Dehydration of monohydric alcohols via pervaporation using nano NaX zeolite/ polyvinyl alcohol mixed matrix membranes for biofuel production

摘要

This paper focuses on the dehydration of monohydric alcohols via pervaporation process for using as biofuel additive. For this purpose, two-layer polyvinyl alcohol (PVA)/polyethersulfone (PES) mixed matrix membranes containing nano NaX zeolite were fabricated. The ATR-FTIR, SEM, AFM and swelling tests were employed to characterize surface properties and morphology of the prepared membranes. The results revealed that incorporation of nano NaX zeolites into the cross-linked PVA layer of membranes improved the separation performance. The total and water fluxes enhanced by increasing the zeolite content, whereas the water separation factor had a maximum at the zeolite concentration of 2%wt. for dehydration of a 90% wt. aqueous ethanol solution. The pervaporative dehydration of aqueous solution of methanol, ethanol and isopropanol indicated that the total permeation flux decreased in the order of methanol > ethanol > isopropanol, while the water separation factor had a reverse trend. Finally, the performance of the papered mixed matrix membranes was compared with a commercial hydrophilic PVA membrane and it was observed that the mixed matrix membrane containing 2% wt. NaX zeolite had higher permeation flux and separation factor than the commercial membrane.