Nanocomposite Silicalite-1/Polydimethylsiloxane Membranes for Pervaporation of Ethanol from Dilute Aqueous Solutions

Separation of alcohols from dilute aqueous solutions is important to enable continuous microbial production of biofuels. Pervaporation is a process with great potential for continuous extraction of alcohols from biological fermentation broths. Here, we report on the synthesis and pervaporation performance of thin, supported pure polydimethylsiloxane (PDMS) and silicalite-1/PDMS nanocomposite membranes with nanoparticle contents of 10, 20, and 30 wt %. Using a batch pervaporation system, we measured flux and separation factors of the membranes for solutions of 4 wt % ethanol in water at 25 °C, 50 °C, and 65 °C. With increased nanosilicalite loadings in the nanocomposite membranes, we obtained both increased flux and increased alcohol separation factors.