Optimization of steam pretreatment of SO2-impregnated corn stover for fuel ethanol production.

In this study, corn stover with a dry matter content of 20% was impregnated with SO2 and then steam pretreated for various times at various temperatures. The pretreatment was evaluated by enzymatic hydrolysis of the solid material and analysis of the sugar content in the liquid. The maximum overall yield of glucose, 89% of the theoretical based on the glucan in the raw material, was achieved when the corn stover was pretreated at 200 degrees C for 10 min. The maximum overall yield of xylose, 78%, was obtained with pretreatment at 190 degrees C for 5 min.