Hydrophobic-ZIF-71 filled PEBA mixed matrix membranes for recovery of biobutanol via pervaporation

As an alternative energy source to fossil fuels, biobutanol has received increasing attention. In this work, new mixed matrix membranes (MMMs) incorporating zeolitic imidazolate frameworks (ZIF-71) particles into polyether-block-amide (PEBA) were prepared for biobutanol recovery from acetone–butanol–ethanol (ABE) fermentation broth by pervaporation (PV). FESEM, EDS, XRD, FT-IR, DSC and contact angle measurements were conducted to study the morphologies, physical and chemical properties and surface properties of the MMMs. The PV performance of the prepared MMMs with various ZIF-71 loadings for separating n-butanol from its aqueous solution was investigated. As a result, both separation factor and thickness-normalized flux of the PEBA membranes were improved by incorporating appropriate amount of ZIF-71 (≤20 wt%). The membrane with 20 wt% ZIF-71 was evaluated in ABE model solution and ABE fermentation broth, and exhibited high n-butanol separation performance. ZIF-71 particles were confirmed as promising fillers to enhance the separation performance for butanol recovery because of their excellent compatibility with polymer and organophilicity. This work demonstrated the ZIF-71/PEBA MMMs could be potential candidates for practical biobutanol production.