A kind of method that dichloromethane prepares trichlorethylene

Abstract

The invention discloses a method for preparing trichloroethylene from dichloromethane. The method comprises the following steps: enabling reaction between dichloromethane and oxygen to produce trichloroethylene under the condition of the presence of a catalyst with methane oxidation coupled reaction activity, wherein the molar ratio of dichloromethane to oxygen is 1:(0.1-2); the reaction temperature of the reaction is 450-700 DEG C, and the reaction pressure is 1-10 atm. The method disclosed by the invention has high raw material conversion rate and trichloroethylene selectivity, and byproducts such as tetrachloroethylene and trichloromethane are produced simultaneously. The method disclosed by the invention has the advantages that an expensive raw material such as carbide acetylene or ethylene does not need to be used, so that the production cost of the trichloroethylene can be reduced, and the problems of high energy consumption and high pollution brought in the process of producing and using calcium carbide can be solved.

Description

technical field [0001] The invention relates to a method for preparing trichlorethylene, in particular to a method for preparing trichlorethylene by oxidative coupling reaction of methylene chloride. Background technique [0002] Trichlorethylene (TCE) is an important organochlorine product with strong dissolving power. It is mainly used in metal cleaning (degreasing thoroughly), fiber degreasing, and cleaning of electronic components in industry. Secondly, trichloroethylene can also be used as a raw material intermediate for the production of tetrachloroethylene, chloroacetic acid, dichloroacetyl chloride, octachlorodipropyl ether, HFC-134a and other products. In addition, trichlorethylene can also be used as extractant and solvent. [0003] According to the different raw materials used, the production methods of trichlorethylene mainly include acetylene method and ethylene method. [0004] According to the different dehydrochlorination methods, the acetylene method can b...

AI Technical Summary

Problems solved by technology

However, the acetylene raw material used in this method mainly comes from calcium carbide, and there are still some problems in terms of environmental protection and economy: on the one hand, there are high energy consumption and high pollution problems in the production process of calcium carbide; A large amount of calcium carbide slag will be produced in the process, although the carbide slag can be made into cement for sale, but in the current situation of severe excess cement production capacity in China, its profit margin has been greatly squeezed

It is worth noting that although alkaline earth metal oxides and rare earth metal oxides have methane oxidative coupling reaction activity, the catalyst components used in this patent do not contain these two types of compounds

In addition, although the patent pointed out that the methyl halide it uses contains at least one halogen atom but is not limited to one, and the resulting product is a halocarbon hydride with a carbon number of 2 or more, but the patent does not clearly point out the use of methane chloride Trichloroethylene can be obtained

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