公开(公告)号：EP0919661A1

公开(公告)日：1999-06-02

申请号：EP98204179.0

申请日：1995-06-29

申请人： BELOIT TECHNOLOGIES, INC. ,  Pulp and Paper Research Institute of Canada

发明人： Shackford, Lewis D. ,  Miller, William J. ,  Roy, Brian P. ,  Van Lierop, Barbara ,  Berry, Richard M.

IPC分类号： D21C9/16 ,  D21C9/10

CPC分类号： D21C9/1026 ,  D21C9/1057 ,  D21C9/163

摘要： A method for bleaching cellulosic and lignocellulosic pulp using hydrogen peroxide as a bleaching reagent, utilizes a three stage reaction, viz. two short high temperature peroxide bleaching steps (50,160) at a pressure sufficient to suppress boiling and an interstage treatment (90) including a longer atmospheric pressure reduced temperature bleaching step. The two short peroxide bleaching stages include the steps of introducing pulp, at a consistency of 10%-18%, to a mixer (20,130) in which the pulp is heated to a temperature above 100 degree Celsius; adding sufficient sodium hydroxide (32,142) to bring the pulp to a pH of 8.5; adding sufficient hydrogen peroxide (33,143) to equal from about 0.5%-5.0%, by weight, of the pulp; passing the pulp through a pressurized reactor column (50,160) at a rate providing a reaction time in the column of less than 45 minutes, cooling the pulp and discharging the cooled pulp to a washer. It may be desirable to introduce the pulp to a mixer and add alkali to reactivate residual hydrogen peroxide by bringing the pulp to a pH of at least 9 after the first bleaching stage, deposit the pulp in a reaction tower and allowing the reaction to proceed until a substantial portion of the residual hydrogen has been consumed.

摘要翻译： 使用过氧化氢作为漂白试剂漂白纤维素和木质纤维素纸浆的方法采用三步反应，即， 在足以抑制沸腾的压力下进行两个短的高温过氧化物漂白步骤（50,160）和包括较长的大气压降低温度漂白步骤的级间处理（90）。 两个短的过氧化物漂白阶段包括将纸浆以10％-18％的浓度引入到其中将纸浆加热至高于100摄氏度的混合器（20,130）的步骤; 加入足够的氢氧化钠（32,142）使纸浆的pH值达到8.5; 将足够的过氧化氢（33,143）加入至纸浆重量的约0.5％-5.0％ 使纸浆通过加压反应器塔（50,160），其速率在柱内提供少于45分钟的反应时间，冷却纸浆并将冷却的纸浆排出到洗衣机中。 可能需要将纸浆引入混合器中并通过在第一漂白阶段使纸浆至少为9的pH将碱添加到碱中以再活化剩余的过氧化氢，将纸浆沉积在反应塔中并允许反应进行直至 剩余氢的大部分已被消耗。

公开(公告)号：EP0206560A3

公开(公告)日：1988-07-20

申请号：EP86304123

申请日：1986-05-30

申请人： Pulp and Paper Research Institute of Canada

发明人： Liebergott, Norman ,  Van Lierop, Barbara

IPC分类号： D21C09/10

CPC分类号： D21C9/10

摘要： There are provided improvements relating to the delignification and/or the bleaching of a chemical pulp wherein the cellulosic material is simultaneously treated with an alkali compound, a peroxygen compound and an oxygen gas at partial pressure in the presence of a viscosity protecting catalyst.