Bioethanol recovery using the pervaporation separation technique

Purpose The purpose of this paper is to demonstrate applicability of the pervaporation technique for separation ethanol/water mixtures. Design/methodology/approach For the purposes of membrane material development for pervaporation zeolite filled and unfilled cellulose acetate membranes were prepared. Zeolite types were 4A, 13X. The effect of incorporation of nano‐sized zeolites prepared in a colloidal form in membranes was also investigated. Equilibrium sorption experiments were carried out. Degrees of swelling were calculated at different liquid feed mixture compositions for separating an azeotrope forming mixture, ethanol/water by pervaporation. Findings Zeolite 13X filled CA membrane may have the better pervaporation performance than zeolite 4A filled CA membrane. From the sorption tests it is concluded that ethanol/water azeotropy can be achieved by pervaporation. Practical implications Application of CA membranes in industrial scale pervaporation units may be feasible for separation of ethanol/water mixtures. Specially ethanol/water azeotropy will be achieved by pervaporation. Using distillation and pervaporation hybrid systems, bioethanol can be produced economically. Orginality/value The paper illustrates the success of pervaporation techniques in separating ethanol/water mixtures.