STUDY ON THE REACTION KINETICS OF SALT-CATALYZED ETHANOL-WATER PULPING OF ASPEN

摘要

The delignification kinetics of salt-catalyzed ethanol-water pulping of aspen was studied in this paper. The pulping was carried out under the optimum conditions of liquid ratio of 1: 10, ethanol volume percentage of 65%, holding temperature of 175°C, holding time of 210 min, and MgCl2 dosage of 3%, and pulp components were analyzed to educe the relationship between lignin removal and carbohydrate dissolvability. The result showed that there was an obvious linear relationship between natural logarithm of lignin content and cooking time during the cooking. It indicated that delignification of aspen by the salt-catalyzed ethanol-water pulping followed a first order reaction. The activation energies of the mass delignification phase and the residual delignification phase were 51.85kJ/mol and 87.31kJ/mol respectively. It revealed that the saltcatalyzed ethanol pulping method was feasible to make pulp from aspen.