The potential of different hemicelluloses extraction methods in conversion of environmentally friendly ECF and TCF bleached paper-grade bagasse soda pulp to dissolving-grade pulp

Abstract

Dissolving pulp as a purified chemical pulp with high cellulose content, is an important raw material for many applications such as cellulose derivatives and regenerated cellulose, hence paper-grade bagasse pulp as a cheap alternative non-wood raw material can be used to produce dissolving-grade pulp. In this work, the potential of ECF and TCF bleached paper-grade soda bagasse pulp in the production of dissolving pulp was studied. To find an effective method, bleaching sequences followed by the different hemicellulose extraction processes including CCE, xylanase treatment, IONCELL-P, combination of xylanase treatment and IONCELL-P were investigated. The unbleached bagasse pulp was subjected to the IONCELL-P process using mixtures of 1-ethyl-3-methylimidazolium acetate/water for the extraction of xylan from an initial of 30.5 to 7.0%. The ECF (ODEpQP1.5%) sequence resulted in the optimum bleached pulp in terms of physical and chemical properties and the consumption of bleaching chemicals, which was selected for subsequent treatments to remove xylan to produce dissolving pulp. In the IONCELL-P treatment of bleached pulp, the xylan content could even be reduced to 5.9% (80% removal) and in X-IONCELL-P to 3.3% (90% removal). All the extraction methods investigated in this study removed xylan with differences in the selectivity and efficiency successfully.