麦草碱预提取制备低聚木糖并改善纸浆及黑液性能

Preparation of Xylo-oligosaccharides from Wheat Straw Alkali Pre-extraction and Improvement of Qulities of the Pulp and the Black Liquor of Subsequent Pulping

关键词:  麦草  预提取  低聚木糖  纸浆  黑液

Key Words:wheat straw  pre-extraction  xylo-oligosaccharides  pulp  black liquor

摘要:利用稀碱蒸煮对麦草进行预提取，对提取液进行纯化、酶解，并对预提取后的固体物料进行烧碱法蒸煮。分析了提取液、低聚木糖溶液的成分和预提取后固体物料及所制得纸浆的组分含量，考察了纸浆的特性及黑液物化性能，探讨了预提取的作用效果。结果表明，预提取最佳用碱量为4%~6％，低聚木糖得率可达7.22%，聚合度为2.32；后续低碱蒸煮获得纸浆的卡伯值、黏度均与对照纸浆相近，白度、裂断长、撕裂指数和耐折度等均高于对照浆；黑液黏度低于对照黑液，高位发热量高于对照黑液，可达到15 MJ/kg以上。

Abstract:Dilute alkali pre-extraction of wheat straw before pulping was carried out, and purification and enzymatic hydrolysis of the extract were conducted, at last, wheat straw pulp was manufactured using the solid material after pre-extraction with low alkali charge. The extract and xylo-oligosaccharides solution, components of the solid material after extraction and the pulp were analyzed, and the properties of the pulp and black liquor, the effect of the pre-extraction were investigated. The results indicated that the yield of xylo-oligosaccharides can reach 7.22%, and the degree of polymerization of xylo-oligosaccharides is 2.32 when optimal dosage of alkali 4%~6% in pre-extraction is used. The Kappa Number and viscosity of the subsequent pulp are closely to the control pulp, and brightness, breaking length, tear index and folding endurance are higher than the control. The viscosity of the pulping black liquor is lower than control black liquor, and the heat value of black liquor is over 15 MJ/kg and higher than the control.