A method for removing pigment and impurities in crude lactide

A technology for lactide and impurities, applied in the fields of organic chemistry, products, reagents, etc., can solve the problem of a large number of theoretical plates, achieve good removal effect, reduce operating temperature and operating difficulty, and improve product quality.
CN111100107BActive Publication Date: 2021-03-05CHINA PETROLEUM & CHEM CORP +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
CHINA PETROLEUM & CHEM CORP
Publication Date
2021-03-05

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Abstract

The invention relates to a method for removing pigments and impurities in crude lactide. First, the temperature and pressure in the rectification tower are adjusted, and supercritical CO 2 into the rectification tower; then the crude lactide is crushed or heated and melted, and then sent into the rectification tower for decolorization and impurity removal; the product after rectification and CO 2 Separation to obtain de-impurity and decolorized lactide. The present invention uses supercritical CO 2 The combination of extraction and rectification process can not only effectively remove the pigment and impurities in the crude lactide, but also effectively reduce the operating temperature and difficulty of the rectification process, and reduce the coking, oxidation and polymerization of lactide caused by high temperature And side reactions such as mesization, to ensure the yield and quality of lactide products, is a purification method with high operational feasibility, simple separation process, and high-efficiency removal of impurities.
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Description

technical field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a method for removing pigments and impurities in crude lactide. Background technique

[0002] Polylactic acid (PLA), with good mechanical strength, biocompatibility, biodegradability and bioabsorbability, is a green polymer material with broad application prospects and fields. With the continuous maturity of polylactic acid production technology and the continuous development of its application market, the production of polylactic acid from non-food crops → lactic acid → polylactic acid has begun to enter the period of industrialization development. Natureworks of the United States is currently the largest polylactic acid producer in the world, with a production capacity of 140,000 tons, of which L-lactide production capacity has reached 150,000 tons. It is estimated that by 2020, the global production capacity of L-lactide and D-lactide will exceed 500,000...

Claims

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