热水预水解对杨木半纤维素提取及后续硫酸盐法制浆的影响

Effect of Autohydrolysis on Pre-extraction of Hemicelluloses andSubsequent Kraft Pulping of Triploid Poplar

基于制浆造纸过程中的生物质精炼理念,利用热水预水解预先提取杨木木片中的半纤维素,然后对水解后的木片进行硫酸盐法蒸煮,探讨预水解因子(P因子)对半纤维素提取和后续硫酸盐法制浆的影响。研究结果表明,热水预水解对半纤维素的提取效果显著,且P因子可较好地控制预水解反应过程;预水解处理能提高后续硫酸盐法蒸煮脱木素的效果,降低蒸煮用碱量,但会增大后续浆料打浆难度,同时降低成纸的某些物理性能。综合考虑后续水解液的生物质利用和水解木片的硫酸盐法制浆,当P因子为608～1060时,水解液中的聚戊糖提取率为33.18%～35.31%,相应的预水解KP制浆得率为39.47%～37.12%;与未经热水预水解处理的对照样相比,热水预水解处理后浆料性能和黑液性能均较好。

Based on the concept of biorefinery in pulp and paper industry, pre-extracting hemicelluloses sugars from poplar chips via auto- hydrolysis was carried out , and then the extracted chips were used for the kraft pulping. The influence of P-factor on pre-hydrolysis and subsequent kraft pulping were investigated. The results indicated that autohydrolysis is a satisfactory process for pre-extracting hemicelluloses, and the autohydrolysis process can be well controlled by the P-factor. Besides, autohydrolysis treatment can significantly improve the delign- infication efficiency in subsequent kraft pulping, decrease the EA charge at the sacrifice of the beatability of the pulp and some physical prop- erties of the paper. Considering the subsequent biomass utilization of pre-hydrolysis and pulping performance of the treated wood chips, the P-factor of autohydrolysis is controlled in the range from 608 to 1060, which the extraction rate of pentosan in pre-hydrolysate is from 33.18% to 35.31% and the yield of the kraft pulp is from 39.47% to 37.12%. Compared with the control sample, the properties of the kraft pulp and the pulping black liquor of the pre-hydrolysis treated sample are better at the reasonable P-factor.