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.

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