Butanol fermentation liquor production and separation by reverse osmosis

Abstract
The problem of dilute solvent concentration in butanol-acetone fermentations can be solved by using reverse osmosis to dewater the fermentation liquor. Polyamide membranes have a potential application in a butanol-acetone fermentation and exhibited rejection rates as high as 98%. Optimum rejection of butanol in the fermentation liquor occurred at recoveries of 20–45%. Flux ranged from 0.05 to 0.6 L m−2 min−1.