Spray-Coatedpdms/Pvdfcomposite Membrane For Enhanced Butanol Recovery By Pervaporation

In this study, spray-coating was used to prepare dihydroxypolydimethylsiloxane (PDMS) composite membranes with high flux and separation factor for biobutanol recovery from aqueous solution. A thin, smooth, and defect-free PDMS layer was prepared by spray-coating on polyvinylidene difluoride ultrafiltration membrane with little PDMS penetration. The effects of process parameters for membrane fabrication and pervaporation on membrane performance were investigated. A membrane with 2 mu m active layer was obtained with a high flux of 1306.9 g/m(2)h. The optimal membrane with the highest pervaporation separation index (PSI) (19.15 kg/m(2)h) showed a total flux of 530.6 g/m(2)h and a separation factor of 36.1 at 37 degrees C, and a PSI of 65.61 kg/m(2)h and a flux of 1927.0 g/m(2)h at 70 degrees C. Membrane performance was affected by feed composition and temperature. Acetone-butanol-ethanol solution and fermentation broth gave lower butanol fluxes and separation factors compared to butanol model solution.