Pervaporation of binary water-ethanol mixtures through bacterial cellulose membrane

摘要

Cellullose membrane produced by the bacterium Acetobacter xylinum was deproteinated andinvestigated for pervaporation (PV) of binary water-ethanol mixtures.The membrane was characterisd using elemental analysis,infra-red spectroscopy,scanning electron microscopy as well as for mechanical strength and sorption characteristics.A batch stirred cell was used to study the PV behaviour of water-ethanol mixtures through the membrane.The permeate flux,selectivity,PV separation index (PSI),solubility and degree of sorption were studied as a function of increasing ethanol concentration in the feed.The membrane was found highly selective to water.Even when the feed was rich in ethanol (>70% (w/w)) the permeate contained higher than 95% (w/w) of water.For feed compositions containing less than 30% water,the selectivity towards water was in the range of 125-287,the flux was greater than 100 g/m~2h and PSI was of the order of the order of 10~4 g/m~2h.