Rethinking the Chemical Engineering Curriculum

In the last post, I proposed a definition of what I believe Chemical Engineering to be: manipulating matter by managing energy.  It has generated some comments, with most of the disagreements either trying to embellish the definition to include jargon, or saying that the definition was not broad enough.  An interesting thing about definitions – the more words it takes to define a thing, the more restrictive the definition becomes.

In the previous piece, I described how the various courses fit into the spirit of the overall definition, without showing how the various courses interact with one another.  One thing that bothers me is that we, as a society, discuss the need for more STEM majors to remain competitive as a nation.  STEM is an acronym that stands for Science, Technology, Engineering and Math, and while one may quibble with the implied hierarchy from the order, it does appear that these are the “hard skills” that many college bound youth seem to avoid, because as Barbie once said “Math is hard”.

It is increasingly difficult to fail to see that people with BS degrees in Engineering, if they are lucky enough to find jobs, will significantly out earn almost every other BS or BA degree.  Of course this is due primarily to the law of Supply and Demand – if the demand for a specific major exceeds the supply, salaries will be higher than if there is a higher supply of a specific major than the demand.  This is as true for a group of Communications majors as it is for mulch.  This is not to compare the utility of a BA in Communications to the utility of mulch, but I will allow others to make that judgment.

One cannot hope to become an Engineer without a solid foundation in mathematics.  In fact, since almost all engineering theory is based on calculus, it would be impossible to survive the undergraduate curriculum.  While Chemical Engineering is manipulating matter by managing energy, it is the role of mathematics that ties these two concepts together.

In the Venn diagram below, I have tried to show how the basic Chem E curriculum ties matter, energy, and math together.  The diagram is based on my recollections of the curriculum as it was about 30 years ago; I do not know how much this picture has changed, if at all.  Basically, the further away from the center a subject is placed, the more theoretical.  Subjects are also placed according to my perception of how they strike the balance between matter, energy, and math.  For  example, Physics is far away from the center (very theoretical), but close to the Energy/Mathematics boundary; Mass Transfer is within the Matter/Mathematics zone, but closer to the center, indicating its practical content for designing equipment.  Of course, your mileage may vary, and I would like to hear suggestions as to how to make the placements more in line with a general perception.


There are two anomalies that do not fit the Theoretical vs. Practical model: Process Control and Reactor Design.  Both of these courses have the potential to be very practical courses, and I view these as a huge opportunity wasted.

 My recollection of Process Control was that it was almost totally theoretical, but not on the abstract level of pure mathematics.  If I had to guess, it is still taught that way today – students work with Laplace Transforms, trying to develop a mathematical description of a unit operation, inverting the transfer function, and graphing the response.  All theoretical and complete nonsense based on how actual design professional and plant process engineers actually design and specify control systems.  In my opinion, time would be better spent on actually discussing the pros and cons of various instruments, selection, symbology on a P&ID, and field installation.

Reactor Design is a more difficult question.  Students were/are taught about residence time distribution theory (highly math based), how to couple that with reactions kinetics, and managing the endo- or exothermic nature of the reaction.  In some instances they discuss catalysis, again focusing on the mass and heat transport equations.  All vey theoretical because we are taught that theory rules everything.  So the course has a very intensive practical component, but it is taught in almost a purely theoretical manner because the math is beautiful (well, it is, but that is not the point).

 Why not teach students about what passes in industry for the venerable old CSTR?  In industry, there are more types of reactors that behave as CSTRs than the plain vanilla stirred tank.  How about loop reactors, fluid bed reactors, forced recycle evaporators, etc?  Give students a glimpse as to what they may actually find in the real world.


6 Responses

  1. I am very impressed with the depth of this discussion. How do we continue to grow our math skills when we are employed in jobs that do not require us to think, but serve as emotional coaches for persons who avoided math at all costs?

  2. While I think your concept of Ch. E. as a three component mix is a good point of view, I disagree with your disdain for the theory even when you say Math is the basis of the profession. In my 30+ years of experience in the field I can say a chemical engineer is nothing if he or she does not have a solid base of theoretical concepts. I have designed a lot of processes, process plants or plant operations, and solved a great amount of problems and troubles in the industry just doing conceptual analysis, relying in time-tested procedures and applying the calculations that we learn at school and confirm in the practice. With your practical proposition of discarding process control theory or asking to reduce reactor kinetics theory, or in general, reducing the importance to the theory, the future chemical engineers would be no more than educated technicians following the written recipes, unable to really solve new problems.
    In respect to the Process Control Theory, I think it depends on how the course is teached. In my experience, most of the problems that arise in a process that once worked well are solved after an evaluation applying the process control and process dynamics theory. Then again, if you do not have a strong conceptual (theoretical) base you will not be able to solve the problem and will rely on trial-and-error methods as other non chemical engineers turned into process control engineers do, and await to have good luck.

    • Well … if you have ever worked in a production plant , you may recall not to even know the importance of lubricating the ball bearings , nor putting any attention to the elctric groundings … just two examples of waht is important in a plant in addition of knowing the Laplace derivate. I think it is matter of balancing what theory with practical knowledge not just reamin theoric , not become just a technician.

  3. I have just finished my junior year at the University of Utah. I entirely agree with what you’re saying. I’ve only learned about theory up to this point. Although what I’ve been taught works theoretically, it only works if the same bucketful of assumptions are made.

    I maybe able to soze a distillation column if it has constant molal overflow, but if it didn’t I wouldn’t even know how to fond the operating line. As for the good old CSTR, it was only the last week of class that the professor mentioned they aren’t perfectly mixed and their is pass through.

    Our rising generation of Chemical Engineers, myself included, would highly benefit from a change in the curriculum. Companies hiring new engineers want them to have hands on experience. Yes, internships help with that, but if it was built into the curriculum then it would better improve our abilities, as engineers, once we do graduate.

    I’m not saying that theory shouldn’t be apart of the curriculum. As Celso said, without the theory we can’t solve new problems. However, the current lack of a practical component hinders our ability to solve current problems.

  4. That is correct. Without practice we cannot apply theory. We need more practice while we are at school, however the question is: Can your school afford a 6-month practice as part of the 3-year instruction? Most if not all will relay the practice to the graduate’s first job. In my country it is common for big companies to have practice periods for graduates concerted with Universities. They usually hire the better ones. I know a company in Brazil that promotes an Engineering Contest among universities and hires the winners after a training period.

  5. Theory is important as long as you can transform it practical applications. After some years of practice in a petrochemical plant , engineers may become 70% practical 30% theoretical or less. I remember an Engineer now working as Project Manager for a very important Petrochemical Company , once trying to deploy a process to increase the reactor output in a PVC reaction. His first very practical decision was to increase the reactor’s yield… many chemical escalations were made to adequate formulations, the result was awful to say the less. Pressure was so high that the plant fire alarms started , so the reactor was shut down. Thing was that this engineer forgot , that thermodynamics had to be considered , simply the reactor jacket could not remove the amount of heat produced by the PVC reaction . The best process to increase the reactor output per day, as exactly the other way around, meaning reducing the reactor yield ,so the overcapacity of the reactor jacket removing heat ,increased the reaction rate increasing the total production per day by 30%. Pure Engineering theory applied to the same reaction and reactor…

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