Processing and recovering process of chemical fiber pulp cellulose alkali pressed liquor

A squeeze liquid and cellulose technology, which is applied in the field of processing and recovery of chemical pulp cellulose alkali squeeze liquid, can solve the problems that cannot be directly reused, cannot meet the concentration of alkali liquid in the impregnation process, etc., achieve high value-added recycling, realize Recovery, the effect of improving the recovery rate of alkali

Active Publication Date: 2014-02-12
SHANGHAI KAIXIN ISOLATION TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At this time, although the alkali is purified, the concentration of the obtained alkali is diluted, which cannot meet the concentration of alkali solution requi...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Alkali squeeze liquid is 100 cubic meters, the concentration of sodium hydroxide in the feed is 250g / L, and the content of hemicellulose is 25g / L. Enter the primary membrane separation system at a temperature of 50 degrees Celsius and operate at a pressure of 2 MPa. When concentrated to a hemicellulose content of 80g / L, the concentrated solution enters the secondary membrane separation system to continue to concentrate. Operated under the conditions of 50 degrees Celsius and 0.5 MPa, the semi-fiber content of the net liquid is 19g / L, and the alkali concentration is the same as that of the original liquid. The membrane filtrate of the primary membrane separation system and the secondary membrane separation system is placed in the filtrate tank for standby. When the permeate volume reaches 95 cubic meters, the hemicellulose content in the concentrated solution is about 460 grams per liter. The filtrate is combined with the primary filtrate. Total filtrate hemicellulose...

Embodiment 2

[0046] Example 1 Put 5 cubic meters of the hemicellulose concentrate after membrane concentration into a tank, and pump it into a secondary membrane separation system or a tertiary membrane separation system. Add dialysis water. As the filtration proceeds, sodium hydroxide enters the filtrate end along with the water, and the concentrated liquid end follows the gradual reduction of sodium hydroxide and the pH value gradually decreases, and hemicellulose is gradually separated out. Concentrate further to obtain 5 cubic meters of hemicellulose concentrate and 20-30 cubic meters of dilute lye. The hemicellulose concentrate can be directly used to produce xylose. Hemicellulose powder was obtained by spray drying.

Embodiment 3

[0048] The membrane concentrate of the alkali recovery system is 5 cubic meters, of which the hemicellulose content is 400g / L, and the sodium hydroxide concentration is 200g / L. Add 95% ethanol to the container where the concentrated solution is placed, stir while adding, and the volume of the added ethanol is 1-2 times the volume of the stock solution. Hemicellulose is precipitated. Let stand for more than 2 hours. Enter the three-stage membrane separation system for separation. At a pressure of 0.4 MPa, the membrane surface flow velocity was maintained at 4 m / s. Concentrate to the original volume first, then dialyze with water, and add 20 cubic meters of water. A hemicellulose concentrate that can be directly recovered is obtained.

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PUM

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Abstract

The invention provides a processing and recovering process of a chemical fiber pulp cellulose alkali pressed liquor. The processing and recovering process mainly comprises the steps of primary film separating, secondary film separating, hemi-cellulose separating-out, ternary film separating, hemi-cellulose recovering, and the like. The invention provides a process for recovering the hemi-cellulose and alkali from the alkali pressed liquor. Compared with the prior art of recovering the alkali by using a nano-filtration system, the process provided by the invention has the advantages that the alkali recovering rate is higher and can reach 95% under the precondition that the concentration of the alkali is unchanged. Meanwhile, the recovering of the hemi-cellulose in the pressed liquor is realized, the obtained hemi-cellulose can be used as xylose producing raw material or directly used as a dispersing agent. In addition, the service life of the films can be prolonged.

Description

technical field [0001] The invention relates to the treatment of three wastes, in particular to a treatment and recovery process of chemical pulp cellulose alkali squeeze liquid. Background technique [0002] In the production process of viscose fiber (rayon) using chemical fiber pulp (wood pulp or cotton pulp, straw pulp, bamboo pulp, reed pulp and other plant cellulose) as raw materials, the cellulose alkali treatment process is the key to the production of viscose fiber. first step. Usually the manufacture of fiber products requires that the purity of α-cellulose used as raw material reaches more than 92% (not less than 90%). Since the raw material still contains more hemicellulose, it is necessary to dissolve the hemicellulose with alkaline solution in the impregnation process to obtain high-strength cellulose. The high concentration of hemicellulose will have extremely adverse effects on the production process of viscose fiber and the quality of finished products. ...

Claims

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Application Information

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IPC IPC(8): D21C11/00
Inventor 申雅维曹厚康田灿彬张芸
Owner SHANGHAI KAIXIN ISOLATION TECH CO LTD
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