Membrane reactors in chemical production processes and the application to the pervaporation-assisted esterification

When appropriate membranes are used for the assistance of chemical and biochemical equilibrium reactions, it is possible to enhance the yield and the purity of the reaction products by selectively adding educts or selectively removing products and to a lower the energy input and the reaction time compared to conventional processes. In this paper a review on membrane reactors with special emphasis on membrane-assistance of esterification reactions and a continuous tube membrane reactor for the pervaporation-assistance of the esterification are presented. The heterogeneously catalyzed esterification of ethanol and acetic acid to ethyl acetate and water was investigated as a typical chemical equilibrium reaction. The selective and simultaneous water separation from the reaction mixture of the esterification with polyvinyl alcohol pervaporation membranes is considered to be an interesting process alternative to the conventional distillation process. Compared to the distillation process, for the pervaporation-assisted process a decrease of the energy input of over 75% and of the investment and operating costs of over 50% each was calculated.