Separation of ethanol—water mixtures by pervaporation—membrane separation process

Abstract

In this paper, the experimental studies on the separation of ethanol—water mixtures by pervaporation are presented and evaluated with special attention to the purification of alcohol dilute aqueous solution from fermentation and the separation of an ethanol—water azeotropic mixture with ethanol-permeable and water-permeable polymeric membranes, including cellulose acetate, cellulose triacetate, polydimethylsiloxane, polyvinylidene fluoride, and polysulfone membranes. The main parameters such as the separation factor and permeability are determined for both single and composite membranes. The feasibility and economic performance of the membrane separation process in combination with conventional distillation are compared with those of conventional azeotropic separation methods. The mechanism of separation is examined with the aid of the basic and a modified solution—diffusion model.