Simultaneous saccharification and fermentation of several lignocellulosic feedstocks to fuel ethanol

Abstract

When ethanol fuel is produced from lignocellulosic materials such as wood, herbaceous plants, and agricultural and forestry wastes, its use as a transportation fuel reduces dependence on imported petroleum, decreases the balance of trade deficit, improves urban air quality, contributes no net carbon dioxide to the atmosphere, and provides new markets for depressed farm economies. The simultaneous saccharification and fermentation (SSF) process is a favored option for conversion of the lignocellulosic biomass into ethanol because it provides enhanced rates, yields, and concentrations of ethanol with less capital investment compared to competing processes. In this study, the performance of four woody crops (aspen, two hybrids of populus, and a native strain of sweetgum), three herbaceous crops (switchgrass, weeping love grass, and Sericea lespedeza), and three agricultural residues (corn cobs, corn stover, and wheat straw) is reported for the SSF process. For the pretreatment conditions employed for these feedstocks, excellent results were obtained for corn cobs followed by corn stover, wheat straw, weeping love grass, the woody crops, and switchgrass. Only the legume S. lespedeza did not give good ethanol yields for the pretreatment conditions chosen. © 1992.