公开(公告)号：WO1997015715A1

公开(公告)日：1997-05-01

申请号：PCT/SE1996001154

申请日：1996-09-18

Applicant: SUNDS DEFIBRATOR INDUSTRIES AB

Inventor： SUNDS DEFIBRATOR INDUSTRIES AB ,  BOKSTRÖM, Monica ,  MELLANDER, Pia ,  NORDÉN, Solveig

IPC: D21C09/147

CPC classification number: D21C9/147

Abstract: A method of oxygen delignification of pulp from lignocellulosic material at medium concentration in two steps. An extended delignification is obtained in that the temperature in the first step is held below 90 DEG C, that the difference in temperature between the steps is lower than 20 DEG C. The pressure in the first step is 4-10 bar and in the second step 2-5 bar, and the pressure in the first step is higher than in the second step. The oxygen addition to the first step is high, 25-50 kg/ton pulp, that alkali is added only to the first step for obtaining high alkalinity in the pulp, 25-50 kg alkali per ton pulp. The stay-time in the first step is 10-30 min and in the second step 45-180 min.

Abstract translation: 在两个步骤中，中等浓度的木质纤维素材料的纸浆的氧脱木质素的方法。 获得延长的脱木质素，其中第一步骤中的温度保持在90℃以下，步骤之间的温度差低于20℃。第一步中的压力为4-10巴，第二步中的压力为 步骤2-5巴，第一步骤中的压力高于第二步骤。 第一步中的氧添加量高，为25-50kg /吨纸浆，仅在第一步中添加碱，以获得纸浆中的高碱度，每吨纸浆25-50kg碱。 第一步的停留时间为10-30分钟，第二步为45-180分钟。

公开(公告)号：EP0909354A1

公开(公告)日：1999-04-21

申请号：EP97930929.0

申请日：1997-06-16

Applicant: SUNDS DEFIBRATOR INDUSTRIES AB

Inventor： BOMAN, Rolf ,  BOKSTRÖM, Monica ,  GERMGARD, Ulf ,  MELLANDER, Pia ,  NORDEN, Solveig ,  SUNDIN, Matts

IPC: D21C9

CPC classification number: D21C9/1026 ,  D21C9/144

Abstract: The present invention relates to a multi-stage paper pulp bleaching process in which at least one of the bleaching stages is carried out in a reactor with chlorine dioxide at a pulp concentration of 8-40 %. The pulp is bleached with chlorine dioxide in a pressurized vessel at an overpressure of 0.1-10 bars and at a temperature of between 90-110 °C and for a reaction time of 1-90 minutes. The pressure of the pulp is lowered in a downstream tower in a manner such as to also lower the temperature of the pulp and enable residues of chlorine dioxide to be extracted in gas phase.