Method for preparing methyl glycollate and byproduct methyl methoxy acetate by molecular sieve catalyst

Abstract

The invention provides a method for preparing methyl glycollate and a byproduct methyl methoxy acetate by a molecular sieve catalyst and relates to methods for preparing chemical raw materials. According to the method, methylal serves as a solvent, tripoly-, tetrapoly-or paraformaldehyde serves as a formaldehyde source, metal element doped modified molecular sieves of different topological structures serve as a catalyst, and methyl glycollate (MG) is synthesized in one step in a high conversion ratio and high selectivity manner on the premise that a proper volume of water is present in a system. The two kinds of products, i.e., the methyl glycollate (MG) and the methyl methoxy acetate (MMAc) are relatively large in boiling point difference and can be separated subsequently through simple distillation. According to the one-step synthesis method for the methyl glycollate and the byproduct methyl methoxy acetate, under the reaction conditions that the reaction temperature is 130 DEG C, the reaction pressure is 6.0MPa and the reaction time is 6h, 5% Ni / Y prepared by an isometric dipping method serves as a catalyst, the conversion ratio of DMM can reach 89.59%, the selectivity of MG can reach 80.40%, and the catalyst is not deactivated in 2,000h of stable use.

Description

technical field [0001] The invention relates to a method for preparing chemical raw materials, in particular to a method for preparing methyl glycolate with a molecular sieve catalyst and producing methyl methoxyacetate by-product. Background technique [0002] Methyl glycolate (HOCH 2 COOCH 3 ), abbreviated as MG, is a colorless liquid with a pleasant smell, with a melting point of 74°C, a boiling point of 150°C, and a density of 1.168g / cm 3 , soluble in water, and soluble in alcohol and ether in any proportion. Methyl glycolate has α-H, hydroxyl and ester functional groups, so it has both the chemical properties of alcohols and esters, and can undergo carbonylation reactions, hydrolysis reactions, ammoniation reactions, oxidation reactions, etc. Methyl glycolate itself is an excellent solvent for many celluloses, resins and rubbers, and is easily soluble in nitrocellulose, cellulose acetate, polyvinyl acetate, etc. Methyl glycolate is also an important intermediate in ...

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Problems solved by technology

A.T.Bell et al. used methyl formate instead of gaseous CO and formaldehyde for carbonylation reaction, but since the decomposition of methyl formate and release of CO is a rate-controlling step, it affects the performance of the catalytic reaction

[0028] In summary, the current synthetic methods of methyl glycolate all have problems such as too long synthetic route, low raw material conversion rate or low product selectivity, and environmental pollution during the synthetic process.

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