, from Eq. (21). The EE is obtained from Eq. (24) and EEP from Eq. (25). Thus EE and EEP longevity tracks can be constructed, just as they can SUMMER 1989 be (and have been) for the living system. CONCLUSION In the classroom I offer undergraduate and graduate students the opportunity to explore another meaning of entropy, applied to: open systems; dissipa- tive systems; stationary states exhibiting minimum entropy production; stability through fluctuations; en- tropy driving forces; excess entropy and excess en- tropy production concepts; the entropy nature of liv- ing systems; the entropic evolution of inanimate sys- tems such as corporations; the meaning of life as an entropy-driven process; the finality of death from an equilibrium viewpoint; change processes which can af- fect entropy content of systems; aging, evolving sys- tems and increasing disorder and entropy. This leads our discussions into diverse fields such as gerontology and geriatrics, systems research, cor- porate planning, history, economics and process con- trol. We become interdisciplinary for one quarter at least. Or longer. REFERENCES 1. Bailey, K. D., "Equilibrium, Entropy, and Homeosta- sis: A Multidisciplinary Legacy," Syst. Res. 1, 25-43 (1984) 2. Balmer, R. T., "Entropy and Aging in Biological Sys- tems," Chem. Eng. Com., 17, 171-181 (1982) 3. Fast, J. D., Entropy, Gordon and Breach, New York (1968) 4. Gatlin, Lila L., Informational Theory and the Living System, Columbia University Press, New York (1972) 5. Georgescu-Roegen, Nicholas, Entropy and the Eco- nomic Process, Harvard University Press, Cambridge, MA (1971) 6. Gump, F. E., "Whole Body Metabolism," in S. M. Altura et al (eds) Handbook of Shock and Trauma, Vol 1: Basic Sciences, Raven Press, New York (1983) 7. Hahn Jr., John, "An Application of Informational En- tropy Concepts to Profit-Seeking Organizations; MS Thesis in Chemical Engineering, University of Cincinnati (1979) 8. Herniter, J. D., "An Entropy Model of Brand Purchase Behavior," J. of Market. Res., 10, 361-375, Nov. (1973) 9. Hershey, D., and H. H. Wang, A New Age-Scale for Humans, Lexington Books, Lexington, MA (1980) 10. Hershey, D., V. Patel, and J. Hahn, "Speculations on the Use of Shannon's Formula to Characterize an Or- ganization," Systems Res., 4, 211-212 (1987) 11. Hershey, D., and W. E. Lee, "Entropy, Aging, and Death," Syst. Res., 4, 269-281 (1987) 12. Hershey, D., "Excess Entropy (EE) and Excess Entropy Production (EEP) in Aging, Evolving Systems, Sys. Res. (in press) 13. Hershey, D., "Aging and Evolving Systems," Syst. Res., 5, 167-170 (1988) 14. Hershey, D., "Aging of Cities, Corporations, and Civi- lizations," Syst. Res., 3, 3-8 (1986) 15. Horowitz, A. R., and J. Horowitz, "Entropy, Markov Processes and Competition in the Brewing Industry," J. Ind. Economics, 16, 196-211 (1968) 16. Horowitz, A. R., and I. Horowitz, "The Real and Illu- sory Virtues of Entropy-Based Measures for Business and Economic Analysis," J. of the Amer. Inst. for Decision Sci., 7, 1; 121-136 (1976) 17. Horowitz, I., "Employment Concentration in the Com- mon Market: An Entropy Approach," J. of the Royal Statistical Soc., 133, part 3, 617-625 (1970) 18. Jones, D. D., "Entropic Models in Biology: The Next Scientific Revolution?" Persp. Biol. Med., 20, 285-299 (1977) 19. Lee, W., "Analysis to Understand the Thermodynam- ics of Living Aging Systems," PhD Thesis, Univ. of Cincinnati (1984) 20. Lepkowski, W., "The Social Thermodynamics of Ilya Prigogine," Chem. Eng. News, pp 30-33, April 16 (1979) 21. Lev, B., "The Aggregation Problem in Financial Statements: An Informational Approach," J. of Ac- count. Res., 6, 247-261, Autumn (1968) 22. Miller, I., and Freund, J. E., Probability and Statistics for Engineers, Prentice-Hall, Inc., New Jersey (1977) 23. Murphy, D. C., and Hasenjaeger, J. T., "Entropy as a Measure of Decentralization," Proc. of the Amer. Inst. for Decision Sci., Boston, MA, 67-69, Nov (1973) 24. Nicholas, G., and I. Prigogine, Self-Organization in Non-Equilibrium Systems, John Wiley and Sons, New York (1977) 25. Onsager, L., "Reciprocal Relations in Irreversible Processes," Phys. Rev., 37, (1931) 26. Patel, V., "Entropy Analysis of the Structure of a Cor- poration," MS Thesis, Univ. of Cincinnati (1982) 27. Philippatos, G. C., and C. J. Wilson, "Entropy, Market Risk, and the Selection of Efficient Portfolios," Apl. Economics, 6, 77-81 (1974) 28. Prigogine, I., "Entropy, Time, and Kinetic Descrip- tion," in G. Nicolis et al (eds) Order and Fluctuations in Equilibrium and Nonequilibrium Statistical Me- chanics, John Wiley, New York (1981) 29. Prigogine, I., "Time, Structure, and Fluctuations," Science, 201, 777-785 (1978) 30. Prigogine, I., and J. M. Wiame, "Biologie et Thermo- dynamique des Phenomenes Irreversibles," Experi- mentia, 2, 451-453 (1940) 31. Quastler, H., The Emergence of Biological Organiza- tion, Yale Univ. Press, New Haven, CT (1964) 32. Schrodinger, E., What is Life? The Physical Aspects of the Living Cell, Cambridge Univ. Press, Cambridge (1955) 33. Shannon, C. E., and W. Weaver, The Mathematical Theory of Communication, Univ. of Ill. Press, Urbana (1949) 34. Thiel, H., Economics and Information Theory, Rand- McNally and Company, New York (1967) 35. Von Bertalanffy, L., "The Theory of Open Systems in Physics and Biology," Science, 111, 23-29 (1950) 36. Warnold, I., K. Lundholm, and T. Schersten, "Energy Balance and Body Composition in Cancer Patients," Cancer Res., 38, 1801-1807 (1978) 37. Zotin, A. E., "The Second Law, Negentropy, Thermo- dynamics of Linear Irreversible Processes," in I. Lamprecht and A. I. Zotin (eds) Thermodynamics of Biological Processes, Watler de Gruyter, Berlin, 21 (1978) 0 CHEMICAL ENGINEERING EDUCATION book reviews INTRODUCTION TO MATERIAL AND ENERGY BALANCES by G. V. Reklaitis John Wiley & Sons, New York, NY (1983) Reviewed by Gerald B. Westermann-Clark University of Florida Several textbooks are available for an introductory course on chemical engineering calculations. Such texts share similar goals, including bridging from pre-engi- neering courses to the chemical engineering curriculum, illustrating the broad applicability of chemical engineer- ing concepts, even outside chemical plants, and develop- ing skills used later in the curriculum. If achieved, these goals can show students who still may be unsure about continuing in chemical engineering how chemical engi- neering is related to, but different from, other areas. Despite the similarity of goals, one of two different approaches usually emerges in introductory texts: 1) a survey of chemical engineering calculations, including not only steady state material and energy balances, but also a sampling of other topics, such as unsteady state mixing in stirred tanks and plug-flow reactors; and 2) a development of strategies for material and energy balance calculations-an approach that usually adopts a notational system that is easily adapted to more complex, multi-unit processes than are usually seen in approach number one. The first approach typically draws more heavily on dynamics concepts, while the second gives students a deeper perspective on process synthesis and design. Either approach can illustrate the diversity of problems amenable to chemical engineering analyses, and in fact, most introductory courses are a mixture of the two per- spectives mentioned. As examples of these approaches, Introduction to Chemical Engineering Analysis (T. W. F. Russell and M. M. Denn, Wiley, 1972) may be cited as an example of the first, Process Synthesis (D. F. Rudd, G. J. Powers, and J. Siirola, Prentice-Hall, 1973) as an example of the second, and Elementary Principles of Chemical Processes (R. M. Felder and R. W. Rousseau, Wiley, 1986) as an example of a mixed approach. The present textbook is divided about equally be- tween material and energy balances, with each type of balance treated in nearly parallel fashion. After present- ing the appropriate balance equations, each half of the text contains chapters on balances for nonreacting and reacting systems. Each half also contains a chapter on the use of balances in process flowsheets, with sections on strategies for manual and machine computations. The discussion of material balances also contains a beneficial chapter on the relation between elemental and species balances, and the final chapter shows how material and energy balances can be solved simultaneously by means of a discussion of computational strategies. Overall, topics are very logically presented, and the parallel pre- sentation of topics assists assimilation of the more diffi- cult energy balances. Although instructors will appreciate the degrees-of- freedom analyses, it is unusual for students (who gener- ally try to solve a problem without first ascertaining whether it has a solution) to fully appreciate their value. However, the chapters on strategies for manual and ma- chine calculations, which discuss linearizing nonlinear problems and simultaneous methods for solving systems of linear and nonlinear equations, show students that they can tackle relatively large problems with techniques from numerical methods courses. The discussion also apprises students of the limitations of the methods pre- sented. In each section consistent notation is developed, with Nj (or Fj) denoting the molar (mass) flowrate of species j throughout, for example, and with summation signs frequently used to obtain more compact equations. The very useful open system analysis, consistent with that in Chemical and Engineering Thermodynamics (S. I. Sandler, Wiley, 1988), is developed for energy balances. Numerous examples serve as excellent aids to dis- cussions of concepts. The homework problems amply il- lustrate ideas advanced in each chapter. For use in prob- lems and examples, the appendix contains a relatively large compilation of physical properties, including heat capacities, heats of formation, Antoine constants, and steam tables. Most obvious by their omission are un- steady state problems. Furthermore, the problems tend not to give students a representative cross-section of the range of problems that they can solve; rather, the empha- sis is on problems encountered in chemical plants. The content of this textbook places it between the books mentioned previously by Rudd et al. and by Felder and Rousseau. This text would fit very well into a cur- riculum in which numerical techniques are presented prior to or even concurrently with the material presented. The use of the open system energy balance, the most use- ful form of this balance for process calculations, makes this text consistent with what students are likely to need later. Although the author, an eminent process design en- gineer, has put forward a text that leans toward process design, this is a very readable, substantial contribution that, with minor adaptations to the needs of particular curricula, would be welcomed enthusiastically by stu- dents in introductory courses. J SUMMER 1989 EDITORIAL NOTE: The following detachable pages describe some industrial employment opportunities for graduating chemical engineers. Please post the information in a conspicuous place for the benefit of your students, or distribute the pages to students who may be interested. These companies have expressed a definite interest in hiring chemical engineers in the areas described, and we strongly encourage students seeking employment to respond as indicated. Ray W. Fahien Editor Chemical Engineering Education CHEMICAL ENGINEERING EDUCATION CH2M HILL P.O. Box 22508 Denver, CO 80222-0508 0 GENERAL INFORMATION 0 CH2M HILL was founded in Corvallis, Oregon, in 1946 by three students and a professor from Oregon State University. It was originally called CH2M, as an acronym of the founders' last names: Cornell, Howland, Hayes, and Merryfield. In 1971, the firm merged with Clair A. Hill & Associates and became CH2M HILL. The company provides comprehensive consulting, planning, and design services in water and wastewater management, water resource and agricultural development, transportation systems, hazardous- and toxic-waste management, and energy systems. A staff of 3,600 employees in more than 57 offices throughout the United States, Canada, and abroad provides full support and complementary services in economics, environmental sciences, construction/program management, mining infrastructure planning, and general planning, surveying, photogrammetry, and mapping. CH2M HILL is one of the 10 largest consulting engineering firms in the United States. CITIZENSHIP REQUIREMENTS U.S. Citizenship or Permanent Resident Visa HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW Write: Manager of Recruiting CH2M HILL P.O. Box 22508 Denver, CO 80222-0508 0 ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS * Positions require a traditional BS in CE, ChE, or ME and a MS in Sanitary/Environmental Engineering. Experience is essential and varies from two to ten-plus years. Submit your credentials for evaluation. FE or PE required. 0 POSITIONS * Industrial Process Engineer * Industrial Water/Wastewater Engineer * Hazardous Waste Engineer * ADDITIONAL INFORMATION 0 CH2M HILL is an employee-owned firm which offers flexible benefits and a salary commensurate with experience. An Equal Opportunity Employer Advertisement published in Chemical EnineerinO Educatio. Volume 23, No 3 (1989) MERCK & CO. INC. P.O. Box 2000 RAHWAY, NJ 07065 GENERAL INFORMATION 0 Merck & Co. is a worldwide, research intensive health products company that discovers, develops, produces, and markets human and animal health products and specialty chemicals. The company has 32,000 employees and had sales of over$5 billion in 1988.

CITIZENSHIP REQUIREMENTS: U.S. citizen or permanent visa
REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: We recruit on campus nationwide
(U.S.)
HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Please submit resume or
application which clearly states educational background, objectives, and work
experience to: Theresa Marinelli, Manager College Relations
Merck & Co., Inc
P.O. Box 2000
Rahway, NJ 07065

ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS *

BS/MS
Functional Area Degree Level Major Hiring Locations

Corporate Division
Merck Sharpe & Dohme Research Labs
Merck Chemical Manufacturing Division
Merck Chemical Manufacturing Division
KELCO Division
Calgon Water Management Division

BS
BS/MS
BS/MS
MS
BS/MS
BS/MS

Rahway, NJ; Woodbridge, NJ
Rahway, NJ; West Point, PA
Rahway, NJ; Danville, Pa: Elkton, VA
Rahway, NJ; Danville, PA
San Diego, CA
Pittsburgh, PA

PhD

Fields of Special Interest Tech Center Locations

environmental aspects of plant operations

SProcess development-from conception through
to scale-up and eventual plant start up

Chemical modification and analysis of
natural polymers

Merck Chemical Manufacturing Division
Rahway, NJ; Danville, PA

Merck Sharpe &Dohme Research Labs
Rayway, NJ; West Point, PA

KELCO
San Diego, CA

Merck hires chemical engineers in several divisions to play a critical role in the
In each division we have highly skilled chemical engineers and we will continue to hire
highly qualified applicants in the chemical engineering field.

Ad published in Clmial Emineei Education. Vol 23, No 3 (1989)

MILLIKEN & COMPANY
College Relations Department, M-260E
P.O. Box 1926
Spartanburg, SC 29304

GENERAL INFORMATION *
Milliken is a major manufacturer of textile products for apparel, commercial,
home and industrial markets. Milliken Chemicals operates two modern
Specialty Chemicals plants in South Carolina. The company was founded in
1865 and now has 50 plants and 15,000 associates in the US (16,000 worldwide).
The Milliken environment is characterized by challenge, accomplishments,
innovation, advanced technology, promotion from within based on individual
performance, and extensive education and training opportunities. The chemical
engineering jobs are in South Carolina and Georgia.

CITIZENSHIP REQUIREMENTS: U.S. citizenship or Permanent Resident Visa

REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: Southeastern United States

HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Send cover letter with functional
area interests and geographic preference statement, resume, and a copy of your

ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS *

BS/MS

Process Engineering:

Manufacturing Management:

Provides technical support in textile dyeing and finish-
ing operations and in Specialty Chemicals production.
Responsibilities include manufacturing compliance
with customer product quality specifications and pro-
cess efficiency/improvement project assignments.
Responsible for the production resources of people and
machinery. The first line production manager may be
promoted to either Advanced Production Manager or
Process Engineer in the dual career ladder.

Research: Develops new products and associated machinery or
processes. Prefer PhD, but will consider MS.

An Equal Opportunity Employer

Ad Published in Chemical Enpinering Educaion. Vol. 23 No 3 (1989)

ASHLAND PETROLEUM COMPANY
P.O. Box 391
ASHLAND, KY 41114

GENERAL INFORMATION *

Ashland Petroleum Company is the largest operating division of
Ashland Oil, Inc., a Fortune 60 company with 37,600 employees and
$8.2 billion in annual sales. Recognized as the nation's largest independent refiner and leading supplier of petroleum products, the company also manufactures and markets fuel oils, lubricants, asphalt, jet fuels, and many other specialty products for both industrial and governmental customers. CITIZENSHIP REQUIREMENTS: U.S. Citizen or authorized to work in the U.S. REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: Midwest, Southeast HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Contact: Marc E. Washington, Manager of Professional Employment, at the above address. ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS * BS/MS Functional Area SProcess * Technical Services * Control Systems Research Degree Level BS BS BS BS Fields of Special Interest Major Hirina Locations Catlettsburg, KY Catlettsburg, Catlettsburg, Catlettsburg, KY Tech Center Locations Catalysis * Reaction Kinetics Catlettsburg, KY Catlettsburg, KY Ad published in Chemical Emnineerin Education. Vol 23, No 3 (1989) PhD KY KY E. I. DU POINT DE NEMOURS & CO, INC. Employee Relations Department 1007 Market Street, N-13451 Wilmington, DE 19898 GENERAL INFORMATION 0 Established in 1802, Du Pont today is a diversified international company, strongly backed by scientific and engineering capabilities, with business operations in more than 48 countries, with approximately 140,000 employees worldwide, and with sales exceeding$30 billion.

CITIZENSHIP REQUIREMENTS: U. S. Citizenship or permanent resident

REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: Continental U.S.

HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Send resume and cover letter to:
Professional Staffing Section
Employee Relations Department
E. I. Du Pont de Nemours & Co., Inc.
Wilmington, DE 19898

0 ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS 0

> BS/MS
Functional Area Degree Level Major Hiring Locations

Process/Project
Design/Manufacturing
Construction/Distribution
Technical Sales and Service
Research and Development
(Other)

Fields of Special Interest

Process, Project, Research and Development

BS/MS Continental United States
BS/MS Continental United States
BS/MS Continental United States
BS/MS Continental United States
BS/MS Continental United States
BS/MS Continental United States

Tech Center Locations

Mid-Atlantic Region

An Equal Opportunity Employer

Ad Published in Chemie Eninaerin Edufation Vol 23, No 3 (1989)

> PhD

OLIN CORPORATION
Stamford, CT 06904

GENERAL INFORMATION *

Olin Corporation is a diversified company with core business in chemicals,
metals, and ammunition. A Fortune 200 company headquartered in
Stamford, Connecticut, Olin employs 16,000 people worldwide and has
annual sales exceeding $2 billion. CITIZENSHIP REQUIREMENTS U.S citizenship or permanent resident visa is required for employment REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED Nationwide-undergraduate and PhD HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW Resume and cover letter to Ms. Leah Lethbridge Regional Supervisor, College Relations Olin Corporation 120 Long Ridge Road Stamford, CT 06904 0 ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS * Functional Area Sales Business Evaluation Development, Process, Maintenance, Production, Project Degree Level BS BS/MBA Major Hiring Locations Stamford, CT Stamford, CT Lake Charles, LA; Charles- ton, TN; Doe Run, KY; McIntosh, AL PhD Fields of Special Interest Tech Center Locations * Research and Development and Process/Production New Haven, CT; Charleston, TN; Lake Charles, LA; Joliet, IL; Rochester, NY; Doe Run, KY; Cheshire, CT Ad published in Chemical Enineerine Education. Vol 23, No 3 (1989) UNION CARBIDE CORPORATION CHEMICALS & PLASTICS GROUP Section D3226 39 Old Ridgebury Road Danbury, CT 06817 GENERAL INFORMATION 0 Fortune 50 Company, recognized globally for leadership in its three business groups: Chemicals & Plastics; Industrial Gases; and Carbon Products. Founded in 1917, Carbide employs 44,000 worldwide, with 24,000 in USA. Annual sales for Chemicals & Plastics Group exceeded$5.5 billion in 1988. Key C&P products include polyethylene, latex and
specialty polymeric resins; ethylene oxide/glycol and derivatives; urethane intermedi-
ates; silicones; alcohols and organic solvents; and polycrystalline silicon.

CITIZENSHIP REQUIREMENTS: U.S. citizenship or Permanent Resident Visa (for BS/MS)

REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: Gulf coast, northeast, midwest,
southeast, southwest, and Rocky Mountain
HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Send resume and photocopy of
transcripts) to above address "Attention: Chemical Engineering Employment
Coordinator." Be sure to include a cover letter specifying your functional and location
preferencess. (See below)

ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS 0

Functional Area Degree Level

Design (Process; Control Systems)
Environmental/Safety Engineering

Manufacturing
and
Process/Project Engineering
R&D (Polymer Applications/Tech Service;
Process Development)

Technical Sales

BS,MS
MS

BS,MS

BS

MS

BS

Fields of Special Interest

Catalysis, Polymers, Separations

Major Hiring Locations

Charleston, WV; Tarrytown, NY
Charleston, WV

Bound Brook, NJ; Charleston and Sistersville, WV;
New Orleans, LA; Houston and Victoria, TX;
Moses Lake, WA
Charleston, WV

Bound Brook, NJ; Charleston, WV; Tarrytown, NY

Metropolitan areas, nationwide

Tech Center Locations

Bound Brook, NJ; Charleston, WV

UCC has been recognized for its innovative technologies by receiving several prestigious
Kirkpatrick Awards (sponsored by Chemical Engineering Magazine). Two of these, UNIPOL
(polyolefins) and Low Pressure Oxo (alcohols), are licensed internationally and account
for >15 billion lbs/yr of plastics and solvents.

An Equal Opportunity Employer

Ad published in Chemical Enineering Education. Vol 23, No 3 (1989)

SHELL OIL COMPANY
AND SUBSIDIARIES

GENERAL INFORMATION *
Shell began operations in the United States in 1912. Emphasizing innovative
technology and sound engineering, it has grown to be a major company employing
in excess of 30,000 people throughout the United States. Chemical engineers are
utilized in the recovery of oil and natural gas, refining and chemical plant
operations, and sales activities.

CITIZENSHIP REQUIREMENTS: Candidates must be legally authorized to work in the United
States. Will not consider candidates with student visas.

REGIONS OF USA AND/OR CANADA WHERE BS/MS CAMPUS RECRUITING IS GENERALLY CONDUCTED:
Primary work locations include the Gulf Coast, California, Illinois, and Washington
state.

HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Send resume and transcripts to
Manager Recruitment
Shell Oil Company
Department D2
P.O. Box 2463
Houston, TX 77252

ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS 0
BS/MS

Process Engineering: Provide technical support to petrochemical operating units,
plan and develop new facilities plus major and minor revisions to existing facilities.
Computer Process Control: Provide technical support to petrochemical process
control systems, including systems modification/enhancement.
Production Engineering: Optimization of oil/gas wells and reservoir performance,
design and application of enhanced recovery programs, thermal recovery
processes, planning and economic evaluation of operations and multiple flow
analysis and application.
Chemical Sales: Provide market intelligence and customer service in support of sales
efforts. Perform market research and development and market chemical and
polymer products.

An Equal Opportunity Employer

Ad published in Chemical Engineern Education Vo. 23, No. 3 (1989)

ROHM AND HAAS COMPANY
CORPORATE STAFFING DEPARTMENT
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GENERAL INFORMATION *
Rohm and Haas Company is a highly successful multinational chemical company
producing over 2,500 products for use in industry and agriculture. Most of our annual
sales of over $2.5 billion come from complex specialty chemical products designed for specific applications: plastics and modifiers for PVC resins, electronics chemicals, biocides, additives for motor oils, polymeric finishes for leather and textiles, acrylic resins for paints, and agricultural pesticides. We have offices and manufacturing facilities in 30 countries and employ over 13,000 people. CITIZENSHIP REQUIREMENTS: U.S. citizens and those who have a legal right to work and remain permanently in the U.S., or who qualify as "Intending Citizens" under the Immigration Reform and Control Act of 1986. REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: Nationwide in Continental U.S. HOW TO APPLY IF UNABLE TO SCHEDULE CAMPUS INTERVIEW: Send your resume and cover letter to the above address. ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS * BS/MS Functional Area Research Process Engineering Plant Development Process Design Technical Sales Fields of Special Interest Process Engineering Process Design Separations Materials Polymer Science Major Hiring Locations Philadelphia Area Philadelphia and Bristol, PA; Houston, TX; Louisville, KY; Knoxville, TN Philadelphia Area Major Cities Nationwide Tech Center Locations Philadelphia Area Philadelphia Area Philadelphia Area Philadelphia Area Philadelphia Area * ADDITIONAL INFORMATION * An Equal Opportunity Employer M/F Ad published in Chemical Engineerin Education. VoL 23, No 3 (1989) PhD DOW CHEMICAL USA University Relations Box 1713-CH Midland, MI 48674 GENERAL INFORMATION S Dow manufactures and markets chemicals, plastics, metals, consumer products, pharmaceuticals, specialty products and services, and agricultural products. Dow USA will hire over 275 chemical engineers in 1989 and has over 2400 chemical engineers working in all functions and geographic locations. In a 1988 magazine survey, chemical engineering students named Dow as the number-one company for which they would like to work. CITIZENSHIP REQUIREMENTS: Only U.S. citizens, aliens who have a legal right to work and remain permanently in the U.S. or aliens who qualify as "Intending Citizens" under the Immigration Reform and Control Act of 1986 are eligible for employment. REGIONS WHERE BS/MS CAMPUS RECRUITING IS CONDUCTED: Nationwide HOW TO APPLY IF UNABLE TO SCHEDULE A CAMPUS INTERVIEW: Send resume and letter to above address, stating your job interests and geographic preferences. * ENTRY LEVEL OPPORTUNITIES FOR CHEMICAL ENGINEERS 0 Functional Area Design Process Engineering Manufacturing Research and Development Sales Degree Level Major Hiring Locations BS,MS BS,MS BS,MS BS.MS BS,MS Fields of Special Interest Math Modeling Polymer Processing Polymer Characterization Catalysis Michigan, Texas, Louisiana, Ohio, California Michigan, Texas, Louisiana, Ohio, California Michigan, Texas, Louisiana, Ohio, California Michigan, Texas, Louisiana, Ohio, California Offices in over thirty major cities Tech Center Locations Michigan, Texas, California Michigan, Texas, California, Ohio Michigan, Texas, California, Louisiana Michigan, Texas An Equal Opportunity Employer Advertisement published in Chemical Engineering Education, Volume 23, No 3 (1989) BS/MS PhD class and home problems The object of this column is to enhance our readers' collection of interesting and novel problems in chemical engineering. Problems of the type that can be used to motivate the student by presenting a particular principle in class, or in a new light, or that can be assigned as a novel home problem, are requested as well as those that are more traditional in nature, which elucidate difficult concepts. Please submit them to Professor H. Scott Fogler, ChE Department, University of Michigan, Ann Arbor, MI 48109. A PRACTICAL APPLICATION OF MASS BALANCES WILLIAM F. FURTHER MICHAEL J. PEGG2 and PAUL R. AMYOTTE2 A COURSE IN MASS (and energy) balances is essen- tially a course in solving a large number and variety of problems. This has been our approach to teaching mass balances, and many of the problems we assign can be described by given this and this, calcu- late that. This seems reasonable in light of the fact that one of the primary reasons for doing mass balances is to determine unknown flowrates and compositions from a limited amount of data. Another application of the mass balance technique is in checking the consistency of measured data from a process. It is, therefore, also useful to assign prob- lems which demonstrate this concept. The problem presented here is one such example. PROBLEM (a) A process steam boiler (operating at steady state) at a coal conversion plant fires coal gas from a continuous vertical retort. The fuel analysis is given in Table 1. An environmental test crew has made meas- urements of the flue gas emissions in the stack; the measured dry flue gas analysis is given in Table 2. Over the duration of the testing, the molal humidity of the combustion air supply was 0.05 mole moisture per mole dry air. Using the law of conservation of mass, check the consistency of the data. (b) The boiler described in part (a) operates at a thermal input of 25 MW, and the higher heating value of the fuel gas has been determined as 17.97 MJ/m3 at 15C and atmospheric pressure. In addition to deter- 'Royal Military College of Canada, Kingston, Ontario, CANADA K7K 5LO 2Technical University of Nova Scotia, Halifax, Nova Scotia, CANADA B3J 2X4 TABLE 1 Fuel Analysis TABLE 2 Dry Flue Gas Analysis Component Volume % CO2 10.0 CO 0.8 02 4.0 N2 85.2 mining the dry flue gas analysis, the environmental test crew has made several other measurements. The temperature of the flue gas was found to be 325C. A particulates traverse revealed negligible stack solids, a flue gas moisture content of 38% by volume, and a stack gas velocity of 5.75 m/s. The chimney diameter is known to be 2.06 m, and the burners were thought to be operated with about 17% excess air over the duration of the testing. Using the law of conservation of mass, check the consistency of the data. 0 Copyright ChE Division ASEE 1989 SUMMER 1989 I IBEJ SOLUTION (a) The flow diagram is shown in Figure 1, with the system defined as the boiler plant. The basis for subsequent calculations is 100 mol of fuel gas fed to the boiler (actually the time required to fire this quan- tity of fuel gas). The solution strategy follows that outlined for this type of problem by Lewis et al. [1]. Their procedure first calls for the assumption that there is a balance between input and output of all major elements in the process except one. The data consistency check is then achieved by seeing if an equality exists between input and output of the last element. To systemize the choice of elements and balances, the following scheme is recommended in ref. [1] for this sort of process: 1. carbon balance to relate fuel to dry flue gas 2. nitrogen balance to relate dry flue gas to air supply 3. oxygen balance to determine moisture in flue gas 4. hydrogen balance to check data consistency The parameters for these balances are shown in Table 3. The amounts of dry flue gas (X), dry air (Y) and flue gas moisture (Z) calculated from Table 3 via William F. Furter is professor of chemical engineering and dean of graduate studies and research at the Royal Military College of Canada. He received his BASc and PhD degrees from the University of Toronto and his SM from the Massa- chusetts Institute of Technology. During his teaching career he has served as a con- sultant to several major corporations, both in the US and in Canada. He is a Fellow of the Chemical Institute of Canada. Michael J. Pegg received his BSc in Fuel and Combustion Engineering, and his PhD in Combustion from the University of Leeds, England. He is an associate profes- sor at the Technical University of Nova Scotia where he teaches combusion courses in the chemical engineering de- partment. His applied research interests are in the combustion of coal-based alter- nate fuels and his fundamental research in- i terests are in dust explosions. Paul R. Amyotte received his BEng from the Royal Military College of Canada and his MSc (Eng) from Queen's University. He graduated from the PhD program at the Technical University of Nova Scotia in 1986 and is currently an assistant professor in the chemical engineering department there. His research interests are grain drying, dust explosions, and engineering education. 49 4 % H 0.4 % 02 40% CO2 6 2 % N2 DRY AIR (Y mol) 21.0 % 02 79.0 % N2 AIR MOISTURE 0 05 mol H20/ mof DRY AIR 10.0 % CO2 0 8% CO 40 % 02 85 2 % N2 FIGURE 1. Flow diagram for process steam boiler plant. the carbon, nitrogen and oxygen balances are 407.4 mol, 431.5 mol, and 112.3 mol, respectively. The hydro- gen balance yields an input of 115.0 mol H2 and an output of 112.3 mol H2 (less than 3% difference). Con- sidering that all measurement errors have been lumped in the hydrogen balance [1], the input and output of hydrogen show good agreement. The data from this part of the problem are considered to be consistent. (b) The data which are to be checked for consistency in this part are the percent excess air, flue gas moisture content, and stack gas velocity. Table 4 shows the calculations for the theoretical oxygen (77.3 mol), TABLE 3 Mass Balance Parameters on a Basis of 100 mol Fuel Gas (equating volume % and mole%) CARBON NITROGEN OXYGEN HYDROGEN STREAM (mol) (moD (mol) mo) Fuel 22.0 (as CH4) 6.2 (as N2) 0.4 (as 02) 49.4 (as H2) gas 18.0 (as CO) 9.0 (as CO) 44.0 (as CH4) 4.0 (as CO2) 4.0 (as CO2) Dry air 0.79 Y (as N2) 0.21 Y (as 02) Air 0.05 Y/2 (as H20) 0.05 Y (asH20) moisture Dry 0.008X (as CO) 0.852X(as N2) 0.04 X (as 02) flue 0.1X (as CO2) 0.008 X/2 (as CO) gas 0.1 X (as CO2) Flue gas ------ 0.5 Z (asH20) Z (as H20) moisture X = mol dry flue gas Y = mol dry air Z = mol flue gas moisture CHEMICAL ENGINEERING EDUCATION TABLE 4 Theoretical Oxygen Calculations on a Basis of 100 mol Fuel Gas COMPLETE AMOUNT COMBUSTION THEORETICAL 02 COMPONENT (mol) EQUATION (molb CH4 22.0 CH4 + 202- C2 + 2H20 44.0 CO 18.0 CO +1/2 02 C2 9.0 H2 49.4 H2 +1/2 02 H20 24.7 02 0.4 -0.4 77.3 which corresponds to a theoretical air value of 368.1 mol. From part (a), the actual dry air supplied is 431.5 mol. The calculated value of 17.2% excess air agrees with the estimate given in the problem statement. The amounts previously determined for the dry flue gas (407.4 mol) and flue gas moisture (112.3 mol) indicate a moisture content of approximately 22% in the flue gas. Clearly this does not agree with the meas- ured value of 38%; one explanation is that the measure- ment is incorrect [2]. As shown in the following analysis, however, there is a more likely explanation. The fuel firing rate is calculated as 58.8 mol/s by dividing the boiler thermal input by the higher heating value of the fuel gas, correcting to STP, and assuming ideal gas behavior. Since the basis previously used was 100 mol of fuel gas, the scale factor for the process is 0.588 mols/s/mol. Using 407.4 mol dry flue gas from part (a) and a flue gas moisture content of 38%, the amount of mois- ture in the flue gas is determined to be 249.7 mol. This gives a value of 657.1 mol for the total amount of flue gas, which, when multiplied by the scale factor, be- comes a molar flowrate of 386.4 mol/s. Correcting from STP to 325C and assuming ideal gas behavior, the volumetric flowrate of the flue gas is 19.0 m3/s. Dividing this by the cross-sectional area of the chimney, a stack gas velocity of 5.70 m/s is obtained. This compares favourably with the given value of 5.75 m/s. It is unlikely that the measurements of both flue gas moisture content and stack gas velocity are wrong. The data, therefore, indicate that more water is leaving the system than is entering. A plausible explanation is the existence of a leak in a water tube inside the boiler. CONCLUSION Although the solution has been presented here in a straightforward manner, the open-ended nature of the problem can create difficulties for some students. In particular, part (b) requires analysis and judgement skills in addition to the knowledge of how to perform a mass balance. For this reason we have found it best to offer exposure to problems of this type in class tuto- rials and home assignments before using them on tests and exams. This approach generally results in a favour- able student response, in addition to illustrating the power and usefulness of the mass balance technique. REFERENCES 1. Lewis, W. K., A. H. Radasch, and H. C. Lewis, Indus- trial Stoichiometry: Chemical Calculations of Manufacturing Processes, second edition, McGraw- Hill, New York; pp 114-118 (1954) 2. Felder, R. M., and R. W. Rousseau, Elementary Prin- ciples of Chemical Processes, second edition, John Wiley & Sons, New York; pg 85 (1986) 0 DEPARTMENT: New Jersey Institute Continued from page 133. and have a number of interesting projects that have been on the back burner for the lack of such students. DEPARTMENTAL ADMINISTRATION Because of the size of the department and the number of degrees it awards (we also administer the freshman chemistry program required of all engineer- ing undergraduates), the chairman is assisted by five associate chairmen. Barbara Kebbekus acts as ad- ministrative officer for the chemistry division, and Re- ginald Tomkins is responsible for recruiting and advis- ing all of our undergraduate students and handles in- dustrial liason. Richard Trattner administers the en- viromental science program. Arthur Greenberg ad- vises graduate students in the applied chemistry pro- gram, and Basil Baltzis is responsible for recruiting and advising chemical engineering graduate students. Departmental staff includes two administrative as- sistants, two secretaries, a machine shop supervisor, a laboratory supervisor, and two lab assistants. REFERENCES 1. National Action Council for Minorities in Engineering, NACME News, p 6 (August, 1988) 2. "Frontiers in Chemical Engineering Education: Re- search Needs and Opportunites," National Research Council, National Academy Press, Washington, DC (1988) 0 SUMMER 1989 Random Thoughts... THE VIEW THROUGH THE DOORS RICHARD M. FIELDER North Carolina State University Raleigh, NC 27695 One of my favorite leisure-time activities is to walk down the hall and listen to classes in progress, hoping to get some teaching tips. I've got some time this morning-come along with me and let's see what we can pick up. There's Professor Frobish-he's got the junior fluids course this semester. Frobish: "...and on Monday we saw that if you write the coupled partial differential equations of change for this pseudoplastic fluid flowing in a cloverleaf-shaped channel and impose the usual singular perturbation theory boundary conditions you can easily prove that the liquid will emerge at the outlet as long as the pipe is tilted downward." Student: "Professor Frobish." Frobish: "That result by itself is of course only mildly interesting but Monday was the first day of class and I wanted to start slowly. Now today we'll see what hap- pens if we relax some of those simplifying assump- tions. Suppose, for example, we say that instead of a pseudoplastic fluid we have a virial gas moving at sonic velocity and the channel is made of expandable rubber and is mounted on a satellite in a decaying or- bit. Now if we invoke a six-dimensional stress tensor we can easily see that..." Student: "Professor Frobish!" Frobish: "What is it already?" Student: "You never finished the proof you were doing Monday and I didn t understand any of it as far as you got." Frobish: "Finishing it was an exercise for the class...the mathematics is completely straightfor- ward...but if you need help you'll find something simi- Richard M. Felder is professor of ChE . N.C. State, where he has been since 1969. H; received his BChE at City College of C.U.N.Y. and his PhD from Princeton. He has worked at the A.E.R.E., Harwell, and Brookhaven Na- tional Laboratory, and has presented courses on chemical engineering principles, reactor design, process optimization, and radioiso- tope applications to various American and for- eign industries and institutions. He is coauthor of the text Elementary Principles of Chemical Processes (Wiley, 1986). lar in that paper by Lundquist I cited." Student (a trace of hysteria entering his voice): "But I can't read Swedish." ****** Oh well, that will probably go on for awhile, so let's move on. Good man, Frobish, although some of the faculty feel that he's too applied-they want more fundamentals in the curriculum. Look in there now...see that guy with the mustache and the tee shirt that says "Chemical Engineers Do It In Fluidized Beds"? That's Greg Furze-he teaches kinetics and gets consistently high ratings. Seems to be some action in there-let's check it out. ****** Furze: "Ok, guys...get the chairs in a circle and let's get down to it. You people there are A molecules, got it, and you over there are B's. A's-put on your little hats so we'll all know which species you are. Good. Now, when I yell STARTUP you all get going, ok, and Angle there will keep count." Student: "Hey, Greg, I forget what we're supposed to do." Furze: "No sweat, Joe...this is tough stuff-I don't ex- pect you to get it right away. When I yell you all start milling around inside the chairs...move in straight lines until you bump into someone else. If it's your CHEMICAL ENGINEERING EDUCATION species, you just bounce off and keep going. If it's the opposite species you roll a die,, and if you throw a 1 then you yell out REACTION and sit down. Got it?" Student: "Why are we doing this again?" Furze: "Great question, Amy. We're demonstrating the kinetics of...what, gang? Right, a second-order reac- tion in a well-mixed batch reactor. Now, after this run, just for fun we're going to say that Pete over there is a catalyst and unknown to him there's a trace amount of sulfur in the reactor, which he's deathly allergic to. Pete, as the reaction proceeds you'll start gasping and clutching your throat, and the rest of you..." Interesting fellow, Furze-students like him, but for some reason I've never understood, Frobish doesn't...ah, we've got a treat coming up now. There's Professor Snavely-he's teaching the sophomores this semester and always keeps them laughing. ****** Snavely: "...and that's the flow chart. You people un- derstand?...Wonderfull Now, what do we do next...let's see what our old friend Miss Albright has to say. Miss Albright-give us the benefit of your wisdom." Student: "Um...l'm not sure what you're asking, Dr. Snavely." Snavely: "Oh, really? Well, I'll try again, more slowly. Miss Albright. What...do...we...do...next? Got it that time?" Student: "Uh...l guess we need to find the amount of CO2 in the product." Snavely: "The amount of CO2 in the product. Miss Albright, have you ever had a chemistry course? Yes? Were you awake during the part of it when they talked about such esoteric concepts as mole frac- tions? You were? Amazing...hey, you there, the girl with the glasses. If you think you can teach this stuff better than I can why don't you come up and do that talking from up here. No? All right, then...suppose you tell Miss Albright here how she could determine the mole fraction of CO2 once she learns what it's called." Student: "Uh...l don't know." Snavely: "You don't know? You don't know? Oh, I'm sorry-this is CHE 247...you must have been looking for the medieval history class down the hall and wandered in here by mistake. Why don't you just.." Lot of fun, isn't he? He's on a fast track here- brought in two million dollars in grants last year and is a shoo-in for tenure. He has terrible luck, though-three or four times a year his car turns up with flat tires in the parking lot...you'd almost think someone was...say, there's lovable old Professor Wombat, teaching his course in process design. Believe it or not, he's taught that course since 1937 without missing a year. ****** Wombat: "..and that's the Chamber process, used to make most of the sulfuric acid we use today. Now I'm going to write a ten-year discounted cash flow rate of return on investment table for a typical plant...copy it carefully, since you will be responsible for it on the next test. After that I'll move on to the important reac- tion between steam and coke that gives us...watery coke...ha ha ha, a little humor there, class...actually it gives us water gas or blue gas. used as the fuel for many of the lights that illuminate our streets today. Now, the table...pay special attention to the interest- ing way they treat depreciation in Row 18..." Look how the students are gently nodding their heads as they soak up the wealth of real-world in- formation they're getting. Well, I think it's time to get back to...wait, there's Professor Buffo fin- ishing up today's thermo lecture...looks like another 3-piece-of-chalk day from here. ****** Buffo: "...and the last problem is even more trivial. Look." (Writes on board) dA = PdV SdT = dA = (aA/av)T dV +(aA/iT)V dT & dG = VdP SdT = dG = (aG/aP)T dP + (aG/IT)p dT & dH = (aH/aS)p dS + (a1H/P)S dP = V = (aH/aP)s = (G/aP)T so -S = (aA/aT)v = (aG/aT)p & (aP/aT)v = (aS/aV)T h (aS/aP)T =-PV=- /P Buffo: "...but only for an ideal gas, and the rest obvi- ously follows. Is that clear? Good. Ok, next period we'll learn about some fascinating relationships be- tween m, f, 0, and if we have time for it, G and GP . Class dismissed-dont forget the closed book exam on Friday." ****** Well, I'd better get back to the office. I'm just completing the report for our upcoming accredita- tion visit and I've got to establish that half of our curriculum is really engineering design-should be a piece of cake. I SUMMER 1989 classroom GENERALIZED SATURATION PROPERTIES OF PURE FLUIDS VIA CUBIC EQUATIONS OF STATE MARIA A. BARRUFET, PHILIP T. EUBANK Texas A&M University College Station, TX 77843 THE MAXWELL CRITERIA require that each cubic equation of state (EOS) has unique, reduced sat- uration properties when its constants are fixed by the usual critical constraints. For example, a numerical reduced vapor pressure curve results as a function of reduced temperature. Use of independent, empirical EOS and vapor pressure equations has caused ther- modynamic inconsistencies in previous correlations. First, this work shows that some simplifications result when the reduced densities of the saturated liq- uid and vapor are replaced by their sum s (Pr, + Pr,v) and their difference w= (P,- Pr,v) Second, we tabulated a complete set of saturation properties calculated from the van der Waals EOS. Volume FIGURE 1. A qualitative pressure-volume diagram for a pure substance indicating the coexistence curve with the Maxwell equal area constraint. Maria A. Barrufet is an engineering research associate at Texas A&M Univer- sity. She received her BS and MS degrees from the National University of Salta and from the Southern National University of Bahia Blanca (both in Argentina) and her PhD from Texas A&M University. Her re- search interests are prediction of thermo- physical properties of fluid mixtures, heat and reaction engineering, and software tions. Philip T. (Toby) Eubank is profes- sor of chemical engineering at Texas A&M University. He received his BS degree from Rose-Hulman Institute and his PhD from Northwestern University. His research in- terests are in the thermo-physical proper- ties of fluids and fluid mixtures plus electri- cal discharge machining. ' These properties include reduced vapor pressure pr, (dPr /dT,), Pr,, Pr,v reduced heats of vaporization (X/RT,), Aj CV,v or the jump in the heat capacity from the single to the two-phase side of the vapor pressure curve, A C v,1 all as functions of Tr (Tr from 0.4 to 0.8 at 0.04 inter- vals and Tr from 0.8 to unity at 0.02 intervals). For other cubic EOS such as Redlich-Kwong (RK), Soave-Redlich-Kwong (SRK), and Peng-Robinson (PR), we provided the same set of saturation proper- ties as for the van de Waals case, although for a single reduced temperature of Tr = 0.8. For these last three equations we also give the (1) /R C C v/R or isochoric heat capacity of the saturated vapor or liquid (a = v or 1) from the single-phase side w.r.t. the perfect gas value C* at the same temperature. For SRK and PR equations we used eccentric factors Copyright ChE Division ASEE 1989 CHEMICAL ENGINEERING EDUCATION RC5E m = 0.0, 0.2, 0.4, and 0.6. Finally, graphs of these results are presented for comparison with experimental results for a number of common compounds ranging from argon to water. The successes and failures of the various cubic EOS are shown clearly for a variety of compounds ranging from spherical molecules to highly-polar, hydrogen-bonding species. INTRODUCTION Vapor-liquid equilibrium (VLE) calculations of a pure substance through an EOS are usually made by the same trial and error procedures used to calculate VLE for mixtures. The iteration variables are usually pressure (P), (when the temperature (T) is provided), or T when the pressure is known. A pressure (or T) is continuously updated in order to satisfy the equal fugacity criteria at equilibrium. For each attempted P (or T), one must evaluate liquid and vapor densities which in turn are used in the evaluation of fugacities. Any empirical EOS which is fitting both liquid and vapor densities will exhibit van der Waals loops in the two-phase region. The isothermal form of a polynomial EOS must be of odd order in P(V) in order to satisfy mechanical stability criteria for both phases (i.e., (aP/IV)T < 0, as can be observed in Figure 1). Figure 1 shows qualitatively the Maxwell equal-area con- straint (or equality of the liquid and vapor fugacities) for cubic EOS. The two "humps" in the two-phase region are characteristics of a cubic equation con- strained at the critical point; they are called the van der Waals loops in honor of the first cubic EOS. A fifth degree polynomial would present four of these "humps," a seventh degree six, and so forth. The total derivative of the Gibbs' free energy for a pure substance is TABLE 1: Generalized Cu RT P(V (V-b, dG=- SdT+VdP A phase change, such as vaporization or melting, for a pure substance occurs at constant temperature and pressure. The specific properties of the ther- modynamic functions (A, H, S, etc.) will be different for the two equilibrium phases except for the Gibbs' free energy, as can be observed by applying the above equation at constant T and P. This is equivalent to the equilibrium criterium of equality of fugacities since dG= RTd n f (2) The Gibbs free energy can be expressed in terms of the thermodynamic functions as G=A+PV (3) where A is the Helmholtz function and V is the specific or molar volume. Differentiation of this equation at constant pressure and temperature gives [dG= dA+ PdV] =0 (4) T,P Integration between the equilibrium vapor and liquid phases provides JdA=- r PdV=P(v Vr) (5) Because the right-hand side of this equation is the area of a rectangle, a, = a2 as in Figure 1. Cubic EOS are the simplest polynomials that can satisfy Maxwell's criteria. The capabilities of the avail- able cubic EOS vary from equation to equation, par- ticularly in the calculation of liquid densities. The pur- pose of this study is to evaluate some of the most popular EOS of the van der Waals type with regard to their VLE predictions. The studied equations were bic Equations of State (EOS) ac[a(Tr,o)]2 (V-b2)(V-b3) EOS b2 b3 a, afTr, 27 VdW .12500 RTc/Pc 0 0 .42188R2 T2/Pc 1 3/8 2 2 -1/4 RK .08664 RT /Pc b 0 .42748 R T /P Tr 1/3 SRK .08664 RTc/Pe b 0 .42748R2T2 /Pc 1+ fs)( /Tr) 1/3 PR .07780RTc/Pc b V2 b b b .45724 R2T 2/Pc 1+fp(c)(1- 7) .307 fs(c) = 0.480 + 1.574 c 0.17602 fp(a) = 0.37464 + 1.54226 ( 0.2699202 SUMMER 1989 van der Waals (VdW), Redlich-Kwong (RK), Soave- Redlich-Kwong (SRK) and Peng-Robinson (PR). Be- cause we forced these equations to satisfy the critical constraints they can be written in a generic way using characteristics parameters in terms of the critical con- stants as indicated in Table 1. PROCEDURE In this work, we show an alternative way of solv- ing the classical VLE problem which is much simpler and faster. The saturation properties are presented in a reduced form, which allows the reader to compare their performance with any number of compounds by merely scaling these properties by the critical parameters of the substance in question. The reduced densities of the vapor and the liquid phases are replaced by two new variables: the sum and the width s Pr,l+ Pr,v w= Pr,1- Pr,v of the saturation curve on a temperature/density dia- gram. A simple relation is obtained between w and s from the EOS applied to the liquid and the vapor phases, after equating the pressures. For instance, after substituting the two new variables in van der Waals' EOS we obtain w2=s2 32T/s + 36- 12s (6) When this relation is placed into the equation derived from application of the Maxwell equal-area criteria, it provides a function of a single variable which can be zeroed by any numerical technique (e.g., the Newton- Raphson method or bisection algorithms). For example, from the VdW EOS this single vari- able function becomes Fs(6-s) -(16Tr/3) + sw1 In (6-) (16Tr /3) sw- -3(6-s)w/8Tr=0 (7) with w from Eq. (6). An efficient way of calculating VLE using this method is to step down from the critical temperature (Tr = 1) for which the value of s is known (s = 2), and use this as an initial estimate for the next temper- ature. A continuation algorithm may be begun in this way by using only a hand calculator. Linearity of s TABLE 2: Predicted Reduced Saturation Properties From Van Der Waals Equation of State T0 pT ) 0 A^ (V),r (d- c (a\ ( ( 1.00 .10000E+01 .10000E+01 .10000E+01 .40000E+01 .0OOOE+00 -0oo o .45455E+01* .44554E+00* .95972E+01* 00000E+00 00000E+00 .98 .92191E+00 .13761E+01 .77554E+00 .38091E+01 .84070E+00 -.12412E+02 .44304E+01 .57100E+01 .36166E+01 94849E+01 -10086E+00 -50136E+00 .96 .84762E+00 .16118E+01 .70819E+00 .36206E+01 .11778E+01 -.11510E+02 .26352E+01 .63598E+01 .33139E+01 93632E+01 -13335E+00 -.13256E+01 .94 77707E+00 18438E+01 .66369E+00 .34347E+01 .14288E+01 -.11799E+02 .18970E+01 .69425E+01 .31010E+01 .92344E+01 14148E+00 -.24446E+01 .92 71021E+00 .20869E+01 .63022E+00 .32513E+01 .16340E+01 -.12570E+02 .14834E+01 .75050E+01 .29327E+01 90982E+01 -.13768E+00 -.38633E+01 .90 64700E+00 23488E+01 60340E+00 30708E+01 .18090E+01 -.13676E+02 .12161E+01 .80669E+01 27922E+01 89541E+01 12779E+00 -55945E+01 88 58736E+00 26360E+01 58106E+00 .28932E+01 19619E+01 -15088E+02 .10282E+01 86393E+01 26708E+01 88015E+01 -11500E+00 76555E+01 86 53125E+00 .29545E+01 56195E+00 .27188E+01 20978E+01 -.16822E+02 88863E+00 92302E+01 25636E+01 86400E+01 -.10115E+00 -10066E+02 84 47859E+00 .33113E+01 .54530E+00 25477E+01 22197E+01 18919E+02 78072E+00 98461E+01 24673E+01 .84690E+01 .87331E-01 -12851E+02 82 .42932E+00 .37141E+01 .53058E+00 .23801E+01 23299E+01 -.21444E+02 69475E+00 10493E+02 23798E+01 .82881E+01 -.74207E-01 -.16034E+02 80 38336E+00 41725E+01 .51741E+00 .22162E+01 24301E+01 -.24486E+02 62465E+00 11177E+02 22994E+01 80966E+01 -62143E-01 -19644E+02 .76 30108E+00 53041E+01 .49469E+00 19005E+01 26050E+01 -.32622E+02 51724E+00 12682E+02 .21560E+01 76795E+01 -.41814E-01 -.28277E+02 72 23108E+00 68354E+01 47565E+00 16025E+01 27517E+01 44780E+02 43888E+00 .14417E+02 .20305E+01 .72132E+01 -.26628E-01 -.39043E+02 .68 17262E+00 .89734E+01 .45933E+00 13242E+01 28750E+01 -63524E+02 .37930E+00 .16451E+02 .19189E+01 66933E+01 -15987E-01 -.52307E+02 64 12485E+00 12066E+02 44513E+00 10678E+01 29782E+01 -93577E+02 33254E+00 .18877E+02 18184E+01 .61163E+01 -89822E-02 68516E+02 .60 86869E-01 .16729E+02 43261E+00 .83568E+00 30641E+01 14410E+03 29496E+00 21821E+02 .17272E+01 54803E+01 -46707E-02 88236E+02 .56 57645E-01 .24110E+02 .42145E+00 .63015E+00 .31348E+01 -.23403E+03 .26414E+00 25458E+02 16438E+01 47871E+01 -22134E-02 -.11219E+03 52 36073E-01 .36517E+02 41141E+00 45339E+00 .31921E+01 -.40569E+03 23849E+00 .30037E+02 15673E+01 .40437E+01 -.93591E-03 -.14131E+03 48 .20967E-01 .58969E+02 .40231E+00 30713E+00 .32377E+01 76275E+03 21684E+00 35923E+02 .14969E+01 .32656E+01 -34303E-03 -.17686E+03 44 11084E-01 .10358E+03 39402E+00 19225E+00 32733E+01 -15901E+04 .19840E+00 43661E+02 14322E+01 24802E+01 -10466E-03 -.22052E+03 40 .51745E-02 .20363E+03 .38641E+00 .10825E+00 33003E+01 37906E+04 .18253E+00 54094E+02 13727E+01 .17293E+01 -25098E-04 -.27467E+03 with Tr, the law of rectilinear diameters, is helpful for sequential temperature calculations. However, cubic EOS do not provide exact compliance with rectilinear diameter except in the immediate critical region. Knowledge of s and w allows back calculation of pr,l and pr,v and the reduced vapor pressure from the EOS itself. This outlined procedure has been followed for all the EOS listed in Table 1. For the SRK and PR equations we calculated equilibrium properties at acentric factors of o = 0.0, 0.2, 0.4 and 0.6. For Redlich-Kwong EOS, the relation between s and w is given by a quartic equation. However, be- cause this equation does not have odd terms in w, it can easily be solved as a quadratic in y with y = w2 (a)(y2) +b(Tr,s)(y)+c(Tr,s) =0 where 3 a=y12 -b=4T, 7 2 2 =8) 1.5 2 + c= s 7 2 y2 s 4+7 s) 4 Tr \ 2 s) with 71 = 1.282441, 72 =0.259921 Once w is calculated from this expression it is placed in the equation derived from application of the Max- well equal-area constraint and that nonlinear equation is solved for the single variable s which for Redlich- Kwong is 2(s w)-y2(s2 -w2) 4wy2 2(s + w) y(2 2) (2-2 s)2- 7 ( 2W)2 YY 2+ 2(s+-w) 4w 0.51 22+ 72 (s- + )2 )2 T, (2+ 72S) W) (10) Table 2 contains a complete set of saturation prop- erties calculated from the Van der Waals EOS. Table 3 contains an example of the saturation properties ob- (9) tained using the RK, SRK and PR EOS for one re- TABLE 3 Predicted Reduced Saturation Properties From Classical Cubic EOS at Reduced Temperature Tr = 0.8 REDUCED REDLICH SOAVE-REDLICH- KWONG PENG-ROBINSON PROPERTY KWONG S= 0.0 W = 0.2 = 0.4 W = 0.6 = 0.0 W = 0.2 = 0.4 W = 0.6 Pr .24594E+00 .25893E+00 .20117E+00 .15707E+00 .12333E+00 .25789E+00 .19878E+00 .15521E+00 .12289E+00 V0, .79603E+01 .74502E+01 .10029E+02 .13288E+02 .17371E+02 .80567E+01 .10981E+02 .14578E+02 .18910E+02 V .41194E+00 .41443E+00 .39516E+00 .38057E+00 .36914E+00 .39904E+00 .37983E+00 .36587E+00 .35533E+00 (-)" 21862E+01 .21592E+01 .20216E+01 .18490E+01 .16646E+01 .21355E+01 19912E+01 .18180E+01 16411E+01 TT 44006E+01 40698E+01 52176E+01 .63934E+01 .75818E+01 40162E+01 .51844E+01 .63456E+01 .74784E+01 ) 72483E+02 63550E+02 10192E+03 15671E+03 .23318E+03 .68997E+02 .11209E+03 .17203E+03 .25225E+03 (dVr ) .63407E+00 .62219E+00 .58449E+00 .55127E+00 .52218E+00 .60137E+00 .55864E+00 .52310E+00 .49355E+00 /(c1)_c- \ c~-c ) -.16617E+00 .24828E-01 .28603E-01 .27945E-01 .25326E-01 21050E-01 .26367E-01 .26618E-01 .24722E-01 lC'(-i-) -.25298E+00 35279E+00 .56557E+00 75167E+00 .90986E+00 .30114E+00 .53008E+00 72745E+00 .89315E+00 i .33933E+02 .29054E+02 .45892E+02 66805E+02 .91731E+02 28595E+02 .45605E+02 66117E+02 .89610E+02 a jCv.t 7r .46097E+01 .41213E+01 .53144E+01 .64638E+01 75550E+01 .40378E+01 52281E+01 .63382E+01 .73565E+01 ( dT2 1 .13393E+02 .13402E+02 .15930E+02 .17660E+02 .18676E+02 .13206E+02 .15701E+02 17327E+02 .18240E+02 S P-) .24220E-01 .26854E-01 16490E-01 .10154E-01 .62976E-02 24456E-01 14779E-01 .90961E02 .57342E-02 42996E+02 .39739E+02 .58069E+02 79396E+02 10343E+03 .45461E+02 68210E+02 .94312E+02 .12297E+03 T*',(T duced temperature (Tr = 0.8). For PR and SRK, we used acentric factors of (w) 0.0, 0.2, 0.4, and 0.6. The interested reader, however, may obtain from us an unabridged version of Table 3 with a finer grid of o and a complete range of Tr. We compared the saturation properties for a number of substances ranging from spherical to highly-polar, hydrogen-bonding species. The critical properties were taken from Ambrose [1, 2]. The sources for the experimental data of water were taken from Haar, et al. [3]. Argon, CO2 and methane were taken from the IUPAC international tables [4], [5], and [6], respectively. For pentane and neopentane, we took the correlated values of [7] and [8], respec- tively. Figure 2 is a plot of reduced temperature against reduced density obtained from the VdW, RK, SRK and PR EOS-the last two equations of state with zero acentric factors; this diagram emphasizes the liq- uid-phase predictions, which are generally poor, par- ticularly for CO2 and water. Use of the acentric factor in the VLE calculations of SRK and PR EOS slightly improves the liquid-phase predictions. We encourage the reader to compare the performance of all the equa- tions at Tr = 0.8 and at different values of the acentric factor w where applicable. The difficulties with all the EOS for the vapor side predictions are enhanced in Figure 3, which shows Tr against Zr (the reduced compressibility factor). This 12 o Argon CH4 n-C. L neo-C5 a CO2 V H20 _van der Waals Redlich-Kwong SRK with -= 0 0 --- PR with v= 0 0 V .. \ *. \\ "\," iv x\ **. \ ,a\\\ 0 05 1 15 2 25 3 35 Reduced Density FIGURE 2. Comparison of reduced temperature vs. re- duced densities in the coexistence curve. j/ plot emphasizes the difficulties that cubic EOS, con- strained at the CP, have in the prediction of saturation properties. The non-universality of the critical com- pressibility factor (Z,) is clearly seen by comparing the spread of the data points as the perfect gas value is approached (Tr < 0.6). All the EOS tested produce a unique limiting value which is the inverse of their predicted Zc. Once the basic properties Prl Prv Pr are obtained from the Maxwell minimization technique, the rest of reduced saturation properties are obtained sequentially upon application of the Clapeyron equation and standard thermodynamic re- lations as follows. ADDITIONAL SATURATION PROPERTIES The dimensionless heat of vaporization, A/RTc, can be calculated using density residual properties: I H H (11) RT, RT, RT, Where H' is the residual enthalpy defined as the ac- tual enthalpy minus that of the ideal gas [9]: 12o Argon CH4 n-C, n neo-C, a CO, v H,O P van der Waals CP - Redlich-Kwong v1 a. SRK with 0 0.0 a <- PR with == 0.0 ----------- i f/ \ ' 0. 8f \ " 2) +/ 2\ \" '+ 0.6 \ 0.4 0 0.8 16 2.4 3.2 Reduced Compressibility Factor FIGURE 3. Comparison of reduced temperature vs. re- duced compressibility factors in the coexistence curve. CHEMICAL ENGINEERING EDUCATION H ) =Hi -Hi (12) The residual enthalpies are evaluated from P__i 3Zr dPrI T, r, dPr This integral is easily evaluated from any of the EOS listed in Table 1 with the limits from the VLE calcula- tions. Upon use of the Clapeyron equation, the dimen- sionless vapor pressure slope then becomes dPT (R 1 (14) r]ZT Tr( Vrv V1 The slopes of the saturated liquid and vapor volumes are calculated as a (1a) dVrTj dPrj (Iar r r Nar (15) r) d-r) Lr Vr, r r 5 The dimensionless isochoric heat capacity of the vapor evaluated from the single phase side is calculated from (1) r,a 2 ( C r a2pr dp (16) R 2 2 Pr 0 r Prr Since the equation of Van der Waals provides straight isochores L =0 aT2 the isochoric heat capacity coincides with the ideal gas heat capacity CQ. The jumps in the heat capacities are evaluated as AJCv,a dVr, a aPr dPr -- ) = ZT, (17) R dTr Tr dTr ( In Eq. (12), a indicates that the quantity can be evaluated either for the liquid or for the vapor side. The isochoric heat capacity for the vapor phase evaluated from the two phase side is not reported in Table 2, but can be calculated as follows: (2) (1) I Cv, CV AjC Cv, Cv R R + R with an equivalent expression for the isochoric liquid heat capacity. A CLASSROOM APPLICATION This example could be used as a part of a test or a graduate qualification exam. Assuming that the properties of iso-octane can be represented by the Redlich-Kwong EOS, the student is asked to use the generalized saturation properties given in Table 3 to estimate the following quantities at Tr = 0.8. [1] The vapor pressure (in bars), as well as the satura- tion volumes for the liquid and the vapor phase in (cm3/mol). [2] How could he/she verify the consistency of the heat of vaporization X, given in the table with the corresponding values of the vapor pressure and the saturation volumes? [3] Using the Redlich-Kwong, derive an expression for the residual isochoric heat capacity (Cv C*), as a function of pressure (or volume) along an isotherm in the gas phase, and calculate the value of C, for saturated iso-octane vapor at Tr = 0.8 as taken from the two-phase side using their de- rived equation. (Note CQ = 21 J/mol-K). DISCUSSION The limiting values of the saturation properties at the critical point were evaluated analytically or nu- merically (the starred values). The slope of the vapor pressure curve evaluated at the critical point is col- linear to the isochoric slope aT lr v CP taken from the single phase side. Even though the analytical expression resulting from Clapeyron equa- tion (Eq. (11)) diverges at the CP, this divergence is removed upon application of L'Hopital's rule taking the limit when the reduced densities approach to unity. The "critical" values for A Cv,a Sa and for R dT, r dTr were evaluated at a reduced temperature of Tr = 0.9999 which for most practical applications is suffi- ciently close to the critical point. It is well known that the curvature of the isochores S2pr aTr is negative for gas densities, increases with density becoming zero near the critical density, and then posi- SUMMER 1989 tive for liquid densities. None of the cubic EOS tested is able to reproduce this feature which is reflected in Cvv -Cv (I cJ (since Cv is smaller than C:'2 I,v VdW provides straight isochores everywhere. For the other EOS analyzed, the sign of the curvature is either fixed and negative as in the RK EOS, or tem- perature dependent as in the PR and SRK EOS. In either case, for a given temperature the sign remains regardless of the density (vapor or liquid). For exam- ple, RK provides the right physics for the curvature of vapor densities but fails for the liquid. The Soave-Redlich-Kwong and Peng-Robinson EOS were designed to give a better representation of the liquid phase behavior. This they do so even with the isochoric curvature [ft] 2 Tr, although not in the full temperature range and at the expense of misrepresenting the vapor curvature. Along any isochore the curvature will be negative for all temperatures above the "switching" temperature, zero itself at this temperature, and positive below. This switching temperature depends upon the acentric factor. Table 4 contains these temperatures for SRK and PR EOS as a function of o. CONCLUSIONS We believe that Table 2 constitutes a most com- plete thermodynamicc dictionary of reduced saturated properties." Further, we can provide the reader with the unabridged version of Table 3 which shows the TABLE 4 Reduced Switching Temperature in SRK and PR EOS as a Function of co Soave-Redlich-Kwong Peng-Robinson o f,(Co) T fp(O) T 0.0 0.48000 0.56035 0.37464 0.54858 0.2 0.78776 0.59106 0.67229 0.58012 0.4 1.08144 0.61625 0.94836 0.60527 0.6 1.36104 0.63727 1.20285 0.62569 fs(co)= 0480+ 1574( o- 0.176)(o 2) fp(c) = 0.37464+ 1.54226 (0 026992) ( 2) real goodness (or weakness) of the most popular equa- tions of state. Our procedures are different and some- what more general than those of Adachi [10], and Soave [11, 12]. These reduced properties may have multiple uses either as reference values for experimental designs or as valuable information (initial guesses, initiation al- gorithms) in multicomponent VLE calculations. We have also given the basis for calculating VLE in terms of convenient variables (s and w) that allow the calcu- lations in a much faster and convenient way. ACKNOWLEDGMENTS Financial support by the National Science Founda- tion Grant No CBT 8718204 is gratefully acknowl- edged. We also thank C. D. Holland, J. C. Holste, and K. R. Hall for their helpful advice. NOMENCLATURE A = Helmholtz free energy function. C,,v = Isochoric heat capacity of the vapor Cv,1 = Isochoric heat capacity of the liquid EOS = Equation of State Hi = Molar Enthalpy of component i P,V,T = Pressure, Volume, Temperature R = Universal Gas Constant VLE = Vapor Liquid Equilibria Z = Compressibility factor Greek Letters AjCv,/R X/RT, O) p a Subscript! jump in Cv single minus two-phase side = reduced heat of vaporization = acentric factor = density = property at saturation s c = critical property i = component i 1 = liquid value r = reduced property with respect to critical parameters v = vapor value Superscripts a = property at saturation * = ideal gas value, or extrapolated value in Table 2. (1,2) = single-two phase value 1 = liquid v = vapor REFERENCES 1. Ambrose, D., and R. Townsend, "Critical Tempera- tures and Pressures of Some Alkanes," Trans. Fara- day Soc., 64, 550 (1968) CHEMICAL ENGINEERING EDUCATION 2. Ambrose, D., "Vapour Liquid Critical Properties," Na. Phys. Lab. Report, No. 107, London (1980) 3. Haar, L., J. S. Gallagher, and G. S. Kell, NBS/NRC Steam Tables, McGraw-Hill, New York (1984) 4. Angus, S., B. Armstrong, IUPAC. International Thermodynamic Tables of the Fluid State: Argon, 1, Butterworths, London (1972) 5. Angus, S., B. Armstrong, and K. M. de Reuck, IUPAC. International Thermodynamic Tables of the Fluid State: Methane, 5, Pergamon Press, Oxford (1978) 6. Angus, S., B. Armstrong, and K. M. de Reuck, IUPAC. International Thermodynamic Tables of the Fluid State: Methane, 5, Pergamon Press, Oxford (1978) 7. Das, T. R., C. O. Reed, Jr., and P. T. Eubank, "PVT Surface and Thermodynamic Properties of Neopen- tane," J. Chem. Eng. Data, 22, 1 (1977a) 8. Das, T. R., C. O. Reed, Jr., and P. T. Eubank, "PVT Surface and Thermodynamic Properties of n-Pen- tane," J. Chem. Eng. Data, 22, 3 (1977b) 9. Adachi, Y., "Generalization of Soave's Direct Method to Calculate Pure-Compound Vapor Pressures Through Cubic Equations of State," Fluid Phase Equilibria, 35 (1987) 10. Soave, G., "Improvement of the van der Waals Equa- tion of State," Chem. Eng. Sci., 39, 357 (1984) 11. Soave, G., "Direct Calculation of Pure-Compound Vapour Pressures Through Cubic Equations of State," Fluid Phase Equilibria, 31, 203 (1986) 0 book reviews TRANSPORT PHENOMENA IN TURBULENT FLOWS: Theory, Experiment, and Numerical Simulation M. Hirata, N. Kasagi, Editors Hemisphere Publishing Corp., New York; 921 pages,$150 (1988)

Reviewed by
Robert S. Brodkey
Ohio State University

About one hundred fifty authors have contributed
fifty-six general papers and eight keynote addresses to
the 2nd International Symposium on Transport Phe-
nomena in Turbulent Flows, held at the University of
Tokyo in October, 1987. Over one hundred ten extended
abstracts were submitted; thus the volume represents a
selection of half of those submitted. The volume (921
pages) was delivered to me for review in less than a year
from the date of the symposium; a positive note for the
editors, Hirata and Kasagi, and for the publisher, Hemi-
sphere. The copy-ready text varies from papers that are
as good as a press-printed journal article to those of poor
quality that require the reader to guess at what was in-
tended. One would hope that in the future these few

authors could obtain new equipment like a laser printer,
or at least a new ribbon. There are quite a few minor ty-
pographical errors that might have been eliminated by
better proofreading by the authors. Neither the editors
nor the publisher are responsible for this.
It was not clear if any of the discussion (not in-
cluded) at the meeting was incorporated into the papers
as they appeared. There is a brief note included that was
an outgrowth of a discussion that arose at the meeting.
The editors grouped the contributions into nine sec-
tions: fundamentals (5 papers), coherent structures (10),
wall shear flow (7), free shear flow (7), scalar and buoy-
ant transport (5), modeling and prediction of turbulent
transport (9), numerical simulations of turbulence (4),
measurement techniques (6), and turbulent transport in
applications (4).
The eight keynote papers are all noteworthy and are:
1) Coherent Structures Associated with Turbulent Trans-
port, by Blackwelder, 2) The Organized Motion and Its
Contribution to Transport in Shear Flows, by Antonia, 3)
Turbulence Management in Free Shear Flows by Control
of Coherent Structures, by Husian, Bridges, and Hussain,
4) Turbulent Transfer to a Wall at Larger Schmidt Num-
bers, by Hanratty and Vassiliadou, 5) Natural Convection
Mass Transfer in an Inclined Enclosure at High Rayleigh
Number, by Goldstein, Chiang, and Sayer, 6) Recent Re-
sults in the Prediction of Turbulent Separated Flows, by
Pletcher, 7) Advances in Turbulent Transport Modeling
Based on Direct Simulations of Turbulence, by Reynolds,
Rogers, and Sandham, and 8) Investigation of Heat and
Momentum Transport in Turbulent Flows Via Numerical
Simulations, by Kim.
The topics cover the broad areas of turbulent trans-
port research and thus will find limited use by any one
individual. Certainly, institutions that have research in-
terests and programs in the areas will want the volume
for library use. About 20% of the contributions are on a
variety of fundamentals and the remainder on a wide
range of applied problems that involve coupled phenom-
ena and/or a complex geometry. There is a clear increase
in the use of computers in experimental and numerical
investigations of turbulent flows. The use of large data
bases generated on supercomputers is evident.
In the time and space available for this review it was
impossible to read all the contributions in detail. Thus, I
have concentrated on the keynote lectures and those con-
tributions in the fields that I have worked in. The more
senior and well-known authors did speculate on ideas
that are neither proven nor necessarily shared by others.
They did this honestly, and their efforts are appreciated
by this reviewer. Many of the contributions are complete
to a degree that they could be considered for publication
in the best peer-reviewed journals. There are also papers
that are incomplete in their background review and in
their understanding of principles. These would not re-
ceive consideration for journal publication in their pres-
ent state.
Continued on page 181.

SUMMER 1989

curriculum

DYNAMIC BEHAVIOUR OF CATALYTIC REACTIONS

K. KLUSACEK*, R. R. HUDGINS,
and P. L. SILVESTON
University of Waterloo

BY THE TIME students take their first reaction
engineering course, they have usually become
very familiar with triangular diagrams. These are
often introduced in the first or second year
stoichiometry courses and are a part of physical
chemistry and most engineering thermodynamics
courses.
Triangular diagrams turn out to be quite useful in
illustrating the dynamic behaviour of heterogeneous
catalytic reactors. Thus, there is a good case for intro-
ducing them into an undergraduate chemical reaction
engineering course.
triangular diagram can aid in presenting some of the
rather complex transient interactions that occur
among gas and surface species during heterogeneous
catalytic reactions. To avoid undue complexity, we as-
sume a catalyst bed in which there are no limitations
of transport either in or around the catalyst particles.
Both CSTR's and differential reactors are described
by identical equations for a gradientless system in the
following derivation so what follows applies to both
reactor types.
In chemical reaction engineering, triangular dia-
grams are used to represent selectivity in complex
reactions. Wei and Prater [1] seem to have pioneered
their use to illustrate the course of a complex
homogeneous reaction sequence. States of the system
rather than time appear in triangular diagrams. Occa-
sionally, these diagrams have appeared in textbooks
[2, 3], but usually in conjunction with an example. We
have not seen their use for heterogeneous catalytic
The triangular diagram is helpful for showing the

*Institute of Chemical Process Fundamentals. Czechoslovak
Academy of Sciences, 165 02 Prague 6, Czechoslovakia

progress of the reaction both in the gas phase and on
the catalyst surface. It provides a wealth of informa-
tion that is hard to present otherwise.

BASIC EQUATIONS
Figure 1 is a schematic diagram of a reactor with
an ideally mixed gas phase. Let us suppose that in the
reactor k gaseous components Ai (i = 1,...,k) are pres-
ent with molar concentrations c, (mol/mL) at the reac-
tor inlet and ci at the reactor outlet (equal to the con-
centrations inside the reactor). Components A (j =
k+ ,...,n) are adsorbed on the catalyst surface with
molar concentrations cj (mol/geat).
The reactor has a gas phase volume V (mL) and

Karel Klusacek is a senior scientist at
the Institute of Chemical Process Funda-
mentals in Prague, Czechoslovakia. He has
degrees from the Technical University in
Prague and from the Czechoslovak
Academy of Sciences. His research fo-
cuses on the dynamics of catalytic reactors
and bioreactors, and regeneration of
industrial catalysts.

Bob Hudgins is a professor of chemi-
cal engineering at the University of Water-
loo, Canada, and holds degrees from the
University of Toronto and Princeton Uni-
versity. He teaches reaction engineering,
staged operations, and laboratories that go
with them. His research interests lie in peri-
odic operation of catalytic reactors and in
the improvement of gravity clarifiers.

P. L. Silveston has been a the Uni-
versity of Waterloo since 1963. Originally
from the U.S. he was educated at M.I.T. and
the Technical University of Munich (West
Germany). His teaching activities have been
in reactor engineering, thermodynamics,
engineering economics, process design,
and entrepreneurship. Research interests
are in the cyclic forcing of chemical reactor
and coal carbonization and gasification.
E Division ASEE 1989

CHEMICAL ENGINEERING EDUCATION

Ch3

REACTOR

Gas Phase (V)
Ai, i

Catalyst (W)
Aj cj

- Ci,-

FIGURE 1. Reactor scheme

contains a stationary catalyst bed of weight W (g), the
whole reactor system being maintained at constant
temperature and pressure. The reaction mixture is
introduced into the reactor with the inlet space veloc-
ity ~o (s-1), defined as the ratio of the volumetric flow
rate and reactor volume, and leaves the reactor with
the outlet space velocity c. Generally ua ao because
the total number of moles may be changed by the reac-
and/or desorption processes. Mass balances on the
reaction components in the fluid phase of the reactor
give k differential equations

dct

aci + ;

i = 1,...,k (1)

where Ri (mol/gcat'S) is the rate of formation of any
gaseous component Ai (i= 1,...,k) and t(s) is time.
Similarly, for the components on the catalyst surface,
we have

dtc =Rj
_dtJ R R ;

j=k+l,...,n

Concentrations in the reactor fluid
total molar concentration, CT (mol/mI
the surface and any free sites sum to
tration of the active sites (assumed
the catalyst surface, cL(mol/gcat). Th
Eqs. (1) and (2) is complemented by
tions, for the n species. The mass b
may be recast in dimensionless form

I a -Cai + Pi

phase sum to the
L), while those on
the total concen-
constant here) on

C ,0- --

e set of n balance The solution of the model for initial conditions gives
the initial condi- the time profiles of concentrations in the reactor gas
balance equations phase as well as on the catalyst surface either for
as follows steady state or during transient operation of the reac-
tor. What triangular diagrams show may be seen from
i= 1,...,k (3) the following example.

NUMERICAL EXAMPLE

daj
dz)= P j;

j= k + 1,...,n

Dimensionless variables used in Eqs. (3) and (4) are

Kinetic model
Consider a simple irreversible heterogeneous
catalytic reaction between gaseous components A and

SUMMER 1989

Triangular diagrams turn out to be quite
useful in illustrating the dynamic behaviour of
heterogeneous catalytic reactors. Thus, there is a good
case for introducing them into an undergraduate
chemical reaction engineering course.

TABLE 1
Dimensionless Variables

Variable Definition

dimensionless bulk concen-
tration at the reactor inlet aiO= cio/cT; i = 1,...,k

dimensionless bulk concen-
tration in the reactor ai = ci/cT; i = 1,...,k

dimensionless concentration
on the catalyst surface aj = cj/cL; j = k+l,...n

dimensionless time = too

dimensionless rate of forma-
tion of gaseous component Ai pi = Ri/(cLaO); i = 1,...k

dimensionless rate of forma-
tion of surface component A. pj = R./(CLo0); j = k+l,...,n

capacity factor = WcL/(VcT)
(molar capacity of catalyst
surface/molar capacity of
fluid phase)

summarized in Table 1. The material balances, Eq.
(3), contain the space velocity at the reactor outlet, a,
which can be determined only with difficulty. This
quantity can be expressed as the function of the space
velocity at the reactor inlet, cr, by summing the k
equations [Eq. (3)] and noting that the summation of
derivatives must equal to zero. After rearrangement
k
0= o l+<( Pi (5)
i=l

B forming gaseous product C proceeding via the fol-
lowing elementary steps

A+S A S

k2
B+ S B- B- S

(surface reaction)
A.S+B C+S
S+ B. S LC+ 2S

(6a)

(6b)

(6c)

Forward and reverse reaction rate constants are
denoted as ki and kl, respectively. Gaseous compo-
nents are represented as
A=A ; B-A2; C-A3

and for components on the catalyst surface

A-.SA4; B.S=A5; S-A6

The dimensionless rates of formation of individual
components are given in Table 2, while the dimension-
less rate constants with numerical values are shown
in Table 3.
Defining the normalized rate of product formation,
p, as the ratio of actual to maximum possible rates,
p3, where the maximum possible rate of product for-
mation, p3,max, is attained for a4 = a5 = 0.5,

a4a5 a4a5
P(a4 a5) (5)(Q5) 4a4a (7)
max

The material balance [Eqs. (3) and (4)] for k = 3
and n = 6 can then be used to simulate steady-state
and transient behaviour of the A + B -> C catalytic
reaction in a CSTR. The values of the parameters used
for numerical calculations are as follows: W = 5 g, V =
10 mL, CT = 2.437 x 10-5 mol/mL, CL = 1.0 x 10-4
mol/g. The dimensionless rate constants Ki (i = 1, 2,
3) and Kj (j = 1,2) are dependent on the space velocity
&O (see Table 3). Thus, numerical values of rate con-
stants in Table 3 correspond to the space velocity, o
= 1.0 s-1. The value of the total molar concentration,
CT, follows from its definition, CT = P/(RT), for P =
101.3 kPa and T = 500 K.

terms) on the left side of Eqs. (3) and (4) are equal to
zero, reducing the set of coupled differential equations

TABLE 2
Dimensionless rates of Formation

Rate Defrnmon

P, Klala6+ K'a

P2 K2a2 a6 + K2a5
P3 K3 a4a5
P4 -(P + P)
Ps (P2 + P3)
6 (P4 + P5)

TABLE 3
Dimensionless Rate Constants

Costant Definition Numerical Value

K1 (CT/a0)k1 1.00

K' (1/a0) k 0.05
1 1
K2 (CT/O0)k2 0.30
K2 (1/ao) k'2 10
K3 (CL/0)k3 010

4

3

A9
A 2

FIGURE 2. Steady-state gas concentrations in the
reactor for different feed compositions, a10 / a20

(I) 0.9/0.1
(4) 0.6/0.4
(7) 0.3/0.7

(2) 0.8/0.2
(5) 0.5/0.5
(8) 0.2/0.8

(3) 0.7/0.3
(6) 0.4/0.6
(9) 0.1/0.9

CHEMICAL ENGINEERING EDUCATION

to algebraic ones. Because of the nonlinearity result-
ing from the reaction rate expressions the system has
to be solved numerically (see for example, Ralston
[4]).
Figure 2 shows typical results for the bulk phase
of the reactor for different feed composition ratios al/
aq. For example, let us suppose that the reaction mix-
ture at the reactor inlet has the stoichiometric compo-
sition a? = a4 = 0.5 (no product A3 is present). This
composition corresponds to the point P1 on the dia-
gram. Depending on the space velocity, cr, used, the
composition of the gaseous phase in the reactor will
move along the line P1A3. For example, for To = 0.03
s-1, the steady-state composition of the reactor gas
phase is given by the point P2 (a1 = 0.22, a2 = 0.22,
a3 = 0.56).
The smaller a. is the closer to the point A3 the
resulting composition will be. For infinitesimal aO, full
conversion of reaction components will be attained and
only pure product A3 will be present in the reactor.
For non-stoichiometric inlet compositions, the result-
ing reaction mixture will always contain unreacted
components A1 and/or A2 as is shown in Figure 2. The
location of the composition point will again depend on
the space velocity used.
Figure 3 gives the catalyst surface concentrations
corresponding to the gas-phase concentrations in Fig-
ure 2. The asymmetry of Figure 3 is striking and is a
direct result of the fact that A1 is more strongly ad-

1 ,

A v4 i / -' \b \c \d
J_ \ \ \
44 5 5
FIGURE 3. Steady-state surface concentration for
different feed compositions, a10 / a20
(1) 0.9/0.1 (2) 0.8/0.2 (3) 0.7/0.3
(4) 0.6/0.4 (5) 0.5/0.5 (6) 0.4/0.6
(7) 0.3/0.7 (8) 0.2/0.8 (9) 0.1/0.9
Lines of constant normalised rate, p (dashed lines):
(a) p =0.8 (b) p =0.6 (c) p = 0.4 (d) p = 0.2

sorbed on the catalyst than A2 (cf. values of rate con-
stants in Table 3).
As in Figure 2 the steady-state combination of the
surface concentrations depends on the space velocity.
The origins of the surface concentration lines have
been calculated for a very high space velocity (aO = 1
x 106 s-1) for which the composition of the reaction
mixture leaving the reactor is essentially the feed
composition (zero conversion). The feed composition
ratios lying along axis A1A2 in Figure 2 do not corres-
pond to the axis A4A5 in Figure 3. Instead, they cor-
respond to surface concentrations along a curve
formed by joining the lowest points in lines 1 to 9.
This curve then accounts for the number of unoccupied
catalyst sites (A6) which varies with the feed composi-
tion. For example, the surface concentrations for the
fluid-phase composition, given by the point P1 (at =
a = a -= a2 = 0.5) in Figure 2, is denoted as Pi in
Figure 3 (a4 = 0.82, a5 = 0.08). The gas phase concen-
tration given by the point P2 in Figure 2 corresponds
to point PA in Figure 3. For stoichiometric feed, the
composition on the catalyst surface will follow line 5
in Figure 3, finally attaining the vertex A6. This point
corresponds to the total conversion of both reaction
components A1 and A2 (product A3 is not adsorbed).
The normalized steady-state rate p (Eq. 7) is pro-
portional to the product of surface concentrations a4
and a,. The dashed curves in Figure 3 are lines of
normalized rate p = 4a4a5. The highest value of p
occurs at point B (a4 = a5 = 0.5; p = 1); and p de-
creases with increasing distance from B (i.e., with in-
creasing space velocity). The curves depicted in Fi-
gure 4 for two different feed compositions are typical

0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0
log o-(-)
FIGURE 4. Steady-state normalized rates, p, for
different space velocities, o and two feed
compositions, a10 / a20, corresponding to line 5 in
Figure 3 and line 8 in Figure 3.

SUMMER 1989

p(-)

S(-)

S(a) (b)
0 .0 i i i i i i I i ,
0 10 20 30 40 50 60 70 80
r (-)

FIGURE 5. Transient of normalized rate, p, after step-
change of feed composition a10 / a20
(a) a80/a20 = 0.5/0.5 -step-change- a0/820 = 0.2/0.8
(b) a10/a20 = 0.2/0.8 --step-change-- a0/a20 = 0.5/0.5

Transient Reactor Behaviour
In general, a catalytic reactor seldom operates
under ideal steady-state conditions. Small random
fluctuations of the system variables (e.g., tempera-
ture, pressure, space velocity, and composition) and
changes in the catalyst activity are common. Another
kind of transient reactor behaviour occurs after the
forced change of either feed composition or reactor
temperature. Analysis of forced transient reactor be-
haviour can furnish mechanistic information (such as
the surface populations during reaction) that cannot
In the following example, a step-change of the feed
composition is used. The dynamic operation of the
reactor can be predicted by the numerical integration
of balance Eqs. (3) and (4).
The normalized transient rate, p, after a step-
change in the feed composition is shown in Figures 5a
and 5b. The reactor is initially at steady-state with
feed composition ao = a4 = 0.5, and space velocity &o
= 0.03 s-1. At time zero, the feed composition is step-
ped to a- = 0.2, a4 = 0.8 while o& remains unchanged.
After the period 7 = 40, the original feed composition
(a? = a4 = 0.5) is restored. The effect of switching
the feed composition can be seen in Figure 5a. An
overshoot in p occurs immediately after the step-
change of input. The maximum is reached at T = 2.
Figure 6 illustrates the changes occurring on the
catalyst surface for the cycle given in Figure 5, and
explains the overshoot. The value of p is proportional
to a4 x a5. The starting point P', being low in compo-

nent A5 on the catalyst surface, is not conducive to a
high rate of product A3 formation. Immediately after
the feed step-change, the value of a4 suddenly de-
creases as a result of the low concentration of A1 in
the feed (ao = 0.2). Thus the surface concentration of
A5 increases and moves towards the region of higher
p. The direction of the movement of the surface con-
centration is illustrated by the arrows in Figure 6.
These surface changes lead immediately to a reduced
surface coverage (As = free centers) and a higher
value of the rate (p = a4a5). For dimensionless time 7
> 2, the surface concentration a4 becomes small and
the rate p decreases. At T = 40, the catalyst reactor
reaches a new steady-state (point P') and at this time
the feed composition is stepped back to the original
value (ao = a2 = 0.5). The processes on the catalyst
surface are represented by the closed trajectory re-
turning from point P' to Pi. At time T = 80, the sys-
tem resumes its original steady-state (point P').
Figure 6 thus illustrates that the surface, passing
between two separate steady states, does not follow
the same path. Instead, the path depends on the direc-
tion of the change in feed composition.

CLASSROOM USE
Figures 2 and 3 illustrate the importance of the
adsorption equilibrium coefficient. For the param-
eters used it can be seen that the compositions of the
adsorbate phase and the fluid phase are very differ-
ent. In a similar fashion, as the composition of the
feed varies from A, to A2 in Figure 2, the surface
composition does not move along the axis A4A5 in
A6

Pmox in Fig 5b

PmaA in Fig. 50

p / \ d \
"/ // "" \ \

.b

A4 As

FIGURE 6. Transient of surface concentrations after
step-change of feed composition as in Figure 5. Lines
of constant normalized rate, p (dashed lines);
(a) p =0.8 (b) p =0.6 (c) p =0.4 (d) p = 0.2

CHEMICAL ENGINEERING EDUCATION

Figure 3; instead, it follows a curved path given by
the locus of the lowest points of the numbered lines in
Figure 3 as discussed above.
Normally students conceive of reactions in terms
of the microreversibility theorem and would assume
that the reverse path following a reversal of the step-
change would be the same as the forward path. Fig-
ures 5 and 6 show that this is not the case. Thus.
microreversibility is inappropriate for describing sur-
face concentrations in this and similar systems.
An exercise that students will find interesting is
to calculate the surface composition for a non-reaction
system and a reacting one even if the rate constants
are very small. Will these compositions be identical?
CONCLUSIONS
Triangular diagrams are useful for teaching
steady-state and transient reactor behaviour of cataly-
tic reaction models. Concentrations of surface species,
not normally measurable, are particularly easy to re-
veal and to use to suggest interpretations of transient
operation. Similar calculations can, of course, be per-
formed for catalytic reactions with arbitrary
mechanisms. In the example presented, the transient
reactor behaviour was excited by the step-change of
feed composition. Other types of steady-state feed dis-
turbances (e.g., sine, ramp, etc.) can be used after
proper formulation of the initial conditions.
For systems having more than three components.
appropriate subsystems of variables may be chosen.
The main advantage of the triangular diagram lies in
its power to compress into understandable form a
great deal of information about the progress of gas
and surface species in catalytic reaction. The FOR-
TRAN programs used in this study are available from
the authors.
ACKNOWLEDGEMENTS

The authors are grateful for support through the
Natural Sciences and Engineering Research Council
of Canada in the form of an International Scientific
Exchange Award (to K.K.) and an operating grant (to
R.R.H.).
REFERENCES
1. Wei, J., and C. D. Prater, "The Structure and Analysis
of Complex Reaction Systems," Advances in Catalysis,
13, Academic Press, New York (1965)
2. Westerterp, K. R., W.P.M. van Swaaij, and A.A.C.M.
Beenackers, Chemical Reactor Design and Operation,
John Wiley & Sons, New York (1983)
3. Fogler, H.S., Elements of Chemical Reaction
Engineering, Prentice-Hall, Englewood Cliffs, NJ
(1986)
4. Ralston, A., A First Course in Numerical Analysis,
McGraw-Hill, New York (1965) 0

REVIEW: Transport Phenomena
Continued from page 175.
I would like to single out a few papers that are worth
extended attention. The keynote lectures all fall into this
class, although their coverage varies considerably. They
do provide the reader a wealth of information gathered
by the authors. In addition, on coherent structures,
Blackwelder's short post-conference note is noteworthy.
Criminal's contribution offers new insight. Other note-
worthy contributions are by Walker and Herzog, and
Nishino, et al. On wall shear flows, the contributions by
Nagano and Tagawa, Usui and Sano, and Ueda et al.,
should receive more than casual consideration. On free
shear flows, I enjoyed reading contributions by Tabatabai
et al., Stapountzis, and Kobayashi et al. Since I have a
special interest in scalar transport, I read all of these. My
knowledge of modeling details is more limited; these pa-
pers appear to be of interest to one involved in transport
modeling, a necessity in our modern engineering society.
The numerical simulations of turbulence and transport is
a new and budding field; thus contributions rapidly be-
come dated. The two keynote lectures form a good start-
ing place, and the general contributions add to them.
Measuring techniques are varied and should receive the
researcher's careful attention. The ideas advanced by
Bawirzanski et al., Ciccone et al., Akino et al., and
Hardalupas et al., are all worthwhile contributions. i

BUOYANCY-INDUCED FLOWS AND
TRANSPORT
by Benjamin Gebhart, Yogesh Jaluria, Roop L. Mahajan,
and Bahgat Sammakia
Hemisphere Publishing Corp., 79 Madison Ave., New
York, NY 10016; 1001 pages, $95 (cloth); 971 pages,$49
(paperback); 1988

Reviewed by
J. S. Vrentas
The Pennsylvania State University

With seventeen chapters and more than nine hun-
dred pages, this book deals with a wide range of
buoyancy-induced flow problems. The analysis of steady
and unsteady laminar external flows driven by both
thermal and concentration effects is the focus of the first
third of the book. Fluid property variations, turbulence,
mixed convection, non-Newtonian effects, and the char-
acteristics of instabilities are considered in subsequent
chapters. Buoyancy-driven motions in fluid layers and in
enclosures as well as natural convection in porous media
are also discussed. Since problems are presented at the
end of each chapter, this book can be used not only as a
reference source but also as a textbook for a graduate
specialty course. A significant part of the book could be
covered in a one-semester course at the graduate level.
The authors present their analysis from an engi-
Continued on page 193.

SUMMER 1989

SEKI

laboratory

BIOTECHNOLOGY LABORATORY METHODS

ROBERT H. DAVIS and
DHINAKAR S. KOMPALA
Boulder, CO 80309-0424

THE PAST TWO DECADES have seen tremendous
growth and interest in biotechnology. As a result
of recent advances in molecular biology and genetics,
many new pharmaceutical, chemical, and agricultural
products of microorganisms and cultured plant, ani-
mal, and insect cells are now available, or soon will
be. The successful industrial-scale manufacture of
these products will, in large part, depend upon new
engineering initiatives in the development of high-rate
bioreactors, efficient separation and purification tech-
niques for bioproducts, and computer-interfaced in-
strumentation for optimal bioprocess control. These
needs represent a major challenge to chemical en-
gineering education-a challenge to provide students
with appropriate training in both engineering and biol-
ogy.
In order to help meet this challenge, many if not
most chemical engineering departments now offer one
or more elective courses in biochemical engineering,
such as the course described by Bailey and Ollis [1].
In addition, interested students are encouraged to
take technical electives from other departments in
areas such as biochemistry, microbiology, and molecu-
lar biology. However, relatively few opportunities
exist for these students to obtain direct laboratory
experience in biotechnology methods, most likely be-
cause of the cost and effort associated with developing
such opportunities. An exception is the biochemical
engineering laboratory course described recently by
Ng et al. [2]. At the University of Colorado, we have
developed a course entitled "Biotechnology Labora-

At the University of Colorado we have
developed a course ... which introduces the students to
a variety of laboratory methods associated
with biotechnology and yet which has
required only limited resources.

Robert H. Davis is an associate pro-
fessor in chemical engineering at the Uni-
versity of Colorado. After receiving his doc-
toral degree from Stanford University in
1983, he was a NATO Postdoctoral Fellow
in the Department of Applied Mathematics
and Theoretical Physics at the University of
Cambridge. His research interests lie in the
area of fluid mechanics of suspensions, in-
cluding microbial suspensions.

Dhinakar S. Kompala is an assistant
professor of chemical engineering at the
BTech (1979) from the Indian Institute of
Technology, Madras, and his MS (1982)
and PhD (1984) from Purdue University.
His current research interests are in
fermentation of recombinant bacterial,
mycelial and hybridoma cells, and in affinity
separations of proteins and cells.

tory" which introduces the students to a variety of
laboratory methods associated with biotechnology and
yet which has required only limited resources.

HISTORY OF THE COURSE
In the spring semester of 1984, our department
initiated a lecture course entitled "Recent Advances
in Biotechnology" [3]. This course, which is open to
seniors and graduate students in both engineering and
science, exposes the students to the many facets of
biotechnology, including microbiology, molecular biol-
ogy, biochemistry, biochemical engineering, and in-
dustrial applications. Guest lectures are given by fac-
ulty members from several disciplines and by local
industry representatives. After our initial offering of
this course, however, it became apparent that a labo-
ratory component was an important missing ingre-
dient.
In October of 1984, the five officers of our under-
graduate Biomedical Engineering Society sent a
memo to our then department chairman, Max Peters,
stating:

At a recent BMES meeting, we discussed the possibility
of the Chemical Engineering Department offering a "hands
on" laboratory course for students who are planning careers
in the biotechnology area. Although other departments offer

CHEMICAL ENGINEERING EDUCATION

laboratory courses in the bio area, there are no courses pres-
ently given that would fit the needs of an engineering student
wishing to pursue a career in biotechnology.
We would like to suggest that the Department of Chemical
Engineering offer a one hour credit optional laboratory
course for students taking ChE 580, Recent Advances in
Biotechnology ...

In response to this request, Professors Robert
Davis and Igor Gamow introduced a one credit hour
course, "Biotechnology Laboratory," in the spring
semester of 1985. The initial course offering was taken
cluded experiments in microbiology, fermentation,
genetic engineering, and ultrafiltration. With the aid
of the latest addition to our faculty, Dhinakar Kom-
pala, the course has been expanded to two credit
hours. This expansion has led to a modest but welcome
reduction in the class size. Unlike the associated lec-
ture course, this laboratory course has been taken al-
most exclusively by chemical engineers. It is com-
posed of graduating seniors who plan to attend
graduate school or to work as biochemical engineers,
and of graduate students who have chosen research
projects in the biotechnology area.

COURSE CONTENT AND PHILOSOPHY
Experiments in biotechnology often require
sophisticated equipment and can be quite expensive
to undertake, and yet we were charged by our chair-
man to spend "a few thousand dollars at most" in de-
veloping this new laboratory course. Fortunately, we
have been able to develop an effective course with
available equipment in our undergraduate laboratory,
borrowing of speciality items from our research
laboratories, government surplus equipment, and a
minimum of new purchases.
During the last few years, several new experi-
ments have been introduced, and the original experi-

TABLE 1
List of Experiments
MICROBIOLOGY AND MOLECULAR BIOLOGY
Recombinant Bacterial Growth and Instability
Recombinant DNA and Molecular Cloning
KINETICS AND FERMENTATION
Enzyme Kinetic Measurements
Mass Transfer Coefficients in a Stirred Fermentor
Yeast Growth Kinetics and Fermentation
DOWNSTREAM PROCESSING-BIOSEPARATIONS
Microfiltration and Ultrafiltration
Column Chromatography

S. we have been able to develop an
effective course with available equipment in our
undergraduate laboratory, borrowing of speciality items
from our research laboratories, government surplus
equipment, and a minimum of new purchases.

ments have evolved with time. Our current repertoire
of seven experiments is given in Table 1. Each year,
typically four or five of these experiments are offered.
Our philosophy is to choose the experiments to cover
a spectrum of the subfields of biotechnology: micro-
biology, molecular biology, enzymology, microbial
kinetics, biochemical reactor design, and biosepara-
tions. A specific goal is to introduce the students to
important laboratory methods such as sterile tech-
niques, phenotype identification, fermentation,culture
monitoring, electrophoresis, chromatography, ul-
trafiltration and microfiltration.
In order to maintain our original objective of pro-
viding each student with hands on experience in
biotechnology, the experiments are performed by
teams limited to four or five students. Since most of
the tasks, such as plating cultures and taking and
analyzing samples, are repeated many times during
the course of an experiment, this requires that all of
the students participate fully. The students receive
grades based upon their participation and the brief
reports which they prepare on the experiments.
Because of the diversity of experiments and
methods involved, we have drawn on expertise out-
side of our department to assist with the experiments.
Ray Fall from the Chemistry and Biochemistry De-
partment at the University of Colorado has assisted
with the recombinant DNA and molecular cloning ex-
periments, Dale Gyure from Coors Biotech Products
Company has assisted with the mass transfer and fil-
tration experiments, and Geoff Slaff from Synergen
has assisted with the chromatography experiments.

EXPERIMENT SUMMARIES
Recombinant Bacterial Growth and Instability
The excitement and interest in modern biotechnol-
ogy are primarily generated by the ability to produce
foreign proteins through recombinant DNA technol-
ogy. To familiarize our students with some charac-
teristics associated with the cultures of recombinant
organisms, we have designed this experiment involv-
ing simple shake flask batch cultures of recombinant
bacteria E. coli (RR1/pBR322). The equipment items
required are a spectrometer (visible range) and a

SUMMER 1989

water bath shaker (see Table 2 for a list of our source
and estimated new purchase price for each item). The
materials required include shake flasks, petri dishes,
media, culture stocks, pipets, and antibiotics (total es-
timated cost of $50 per experiment). Three shake flasks are prepared with appropriate media to culture the following: (i) plasmid-free host cells in M9 minimal medium (see Maniatis et al. [4] for media recipes); (ii) plasmid-bearing cells in M9 medium plus tetracycline, and (iii) plasmid-bearing cells in M9 medium with no antibiotics. By measuring optical density at regular intervals and plotting it ver- sus time on a semi-log graph for the first two cultures, we determine V- and p+, the specific growth rates of plasmid-free and plasmid-bearing cells, respectively. For the third flask containing recombinant cells with no antibiotics, the fraction of cells containing the plas- mids is also determined at two and five hours by plat- ing the cells, after serial dilutions, on a petri dish con- taining a rich medium such as LB, and then replicating the grown colonies onto a dish with LB medium plus ampicillin, using a sterile nylon pad. The phenomenon of 'segregational instability' becomes obvious as the fraction of plasmid-carrying cells drops dramatically. Further, with all the measurements made here, plus the simple mathematic model proposed by Imanaka and Aiba [5] for the dynamics of these cultures, it is possible to estimate the average plasmid copy number for this host/plasmid system. Recombinant DNA and Molecular Cloning This experiment is designed to familiarize the stu- dents with some of the basic recombinant DNA methods such as bacterial transformation with extra- chromosomal DNA, testing for gene expression, and restriction enzyme analysis. The equipment items re- quired are a microcentrifuge, a small refrigerator, an incubator oven, and an electrophoresis unit. The ma- terials required include culture stocks, media, plasmid stocks, petri dishes, restriction enzymes, pipets, anti- biotics, microfuge tubes, and molecular weight mark- ers (total estimated cost of$75 per experiment).
In the first part of the experiment, E. coli HB101
cells are grown in a rich liquid medium, centrifuged,
chilled, and subjected to calcium chloride shock, ac-
cording to the detailed protocol by Maniatis et al. [4],
to make them 'competent' for taking up plasmid DNA.
About 5 .LL of pBR322 plasmid DNA at a concentra-
tion of 0.1 g/l is added to cold culture tubes containing
100 VLL of competent cells. After incubating for 30 min
at 4C, the tubes are kept at 42C for 2 min and then
incubated at 37C for 30 min with addition of 1 ml of

ITEM

SOURCE

Spectrometer
Water Bath Shaker
Microcentrifuge
Electrophoresis Unit
Refrigerator
Incubator Oven
Fermentor
Oxygen Electrode
Chart Recorder
Microscope
Plate-and-Frame Filter
Hollow-Fiber Filter
Peristaltic Pump
Ultrafiltration Cell
Magnetic Stirrer
UV-vis Spectrophometer
Chromatography Col.

EST.
PUR. PRICE

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$800 800 1,300 800 200 200 12,000 300 800 500 1,500 600 400 150 150 7,000 200 LB medium. Finally, these cells are plated on culture plates with and without ampicillin or tetracycline to determine the transformation efficiency, since the pBR322 plasmid contains genes that render the trans- formed cells resistant to these antibiotics. In the second part of this experiment, two plas- mids, pBR322 and pSY426, a poorly characterized re- combinant plasmid derived from pBR322 and contain- ing an extra piece of DNA encoding for p-glucosidase, are digested with the restriction endonucleases Eco RI, Sal I and Bam HI in single, double, and triple digests. These digests are loaded and run on agarose gel electrophorsis units, along with known molecular weight markers. From the size of fragments on the gel and the known map of pBR322, a partial restric- tion map of pSY426 is then constructed. Enzyme Kinetic Measurements This experiment is designed to study the effects of competitive and non-competitive inhibitions, sub- strate and enzyme concentrations, thermal denatura- tion and pH on enzyme activity. The enzymes used are urease and amylase. These enzymes, their sub- strates, buffers, and other supplies may be obtained as an experimental enzymology kit from Carolina Biological Supply Company (estimated cost of$50 per
experiment). A detailed laboratory procedure manual

CHEMICAL ENGINEERING EDUCATION

TABLE 2
Major Equipment Needed

is supplied along with these materials, which we mod-
ified slightly to provide a more quantitative study of
each effect.
Urease is used to study the effect of inhibitions
and concentrations. Mixtures of urea and thiourea at
four different relative concentrations are used to
measure the effect of competitive inhibition. Potas-
sium iodide is used to demonstrate non-competitive
inhibition. The enzymatic reaction is conducted in one-
half of a divided circular dish, supplied by the vendor.
Gaseous ammonia produced by the reaction diffuses
to the other half of the dish and changes an acidic dye
solution to a basic solution with a change in color. The
same reaction may also be conducted in the presence
of the dye solution in either a test tube or a small
shake flask. The time of reaction before the color
change is noted and used as a quick measure of the
inverse of enzymatic activity. Similarly, the enzymatic
activity for different substrate and enzyme concentra-
tions are measured. The effects of pH and thermal
denaturation are measured on the amylase activity
using iodine-potassium iodide drops to indicate the

Mass Transfer in a Stirred Fermentor
One of the most important control variables in an
aerobic fermentation is the dissolved oxygen concen-
tration. The purpose of this experiment is to deter-
mine the effects of aeration and agitation on the rate
of oxygen mass transfer from air bubbles to the fer-
mentation medium, as quantified by the so-called k1a
value [5]. The required equipment items for this exer-
cise are a stirred vessel with an air supply (we used
the fermentor described in the next experiment, al-
a gallon jar and a motorized stirrer for about $200), a rotameter for gas flowrate, a dissolved oxygen elec- trode, and a strip chart recorder. In addition, a half- full nitrogen tank with a regulator is required (approx- imate cost of$15 per set of experiments).
The experimental procedure involves filling the
vessel to its working volume with water or fermenta-
tion broth and then saturating the liquid with air.
Once a steady electrode response is achieved, the air
flow is suddenly replaced by nitrogen flow, which then
strips the oxygen out of solution in a transient man-
ner. From the decay characteristics of the voltage re-
sponse of the probe, the corresponding kza value may
be inferred [6]. This procedure is then repeated for
each desired stir rate and gas flow rate. Conclusions
may then be drawn regarding the relative influence of
agitation and aeration in order to provide an adequate

dissolved oxygen supply for an actual fermentation.

Yeast Growth Kinetics and Fermentation
The goals of this experiment are to familiarize the
students with the various steps involved in a typical
fermentation run and to determine the fermentation
characteristics of baker's yeast growing on carbohy-
drates with and without air. For this experiment, we
have used an available twenty year old New
Brunswick Scientific's Labroferm fermentor, which
contains three 7-liter fermentation jars in a water
bath. However, the less expensive alternative of three

industry representatives have volunteered their
assistance, the faculty members have participated
in addition to their normal teaching responsibilities,
and the students have elected to take the course
above and beyond the normal requirements.

1-liter flasks on magnetic stirrers is equally appropri-
ate (estimated cost of $600). Other equipment items required for this experiment are a water-bath shaker, a spectrometer, and a microscope with a hemacytom- eter slide. Materials required include shake flasks, test tubes, pipets, media, baker's yeast, and enzyme assay kits (estimated cost of$30 per experiment).
During the first class period, a rich medium con-
taining yeast extract, malt extract, peptone, and glu-
cose is made in three 250 ml flasks and sterilized in an
autoclave. Using sterile techniques near a Bunsen
burner or in a laminar flow hood, a previously grown
inoculum is transferred into each of these flasks. The
flasks are placed in a water bath shaker and allowed
to grow overnight. Also using the previously cultured
cells at various dilutions, a calibration curve is de-
veloped between the optical density measured with a
spectrometer and the cell concentration measured
with a hemacytometer. The three fermentor jars are
filled with rich media and connected with tubing for
air inlet, outlet, and culture sampling devices. In one
of the jars, the 10 g/1 of glucose in the rich medium is
substituted with a mixture of glucose and fructose in
the ratio of 1:4; in a second jar, the air inlet tube is
clamped shut.
During the second class period, usually on a
weekend morning, the three fermentors are inocu-
lated with 100 ml of the cultures from the three small
flasks freshly grown overnight. Samples are with-
drawn every 30 min from each fermentor for measur-
ing optical density. The experiment is continued for
show no further increase. Occasionally, samples are

SUMMER 1989

also collected for determining glucose and ethanol con-
centrations through enzymatic assay kits. Analysis of
the data usually reveals a single growth phase in the
fermentor with no air inlet, two growth phases in the
fermentor with air and glucose as the only carbohy-
drate, and three growth phases with careful data collec-
tion in the other fermentor. Further analysis of the
data, with a semilog graph of cell concentration versus
time, will show identical specific growth rates during
the first growth phases corresponding to the glucose
fermentative pathway. The second and third growth
phases will show decreasing growth rates.

Microfiltration and Ultrafiltration
Downstream processing in order to recover and
purify a fermentation product from dilute solution
often represents the largest cost in a biotechnology
process. This experiment, which is carried out in two
separate parts, uses membrane filtration for cell and
protein separations. In the first part, the yeast cells
from the previous experiment are concentrated using
both a hollow-fiber and a plate-and-frame tangential-
flow microfilter. This requires the filters and hous-
ings, a peristaltic tubing pump, a 4-liter feed jar, a
pressure gauge, a graduated cylinder, and a stop
watch. The filter is operated in a batch concentration
configuration where the permeate is removed and the
retentate is recycled to the feed jar. The purpose is
to measure the decline in permeate flux due to fouling
of the membrane as the cell concentration in the feed
increases. Other process variables that may be
studied include the pressure drop across the mem-
brane and the flow rate at which the suspension is
circulated through the filter.
The second part of the experiment uses an ul-
trafiltration cell with an internal magnetic stir bar in
order to separate two proteins, lyzozyme (MW =
14,600) and bovine hemoglobin (MW = 64,000). A
polymeric membrane with a specified molecular
weight cutoff of 30,000 is used in the ultrafiltration
cell. The proteins and disposable membranes cost ap-
proximately $15 per experiment. The ultrafiltration is carried out at a constant transmembrane pressure drop (40 psig), and the permeate flux as a function of time is measured in order to determine the effects of membrane fouling and concentration polarization. Concentrations of the proteins in the initial sample and in the final filtrate and retentate are measured by UV-vis spectrophotometry (hemoglobin absorbs strongly at 400 nm and so may be measured in the visible range, whereas lyzozyme requires a measure- ment at 280 nm in the ultraviolet range). These meas- urements are then used to determine rejection coeffi- clients, which are important in scale-up calculations. Column Chromatography Column chromatography is the predominant technique used in industry for purifying biological compounds such as proteins, nucleic acids, and anti- biotics. The goal of this experiment is to expose the students to the fundamentals of chromatography, in general, and to the separation of proteins based on their relative sizes using gel filtration chromatog- raphy, in particular. Equipment items required for this lab are two plastic columns, a peristaltic tubing pump, and a UV spectrophotometer. The disposable materials include sephadex G-75 resin, two proteins of different molecular weight (we use cytochrome c with MW = 12,400 and ovalbumin with MW = 43,000), and blue dextran as a void volume indicator (estimated cost of$40 per experiment).
During the lab, the students pack the columns with
resin, load the columns with a mixture of the two pro-
teins and the indicator, run the columns to separate
the proteins, and collect frequent samples from the
eluent streams. Total protein concentration in each
sample is estimated by measuring the absorption in
the ultraviolet range with the UV spectrophotometer.
Two different sized columns are used to familiarize
the students with the problems associated with scale-
up. From the elution diagrams obtained, the students
determine important parameters such as the distribu-
tion coefficient for each protein, the standard devia-
tion of each of the elution peaks, and the resolution
between the two peaks representing the larger and
smaller proteins.

CONCLUDING REMARKS
The biotechnology laboratory course at the Uni-
versity of Colorado has been maintained, and indeed
has flourished, as a cooperative effort. The industry
representatives have volunteered their assistance, the
faculty members have participated in addition to their
normal teaching responsibilities, and the students
have elected to take the course above and beyond the
normal requirements. Because of time requirements,
the experiments have been carried out during evening
and weekend hours. Nevertheless, all involved feel
that it is a worthwhile effort.
Finally, we have not required a published labora-
tory manual, although several manuals describing
many of the general procedures used are available [4,
7-9]. Instead, we have prepared a handout for each of
the experiments. Single copies of a compilation of
these handouts may be obtained free of charge from
the authors.

CHEMICAL ENGINEERING EDUCATION

REFERENCES
1. Bailey, J. E., and D. F. Ollis, "A Course in Biochemical
Engineering Fundamentals (Revisited)," Chem. Eng. Ed. 19,
(4), 168-171 (1985)
2. Ng, T.K-L, J.F. Gonzalez, and W-S Hu, "A Course in
Biochemical Engineering," Chem Eng. Ed., 22, (4), 202-207
(1988)
3. Davis, R. H., and R. I. Gamow, "Bringing Biotechnology into
the Classroom," 1985 Frontiers in Education Conference
Proceedings, edited by J M. Biedenbach, 436-439 (1985)
4. Maniatis, T., E. F. Fritsch, and J. Sambrook, Molecular
Cloning: A Laboratory Manual, Cold Spring Harbor
Laboratory, New York, 249-251 (1982)
5. Imanaka, T., and S. Aiba, "A Perspective on the Application
of Genetic Engineering: Stability of Recombinant Plasmids,"
Annals N. Y. Acad. Sci., 369, 1-14 (1981)
6. Bailey, J. E., and D. F. Ollis, Biochemical Engineering
Fundamentals, 2nd ed., McGraw-Hill, New York, 459-470
(1986)
7. Rodriguez, R., and R. Tait, Recombinant DNA Techniques,
Benjamin Cummings, Menlo Park (1983)
8. Gerhardt, P., Manual of Methods for General Bacteriology,
Am. Soc. Microbiol., Washington, DC (1981)
9. Demain, A. L., and N. A. Solomon, Manual of Industrial
Microbiology and Biotechnology, Am. Soc. Microbiol.,
Washington, DC (1986) 0

FACULTY MOTIVATION
Continued from page 137.

tronic media (expert systems, video transmission,
etc.) might be used to bring the most up-to-date
technology and best practitioners within the reach of
all interested engineering faculty.

CONCLUSION

As Nehari and Bender [22] suggest, it is not just
the transmission of information, but the transmission
of meaning that is important to vital teaching. Educa-
tion succeeds when the student becomes intrinsically
motivated to acquire the learning, and to look upon
the activity as an end in itself. A teacher who sets an
excellent role model for the students, both in terms of
personal enjoyment and intellectual curiosity, has a
good chance to teach the students similar enjoyment.
Before we can consider environments for en-
couraging faculty, either as teachers or as research-
ers, we must consider faculty as individual human be-
ings, with human characteristics. At most, this paper
may be considered to provide some clues, based on a
larger engineering/science faculty sample, concerning
the developmental stages and motivation on the for-
mation of an environment to encourage vital teaching.
Faculty see the opportunity and resources to im-
prove their professional skills in somewhat the same
light as unused computer availability; if opportunities

are made available in a non-threatening manner, the
faculty will naturally seek and use them.

REFERENCES
1. Wergin, J. F., E. J. Mason, and P. J. Munson, "The
Practice of Faculty Development: An Experience-De-
rived Model," J. High. Ed., 47, 289-308 (1976)
2. Bess, J. L., "The Motivation to Teach: Meanings, Mes-
sages, and Morals," in New Directions for Teaching
and Learning: Motivating Professors to Teach Effec-
tively, 10, Jossey-Bass, San Francisco, 99-108 (1982)
3. Whitehead, A. N., The Aims of Education, Macmillan
Company, New York (1929)
4. Levinson, D. J., C. N. Darrow, E. B. Klein, M. H.
Levinson, and B. McKee, The Seasons of a Man's Life,
Alfred Knopf, New York (1978)
5. Gould, R. L., Transformations, Simon and Schuster,
New York (1978)
6. Sheehy, G. M., Passages: Predictable Crises of Adult
Life, E. P. Dutton, New York (1976)
7. Blackburn, R. T., C. E. Behymer, and D. E. Hall,
"Research Note: Correlates of Faculty Publication,"
Social. of Educ., 15, 132-141 (1978)
8. Cole, S., "Age and Scientific Performance," Am. J.
Social., 84,958-977 (1979)
9. Lehman, H. C., Age and Achievement, Princeton Uni-
versity Press, Princeton, NJ (1953)
10. Baldwin, R. G., and R. T. Blackburn, "The Academic
Career as a Developmental Process: Implications for
Higher Education," J. High. Ed., 52, 598-614 (1981)
11. Blackburn, R.T., "Career Phases and Their Influence
on Faculty Motivation," in New Directions for Teach-
ing and Learning: Motivating Professors to Teach
Effectively, 10, Jossey-Bass, San Francisco, 95-97 (1982)
12. Maslow, A. H., "A Theory of Human Motivation,"
Psychol. Rev., 50, 390-396 (1943)
13. Maslow, A. H., Motivation and Personality, Harper
and Row, New York (1954)
14. Schneider, B. and M. D. Zalesny, "Human Needs and
Faculty Motivation" in New Directions for Teaching
and Learning: Motivating Professors to Teach Effec-
tively, 10, Jossey-Bass, San Francisco, 37-46 (1982)
15, Aldefer, C. P., Human Needs in Organizational Set-
tings, Free Press, New York (1972)
16. McKeachie, W. J., "The Rewards of Teaching," in
New Directions for Teaching and Learning: Motivat-
ing Professors to Teach Effectively, 10, Jossey-Bass,
San Francisco, 7-13 (1982)
17. Csikszentmihalyi, M., "Intrinsic Motivation and Ef-
fective Teaching: A Flow Analysis," in New Direc-
tions for Teaching and Learning: Motivating
Professors to Teach Effectively, 10, Jossey-Bass, San
Francisco, 15-26 (1982)
18. Deci, E. L., and R. M. Ryan, "Intrinsic Motivation to
Teach: Possibilities and Obstacles in Our Colleges and
Universities," in New Directions for Teaching and
Learning: Motivating Professors to Teach Effectively,
10, Jossey-Bass, San Francisco, 27-35 (1982)
19. Centra, J. A., "Effectiveness of Student Feedback in
Modifying College Instruction," J. ofEduc. Psycol., 65,
395401(1973)
20. McClelland, D. C., J. W. Atkinson, R. A. Clark, and
E. L. Lowell, The Achievement Motive, Appleton-Cen-
tury, New York (1953)
21. Litwin, G. H., and R. A. Stringer, Motivation and Or-
ganizational Climate, Harvard Business School, Divi-
sion of Research, Boston, MA (1968)
22. Nehari, M.,H. Bender, "Meaningfulness of a Learn-
ing Experience: A Measure for Educational Outcomes
in Higher Education," High. Educ., 7, 1-11 (1978) 0

SUMMER 1989

M report

CHEMICAL ENGINEERING CURRICULA

FOR THE FUTURE

Synopsis of Proceedings of a U.S.-India Conference, January, 1988

D. RAMKRISHNA', P. B. DESHPANDE2,
R. KUMAR3, M. M. SHARMA4

THE GOVERNMENT OF India is committed to rapid
Industrial growth in which new technologies hold
a prominent role, and it shares common concerns at
the educational level and on curricular matters with
chemical engineers from the United States. A seminar
was held at Bangalore, India, in January of 1988, to
deliberate curricular changes in undergraduate chem-
ical engineering in view of emerging technologies. The
International Division of the National Science Foun-
dation provided grants which enabled several Amer-
ican delegates from chemical industries and academia
to attend the seminar, which was also attended by
Indian delegates from both industry and academia.
The seminar approached the issue of chemical en-
gineering education by organizing a first session of
presentations by industrial and academic personnel on
specific areas of technology. In a second session, dele-
gates debated various aspects of the undergraduate
curriculum, including basic science and core courses,
chemical engineering courses, and electives. After
completion of the formal presentations and the discus-
sions, individual committees deliberated on each of the
foregoing curriculum components to arrive at a con-
sensus of specific recommendations for the academic
communities in the United States and India. In addi-
tion, a panel composed of delegates from industry and
academia debated "The Emerging Technologies and
the Role of Chemical Engineering in Them" in an open
forum.
The proceedings of the seminar have been com-
piled into a Report to the National Science Founda-

'Purdue University, West Lafayette, IN
2University of Louisville, Louisville, KY
'Indian Institute of Science, Bangalore, India
4University of Bombay, Bombay, India

The government of India shares
common concerns at the educational level
and on curricular matters with chemical
engineers from the United States.

tion. The purpose of this summary is to provide a brief
report on its results and recommendations.

PERSPECTIVES ON EMERGING TECHNOLOGIES
The discussions on emerging areas of technology
covered biotechnology, materials for structural,
microelectronic, and catalytic applications, and new
separations processes. In each of these areas, perspec-
tives were presented by both industrial and academic
personnel.

Biotechnology
Stanley I. Proctor and Walter Bauer (Monsanto)
presented the areas of opportunity in biotechnology.
Five categories (human health care, animal science,
crop science, waste management, and miscellaneous
products) were presented as the main areas of oppor-
tunity. Dr. Proctor emphasized that most of the unit
operations in bioprocesses are the same as those used
in classical chemical engineering, but distinctive ele-
ments of bioprocessing include special needs for sterile
operating conditions for bioreactors, stringent control
requirements for maintaining living systems, sophisti-
cated separation techniques for dilute systems, etc.
Scale-up methods for equipment operated at labora-
tory scale, such as chromatographic columns (e.g., for
the separation of proteins), were emphasized. Dr.
Proctor also addressed the special needs of biotechnol-
ogy and concluded that the training of chemical en-
gineers to work in biotechnology should be handled as
an option to the traditional program. He pointed out
that although the biotechnology industry is a signifi-
cant employer, it is not viewed as a major employer.

CHEMICAL ENGINEERING EDUCATION

He also encouraged joint appointments of life science
trained faculty in chemical engineering and life science
departments.
George T. Tsao (Purdue University) provided an
academic view of opportunities in biotechnology and
identified five basic components of biotechnology pro-
cessing: reactor engineering, separation, genetic en-
gineering, analysis and characterization, and post-
treatment. The development of a suitable methodol-
ogy to deal with each requires a cooperative effort
with personnel in biochemistry, molecular genetics,
chemistry, and microbiology. Professor Tsao also fo-
cused on the variety of products (foodstuffs, health
products, specialty substances, bulk chemicals, waste
utilization) arising from biotechnology processing and
outlined several research areas of interest to chemical
engineers. He emphasized the need for more back-
ground in general biological sciences, along with elec-
tive courses in bioreaction engineering and biosepara-
tion, and outlined some general guidelines for their
contents.

Material Engineering and Technology
There were five presentations (two by industrial
delegates and three by academic delegates), and the
topics covered polymers and their processing,
ceramics, catalysts, and microelectronic materials.
Presentations varied between those focusing on a
class of materials for different applications (such as
polymers, ceramics, and composites) and those that
were geared to specific applications (such as catalysts
and microelectronic devices). Robert Laurence (Uni-
versity of Massachusetts) and Sheldon Isakoff (Du
Pont) presented surveys of the first type, while Lanny
Schmidt (University of Minnesota) addressed catalyst
materials specifically, and V. R. Raju (Bell
Laboratories) and Tim Anderson (University of
Florida) focused on microelectronic materials
Polymeric and Ceramic Materials-Composites:
Professor Laurence provided an academic perspective
on polymeric materials. He observed that the polymer
industry, while maintaining its involvement with tra-
ditional commodity polymers such as polyolefins and
PVC, has undergone a significant "restructuring" in
its emphasis on new and advanced materials. In re-
derstanding of polymer synthesis, electrochemical
properties, morphology, and analytical methods.
While the curriculum might include some in-depth
courses in polymer science and engineering, he con-
cluded that essential concepts of materials and poly-
mers should also be incorporated in other core
courses.

Dr. Isakoff focused mainly on structural materials.
He covered the applications of various materials (ad-
vanced engineering plastics, structural composites,
ceramic materials, etc.) and outlined the prevailing
problems, avenues for their resolution, and areas
where chemical engineers play a significant role. He
stated that chemical engineers must be able to "speak
the language" associated with advanced materials
technology and believes this can be accomplished by
offering special optional courses and minor specializa-
tion at the undergraduate level. He stated that exam-
ples from the new materials fields can be used in lec-
tures, laboratories, and homework problems just as
effectively as those from more conventional areas.
Catalysis and Materials: Professor Schmidt ob-
served that the traditional scenario of "sequential" de-
velopment of product-process combination in stages
has given way to a situation requiring joint considera-
tion of the entire process (reactor, catalyst, separa-
tions, feedstocks, by-products, and markets). A fun-
damental understanding of solid materials is neces-
sary. He suggested that in order to understand the
principles of crystal structure, phase behavior, elec-
tronic structure, and defects (all essential prerequi-
sites to, and understanding of, catalysts), an introduc-
tory course in materials characterization techniques,
such as X-ray diffraction, is necessary, and he pointed
out that in pursuing the material aspects of catalysis
one is concerned with issues very similar to those in-
volved in processing procedures for microelectronic
and ceramic materials.

Microelectronic Materials: Dr. Raju recounted
chemical engineering principles encountered in the
fabrication of optical fibers and integrated circuits,
with special emphasis on the preparation of ultrapure
glass reforms using the modified chemical vapor de-
position process. He pointed out that the electronics
industry uses a wide variety of processes (deposition,
etching, diffusion, implantation, etc.) in which differ-
ent types of chemical reactors are employed to carry
out both homogeneous and heterogeneous reactions
under precisely controlled conditions and that the
necessary chemical engineering background has not
been brought to bear on the optimal design of such
chemical reactors. He also pointed to the need for an
understanding of interfacial phenomena on a molecu-
lar level in developing processing techniques for man-
ufacturing devices in which minute components are
put together. Interfacial effects are extremely impor-
tant in "thin film" deposition, controlled etching of
microstructures, adhesive bonding, and in the realiza-
tion of high performance organic materials as dielec-
trics in integrated circuits.

SUMMER 1989

Tim Anderson presented an academic perspective
of the opportunities for chemical engineers in elec-
tronic materials processing industries. He pointed out
that these industries present many fundamental
chemical engineering processes, with the major dis-
tinction between traditional chemical processing and
EMP being the smallness of the scale of operation
characterizing the latter. He outlined the various
problems which can be tackled by chemical engineers,
stressing that it is the unique coupling of process en-
gineering with process chemistry that makes chemical
engineering an integral part of electronic device man-
ufacturing. He presented three different approaches
for introducing electronic materials processing con-
cepts to the undergraduate student and recounted in
detail his experience with a specific senior elective
course at the University of Florida.

New Separations Processes
E. N. Lightfoot (speaker) and M. C. M. Cockrem
(both of the University of Wisconsin) presented an
academic perspective on new separations processes.
Using recovery from dilute solutions as an example,
Professor Lightfoot illustrated the power of careful
problem definition and application of transport
phenomena in separations processes and equipment
design. He pointed out that examination of crude
economic data suggests that recovery of potentially
valuable solutes from dilute solutions is dominated by
the cost of processing large masses of unwanted mate-
rial. This suggestion is confirmed by examination of
the most widely used current processing techniques.
He suggested a general strategy for reducing recov-
ery costs.
Shivaji Sircar (Air Products and Chemicals, Inc.)
concentrated on bulk separation of gas and liquid mix-
tures by adsorption and membrane technologies. He
briefly described the process principles and their re-
cent applications in the bulk separation of gas and liq-
uid mixtures. In identifying research needs, Dr. Sir-
car pointed out that fundamental work towards under-
standing single and multicomponent fluid-solid ad-
sorption interactions, both in terms of thermodynamic
equilibria and interactive mass transport, was in-
which fundamental work is needed include the trans-
port of a fluid through solid membranes, durability of
membranes under mechanical and thermal stresses,
etc. He feels that the coverage of adsorption and mem-
brane science technologies in texts on unit operations
The foregoing presentations concluded the session
in which specific technologies were discussed. Of par-

ticular interest in regard to education was the em-
phasis placed by several speakers on retaining the
strong fundamental base of chemical engineering-
some speakers warning against neglect of traditional
areas and others warning against excessive introduc-
tion of technology at the expense of basic issues. The
message came through that the problem is how to en-
hance the fundamental base of chemical engineering
so that students will become literate in different areas
of technology and be able to function efficiently in a
multidisciplinary team of scientists and engineers.

EVALUATION OF CURRENT CURRICULA
In addressing the chemical engineering cur-
riculum, four categories were identified: basic science
courses, core courses, chemical engineering courses,
and electives. Delegates from both sessions were
present for the discussion, although the speakers in
this session were entirely from academia.

Basic Science Courses
H. Ted Davis (University of Minnesota), J. M.
Caruthers (Purdue University), and G. Padmanaban
(Indian Institute of Science) covered different compo-
nents of basic science requirements which are gener-
ally not covered in the present curricula.
Professor Davis made a strong plea for background
in interface science and interfacial engineering, ob-
serving that the traditional background provided very
little training in this area of increasing importance.
He pointed out that interfacial processes impact a sub-
stantial part of a \$150 billion U.S. industry because of
its concern with products affected by interfacial en-
gineering. The mixing of water, oil, and surfactants
under suitable conditions produces applications of in-
terfacial engineering in biotechnology, microelectronic
and ceramic materials processing, etc. Professor
Davis strongly recommended an elective course on the
fundamentals of colloid and interface science which
could also be taken by graduate students seeking
specialization in this area.
Professor Caruthers pointed out that chemical en-
gineers have a special role to play in advanced mate-
rials where the molecular/microscopic structure, man-
ufacturing process, and ultimate product performance
are intimately related. He feels that all chemical en-
gineering students must have some familiarity with
the solid state, but he ruled out the elective approach
and instead proposed a required course in materials
science taught (say) in the sophomore year. He pre-
sented topics that could be covered in the course, plac-
ing emphasis away from metals.

CHEMICAL ENGINEERING EDUCATION

In addressing curricular changes, the diversity of existing curricula makes a universal formula
impossible. The seminar was designed as an intellectual discourse on curricular
changes in the hope of evolving some general guidelines.

science background for chemical engineers and
warned against adherence to engineering methodol-
ogy without sensitivity to biological complexities. He
proposed a life science package of twenty-five credits
in biology courses in a four-year bachelor's degree pro-
gram in biochemical engineering. Since this require-
ment (which he believes is essential for good biochem-
ical engineers) may be oversized, he suggested prun-
ing the requirement down to 8-10 credits in the BS
program, deferring the rest to a master's degree in
biochemical engineering. He feels that not all chemical
engineering institutions need to offer such a program.
He also argued for biology courses to be taught by
biologists, with special books to be written to suit
chemical engineers.

Chemical Engineering Courses
The chemical engineering courses that were dis-
cussed were: thermodynamics, transport processes,
chemical reaction engineering, process design, and
process control. Discussion centered around how
these courses can be modified in the light of newer
requirements.
Thermodynamics: M. S. Ananth (Indian Institute
of Technology, Madras) discussed thermodynamics as
taught to chemical engineers and presented the out-
line of a course at IIT, Madras, much of which is "con-
ventional" by design. He stated that changes are
needed in the type of examples used and cited several
examples with applications in biology and biochemis-
try, and in fuel cells and thermochemical cycles, as
new areas of concern. He also emphasized the impor-
tance of computers in the teaching of ther-
modynamics, citing their impact in solving complex
problems.
Transport Processes: R. A. Brown (Massachusetts
Institute of Technology) argued that the need for un-
derstanding of transport processes was greater than
ever before because in the new areas of application
the focus is on fine-scale structural and chemical fea-
tures of the product, and complex transport processes
abound in the processing of the materials. He ob-
served that a transport course must impart an under-
standing of transport processes and must provide a
basic grasp of the key techniques of analysis. He pro-
vided arguments that the separation of techniques for
analysis from applications was not necessary and pre-

course in "Analysis of Transport Processes" in which
the major emphasis is on teaching basic concepts in
heat, species, and momentum transport and on the
techniques for closed-form analysis of these processes.
He presented the topics in detail and pointed out that
examples from a variety of application areas could be
easily incorporated by using the experiences of the
lecturer and through text sources from these areas.
Process Control: Thomas F. Edgar (University of
Texas, Austin) reviewed the developments in process
control instruction and presented an outline for revi-
sion. He pointed out that in the coming years a process
control course should not only cover analog controllers
and continuous systems, but should also expose the
student to digital control and discrete systems con-
cepts. Hands-on experience in distributed control with
availability of computer-aided instruction software
with graphics would greatly enhance teaching effec-
tiveness. Such software could also expose the student
to plantwide control concepts as opposed to analyzing
only single loop systems.
Professor Edgar feels that a lack of fundamental
understanding is preventing the development of
closed-loop control strategies and mentioned two spe-
cific examples-one in solid-state device processing
and the other in batch and fed-batch bioreactors. As
improved understanding of such processes develops,
it would be worthwhile to include examples built
around them in the course on process control. Profes-
sor Edgar also presented an outline of a futuristic (in
the year 2000) course on process control which focuses
on discrete control systems concepts.

Chemical Engineering Electives
In addition to the elective courses discussed below,
the course on interfacial science and engineering pro-
posed by Professor Davis during the discussion on sci-
ence courses, and the course in electronic material
processing discussed by Professor Anderson in Ses-
sion I must also be regarded as recommended elec-
tives.
Biochemical Engineering: H. C. Lim (University
of California, Irvine) feels that the scientific base of
chemical engineers must be broadened to include life
sciences, and he pointed out that life science concepts
can be incorporated into traditional courses (i.e., one

SUMMER 1989

can cover life science examples in a kinetics and reac-
tor design course). He also asked that the under-
graduate curriculum be flexible enough to allow
specialization through carefully planned elective
courses and that students opting for biochemical en-
gineering be advised to take life science courses in
their sophomore and junior years. He argued that
with a strong life science background, the application-
oriented courses can focus more on the engineering
aspects of emerging technologies. He also feels the
need for flexibility in the rules of accreditation in
order to provide for more strength in life sciences and
biochemical engineering.
Polymer Science and Engineering: S. K. Gupta
(Indian Institute of Technology, Kanpur) observed
that incorporating polymer background into the chem-
ical engineering curricula has been slow. In discussing
an elective course in polymer science and engineering,
Professor Gupta asked for integration of the funda-
mental concepts from the polymer field into the core
courses. He illustrated polymer topics that can be ab-
sorbed into the basic courses in chemistry (mechanics,
thermodynamics, reaction and reactor engineering,
transport phenomena, and process control and optimi-
zation), and he pointed out the scarcity of textbooks
in this vein. He argues that many of the topics cur-
rently covered in polymer electives can actually be
covered in the core courses, leaving newer material
for an elective course. He outlined the contents of such
a course, and although the list of topics is application-
oriented, the treatment of the topics itself is funda-
mental. Heavy emphasis is placed on biopolymers,
which he believes offer considerable scope for contri-
butions by macromolecular engineers.
Artificial Intelligence: Venkat Venkatasubrama-
nian (Purdue University) presented an elective course
in artificial intelligence (AI). He argued that AI and
knowledge-based systems provide an important
framework for the modeling and solution of several
classes of problems in process engineering, and he ob-
served that training in these approaches will better
prepare chemical engineers to cope with the demands
and changes of the industrial environment. From his
personal experience in teaching a course on AI, he
feels that the proper way to educate students about
AI is to teach it from a process engineering perspec-
tive. Students were taught the interdisciplinary area
of AI and process engineering by using examples and
exercises from process engineering. He feels that this
approach is more appropriate and meaningful than
learning from a computer science point of view. The
lack of a suitable text will be remedied in the future
by a series of monographs on AI in process engineer-

filiate of the AIChE.
Colloids and Interfaces: R. Rajagopalan (Univer-
sity of Houston) presented an elective course in col-
loids and interfaces. He asked for integrating basic
concepts of colloid and interface science into the core
courses and listed several topics that could be included
in material and energy balances, transport
phenomena, thermodynamics, and separation pro-
cesses. Although many examples from high technol-
ogy were cited as motivation for the topics discussed,
Professor Rajagopalan echoed the warnings of others
that "high-tech" is not a panacea, stating that ad-
vances in high technology often cannot wait for sys-
tematic research while at the same time academic re-
search and education cannot afford to keep switching
directions based purely on the forces of the market.

The Chemical Engineering Laboratory
M. M. Sharma (Bombay University) began with
the observation that the conventional chemical en-
gineering laboratory course does not realize its stated
objectives. He discussed various remedial measures
to correct this situation, including the use of large-size
equipment, open-ended experiments, demonstration
experiments, and equipment study experiments. He
emphasized open-ended experiments and suggested a
regular turn-over from a "bank" of experiments. He
proposed the inclusion of an experimental design pro-
ject in which the student would be required to suggest
an aim, the equipment required, and the measure-
ments to be made for achieving the aim. He also pro-
posed demonstration experiments chosen to satisfy
well-defined criteria.

DISCUSSIONS AND RECOMMENDATIONS
Each presentation was followed by a discussion
period in which all delegates participated, and com-
mittees were formed to discuss the various compo-
nents of the chemical engineering curriculum. The
chairmen of the individual committees then presented
the committee recommendations to the entire group
of delegates. An article by Watters, Laukhuf, and
Plank (University of Louisville) has examined the
committee recommendations in light of ABET re-
quirements and has concluded that implementation is
possible. Generally, the organizers feel that accredita-
tion requirements must be softened to accommodate fu-
ture curricular needs.
In addressing curricular changes, the diversity of
existing curricula makes a universal formula impossi-
ble. The seminar was designed as an intellectual dis-

CHEMICAL ENGINEERING EDUCATION

course on curricular changes in the light of emerging
technologies, with the hope of evolving some general
guidelines. The following sections outline those
guidelines.
Science Courses: The science group, headed by
Professor Davis, felt that the science core should be
taught by scientists and that the chemical engineering
faculty must persuade physical chemists and material
scientists to include concepts and examples related to
emerging technologies in the core courses. More spe-
cifically, examples must include solids, polymers,
catalysts, interfaces, colloids, bioreactions, etc. They
further recommended a course on computational
methods after the completion of the core math
courses, and that chemical engineering students be
allowed to substitute one life science course for one
core chemistry course (the most logical option being
the second organic chemistry course). No changes
were recommended for the physics courses.
Engineering Core Courses: This group, led by Pro-
fessor Gandhi, outlined the topics to be dealt with in
thermodynamics and transport processes. Although
their outline showed no changes in the list of topics
currently covered in chemical engineering curricula,
they suggested that a special effort be made to include
new examples from the emerging technologies.
Another recommendation was to include discussion of
the solid state with respect to deformation, transport
of energy and mass, and chemical reaction, with exam-
ples of applications to the newer technologies of mate-
rials and microelectronic devices.
Chemical Engineering Courses: Arvind Varma
(Notre Dame) headed the group which presented ob-
servations and recommendations on chemical en-
gineering courses such as chemical reaction engineer-
ing, separations, design, control, and laboratory. The
group stressed fundamentals with inclusion of exam-
ples from both traditional and emerging technologies.
Since textbooks on the newer technologies are not yet
available, they recommended that examples be com-
missioned and circulated to chemical engineering de-
partments in a package. They encouraged the use of
realistic problems, with liberal use of computer
software focusing away from numerical methods.
They also recommended that in addition to the two-
semester laboratory course, demonstration experi-
ments and video tapes should be used to firm up con-
cepts and even to introduce new course material.
Electives: This group, headed by J. M. Caruthers
(Purdue University), classified electives in the new
technology areas as microelectronics, biochemical, in-
terfacial, AI, and polymers, and in the traditional
technology areas as environmental, petroleum, pro-

cess metallurgy, and food. A third category was
termed "Advanced Core" and included transport,
thermodynamics, optimization, and control. The
group felt that electives in the new technologies
should not eliminate electives in either the traditional
technologies or the advanced core. They observed that
it is not necessary for each department to offer a com-
plete package in every area.

CONCLUSIONS
The broad conclusions which can be drawn from
this four-day seminar are:
1. Chemical engineering must retain its traditional
interests, but at the same time must expand its funda-
mental base to include applications in the new areas
of technology. In particular, background in states of
matter other than the bulk fluid state (such as solids,
thin films, interfaces, microstructured materials, etc.)
was emphasized.
2. In view of the interdisciplinary nature of the
newer areas and the essentially transient nature of
technological developments, a fundamental back-
ground is necessary to provide a healthy appreciation
of the issues involved in the new fields. Thus, chemical
such areas must function within the framework of a
collaborating team of scientists and engineers of vari-
ous backgrounds.
3. Curricular modifications must entertain two ele-
ments. First, fundamental information must go into
the science and engineering core courses, with exam-
ples to illustrate the new applications, and chemical
engineering courses must be oriented similarly wher-
ever possible (e.g., chemical reaction engineering,
separations, control). Second, more detailed involve-
ment with the newer areas of technology must be ac-
complished through elective courses. O

REVIEW: Buoyancy
Continued from page 181.
neering science point of view. They focus on the
formulation of appropriate forms of the transport equa-
tions in the boundary region and on the development of
similarity or perturbation solutions. Hence, their book
complements the book by Joseph (Stability of Fluid Mo-
tions) where more mathematical aspects of buoyancy-
induced convection are discussed.
This book is clearly written and the material is pre-
sented in an orderly fashion. The book should serve as a
valuable and comprehensive reference source for anyone
interested in the engineering aspects of natural convec-
tion. Engineers and scientists doing research in this field
will certainly want to own a copy of this book. 0

SUMMER 1989

curriculum

A CHEMICAL PLANT SAFETY AND

HAZARD ANALYSIS COURSE

J. P. GUPTA*
Indian Institute of Technology
Kanpur 208016, India

* In January 1966, there was a major fire in LPG stor-
age in Feyzin, France, that killed 17 people, injured
80, and caused extensive damage.
* In June 1974, there was a major fire in the handling
of cyclohexane at Flexborough that killed 28 people,
injured 89, and caused extensive damage.
* In July 1976, there was a massive release of ex-
tremely toxic dioxin produced in a runaway highly
exothermic reaction that contaminated an area of
17.1 sq. km. and acquired global notoriety. (Dioxin
did not directly kill any human being, but a chemist
working near the reactor died due to falling masonry
caused by the explosion.)

If the impact of the above three (and other major)
accidents of the 1960s and the 1970s had been what it
should have been on public opinion, mass media,
educators, the executive, legislative, and judiciary
branches of governments worldwide, then the follow-
ing probably would not have happened (or, so one
wishes):

* In November 1984, there was a massive fire in LPG
storage in Mexico City that killed over 500 people,
injured 7231, and caused incalculable losses.
* In December 1984, there was a tragic release of
highly toxic methylisocynate in Bhopal that killed
at least 2500, injured over 200,000, and caused
unimaginable human suffering for most of the sur-
vivors.

(This is a very small listing of the process industry
accidents taken from Marshall [1], which can be con-
sulted for details of these and other major accidents.)
Everyone concerned has been aroused. The process
industry can now be separated into two eras: Pre-
*Present address: Embassy of India, 2107 Massachusetts Ave. NW,
Washington, DC 20008

J. P. Gupta holds a Bachelor's Degree
from IIT Kanpur (1966), a Master's from the
University of Michigan (1967), and a PhD from
the University of Pennsylvania (1971). He has
worked in the areas of heat transfer, micro
computer control, and safety and hazard anal-
ysis. He is currently the Science Counsellor at
the Embassy of India in Washington, DC, on
deputation from IIT Kanpur where he is a pro-
fessor of chemical engineering. B

Bhopal and Post-Bhopal. A strong case can now be
chemical plant safety and hazards in order to ensure
that future engineers are aware of the importance of
making safety a year-round practice in all spheres of
their activities. With some variations, such courses
should also be taught to students in other branches of
engineering and the sciences.
lated articles appeared in CEE [17, 18]. This speaks
volumes about the importance of this area.

STARTING BLUES
Since it is a new area of study, most teachers did
not have formal exposure to it during their own studies.
Also, research activity in this area has been confined
to a limited number of centers. Hence, ini-
tiating a safety course requires more than mere curios-
ity on the part of the instructor. It requires a deeply
ingrained commitment. The small number of available
texts, the lack of mathematical treatment starting with
the fundamentals, the necessity of working with ques-
tionable probabilities of equipment failure and human
error, the interplay of physical, medical, social, and
political sciences, are enough to thwart any enthusiasm
for the project. However, perseverance brings its own
rewards. Unifying all the disciplines noted above in a
manner never before possible in any course makes the
effort worth-while (see Table 1).
A question that should be answered right at the

CHEMICAL ENGINEERING EDUCATION

('11E

beginning is: Should the safety and hazards aspects
(1) be included as part of all the chemical engineering
courses, or (2) be taught as a separate full course? The
final choice depends upon the teaching philosophy of
each department, but the following points should be
considered.
The first approach has an advantage in that it can
be coordinated with the rest of the course material.
However, it would probably require deleting some
other topics in order to accommodate several lectures
(one or two lectures won't do), and since instructors
are already hard-pressed for time, unwelcome com-
promises may have to be made. It would also necessi-
tate that instructors self-learn the topic, and some in-
structors may only do lipservice. This would leave the
students in even worse shape, erroneously thinking
that they knew about safety and hazard analysis in all
branches of chemical engineering (a tall order even for
an expert). Inevitably, several important topics re-
lated to the transportation of hazardous materials, in-
spection and maintenance of plants, medical and tox-
icological aspects of dangerous chemicals, legal and
social responsibility of plant managers, etc., would not
even be mentioned.
In the second alternative, teaching a separate full
course, the above disadvantages would disappear, the
course would be more coherent, and topics could be
better coordinated. The lectures could be supple-
mented by specialists in specific disciplines, by case
studies, films on safety aspects, etc., and students
could be encouraged to do term papers and to visit
nearby industries to learn first-hand the steps taken
by diverse industries for safe operation. At the end of
the course, they would have had a finite exposure to
safety and hazard analysis in the process industries
that would not only make them better design engineers
but would also improve their job and promotional av-
enues. Also, students from other disciplines such as
mechanical engineering, industrial engineering, man-
agement, etc., could enroll in the course. Hence, the
second alternative appears to be better.
It should be realized at the very outset that the
teaching of safety and hazard is different from teaching
any other course. The students' ingrained attitudes,
their thinking, and their approach to safety all need
to be changed; human inertia has to be overcome; the
viewpoint of "it has not happened thus far so it will
never happen" has to be discarded. It takes as long to
unlearn a wrong attitude as it does to learn a new one.
Students should be taught that minor incidents are
usually precursors of a major one. (There were several
some of the workers, but which were ignored by the

research activity in this area has
been confined to a limited number of centers.
Hence, initiating a safety course requires more than
mere curiosity on the part of the instructor. It
requires a deeply ingrained commitment.

TABLE 1
Disciplines Involved in
Chemical Plant Safety and Hazard Analysis

Physical Sciences (and Engineering) Chemical Kinetics;
Thermodynamics; Chemistry; Equipment Design; Fabrication;
Operation; Maintenance; Dispersion and Diffusion of Gases;
Shock Waves; Combustion; Radiation; Corrosion; Fracture
Mechanics; Transportation of Hazardous Materials;
Environmental Pollution; Pressure Relief Devices;
Instrumentation; Failure; Statistical Analysis; Hazard Analysis;
Reliability and Failure Analysis; Personal Safety; Operator
Training; etc.
Medical Sciences Effects of High Temperature Radiation on
Human Body; Burn Treatment; Toxicity; Ingestion Through
Skin; Lethal Doses; Industrial Hygiene; First Aid and Emergency
Aid; etc.
Social Sciences Public Perception and Social Acceptance of Risk;
Hazards us. Industrial Progress (or Profits us. Public Safety);
Professional Ethics; Information Dissemination to Workers and
Public; Legal Aspects; Tort Law; Emergency/Disaster Manage-
ment Planning; Coordination with Civic Authorities; Educating
Management; Risk Calculation; Insurance Premiums; Attitude to
Safety; Human Error, Operator Reliability; Stress Factors; etc.

plant authorities, local administration, and the national
press.)

COURSE DETAILS

Our list of course topics is similar to that in both
references [17, 18]. We also include a lot of case studies,
and fortunately, the available literature is vast [2-6].
Students are assigned case studies to read at home,
and then they must make brief presentations of the
cases to the class. The causes and effects are discussed,
and conclusions are drawn. This takes up the first eight
to ten minutes of each lecture. Advantages of this ap-
proach are several:

ing several others from the related books and journals.
Since the student has to present the material to the class,
he tries to better understand it, and the chances of his
learning more are increased. (All teachers already know
this to be true.)
The students get into a spirited (but guided) discussion
about the causes, effects, and precautions to take, and this
builds a receptive mood for the remaining forty-five minutes
of the lecture hour.

Students are also encouraged to look for unsafe

SUMMER 1989

situations in the home, the dormitory, on the road, in
railway stations, hospitals, kitchens, laboratories, etc.
These may be related to stair height, sharp corners
on furniture, slippery floors, blind turns, identification
of fire hazards, as well as insufficient light, escape
routes, and/or first-aid facilities. Local industries such
as urea manufacturers, LPG and industrial gas cylin-
der filling stations, tanning industries, and textile,
woolen, and foot-wear mills are visited to see first-
hand the safety measures, the procedures for hazard
identification when making any changes in the process
or piping, the emergency preparedness plans, and
their liason with the civic authorities. The city fire
chief is invited to talk about the city's fire-fighting
capabilities in case of a major fire in any industry.
Some term paper topics are listed in Table 2. Each
topic is assigned to more than one student to work
independently. This results in a little competition and

TABLE 2
Some Topics for Term Papers

Hazards in teaching labs (Unit Operations, Controls) and research
labs in the department
Calculation of safe distance between two storage tanks taking into
account the flammability and contents, size of storage tank,
Inventory of hazardous material in a distillation column depending
on the type of trays used, and its effect on column sizing
Effect of shock or blast wave on columns, horizontal tanks, and their
support structures
Comparison of safety and reliability in nuclear power plants us.
chemical process plants.
Computer program for HAZOP study of small set-ups
Computer program to calculate insurance premiums of plants
allowing for penalties and reductions depending upon the actual
plant layout us. standard requirements
Accidents in transport of hazardous materials: types of accidents,
causes, consequences, probability, emergency measures
Pressure relief devices: types, sizing, calibration, testing, reliability,
detection of failure
Construction and location of control room, installation of instrument
panels and alarms for easy visibility and access
Alarm systems: design, testing, reliability
Dispersion of toxic gases lighter/heavier than air and emergency
procedures to tackle the situation
Automatic explosion suppression, flame arrestors: types, working
principles, installation, reliability
Personal protection items under different hazardous situations
Classification and safe handling of combustible/flammable gases,
liquids, and solids
Toxic effects on human body of various chemicals and dusts inhaled
or ingested or received by skin contact

ensures deeper study. Students are also invited to
suggest topics based upon their own experiences.
They are required to present it to the class using over-

CONCLUSIONS

The time has come when chemical plant safety and
hazard analysis should be taught in classrooms. These
topics have become too important to be left only to
those who have learned it on the job or have taken
some specialized training obtainable only at select
places. The course proposed in this paper is but one
step in the direction that academics should take. The
author will be glad to provide a more detailed listing
of the topics in Table 2 (some of which may also be
included as lecture topics) and a longer list of refer-
ences to anyone interested in starting a course and/or
bringing their library up-to-date in these areas.

ACKNOWLEDGEMENT

Thanks are due to Prof. Stuart W. Churchill, Uni-
versity of Pennsylvania, for his detailed review of the

REFERENCES
(The following is only a representative listing of important
references. For a more complete list, write to the author.)
1. Marshall, V.C., Major Chemical Hazards, Ellis Hor-
wood, Chichester, U.K. (1987)
2. Kletz, T.A., "What Went Wrong," Gulf, Houston (1985)
3. Kletz, T.A., "Cheaper, Safer Plants," I. Chem. E.,
Rugby, U.K. (1984)
4. Kletz, T.A., "An Engineer's View of Human Error," I.
Chem. E., Rugby, U.K. (1985)
5. Kletz, T.A., "Myths of the Chemical Industry," I. Chem.
E., Rugby, U.K. (1984)
6. Lees, F.P., Loss Prevention in Process Industries, Vols.
I, II; Butterworth, London (1980) (Several detailed case
studies are given in appendix.)
7. Journal of Reliability Engineering, Elsevier,
Switzerland
8. Fire Safety Journal, Elsevier, Switzerland
9. Journal of Loss Prevention in the Process Industries,
Butterworth, London
10. Industrial Safety Chronicle, National Safety Council,
Bombay
11. Loss Prevention News, Loss Prevention Association,
Bombay
12. "Loss Prevention" I. Chem. E., Rugby, U.K.
13. Plant/Operations Digest, AIChE, New York
14. Hydrocarbon Processing, Gulf Publishing, Houston
15. Chemical Engineering Progress, AIChE, New York
16. Chemical Engineering, McGraw-Hill, New York
17. Fleischman, M., "Rationale for Incorporating Health
and Safety into the Curriculum," Chem. Eng. Ed., 22
(1), p 30-34 (1988)
18. Crowl, D.A. and J. F. Louvar, "Safety and Loss Pre-
vention in the Undergraduate Curriculum," Chem.
Eng. Ed., 22 (2), p 74-79 (1988) 0

CHEMICAL ENGINEERING EDUCATION

AUTHOR GUIDELINES

This guide is offered to aid authors in preparing manuscripts for
the Chemical Engineering Division of the American Society for Engineer-
ing Education (ASEE).

CEE publishes papers in the broad field of chemical engineering educa-
tion. Papers generally describe a course, a laboratory, a ChE department, a
ChE educator, a ChE curriculum, research program, machine computation,
special instructional programs, or give views and opinions on various
topics of interest to the profession.

Specific suggestions on preparing papers.

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

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

TEXT Manuscripts of less than twelve double-spaced typewritten pages in length will be given pri-
ority over longer ones. Consult recent issues for general style. Assume your reader is not a novice in
the field. Include only as much history as is needed to provide background for the particular material
covered in your paper. Sectionalize the article and insert brief appropriate headings.

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

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

ACKNOWLEDGMENT Include in acknowledgment only such credits as are essential

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

COPY REQUIREMENTS Send two legible copies of the typed (double-spaced) manuscript on
standard letter-size paper. Clear duplicated copies are acceptable. Submit original drawings (or clear
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blue cross-sectional lines; other colors interfere with good reproduction. Label ordinates and
abscissas of graphs along the axes and outside the graph proper. Figure captions and legends may
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manuscript.

ACKNOWLEDGMENTS

The following 154 departments are contributing to the support of CEE in 1989 with bulk subscriptions.

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University of Minnesota
University of Missouri, Columbia
University of Missouri, Rolla
Monash University
Montana State University
University of Nebraksa
University of New Hampshire
University of New Haven
New Jersey Institute of Technology
University of New Mexico
New Mexico State University
University of New South Wales
University of New York, Buffalo
Polytechnic Institute of New York
North Carolina A & T University
North Carolina State University
University of North Dakota
Northeastern University
Northwestern University
University of Notre Dame
Technical University of Nova Scotia
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

Purdue University
Queen's University
Rensselaer Polytechnic Institute
University of Rhode Island
Rice University
University of Rochester
Rose-Hulman Institute of Technology
Rutgers, The State University
University of Sherbrooke
University of South Alabama
University of South Carolina
South Dakota School of Mines
University of South Florida
University of Southern California
University of Southwestern Louisiana
Stanford University
Stevens Institute of Technology
University of Syracuse
Teesside Polytechnic University
University of Tennessee
Tennessee Technological University
University of Texas
Texas A & M University
Texas Tech University
University of Toledo
Tri-State University
Tufts University
University of Tulsa
Tuskegee Institute
University of Utah
Vanderbilt University
Villanova University
University of Virginia
Virginia Polytechnic Institute
University of Washington
Washington State University
Washington University
University of Waterloo
Wayne State University
West Virginia College of Grad Studies
West Virginia Institute of Technology
West Virginia University
University of Western Ontario
Widener University
University of Wisconsin
Worcester Polytechnic Institute
University of Wyoming
Yale University
Youngstown State University

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