Method for producing acetification-grade dissolving pulp by using veneer

A technology for dissolving pulp and board skin, which is applied in the direction of pulping with organic compounds, pulping with inorganic alkalis, and cellulose treatment with microorganisms/enzymes, etc., to achieve the effect of cleaning the production process

Inactive Publication Date: 2019-03-01
QILU UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But there is no record of using poplar veneer to prepare vinegar grade dissolving pulp at home and abroad

Method used

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  • Method for producing acetification-grade dissolving pulp by using veneer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Prehydrolysis with Additives - Soda / AQ Staged Cooking with Additives - O P Q D EpP-enzyme synergistic process to treat poplar veneer raw material: Take 500g of poplar veneer slices from a certain factory, 10-30mm long, with a pentosan content of 24.3% and an α-cellulose content of 43.0%.

[0031] The pre-hydrolysis process conditions for controlling the addition of additives are: liquid ratio 1: 6, additives 0.4%, maximum temperature 160°C, holding time 60 minutes, the content of pentosan after hydrolysis is 8.6%, and the hydrolysis yield is 80%;

[0032]The process conditions of Soda / AQ cooking stage I are: the amount of alkali used is 5%, the liquid ratio is 1:4, magnesium hydroxide is 0.5%, sodium sulfite is 5.0%, the amount of AQ is 0.05%, Tmax=100℃±2℃, holding time 60 minutes;

[0033] The process conditions of Soda / AQ cooking stage II are: the amount of alkali used is 18%, magnesium hydroxide is 0.5%, sodium sulfite is 3.0%, the liquid ratio is 1:7, the amount o...

Embodiment 2

[0042] Prehydrolysis with Additives - Soda / AQ Staged Cooking with Additives - O P Q D EpP-enzyme synergistic process to treat the raw material of poplar veneer, the content of pentosan in the obtained poplar veneer is 22.3%, the content of α-cellulose is 45.0%, and the process conditions are the same as in Example 1. The α-cellulose content that obtains poplar bark vinegar grade dissolving pulp is 97%, polypentose is 2.2%, degree of polymerization 1280, whiteness 90%ISO, ash content 0.01%, DCM extract content 0.02%, vinegar Chemical reaction value (PV value) 820.

[0043] Poplar veneer vinegar-grade dissolving pulp has good detection indexes and can be used to produce high-grade cellulose acetate products.

Embodiment 3

[0045] Prehydrolysis with Additives - Soda / AQ Staged Cooking with Additives - O P Q D EpP-enzyme synergistic process to treat the poplar veneer raw material, the poplar veneer obtained is the same as that in Example 1. Only the pre-hydrolysis holding time was changed to 120 minutes, the content of pentosan after hydrolysis was 8.5%, and the hydrolysis yield was 79%, and other processes remained unchanged. The α-cellulose content of the finally obtained poplar veneer vinegar grade dissolving pulp is 97%, the polypentose is 2.2%, the degree of polymerization is 1200, the whiteness is 89%ISO, the ash content is 0.01%, and the DCM extract content is 0.02%. The esterification reaction value (PV value) is 780.

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Abstract

The invention relates to the technical field of dissolving pulp preparation and particularly relates to a method for producing acetification-grade dissolving pulp by using veneer. The method comprisesthe following steps: adding auxiliaries for prehydrolysis; Soda / AQ cooking stage I; Soda / AQ cooking stage II; OPDQEPP bleaching; enzyme collaborative treatment. The veneer acetification-grade dissolving pulp with high purity and high reaction activity is prepared; the applied chemicals are clean and environmentally friendly, and the production technology is clean.

Description

technical field [0001] The invention relates to the technical field of dissolving pulp preparation, in particular to a method for producing vinegar grade dissolving pulp by using poplar veneer. Background technique [0002] At present, the world's output of cellulose acetate is nearly 1 million tons, while my country's annual output of cellulose acetate is nearly 400,000 tons, and the annual consumption of acetate-grade wood dissolving pulp is about 300,000 tons. The esterification grade dissolving pulp is mainly used to prepare triacetate fiber cellulose diacetate, the hydroxyl groups on the 2, 3, and 6 positions of the cellulose glucose unit in the dissolving pulp are almost completely acetylated to obtain cellulose triacetate (substitution degree > 2.7), and cellulose triacetate is hydrolyzed to obtain Cellulose diacetate (substitution degree is 2.4-2.6), the reaction process is shown in the following formula. [0003] Cellulose triacetate is widely used in films, polari...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21C3/02D21C9/10
CPCD21C3/022D21C9/10D21C3/22D21C5/005D21C1/02D21C3/003D21C3/006D21C9/1005
Inventor 吴朝军于冬梅李荣刚王东李书平
Owner QILU UNIV OF TECH
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