High-Performance n-Butanol Recovery from Aqueous Solution by Pervaporation with a PDMS Mixed Matrix Membrane Filled with Zeolite

Zeolite-filled polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) were developed for pervaporation separation of n-butanol from dilute butanol–water solution. The effects of zeolite, feed butanol concentration, and temperature were studied. In general, the butanol separation factor increased with increasing the temperature, whereas the fluxes increased with the reducing membrane thickness and increasing feed butanol concentration and temperature. At 47 °C, PDMS MMMs filled with 40 wt % zeolite gave the highest separation factor of 77, which would reduce the energy consumption for butanol recovery from 1.0 wt % butanol by ∼75% to ∼10 MJ/kg butanol using a hybrid pervaporation-distillation process compared to distillation. The zeolite-filled PDMS MMM with a thickness of 10 μm would have a high butanol flux of 1000 g/m2·h at 56 °C. With a high separation factor and butanol flux, the zeolite-filled PDMS MMM would be advantageous for recovering n-butanol from dilute solution at significantly reduced energy input and cost.