Hemicellulose and hexenuronic acid removal selectivity to give boosting effect to ECF bleaching

Abstract

Abstract Varies wood structure need difference way of treatment to get the appropriate quality of wood pulp. In pulp industry, wood chips should be cooked and bleached in order to have a good quality of pulp suitable for paper industry. A modified pulp cooking such as Continuous Isothermal Cooking and Super Batch Cooking followed by ECF bleaching is a good alternative for the achievement the necessary standard quality. Effort to achieve better quality in higher yield has so many times been done. Enzyme treatment using xylanase using Ecopuylp TX-200 is a good alternative that could be done in the ECF bleaching stage. Two kinds of unbleached wood pulp from Eucalyptus camaldulensis from AA Thailand, Acacia mangium from RAPP Indonesia is used in this experiment. The bleaching results are analysed for yield, viscosity, hexenuronic acid content, and brightness. The results give an indication that wood structure has a close correlation with the accessibility of enzyme and chemistries in giving peeling effect of lignin from lignin carbohydrate complex (LCC) to get high brightness of pulp with minimum fibre losses. The presence of Na2CO3 in the cooking liquor to gather with the xylanase has positive effect in the cleavage of hemicellulose and lignin through hydrogen bond at – OCH3.