Process synthesis of a reactive distillation system using attainable region results

A binary component system in which a more volatile reactant is converted into a less volatile product in a reaction limited by equilibrium is considered. A number of alternative flowsheets have been proposed for the system, including a reactor-distillation-recycle system, a reactor-stripper-recycle system and two catalytic distillation systems, one with recycle and the other at total reflux. For all the flowsheets separation is achieved in packed columns, while the catalytic distillation column uses a catalyst coated packing. Each flowsheet is optimized with respect to a simple linear cost function. This is done by first simplifying the flowsheet using attainable region results followed by a simplex search. Two different cost functions are considered. If the catalyst is expensive relative to the cost of packing then the optimal catalytic distillation system is marginally more expensive than the optimal reactor-distillation-recycle system. The optimal reactor-stripper-recycle system is significantly more expensive than the optimal reactor-distillation-recycle system. Where the cost of catalyst is inexpensive relative to the cost of packing a similar result is found except that the optimal catalytic distillation system is equivalent to the reactor-stripper-recycle reaction.