A treatment method for reclaiming distillation raffinate from cellulose ether solvent

Abstract

The invention discloses a treatment method adopting cellulose ether solvent to recycle vinasse, which comprises the following steps: during the production process of cellulose ether, an organic solvent medium is adopted to distill the vinasse generated during the recycling process to a supersaturated solution or until the moisture is completely evaporated to dryness, ethyl acetate is adopted to perform first extraction so as to filter and separate lost cellulose ether, the ethyl acetate is distilled for recycling, and the leftover after distillation is a secondary product of etherifying agent; first extraction is performed on the subnatant, quantitative hydrogen chloride is added for acidification, then ethyl acetate is added for secondary extraction so as to recycle acetic acid or glycollic acid, the ethyl acetate is distilled and recycled for recycling, the leftover after distillation is acetic acid or sodium glycollate, secondary extraction is performed on the subnatant, alkali is adopted for neutralization, concentration is performed continuously, and sodium chloride is filtered and recycled. According to the invention, as less organic solvent in the concentrated solution is evaporated, and the organic solvent can be used together with a washing solution in the production technology of cellulose ether, zero emission of the three wastes during the production process of the cellulose ether is realized, waste material is changed into things of value, and higher economic benefit is obtained.

Description

technical field [0001] The invention belongs to the technical field of producing cellulose ether and starch ether by using plant fiber and starch as raw materials through alkalization and etherification, and in particular relates to a treatment method for recovering distillation raffinate from a cellulose ether solvent. Background technique [0002] Cellulose ether, starch ether, and bran mixed ether mainly use plant fiber, starch, bran, etc. as raw materials. After alkalization, different etherifying agents are used to produce a series of cellulose ether, starch ether and other products. Due to etherifying agents, such as: etherifying agents such as chloroacetic acid, methyl chloride, ethyl chloride, ethylene oxide, propylene oxide, 3-chloro-2 hydroxypropyl trimethylammonium chloride, etc. have a low reaction efficiency, resulting in A large number of by-products of etherification agents, such as: sodium glycolate, ethylene glycol and its ethers, propylene glycol and its et...

AI Technical Summary

Problems solved by technology

Due to etherifying agents, such as: etherifying agents such as chloroacetic acid, methyl chloride, ethyl chloride, ethylene oxide, propylene oxide, 3-chloro-2 hydroxypropyl trimethylammonium chloride, etc. have a low reaction efficiency, resulting in A large number of by-products of etherification agents, such as: sodium glycolate, ethylene glycol and its ethers, propylene glycol and its ethers and other organic substances; cellulose ether and starch ether have excessive alkali in the production process, usually neutralized with acetic acid, A large amount of sodium acetate is produced, causing serious environmental pollution

Because the waste liquid contains cellulose ether or starch ether, sodium chloride, sodium acetate, propylene glycol and its ether, propylene glycol and its ether and other substances mixed together, it is difficult to separate. The waste liquid is basically impossible to deal with, which directly affects the survival of the industry

[0003] At present, some domestic manufacturers use biochemical methods to treat cellulose ether and starch ether production waste liquid, but the effect is not ideal, and it is difficult to popularize.

Domestic cellulose ether manufacturers have basically not treated the production waste liquids such as cellulose ether and starch ether, resulting in particularly serious environmental pollution

Due to the difficulty in the treatment of the three wastes, many large-scale production enterprises are unable to expand production and produce some new products of cellulose ether. The three wastes problem has become a bottleneck affecting the development of the cellulose ether industry.

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