UNIVERSITY OF WATERLOO
DEPARTMENT OF CHEMICAL ENGINEERING
ChE 100
CHEMICAL ENGINEERING CONCEPTS 1
FALL 2009
Instructors
Lecturer:
Dr. Eric Croiset
Room DWE 2513F
e-mail: ecroiset@uwaterloo.ca
Ext. 36472
Tutorials:
Dr. Eric Croiset
Room DWE 2513F
e-mail: ecroiset@uwaterloo.ca
Ext. 36472
Eng. Comm. Lab.:
Dr. Michael Fowler
Room DWE 3513A
e-mail: mfowler@uwaterloo.ca
Ext. 33415
Teaching Assistants:
Noorlisa Harun
Room DWE 2536B
email: nharun@engmail.uwaterloo.ca
Ext. 36097
Sheng Lu
Room DWE 1505
email: shenglu@engmail.uwaterloo.ca
Ext. 36864
Karachakorn Panha
Room DWE 3523
email: kpanha@engmail.uwaterloo.ca
Ext. 36164
Monrudee Phongaksorn
Room DWE 1535
email: mphongak@engmail.uwaterloo.ca
Ext. 36981
Faraz Syed
Room DWE 3523
email: f2syed@engmail.uwaterloo.ca
Ext. 36164
WEEF TAs:
Kim Broten, kdbroten@uwaterloo.ca
Ryan Egli, rfegli@uwaterloo.ca
Linda Zacaj, lzacaj@uwaterloo.ca
Texts
Elementary Principles of Chemical Processes, R.M. Felder and R.W. Rousseau, 3rd Edition, J. Wiley &
Sons, 2005.
Introduction to Professional Engineering in Canada. Andrews et al., Prentice Hall, 2006.
Course support on the internet
All online materials for CHE 100 can be at UW-ACE: https://uwangel.uwaterloo.ca/uwangel
Lecture Outline
The course covers material from Chapters 1-5 Felder and Rousseau. About 4 weeks of lectures will be
spent on Introduction and Engineering Problem Analysis, 7 weeks on Material Balances, and 1 week on
Real Gases.
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Tutorials
Each student in the course has a one- hour tutorial each week, at a time and place indicated on his/her
schedule. Please ensure that you come to the correct tutorial. Each tutorial involves a 30 minute quiz on
the previous week’s lecture material. These will be graded and returned the following week. Quizzes are
compulsory, and at least 9 must be completed (unless satisfactorily excused). The remaining tutorial time
will be devoted to a discussion and illustration of lecture material.
Engineering Communication Laboratory: CPH 1346 (See Dr. Michael Fowler)
Lecture Assignments
Assignments are posted on UW-ACE every Wednesday and they are usually due Friday by noon the
following week. They must be submitted in the mailbox outside Room DWE-2518 under the appropriate
section number. These will be graded and returned to the shelves outside DWE-2518, usually within one
week.
Important note related to privacy law: In order to respect privacy law the returned marked assignments
placed on the shelves (public area) should not give direct information as to whom it belongs. As such,
when you submit assignments you are asked to staple a short paper where you indicate both your name
and ID#. This paper will be ripped out before the assignment is returned to you. On the assignment,
however, you will only indicate your ID# on each page. Failure to do so (e.g. writing your name directly
on the assignment) will result in 5 points subtracted from the assignment mark.
Lecture assignments are compulsory, and a minimum of 8 of the 10 assignments must be submitted. The
average grade for the assignment will be based on the 8th best assignment marks. If less than 8
assignments are submitted, the difference between 8 and the # of assignments submitted will be subtracted
to the final mark. E.g., hand in 6 assignments, then 8-6 = 2 pts to be subtracted from the final mark!
Each question on an assignment will be graded as follows:
2 - the solution is correct or very nearly correct
1 - the solution is partially correct
0 - the solution is incorrect or nearly incorrect
You should plan to spend about five hours per week outside classes on this course.
Examinations
There will be a 2-hour mid-term test on Wednesday, October 21st from 7:00-9:00 p.m.
There will be a 2.5-hour final examination (covering the entire course) scheduled by the Registrar during
the final examination period.
Course Grading
The “normal” course grade will be computed as follows:
Communication Laboratory Assignments:
Co-op/PDENG
Midterm
Final Examination
Assignments
Quizzes
18%
2%
20%
50%
5%
5%
Note that if the average of the Midterm and Final exams (with weights of 35% and 65%, respectively) is
less than 50, then this average will become your course grade, resulting in a failed course.
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ChE 100
Chemical Engineering Concepts 1
PROBLEM SOLVING IN ENGINEERING
Engineers are persons who not only are competent to originate, plan, design, construct, and operate, but
also to direct others effectively in such activities. Engineers are able to coordinate the contribution of
many sciences, some arts, business procedures, sound economics, and enlightened social policies, to the
attainment of the desired end.
In short, engineers are problem solvers. To be a competent engineer, therefore, you must become a
competent problem solver. Effective problem solvers may be born, but experience has shown that most of
them are made! A function of problem assignments in chemical engineering is to help you gain the skills
necessary for the achievement of competency in problem solving, in addition to their traditional role of
enhancing understanding of basic concepts.
Problem Scope
Real world problems, of course, vary greatly in both scope and complexity. While the type of approach to
solving a particular problem depends on, for example,
1. the nature of the problem itself: is it (and the perceived goals) well defined or is it open
ended (multiple possible solutions)?
2. imposed constraints (time, money, availability of information, solution techniques),
There are generalized guidelines which have been found to be very useful in solving any type of
engineering problem, including sub-parts of very complex problems.
In ChE 100/101, the assignments largely consist of closely prescribed problems which serve to illustrate,
and to increase the student’s comprehension of the underlying concepts. In later years, the curriculum
provides opportunities for dealing with more extensive and open-ended problems, building on the
techniques developed in ChE 100/101.
Methods of Problem Solving
In engineering, problems may often be designated as belonging to one of two general classifications.
First, those in which rather precise answers (for which accurate data, system models and computations
procedures are obviously required) are either necessary, e.g., process control stability, or desirable, e.g.,
design optimization of established technologies. On the other hand, where the direction or magnitude of
the solution(s) is not readily perceived beforehand, e.g., development of new technologies, or where
economic, environmental or other constraints dictate, we often seek a preliminary description of the
results by applying the principle of successive approximation (fine tuning the input on each go-around in
view of the initial results) or by doing order-of magnitude calculations. The trick is recognizing which of
these approaches is required in order to get a useful (meaningful) solution. How does one do this? The
approach to be taken often depends on the degree of definition of the problem and the end use of the
solution obtained. This is termed the “Principle of optimal sloppiness”. In textbooks, the nature of the
problem (what information is sought) is, usually, clearly stated; on the other hand, the major difficulty
with many real-world problems lies in expressing clearly the actual problem required to be solved (often
the problem description given you by others merely serves to hide the true nature of the problem!).
Experience is the best instructor here.
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Regardless of the specific approach to be taken, complex engineering computations involve translation of
the physical problem into “abstract” terms, i.e., into a mathematical MODEL of the real world,
manipulation of the model to achieve a mathematical solution, and, finally, translation of the abstract
results into terms of physical significance. Such a process is illustrated below.
MATHEMATICS
(abstract world)
STEP 2
solution of the
mathematical problem
Step 1
Step 3
translation of abstract
results into terms of
physical significance
translation of the
physical problem
into abstract terms
THE PROBLEM
(real world)
MATHEMATICAL
SOLUTION
(abstract terms)
(direct route not
feasible in
complex situation)
THE ANSWER
(real world)
The physicochemical principles are of prime importance. The language (mathematical model) in which
we express them and manipulate the relationship between them is of secondary importance, but the ability
to choose the appropriate mathematical tools is an important attribute of an engineer. Although translation
of the problem into mathematics has the disadvantage that we may lose our intuitive feel for cause and
effect, this procedure is essential in complex situations and produces useful results as long as the model
reproduces the essential features of the real world.
It is also important to recognize that in order to achieve a solution when there are complex or ill-defined
relationships, it often is necessary to make one or more ASSUMPTIONS about the physicochemical
behaviour of the system under study. The resulting model will then be subject to the constraints imposed
by the assumption(s) and its use in situations in which the original assumptions are not valid can lead to
serious error. The problem solver must ensure that SIMPLIFYING ASSUMPTIONS ARE CONSISTENT
WITH THE PHYSICOCHEMICAL REALITY OF THE SYSTEM UNDER INVESTIGATION.
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