Method for producing oxalic ester by gas phase CO coupling

A technology of oxalate ester and gas phase method, which is applied in chemical instruments and methods, carbon monoxide or formate reaction preparation, organic chemistry, etc. It can solve the problems of low single-pass conversion rate of raw materials and low selectivity of target product oxalate
CN101993369AActive Publication Date: 2011-03-30CHINA PETROLEUM & CHEM CORP +1
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Patent Information

Authority / Receiving Office
CN Β· China
Current Assignee / Owner
CHINA PETROLEUM & CHEM CORP
Publication Date
2011-03-30

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Abstract

The invention relates to a method for producing oxalic ester by gas phase CO coupling, which mainly solves the problems of low selectivity of the target product oxalic ester and low conversion per pass of the raw materials in the prior art. In the method, a technical scheme is adopted as follows: CO and nitrous acid ester in mol ratio of 1-5:1 are used as raw materials; a first batch of raw material as a cooling medium passes through tubes of a first tube-type fixed bed reactor, after heat exchange, enters a second fixed bed reactor, contacts with a palladium-containing catalyst II in a catalyst bed II in the reactor for reaction to generate a reaction effluent I containing the oxalic ester; and a gas phase effluent II containing CO is obtained by gas-liquid separation of the reaction effluent I, and is uniformly mixed with a second batch of raw material containing the fresh component nitrous acid ester, and the mixture is returned into the first tube-type fixed bed reactor, contacts with a palladium-containing catalyst I in a catalyst bed I outside the tubes for reaction to generate the reaction effluent containing the oxalic ester, wherein the total mol ratio of CO to nitrous acid ester in the raw material is 1-4:1, the mol ratio of the second batch of nitrous acid ester to the first batch of nitrous acid ester material is 0.2-5:1, and at least two reactors are connected in series. By using the method, the problems can be better solved and the method can be used in the industrial production for increasing the yield of the oxalic ester.
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Description

technical field

[0001] The present invention relates to a method for producing oxalate by CO gas phase coupling, more specifically, relates to a gas phase reaction of CO and methyl nitrite or ethyl nitrite in a combined fixed bed reactor to produce dioxalate Methyl ester or diethyl oxalate method. Background technique

[0002] Oxalate is an important chemical raw material, which can be used to prepare oxalic acid, oxalate, carbonate, oxamide, intermediates of drugs and dyes, plastic accelerators and solvents, etc.

[0003] The traditional production route of oxalate is the method of esterification and dehydration of oxalic acid and alcohol with toluene as the dehydrating agent. The production process is long, the energy is high, the pollution is serious, and the cost is high. It is urgent to find a new process route. The gas-phase catalyzed synthesis of oxalate from CO and nitrite opens up a new and important route for C1 chemical production of oxalate. Since the 1980s, fo...

Claims

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