Study on separation of low concentration ethanol/water solutions with polydimethylsiloxane membrane by vapour permeation

The polydimethylsiloxane(PDMS)membrane was used to separate low concentration ethanol/water solutions by vapour permeation.The influences of ethanol concentration,membrane module temperature,cycle gas flow rate and vacuum degree on separation properties were studied.The results showed that permeation flux and ethanol concentration of permeation side increased as ethanol concentration of feed increased,but separation factor decreased;permeation flux increased and ethanol concentration of permeation side decreased as temperature of membrane module increased,affect was significantly;permeation flux and ethanol concentration of permeation side increased significantly as cycle gas flow rate increased,which was effective to vapour permeation process;permeation flux increased and ethanol concentration of permeation side decreased as vacuum degree increased.