Permselective properties of PVA-PAA blended membrane used for dehydration of fusel oil by pervaporation

Dense membranes were prepared by blending poly(vinyl alcohol) with poly(acrylic acid) and tested for the dehydration by pervaporation of fusel oil, by-product issued from brazilian ethanol distilleries. For a PVA-PAA (90-10 in wt%) membrane, pure water permeation rates obtained an three times higher than those reported by Ping et al. at the same temperature. Permselective properties were determined as a function of the blend composition in order to find an optimal blend composition. Then a systematic study has been achieved on both binary water/ethanol, water/isoamylic alcohol and ternary water/ethanol/isoamylic alcohol solution, main components in fusel oil. Sorption equilibriums have shown that at a given water activity, water volume fraction was different, whereas water permeation rates could be known from the water volume fractions. The investigation of temperature effects allowed the determination of the apparent activation energies of water and ethanol, the only two permeants, and then to underscore the mutual interaction between water, alcohol and polymeric membrane.