Evaluation of pretreatments for enzymatic conversion of agricultural residues

The effectiveness of various physical and chemical pretreatments on the enzymatic digestibility of wheat straw was evaluated. Structural features, including crystallinity and lignin content, were measured after pretreatments. Several promising pretreatments were identified. In general, chemical pretreatments were more effective than physical pretreatments. Although the hydrolysis rate was dependent appreciably on the crystallinity index, lignin content of the substrate appeared predominant. The hydrolysis rate increased with an increase in the degree of delignification only up to 50%; it remained unchanged thereafter. Scanning electron microscopic observations were used to facilitate further insight into structural modification of the substrate. A preliminary cost analysis was conducted.