Reliable Fabrication of Thin and (h0l)-Oriented Zeolite Al-beta Membranes for Separation of Methanol/Methyl tert-Butyl Ether Mixtures

Dense, ∼1 μm thick and (h0l)-oriented zeolite Al-beta membranes have been successfully fabricated on randomly oriented seed layers by secondary growth in the fluoride medium. The incorporation of Al species into the zeolite framework is demonstrated by FTIR, EDS, and 29Si and 27Al MAS NMR measurements. The Al incorporation enhances the nucleation rate. The synthesized zeolite Al-beta membranes are applied in methanol/methyl tert-butyl ether (MeOH/MTBE) separation via pervaporation. It exhibits a high flux of 1.83 kg m–2 h–1 with respect to 20 wt % MeOH/MTBE mixture at 50 °C, while the corresponding separation factor is 20.39. Compared with available zeolite membranes reported in the literature, the synthesized Al-beta membrane is more promising for MeOH/MTBE separation because of its high flux with a moderate separation factor.