A novel process for efficient utilization of bamboo fiber resource in dissolving pulp production by fiber fractionation: Laboratory study and mill trials

The rational use of bamboo to make dissolving pulp can offer up new opportunities for cellulose production, alleviating wood scarcity. Bamboo contains a high content of non-fiber cells, which presents technical challenges in dissolving pulp production by the conventional process. In this study, a process concept of separating hemicelluloses is presented by fiber fractionation and purification for cleaner production of bamboo dissolving pulp: bamboo kraft pulp was fractionated into long-fiber and short-fiber fractions. The cellulose-rich long-fiber fraction was converted to dissolving pulp by further purification treatment with acid hydrolysis and cold caustic extraction. The hemicellulose-rich short-fiber fraction was used for papermaking. The laboratory results were confirmed by those from mill trials. The combined pulp yield (dissolving pulp + paper-grade pulp) reached 49 %, which was significantly higher than that of the conventional pre-hydrolysis kraft pulping process. Furthermore, the quality of dissolving pulp was higher due to inherently higher cellulose content of long-fiber fraction.