AbstractThe effect of delignification on the enzymatic hydrolysis of biomass was investigated to determine how different delignification processes affect enzymatic hydrolysis conversion yields. Oxygen, hydrogen peroxide, and sodium chlorite treatments were performed, and the structural and chemical changes in the biomass were evaluated. Sodium chlorite delignification proved the most effective process to remove lignin in hardwood samples, followed by oxygen delignification. Hydrogen peroxide delignification was not as effective as the other two methods. As for the enzymatic conversion of carbohydrates after delignification processes on hardwood, oxygen and sodium chlorite treatments substantially improved conversion yields as the number of successive treatments was increased, compared to untreated hardwood samples. Changes in α-cellulose after delignification were less substantial than those of hardwood samples, and corresponding conversion yields were also lower. Delignification-induced structural changes in treated substrates might be responsible for the changes in carbohydrate conversion yield observed following subsequent enzymatic hydrolysis.