Monday, April 30, 2007

Effects of fermentation byproducts on solvent extraction of ethanol from aqueous solutions

Chuanbin Liu and Ted Aulich. Energy & Environmental Research Center, University of North Dakota, 15 North 23rd Street, Grand Forks, ND 58202-9018

Solvent extraction has long been regarded as  an alternative method for the recovery of ethanol from dilute fermentation broth. Continuous extractive fermentation of ethanol with significantly increased ethanol productivity has been reported. A number of organic solvents have been tested in terms of ethanol extraction performance, product recovery, solvent regeneration, and biocompatibility with ethanol-producing microorganisms. However, very few study has been done on the effects of fermentation byproducts, including lactic acid, acetic acid, and glycerol, on solvent extraction and regeneration. In this work, the partitioning of the aforementioned fermentation byproducts, as well as the influence of temperature and pH on solvent extraction were studied.