SUZ-4 zeolite interlayer enhanced thin-film composite pervaporation membrane for ethanol dehydration

SUZ-4 zeolite is a needle-like porous material with potential in separation. By incorporating a SUZ-4 zeolite interlayer on the macroporous ceramic hollow fibers to remedy the defects on the surface, thin-film composite (TFC) membranes with better pervaporation (PV) performance were expected to be prepared by interfacial polymerization (IP) processes. Through relevant experiments and characterization, high performance SUZ-4 zeolite interlayer enhanced TFC membranes were obtained by incorporating a zeolite interlayer and undergoing two-pass IP process. In addition, the TFC membrane had a special structure in which the inner layer was a nesting of polyamide and zeolite crystals, while the outer layer was a polyamide layer wrapping the inner layer. The structure of the inner layer similar to the mixed matrix membrane allowed the properties of the SUZ-4 zeolite to be utilized, whose performance was significantly better than the TFC membrane without the zeolite interlayer. After further optimization, the SUZ-4 enhanced TFC membrane exhibited a flux of 3.18 ± 0.3 kg/(m2·h) with a separation factor of 1056 ± 150 when applied to the pervaporation of 90 wt% ethanol dehydration at 60 °C. Moreover, the developed novel TFC membranes maintained good stability, which indicated these membranes possess great potential for pervaporation dehydration.