磷酸预水解对竹柳主要组分含量的影响

Effect of Phosphoric Acid Addition in the Pre-hydrolysis Stage on the Main Component Contents of Bamboo-willow

预水解是基于硫酸盐法生产溶解浆过程中的关键一步,主要目的是在原料进行制浆之前尽可能多地从植物纤维原料中去除半纤维素。本研究探索了预水解段添加磷酸对竹柳原料中组分含量的影响。结果表明,在竹柳预水解段添加磷酸和增大液比、增加保温时间均有助于竹柳原料中聚戊糖的脱除,但不利于α-纤维素的保留;当磷酸用量为3%(相对于绝干原料),保温时间为60 min时,液比为6∶1时,预水解后竹柳中聚戊糖去除率为71.8%,α-纤维素含保留率为93.4%。

Pre-hydrolysis is a critical step in the production of dissolving pulp from the kraft process,and its main purpose is to hydrolyze the hemicelluloses as much as possible from cellulose fibers before subsequent pulping. In this paper,the effects of addition of phosphoric acid in the pre-hydrolysis process on the main component contents of bamboo-willow were explored. The result showed that with the addition of phosphoric acid in the pre-hydrolysis process of bamboo-willow and increasing the time at max temperature could help the removal of pentosan,but this was not conducive to the retention of α-cellulose. When the phosphoric acid dosage was 3%（ based on oven dried bamboo-willow）,the max temperature was 165℃,the time at max temperature was 60 min,the pentosan content in the pre-hydrolyzed bamboo-willow was gradually decreasing,the α-cellulose content obviously increased as the liquid-to-wood ratio was 6∶ 1.