PRE-EXTRACTION OF HEMICELLULOSES IN ALKALINE PULPING FROM BAGASSE

摘要

In this paper, the process of hemicelluloses pre-extraction in alkaline pulping from bagasse was investigated, and some parameters which may affect the pre-extraction of hemicelluloses were optimized, such as alkali charge, temperature and time at maximum temperature. In addition, the relationship between the process of hemicelluloses pre-extraction and paper properties were also discussed. The results showed that the optimized conditions were as follows: alkali charge 10%, liquor-to-solid ratio 5:1, temperature 120°C, and time at maximum 80 min. Under these conditions, 18.7% of hemicelluloses was obtained (base on o.d.). The bagasse was pre-extracted using the optimum pre-extraction conditions of hemicelluloses, and then, the bagasse was cooked further by NaoH-AQ proceeding and the properties of handsheets were as follows: tensile index 71.4N·m/g, tear index 8.40 mN·m2/g, bursting index 4.69kPa·m2/g. The properties of handsheets were similar to those of conventional alkaline pulp and satisfied the requirement of papermaking.