PVA/H-β zeolite mixed matrix membranes for pervaporation dehydration of isopropanol-water mixtures

摘要

Mixed matrix membranes (MMMs) of poly (vinyl alcohol) (PVA) containing certain amounts of H-beta zeolite for pervaporation were manufactured by using a solution casting protocol. These zeolite-embedded membranes were then characterized with scanning electron microscope (SEM), X-ray diffraction (XRD) and swelling tests. The membrane separation performance has been examined by means of isopropanol (IPA) dewatering from its highly concentrated aqueous solutions via response surface methodology (RSM). The results have demonstrated that the influences of feed IPA composition (85-95 wt.%), feed temperature (50-70 degrees C), zeolite loading (15-25 wt.%) and their interactive influences are all statistically significant on both pervaporation flux (398-1228 g/m(2).h) and water/isopropanol separation factor (617-2001). The quadratic models based on the RSM analysis have performed excellently to correlate experimental data with very high determination coefficients and very low relative standard deviations. The optimal pervaporation predictions given by using the RSM models demonstrate a total flux of 953 g/m(2).h and separation factor of 1458, and are excellently verified by experimental results. As reflected by these results, PVA MMMs embedded with hydrophilic H-beta zeolite entities have performed considerably better than its pure counterpart and indicated great potential for isopropanol dehydration applications.