Alkaline polyol pulping and enzymatic hydrolysis of softwood: Effect of pulping severity and pulp properties on cellulase activity and overall sugar yield

The saccharification of softwood using alkaline polyol pulping (AlkaPolP) and enzymatic hydrolysis was investigated. It will be demonstrated that the AlkaPolP process yields high quality pulps which can easily be hydrolyzed by celluloses. Temperature (180-230 degrees C) and duration (15-60 mm) of the alkaline glycerol pulping, expressed as pulping severity R-0, were varied to find optimum reaction conditions. The obtained pulps were characterized regarding their residual lignin content, kappa number and crystallinity index. Thus, the dependencies of the conversion during enzymatic hydrolysis on severity, pulp composition and pulp characteristics could be observed. In further experiments it was investigated how the enzymatic hydrolysis is affected by pulp drying or by a reduction of enzyme loading. Up to 83% of the initial cellulose in wood and almost 97% of the cellulose in pulp were converted into glucose using celluloses from Trichoderma reesei and beta-glucosidase from Aspergillus niger. (C) 2013 Elsevier Ltd. All rights reserved.