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 degrees C, 50 degrees C, and 65 degrees C. With increased nanosilicalite loadings in the nanocomposite membranes, we obtained both increased flux and increased alcohol separation factors.