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

The saccharification of beech wood 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 cellulases. In order to find optimum reaction conditions chips of Fagus sylvatica were pretreated by alkaline glycerol at temperatures between 190 and 230 degrees C for 15, 20, and 25 min. The impacts of temperature and time were expressed using a severity factor R-0. The dependencies of the conversion during enzymatic hydrolysis on severity, pulp yield, delignification and pulp composition are shown. In further experiments it was investigated if the sugar yields can be increased by the application of ultrasound or surfactants before enzyme addition. Up to 95% of the initial cellulose in wood were converted into glucose using cellulases from Trichoderma reesei and beta-glucosidase from Aspergillus niger. (C) 2013 Elsevier Ltd. All rights reserved.