SU1756435A1 - Process for producing cellulose - Google Patents

Abstract

The invention relates to the pulp and paper industry and allows for an increase in the yield of pulp. In the method of producing cellulose by boiling wood chips in an ethanolic-aqueous medium in the presence of γ-alumina and an activating additive, glycerol or ethylenediaminetetraacetic acid disodium salt is used as the last ratio of alumina and activating additive 1: 0.01-1: 0.5 at the consumption of an activating additive is 0.1-0.5% by weight of absolutely dry chips. 1 з.п f-ly, 1 tabl

Description

The invention relates to the pulp and paper industry, in particular the production of pulp for the production of paper and paperboard and for chemical processing.

A known method for the production of cellulose by cooking wood chips in an ethanolic-aqueous medium in the presence of y-alumina at elevated temperature.

However, this method does not allow to obtain pulp with high yield and low residual lignin content.

The closest to the proposed method to the technical essence and the achieved effect is a method of producing cellulose by cooking wood chips in an ethanol-water medium in the presence of y-alumina with the additional introduction of activating additives at elevated temperatures

This method makes it possible to produce cellulose with a low residual lignin content at a relatively high cellulose yield.

The purpose of the invention is to increase the yield of pulp.

The goal is achieved by the fact that in the method of producing cellulose by boiling wood chips in an ethanolic-oiodic medium in the presence of γ-alumina and an activating additive, glycerol or ethylenediaminetetraacetic acid disodium salt (Trilon B) is used as an activating additive 5.0% by weight of absolutely dry chips and the ratio of y-alumina to the activating additive is from 1: 0.01 to 1: 0.5.

The achievement of this effect is due to the introduction of y-alumina, which functions as a sorbent in the cooking solution, regulators of the dissolution rate of u-alumina, such as glycerin or Trilok B, capable of forming complex compounds with aluminum ions in aqueous solutions.

During the cooking process, the acidity of the cooking solution is increased due to the release of low molecular weight organic acids from the wood raw material.

WITH

WITH

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that Gf-det to increase the solubility of y and the increase in the contents of aluminum ions in the cooking solution. Aluminum ions can be hydrolyzed to form hydroxocomplexes, while the acidity of the medium further increases, resulting in lower yields. The introduction of complex formations excludes the hydrolysis of aluminum suits, which can later be involved in sorption processes on lignin forms).

The proposed method is carried out as follows.

Wood chips (aspen) 24 g as. placed in a stainless steel laboratory autoclave and poured over a cooking solution consisting of 20 vol. % ethanol, 80 vol. % water containing 10% y-AlaOa with respect to absolutely dry wood chips. Additionally, an activating additive is introduced into the cooking liquor in an amount of 0.1-5.0 May. % relative to absolutely dry wood chips. Cooking is carried out at 180 ° C, module 1.5 for 3 hours.

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five

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Specific embodiments of the proposed method and obtaining the results are presented in the table.

As can be seen from the table, the proposed method allows to increase the yield of cellulose and reduce the residual lignin content.

Claims (2)

1. A method for producing cellulose by boiling wood chips in an ethanol-aqueous medium in the presence of γ-alumina and an activating additive, which is the same. that, and in order to increase the yield of cellulose, glycerol or ethylenediaminetetraacetic acid disodium salt is used as an activating additive. 2. The method according to claim 1, characterized in that they use α-alumina and an activating additive when the ratio is from 1: 0.01 to 1: 0.5 and the consumption of the activating additive is 0.1-0.5% by weight absolutely dry wood chips.