High permeability membranes for the dehydration of low water content ethanol by pervaporation

Energy efficient dehydration of low water content ethanol is a challenge for the sustainable production of fuel-grade ethanol. Pervaporative membrane dehydration using a recently developed hydrophilic polymer membrane formulation consisting of a cross-linked mixture of poly(allylamine hydrochloride) and a blend of 99 and 88% hydrolyzed poly(vinyl alcohol) is found to be an attractive method. These polymeric membranes possess high water permeabilities at low feed water concentrations (<5 wt%) in ethanol compared to similar membranes in which all of the poly(vinyl alcohol) portion was 99% hydrolyzed.