Simultaneous water adsorption from ethyl alcohol and oil extraction from corn

Abstract

Energy-efficient dewatering of fermentation ethyl alcohol is essential whether the alcohol is for fuel or chemical use. Adsorption of water on dried grain such as corn is one method that can meet this objective. Adsorption of water from liquid solutions containing 88–95 wt% ethyl alcohol onto fixed beds of unrefined corn is described here. Water adsorption capacity was 40–50% of the theoretical value for perfectly selective adsorption of water, but still adequate so that the water-saturated grain used in adsorption could also be feedstock to the fermentation, Cincurrent with the dewatering of the ethyl-alcohol by the corn grain, curde corn oil was extracted by the ethyl alcohol. When the capacity of the grain for producing anhydrous alcohol was reached, up to 80% of the oil had been extracted. Benefits include improved energy efficiency for the complete conversion of grain to anhydrous ethyl-alcohols as compared to existing methods, a 7% gain in the fuel value of products relative to conversions where no oil is recovered, and a potential for increased product diversity in small-scale operations where only ethyl alcohol is usually produced.