Selective ethanol extraction from fermentation broth using a silicalite membrane

The selective extraction of ethanol from ethanol fermentation broth through a silicalite zeolite membrane was investigated. Ethanol (98.2 wt.%) at permeate side which is above the azeotropic composition, was continuously obtained from the fermentation broth having a 20 wt.% ethanol concentration. The separation factor of ethanol over water was 218, which is higher than that from water-ethanol mixtures. This high ethanol selectivity was due to the salts that are contained in fermentation broth. The high ethanol selectivity was maintained for 48 h. (C) 2002 Elsevier Science B.V. All rights reserved.