Method for extracting and purifying hydroxy-acetic acid by ester solvents

A technology of glycolic acid and ester solvents, which is applied in the field of ester solvent extraction and purification of glycolic acid and extraction of glycolic acid, can solve the problems of high viscosity, little industrial prospect, and difficult phase separation, and achieve easy recovery and reuse, high Theoretical and practical value, cost reduction effect

Inactive Publication Date: 2007-04-11
SHIJIAZHUANG ZHONGTIAN BIOTECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But the used extraction agent of these methods is more expensive, and the extraction agent component is more, easily emulsifies, and viscosity is big, easily sticks on the vessel wall, phase separation is difficult, and the component ratio of the recovered extraction agent changes easily , so the industrial prospects are not good

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Example 1: In a three-neck flask equipped with a stirrer, a thermometer and a condenser tube, add a solution of 92mL of 95% to 98% sulfuric acid and 60mL of water, start stirring, and heat the flask with an external oil bath. When it reaches 100°C, add 300mL of 50% hydroxyacetonitrile dropwise to produce a strong hydrolysis reaction, control the reaction temperature at 115-120°C, and boil and reflux for 6 hours to obtain a hydrolyzate. The conversion rate of hydroxyacetonitrile was determined to be 99.3%. Add 1g of activated carbon for decolorization, stop heating, filter while hot, and filter out the activated carbon. Adjust the pH value of the hydrolyzate to 0.5-2.0 by using ammonium bicarbonate or ammonia water in the filtrate. Cool to room temperature, and salt out. Filtrate and desalt to obtain a glycolic acid aqueous solution containing inorganic acids and salts, adjust and control the glycolic acid content in the hydrolyzed solution with water.

Embodiment 2

[0018] Embodiment 2: prepare glycolic acid aqueous solution according to embodiment 1, extraction hydrolyzate is water phase (W), pH value 0.5, glycolic acid content: 600g / L, ethyl acetate (O) is oil phase, adopts intermittent stirring extraction. In a three-neck flask equipped with a stirrer, a thermometer and a condenser tube, add 25mL of hydrolyzate and 25mL of ethyl acetate, control the extraction temperature, stir, and make the extractant ethyl acetate and glycolic acid mixed aqueous solution contact. Comparison: O / W=1, extraction temperature=10°C, extraction time=10min. After phase separation, the organic phase was distilled under reduced pressure at a heating temperature of 45°C to obtain white solid glycolic acid. Once extracted, the yield of glycolic acid was 6%.

Embodiment 3

[0019] Embodiment 3: Prepare glycolic acid aqueous solution according to embodiment 1, pH value is 1.0, glycolic acid content: 600g / L. Using the same device as in Example 2 for extraction, comparison: O / W=3, extraction temperature=35°C, extraction time=10min. After phase separation, the organic phase was distilled under reduced pressure at a heating temperature of 45°C to obtain white solid glycolic acid. Once extracted, the yield of glycolic acid was 24%.

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PUM

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Abstract

The present invention relates to process of extracting and purifying hydroxyacetic acid with ester solvent from hydroxyacetic acid aqua obtained through hydrolyzing hydroxyacetonitrile in acid medium. The process includes the steps of treating the hydrolysate, salting out, extracting hydroxyacetic acid, recovering salt and concentrating. The present invention has the technological advantages of simple technological process, low investment, no need of back extraction, facile extractant with stable property, low cost, etc; and may be used in industrial production.

Description

technical field [0001] The invention relates to a method for extracting and purifying glycolic acid with an ester solvent, which belongs to the technical field of organic chemical synthesis and refining, and is particularly suitable for extracting glycolic acid from hydroxyacetonitrile hydrolyzate. Background technique [0002] Glycolic acid (also known as glycolic acid) has low toxicity, low corrosion, low odor, biodegradable, and is a water-soluble metal chelating agent with good performance. From its structural formula HO-CH 2 -COOH It can be seen that glycolic acid also has dual chemical characteristics, which makes it not only widely used in the synthesis of various intermediates, but also its unique chelating ability for metals makes it widely used in both civil and industrial cleaning fields. good effect. Glycolic acid widely exists in plants in nature, but it is difficult to separate and extract because of its low content and coexistence with other substances. At ...

Claims

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Application Information

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IPC IPC(8): C07C59/06C07C51/48
Inventor 王书香李记太陈国锋程丽华李胜辉
Owner SHIJIAZHUANG ZHONGTIAN BIOTECH
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