杂交杨木纤维中碳水化合物的稀酸催化分离  

Dilute Acid-catalyzed Fractionation of Carbohydrates in Hybrid Poplar Fibers

作　　者：张春辉[1] Troy Runge 詹怀宇[1] 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室 [2]Department of Biological System Engineering,University of Wisconsin-Madison,Madison,WI,USA 53706

出　　处：《造纸科学与技术》2012年第6期7-12,共6页Paper Science & Technology

基　　金：国家973计划项目(2007CB210201)

摘　　要：本文采用循环式反应器研究了杂交杨木纤维中聚戊糖和聚己糖在稀酸条件下的催化分离,分别得出了聚戊糖和聚己糖稀酸水解/降解的动力学模型,以预测在不同反应条件下戊糖和己糖的水解得率。反应条件为温度140～170℃,硫酸浓度0.1%～0.9%wt,液比为6∶1。研究发现,较高的酸浓和温度对提高戊糖和己糖的得率都有利,但相同条件下聚戊糖的反应活性更高。经动力学模型优化得出,在较佳条件下有91%的聚戊糖可以以单体、低聚体及其降解产物的形式从杨木纤维中分离出来,同时超过93%的聚己糖可以以固体的形式保留在纤维中。研究表明,在适宜的稀酸催化条件下杂交杨木纤维中的碳水化合物可以得到很好的分离,为下一步戊糖和聚己糖的分别单独转化打下了基础,不仅可以充分利用木材生物质资源,而且为反应提供了相对均一的条件,从而提高反应选择性和产物的纯度。In this paper, the acid-catalyzed fractionation of pentosans and hexosans from hybrid poplar fibers was studied using a circulation reactor. Kinetic models of both pentosan and hexosan hydrolysis/degradation were crea- ted to predict the hydrolysis yield of both substances. The extraction conditions were varied, including a tempera- ture range of 140 - 170℃ , a sulfuric acid concentration range of 0.1% - 0.9% wt with a constant liquor-to-wood ratio of 6： 1. The yields of both substances were favored at high acid concentration and temperature, while pentosan being considerable more reactive. Under optimal conditions, 91 percent of pentosan could be separated from the fi- ber, while more than 93 percent of hexosan was retained in the solids. This study demonstrates that pentosan and hexosans could be fractionated from poplar fibers using acid hydrolysis and converted into liquid fuel and valued chemicals separately.

关 键 词：杂交杨木 稀酸催化 聚戊糖 聚己糖 动力学 

分 类 号：TS743[轻工技术与工程—制浆造纸工程]