Methods for Improvement of Enzymatic Hydrolysis of Lignocellullosic Material

A method of enzymatic hydrolysis of a lignocellulosic material, comprising the steps of:

• a) pretreating the lignocellulosic material using SO2 and/or sulfurous acid to obtain a slurry having a pH of less than 5;
• b) adding Ca(OH)2 and/or CaO to the slurry to increase its pH to at least 8;
• c) reducing the pH of the slurry from step b) to below 7;
• and
• d) adding hydrolytic enzymes to the slurry from c) and allowing the slurry to hydrolyze,
• wherein no washing of the slurry is performed prior to step d).

A method of producing at least one target molecule comprising the steps of:

• a) pretreating a lignocellulosic material to obtain a slurry having a pH of less than 6;
• b) adding NaOH, Ca(OH)2 and/or CaO to the slurry to increase its pH to at least 8;
• c) reducing the pH of the slurry to below 7;
• d) adding hydrolytic enzymes to the slurry from c) and subjecting the slurry to enzymatic hydrolysis to obtain an at least partly hydrolyzed slurry;
• and
• e) utilizing the at least partly hydrolyzed slurry from step d) as a substrate in a fermentation process for production of at least one fermentation product,
• wherein the enzymatic hydrolysis in step d) and the fermentation process in step e) are performed separately and wherein no washing of the slurry is performed prior to step d).