Paiboon Innachitra and Supaporn Chinchiw

pp. 1109 - 1119

Abstract

In this research, experiments were carried out to investigate the effects of operating parameters on the pervaporation performance for the separation of ethanol-water solutions. Composite silicone membranes supported on polysulfone prepared with varied silicone contents and commercial polyvinyl alcohol (Pervap® 2211, Sulzer) membranes were used. The results showed that the composite silicone/polysulfone membranes coated with 3 wt% of silicone exhibited highest permeation flux with slightly lower separation factor for ethanol. Furthermore, it was found that the composite silicone/polysulfone membranes were suitable for the separation of ethanol from a dilute ethanol solutions. Both the separation factor and permeation flux of the composite membranes increased with increasing temperature and feed concentration. A membrane coated with a 7 wt% silicone gave highest separation factor of 7.32 and permeation flux of 0.44 kg/m2h at 5 wt%
ethanol feed concentration and feed temperature of 70ºC. For polyvinyl alcohol membranes, the results showed that the membranes were suitable for the dehydration of concentrated ethanol solutions. The permeation flux increased and the separation factor for water decreased with increasing water feed concentration and temperature. The membrane gave highest separation factor of 248 and permeation flux of 0.02 kg/m²h at 5 wt% water feed concentration and feed temperature of 30ºC.