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Purifying process for high-quality glycolic acid

A glycolic acid, high-quality technology, applied in the separation/purification of carboxylic acid compounds, the preparation of carboxylate, the preparation of organic compounds, etc., to achieve the effects of improving production efficiency, overcoming complex processes, and high purification efficiency

Inactive Publication Date: 2018-03-20
JIANGSU JINJU ALLOY MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Aiming at the problem that the existing purification process is difficult to prepare high-quality glycolic acid, the present invention provides a purification process for preparing high-quality glycolic acid from low-purity glycolic acid with relatively mild reaction conditions and relatively simple process

Method used

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  • Purifying process for high-quality glycolic acid

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Effect test

Embodiment 1

[0040] A purification process for high-quality glycolic acid:

[0041] (1) The low-purity glycolic acid mixed solution obtained by the hydrolysis of chloroacetic acid was reacted for 4 hours under a complex titanium catalyst, 170° C., and a vacuum of 10 mmHg to prepare glycolic acid oligomers;

[0042] (2) According to the molar ratio of glycolic acid and methanol corresponding to the glycolic acid oligomers as a feed ratio of 1:1.1, the alcoholysis reaction was carried out under a zinc oxide catalyst, 120° C., and 0.65 MPa for 6 hours to prepare a methyl glycolate mixture;

[0043](3) Utilizing the difference in boiling point of each component, the methyl glycolate is rectified and purified, and excess methanol is returned to participate in the alcoholysis reaction;

[0044] (4) According to the feed ratio of 1:1.2, a small amount of glycolic acid is added to the purified methyl glycolate and water as a catalyst, and a high-purity product with a purity of 99.6% is obtained th...

Embodiment 2

[0046] A purification process for high-quality glycolic acid:

[0047] (1) The low-purity glycolic acid mixed solution obtained by the hydrolysis of chloroacetic acid was reacted for 3 hours under a complex titanium catalyst, 185° C., and a vacuum degree of 20 mmHg to prepare glycolic acid oligomers;

[0048] (2) According to the molar ratio of glycolic acid and methanol corresponding to the polyglycolic acid oligomer as a feed ratio of 1:1.8, the alcoholysis reaction was carried out under a magnesium oxide catalyst, 135° C., and 0.96 MPa for 5 hours to prepare a methyl glycolate mixture;

[0049] (3) Utilizing the difference in boiling point of each component, the methyl glycolate is rectified and purified, and excess methanol is returned to participate in the alcoholysis reaction;

[0050] (4) According to the feed ratio of 1:3, a small amount of glycolic acid is added to the purified methyl glycolate and water as a catalyst, and a high-purity product with a purity of 99.6% ...

Embodiment 3

[0052] A purification process for high-quality glycolic acid:

[0053] (1) The low-purity glycolic acid mixed solution obtained by the hydrolysis of hydroxyacetonitrile was reacted for 2 hours under a complex titanium catalyst, 200° C., and a vacuum of 30 mmHg to prepare glycolic acid oligomers;

[0054] (2) According to the molar ratio of glycolic acid and methanol corresponding to the polyglycolic acid oligomer as a feed ratio of 1:2.5, the alcoholysis reaction was carried out at 150° C. and 1.8 MPa for 4 hours to prepare a methyl glycolate mixture;

[0055] (3) Utilizing the difference in boiling point of each component, the methyl glycolate is rectified and purified, and excess methanol is returned to participate in the alcoholysis reaction;

[0056] (4) According to the feed ratio of 1:5, a small amount of glycolic acid is added to the purified methyl glycolate and water as a catalyst, and a high-purity product with a purity of 99.7% is obtained through a vacuum hydrolysi...

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Abstract

The invention discloses a purifying process for high-quality glycolic acid. The purifying process comprises the steps of preparing a glycolic acid low polymer from low-purity glycollic acid through condensation polymerization, preparing methyl glycolate at a high temperature and a high pressure by virtue of an alcoholysis process, carrying out rectification and purification, and carrying out a hydrolysis reaction rectification process on methyl glycolate, so as to obtain high-quality glycolic acid. By virtue of the purifying process, various residual impurities in a traditional glycollic acidpreparation process can be effectively removed, the purifying cost of glycolic acid is lowered, the yield of a glycolic acid product is increased, and the purity of prepared glycolic acid is not lowerthan 99.6%.

Description

technical field [0001] The invention relates to a high-quality glycolic acid purification process, which belongs to the field of organic chemical synthesis and refinement, in particular to a process for preparing high-quality glycolic acid from low-purity glycolic acid. Background technique [0002] Glycolic acid is an important organic synthesis intermediate, currently mainly used in daily chemical industry, chemical cleaning, welding, sterilization, coating ingredients, nanomaterials and other industries. At the same time, due to the biodegradability of glycolic acid polymers, it is also widely used in medical polymers and other fields. At present, although domestic production capacity of glycolic acid is increasing day by day, high-quality glycolic acid still needs to be imported, especially in cosmetics, electronic component cleaning, and pharmaceuticals, which are more demanding industrial applications. [0003] Since the application of glycolic acid is becoming more a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C59/06C07C51/493C07C51/42C07C51/487
CPCC07C51/42C07C51/487C07C51/493C07C59/06
Inventor 吴晓金吴维果翁伟明刘志刚贡秀君
Owner JIANGSU JINJU ALLOY MATERIAL