酸洗条件对未漂硫酸盐麦草浆己烯糖醛酸去除的影响

Effect of Acid Washing Conditions on the Removal of Hexenuronic Acids from Unbleached Kraft Wheat Straw Pulp

关键词:  麦草浆  酸洗  己烯糖醛酸  经验模型

Key Words:wheat straw pulp  acid washing process  HexA  empirical model

摘要:考察了不同酸洗条件（pH值、酸洗时间、酸洗温度和浆浓）对未漂硫酸盐麦草浆中己烯糖醛酸（HexA）去除效果的影响。结果表明，在酸洗过程中浆料的碱性物质对初始pH值为3和5的体系pH值有较大影响，进而影响到HexA的去除效果；随着酸洗时间的增加，浆中HexA含量不断减少，其水解速率也不断下降，最佳酸洗时间以40 min为宜；pH值是影响HexA去除的主要因素，在pH值小于3时HexA能进行有效水解；提高酸洗温度（60～90℃）和浆浓（7％～16％）对HexA的去除具有促进作用，但它们作用效果不如pH值显著。建立了未漂硫酸盐麦草浆酸洗过程中HexA含量变化的经验模型，其规律可为分析同类原料酸洗去除HexA的效果提供参考。

Abstract:This paper reported on the effect of the acid washing conditions (pH, time, temperature and pulp consistence) on the removal of hexenuronic acid (HexA) from unbleached kraft wheat straw pulp. The results showed that alkaline substance in the pulp had a great influence on the system with initial pH range from 3 to 5, and then affect the removal efficiency of HexA; the content of hexenuronic acid in the pulp decreased as processing time increasing; pH was the major factor affecting HexA removal, which was more efficient at pH below 3; raising the processing temperature（60～90℃） and the pulp consistence （7％～16％）could slightly promote HexA removal. An empirical model for predicting the change of hexenuronic acid content in unbleached kraft wheat straw pulp during acid washing was established, which could be used as reference for analyzing the removal of HexA from analogous wheat straw pulp in acid washing treatment.