AIChE Journal, Vol.44, No.2, 388-393, 1998
Detrimental influence of excessive fractionation on reactive distillation
Reactive distillation has been demonstrated to reduce the capital cost and increase reactant conversion in MTBE production. These advantages are potentially transferable to the production of ETBE, TAME, and other tertiary ethers. However, the design of reactive distillation columns is complicated by interaction between phase and reaction equilibrium. Whereas in conventional distillation, an increase in fractionation is always associated with an improvement in process performance (separation of key components), the same does not necessarily apply to reactive distillation. Using the production of ETBE as an example, several reactive distillation columns were designed for various feed compositions and design philosophies. It was found that the best designs incorporated high reflux ratios with a restricted number of theoretical stages, and that increasing the number of theoretical stages could actually be detrimental to process performance.