发明名称 |
PEROXIDE BLEACHING PROCESS FOR CELLULOSIC AND LIGNOCELLULOSIC MATERIAL |
摘要 |
A method for bleaching cellulosic and lignocellulosic pulp using hydrogen peroxide as a bleaching reagent, utilizes a two-step reaction, viz. a short high temperature step at a pressure sufficient to suppress boiling and a longer atmospheric pressure reduced temperature step to consume a substantial portion of the hydrogen peroxide remaining after the short phase. The method includes the steps of introducing pulp (15), at a consistency of 10 %-18 %, to a mixer (100) in which the pulp is heated to a temperature above 100 DEG C; adding sufficient sodium hydroxide to bring the pulp to a pH of 8.5; adding sufficient hydrogen peroxide (36) to equal from about 0.5 %-5.0 %, by weight, of the pulp; passing the pulp through a pressurized reactor column (400) at a rate providing a reaction time in the column of between 1 and 30 minutes; and depositing the pulp in a reaction tower and allowing the reaction to proceed for 1-5 hours until a substantial portion of the residual hydrogen peroxide has been consumed. 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 between bleaching steps.
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申请公布号 |
WO9601920(A1) |
申请公布日期 |
1996.01.25 |
申请号 |
WO1995US08137 |
申请日期 |
1995.06.29 |
申请人 |
INGERSOLL-RAND COMPANY;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. |
分类号 |
D21C9/10;D21C9/153;D21C9/16;(IPC1-7):D21C9/16;D06L3/02 |
主分类号 |
D21C9/10 |
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