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 yiel d 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-assistan ce 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 aci d to ethyl acetate and water was investigated as a typical chemical eq uilibrium reaction. The selective and simultaneous water separation fr om the reaction mixture of the esterification with polyvinyl alcohol p ervaporation membranes is considered to be an interesting process alte rnative to the conventional distillation process. Compared to the dist illation process, for the pervaporation-assisted process a decrease of the energy input of over 75% and of the investment and operating cost s of over 50% each was calculated.