硫酸盐制浆过程中硫的分布与变化规律

The distribution and variation of sulfur during wood Kraft pulping

本文研究了兴安落叶松硫酸盐制浆过程中流在蒸煮液、溶出木素和残余木素中的分布及变化情况。结果表明，蒸煮过程中蒸煮液的活性碱和硫化钠浓度不断下降，硫化度则不断上升，活性碱与硫化钠的消耗主要发生在初始脱水素阶段．溶出木素的含硫量在初始脱木素阶段量最高，随着蒸煮反应的进行，其百分含量逐渐下降，但绝对量却不断上升。蒸煮结束时，约占总用硫量1／5的硫与溶出木素结合在一起。木片或纸浆的含硫量与木素的硫化速率和残余木素的含量密切相关。在残余脱木素阶段，残余木素的硫化对木素的说除已没有促进作用。

Dahurian larch (Larix gmelini Rupr.) was employed to study the distributionand variation of sulfur during kra ft cooking. Sodium sulfide is consumed mainly in thestage of initial delignification, which changes little in the phase on temperature. About40% of the total sodium sulfide is consumed at the end of cooking reaction. The sulfidityincreases gradually during the whole process, which has a god linear relationship withdelignification. The sulfur content of dissolved lignin in the initial cooking stage ishigher, and it changes little in the bulk and residual delignification phases. Sulfur linkedchemically with wood or pulp, is interrelated closely with the lignin sulfidation rate andthe content of the residual lignin. Sulfur in the residual lignin increses rapidly in thephase of residual delignification. Because of the structural properties of the residuallignin, such as more condensed and linked chemically with carbohydrate, it is stilldiffcult to be removed in kraft cooking, though the su1fUr content of high.