초록 ▼

A process is disclosed for the pretreatment of lignocellulosic fibrous materials prior to delingification. The process in one of its embodiments is comprised of the following steps: 1. Contacting the pulp material with treated filtrate and alkali for a short reaction period of about 1 to 2 minutes a

A process is disclosed for the pretreatment of lignocellulosic fibrous materials prior to delingification. The process in one of its embodiments is comprised of the following steps: 1. Contacting the pulp material with treated filtrate and alkali for a short reaction period of about 1 to 2 minutes at 40°C., 2. Withdrawing part of the liquid phase by filtration, 3. Displacing substantially all of the remaining liquid phase with treated filtrate, and 4. Allowing the pulp to react under conditions normally used for alkaline extraction or oxygen delignification. The treated filtrate is obtained by subjecting the liquor removed from the pulp at steps 2 and 3 to temperature of 5°to 60°C. for periods of about 5 to 10 minutes. Alternatively, step 3 can be eleminated.

대표청구항 ▼

In the process of manufacturing paper-making pulp in which an alkaline solution is added to wood pulp to cause a reaction that delignifies the pulp, the improvement comprising mixing wood pulp with an alkaline solution containing from about 1.5% to 25% alkali based on oven dry pulp, partially reacti

In the process of manufacturing paper-making pulp in which an alkaline solution is added to wood pulp to cause a reaction that delignifies the pulp, the improvement comprising mixing wood pulp with an alkaline solution containing from about 1.5% to 25% alkali based on oven dry pulp, partially reacting the mixture at a consistency from about 1% to 15% and a temperature from about 20 deg C. to 60 deg C. for about 0.5 to 7 minutes, with the partial reaction time being longer for lower temperatures in the range and shorter for the higher temperatures in the range, withdrawing from about 30% to 90% of the liquid phase from the reacting mixture to raise the consistency of the pulp to about 10% to about 45% before the reaction has been completed, and continuing the reaction of the remaining alkali and pulp at the raised consistency of the pulp at a temperature from about 35 deg C. to 120 deg C. for about 30 to 120 minutes, wherein the withdrawal of liquid phase from the pulp enhances the delignification of the pulp.