麦草浆无氯漂白的研究

Non wood Fibre Pulping and Papermaking TCF BLEACHING OF LAB WHEAT STRAW SODA—AQ PULP

本文对麦草浆无氯漂白的可漂性能进行了研究，指出在保持纸浆具有良好的粘度下，用常规氧碱漂白和强化氧碱漂白分别可脱除残余木素达５０％和７０％以上，纸浆的白度可分别达到３８％ＩＳＯ和４９％ＩＳＯ左右。常规氧漂浆再用过氧化氢强化的氧漂继而可多脱除２０％～３０％的残余木素，纸浆白度高达６０％～６５％ＩＳＯ。麦草浆用ＴＣＦ漂白流程如ＯＯ／ＰＰ，在最终过氧化氢漂段的过氧化氢用量为２．０％时，可获得白度为７５％～８０％ＩＳＯ的纸浆，若采用单段带压的氧气和过氧化氢漂白，可将氧漂浆和本色浆漂到８０％ＩＳＯ的白度，且过氧化氢用量达３．５％～５．０％。考虑到ＴＣＦ漂白废水可逆流回用到碱回收，消除了漂白废水的污染，从而使漂白车间无废水排放。

In this paper,totally chlorine-free(TCF)bleaching sequences such as OO/PP and OO/P were investigated.Lignin removal with these bleaching sequences were claimed to be around 50% and 70% respectively for wheat straw soda-AQ pulp.Brightness of 38%ISO and 49%ISO can be achieved with conventional and intensified oxygen treatment while keeping pulp viscosity within acceptable limits.Conventional oxygen delignified pulp with kappa no.of 6 0,followed by O/P bleaching,further removed about 20%-30% lignin.A brightness of over 60%—65%ISO can be obtained after this stage. The wheat straw soda-AQ pulp can be bleached to a brightness of about 75%ISO in a TCF bleaching sequence whth a 2 0%peroxide charge in the final peroxide stage.In the case of oxygen pressurized peroxide bleaching,a brightness of 80%ISO can be achieved by using 3 5—5 0%peroxide in one P/O stage for virgin pulp of oxygen delignified pulp respectively.Bleaching effluents can be recycled to the chemical recovery plant. TCF BLEACHING OF WHEAT STRAW SODA-AQ PULPAn Guoxing Pulp and Paper Industrial Research Institute of China, Beijing, P. R. ChinaRudolf PattUniversity of Hamburg, Hamburg, GermanyAbstract In this paper, totally chlorine-free(TCF) bleaching sequences such as OO/PP and OO/P were investigated. Liginin removal with these bleaching sequences were claimed to be around 50% and 70% respectively for wheat straw soda-AQ pulp. Brightness of 38%ISO and 49%ISO can be achieved with conventional and intensified oxygen treatment while keeping pulp viscosity within acceptable limits. Conventional oxygen delignified pulp with kappa no. of 6.0, followed by O/P bleaching, further removed about 20%-30% lignin. A brightness of over 60%-65%ISO can be obtained after this stage.The wheat straw soda-AQ pulp can be bleached to a brightness of about 75% ISO in a TCF bleaching sequence with a 2.0% peroxide charge in the final peroxide stage. In the case of oxygen pressurized peroxide bleaching, a brightness of 80%ISO can be achieved by using 3.5～5.0% peroxide in one P/O stage for virgin pulp or oxygen delignified pulp respectively. Bleaching effluents can be recycled to the chemical recovery plant.