Method for preparing glycolate from carbohydrates

Abstract

The invention provides a method for efficiently preparing glycolate from carbohydrates as a raw material. Raw materials comprise carbohydrates and natural wood fiber containing carbohydrates, whereincarbohydrates contain cellulose, starch, hemicellulose, sucrose, glucose, fructose, fructan, xylose and soluble xylo-oligosaccharide. The method has the following advantages: carbohydrates or the natural wood fiber raw material containing carbohydrates is used, a catalyst is a compound containing vanadium or molybdenum, the reaction temperature is 100-450 DEG C in air atmosphere, the catalytic conversion process is completed in one step in an alcohol solvent, glycolate is prepared from carbohydrates with high conversion rate, high selectivity and high yield, raw materials used in the preparation process are renewable, and glycolate has the significant advantages of being natural, environmentally friendly, widely sourced and high in atom economy.

Description

technical field [0001] The invention relates to a preparation method of chemical product glycolic acid ester, in particular to a method for preparing glycolic acidic acid ester by one-step catalysis of carbohydrate in alcohol solution through a catalyst containing vanadium or molybdenum. Background technique [0002] Glycolate has its unique molecular structure: it has α-H, hydroxyl and ester functional groups at the same time, which makes it have the chemical properties of both alcohols and esters, and can undergo carbonylation reactions, hydrolysis reactions, oxidation reactions, etc., and can be widely used It has become an important chemical raw material in many fields such as chemical industry, medicine, pesticide, feed, spices and dyes. As a chemical intermediate, glycolic acid ester has the following uses: hydrogenation reduction to produce ethylene glycol, hydrolysis to produce glycolic acid, which can be used to produce polyester fiber and used as a cleaning agent, ...

AI Technical Summary

Problems solved by technology

[0004] (1) One-step synthesis method of glyoxal and methanol, which was developed by Mitsui East Asia Chemical Co., Ltd. [Document 1: Qingpu, Zhongguang. Manufacturing method of glycolic acid ester [P].1996, JP: 08-104], Using glyoxal or other acetals and alcohols as raw materials, this method has mild reaction conditions, high reaction conversion and selectivity, but the glyoxal used as raw materials is toxic and expensive, which is not conducive to large-scale industrial production ;

[0005] (2) Formaldehyde carbonylation-esterification synthesis method, under high temperature and high pressure, formaldehyde aqueous solution and CO are condensed under the action of catalysts such as concentrated sulfuric acid or boron trifluoride to generate glycolic acid, and then esterified with alcohol to obtain glycolic acid Esters [Document 2: Soumay SanoH. Carbonylation of formaldehydecatalyzed by Cu(I), Ag(I) carbonyls at 1 atm [J]. Nippon Kagaku Kashi, 1982, (2): 163-166] [Document 3: Wei Wende. Organic Chemical Industry Encyclopedia of Raw Materials (Second Edition) Volume [M]. Beijing: Chemical Industry Press, 1999: 913-914], after the 1980s, this method had a major breakthrough, catalyst performance and reaction pressure were improved, and the product The selectivity has also been improved [Document 4: Li Jinchun. Synthesis and development prospects of methyl glycolate [J]. Sichuan Chemical Industry and Corrosion Control, 1998,1(6):24-27]. The disadvantage of this method is that the strong acid catalyst Severe corrosion of reaction equipment, and high pressure reaction, higher requirements for equipment

[0006] (3) Methylal and formic acid method, adopted by E.L.Yeakey et al. (CH 3 O) 2 CH 2 (methylal) and HCOOH are raw materials, under the situation that a kind of organic peroxide exists, and prepare glycolic acid alkyl ester under non-acidic condition, but reaction needs segmental to carry out, and product is difficult to separate [document 5: Production of Alkylglycolates, Patent No. US 4602102]

[0007] (4) Coupling method, this method mainly adopts methyl formate and acetaldehyde (or polyoxymethylene etc.) as raw material, adopts acid catalyzed method to synthesize methyl glycolate [document 6: Qi Weidong. Methyl glycolate coupling reaction The research progress of Yunnan Chemical Industry, 2002,29(4):33-35], this method is very corrosive to equipment, serious environmental pollution, not conducive to industrial production

[0008] (5) Chloroacetic acid method, chloroacetic acid method is to use chloroacetic acid and caustic soda to mix, heat reaction, reaction process is complicated, inconvenient to operate, and needs to neutralize acid-base strong acid [document 7: Duan Xingxin. Practical Fine Organic Synthesis Handbook [M] ]. Beijing: Chemical Industry Press, 2000:129] [Document 8: Xu Kexun. Handbook of Fine Organic Chemical Raw Materials and Intermediates [M]. Beijing: Chemical Industry Press, 1998: 1-268]

[0010] (7) Hydrogenation reduction of dimethyl oxalate. This reaction adopts a relatively novel C1 synthesis route, synthesizes oxalate from synthesis gas, and prepares glycolate by controlling the hydrogenation process [Document 9: Catalyst for hydrogenation of dimethyloxalate tomethylglycolate, comprises copper as active component, auxiliary active component and aluminum as structural carrier, in specifiedweight ratio.patent No.CN103801303-A] [Document 10: Zhang Xu. Research on Catalysts for Gas Phase Hydrogenation of Diethyl Oxalate [D]. Tianjin University, 2008 ], but it is easy to over-hydrogenate to ethylene glycol, resulting in a decrease in selectivity

At present, there is no report on the efficient and selective catalytic degradation of carbohydrates to produce glycolate

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