It has been shown that enzymatic hydrolysis of cellulosic material can be significantly improved by simultaneous attrition. The enhancement is due to the concurrent and continuous formation of reactive sites for association with the enzyme. Various chemical and physical methods are used to modify the substrate and hence increase the rate and extent of hydrolysis. The modification may involve removal of lignin from the plant cell walls. In this study, samples which have been prepared by an organosolv delignification in ethanol-water have been evaluated using simultaneous attrition and hydrolysis. (Refs. 12).