Seeding-free synthesis of large tubular zeolite FAU membranes for dewatering of dimethyl carbonate by pervaporation

Thin, phase-pure and well inter-grown zeolite FAU membranes are synthesized upon modifying the tubular supports using 3-aminopropyltriethoxysilane (APTES). The as-synthesized zeolite FAU membranes are evaluated in the dewatering of dimethyl carbonate (DMC) by pervaporation. Due to the large pore size (0.74 nm) and high hydrophilicity of zeolite FAU, the prepared zeolite FAU membranes exhibit high water flux and separation performance for the separation of H₂O and DMC. With increasing the temperature or water content in the feed, the zeolite FAU membranes show higher flux while maintaining high separation factors. Further, for dewatering of 10 wt% H₂O/90 wt% DMC mixtures at 353 K in a lab device, the DMC concentration in the feed side reaches 99% after continuously dewatering over 9 h. Besides, the zeolite FAU membranes are also successfully prepared on commercial tubular size of 80 cm and 100 cm long α-Al₂O₃ tubes. The obtained membranes show high separation performance for the dewatering of DMC solution as well. The high-performance zeolite FAU membrane offers great potential for dewatering of DMC solutions in industry.