稻草硝酸法制浆工艺的研究

Study on Nitric Acid Pulping Process of Rice Straw

以硝酸水溶液为蒸煮药剂,在常压下对稻草进行制浆工艺和脱木素历程的研究,结果表明:稻草硝酸法制浆较适宜的蒸煮工艺在液比为20:1的条件下,稀硝酸浓度为4.5%,温度为91℃,蒸煮时间约为4 h;纸浆纤维长度主要集中在0.6~2 mm范围,纤维宽度集中于5~10μm范围。稻草硝酸法制浆脱木素历程分为两个阶段,即大量脱木素阶段和补充脱木素阶段。大量脱木素阶段纸浆得率的降低以溶出木素为主,补充脱木素阶段以溶出碳水化合物为主。

The pulping process and delignification course of rice straw were studied using nitric acid aqueous solution as a cooking agent under atmospheric pressure. The results showed that the suitable pulping process was a dilute nitric acid concentration of 4.5%, a temperature of 91℃ and a cooking time of about 4 h at a liquid ratio of 20:1. The pulp fiber length was mainly concentrated in the range of 0.6~2 mm, and the fiber width is concentrated in the range of 5~10 μm. The delignification course of nitric acid pulping of rice straw was divided into two stages, namely, a large amount of delignification stage and a supplementary delignification stage. The reduction of pulp yield was mainly due to the dissolution of lignin in the large amount of delignification stage, and the dissolution of carbohydrates in the stage of supplementation of delignification.