I am preparing a basic course on Separation Processes (5th semester, BSc Chemical Engineering). I can see that many well-known textbooks (e.g. Seader & Henley, Wankat) start by teaching in detail distillation and only then, the chapters on absorption/stripping are presented. As a student, I think I was taught exactly the opposite: first absorption and then distillation, which I believe it is a natural way as absorption is significantly simpler than distillation. My question is, what are the pros and cons of teaching first absorption and then distillation?
My own list would be:
Pros
- Absorption/stripping equilibria are often described by Henry's law (or similar). It is an easier first step than complex VLE expressions
- It's a good way to introduce McCabe-Thiele algorithms
- No condenser or reboiler. Therefore, no need to do energy balances at first (only when vaporization heat is very significant)
Cons
- Distillation is the most relevant separation process and it is important to allocate a lot of time to its thorough study