B1. The Kremser equation can be used for more than just determining the number of stages. List as many types of problems (where a different variable is solved for) as you can. What variables would be specified? How would you solve the equation?
B2. Many other configurations of absorbers and strippers can be devised. For example, there could be two feeds. Generate as many as possible.
B3. You want to use both co-current and countercurrent absorbers in a process. Sketch as many ways of doing this as you can think of. What are the advantages and disadvantages of each method?