Method for preparing chlorohydrocarbon

Abstract

The present invention relates to chlorohydrocarbon preparing process, and is especially one telomerization process of preparing chlorohydrocarbon in the molecular expression CCl3CH2CHnClm, where n is 0, 1 or 2, and m=3-n, inside a tubular reactor, with chloroalkane or chloroalkene as main material and in the presence of composite Fe, Cr and Ni metal catalyst and dimethyl formamide as co-catalyst. The reacted mixture may be distilled to recover un-reacted material and co-catalyst and is decompression distilled to obtain final chlorohydrocarbon product. The telomerization process is simple, high in reaction efficiency and suitable for continuous industrial production.

Description

technical field [0001] The present invention relates to molecular formula is CCl 3 CH 2 CH n Cl m , (where n is 0, 1 or 2, m=3-n), a preparation method of chlorinated hydrocarbons, in particular to a method for preparing chlorinated hydrocarbons by telomerization reaction of chlorinated alkanes and olefins under the action of a catalyst. Background technique [0002] The chlorinated hydrocarbon can produce 3,3,3-trifluoropropene, 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3,3- Hexafluoropropane (HFC-236fa); 3,3,3-trifluoropropene is an important intermediate of fluorine-containing rubber; the ODP value of HFC-245fa and HFC-236fa is zero, and it is an important substitute for Freon. Foaming, cleaning, fire extinguishing and other industries. Preparation of CCl in the prior art 3 CH 2 CH n Cl m The most common reaction is telomerization, that is, the addition of halogenated hydrocarbons to olefins, and try to control the addition of single molecules to reduce t...

AI Technical Summary

Problems solved by technology

Its disadvantages are that the amount of catalyst and co-catalyst required for the reaction is relatively large, there are many wastes that are not easy to recycle during the post-treatment process, the solubility of the catalyst is not good, it is difficult to form a homogeneous phase, the reaction efficiency is not high, and the time required for the reaction is relatively long. long

[0003] Patent US6313360 reports adding iron powder and tributyl phosphate to catalyze the preparation of HCC-240fa in the reaction. The reaction time is as long as 9 hours. The problem of uniform dispersion of iron powder in the solution and blockage of equipment and pipelines during catalyst recovery is not easy to solve

[0004] The preparation process reported in the above-mentioned documents is all completed in a polytetrafluoroethylene-lined autoclave, the equipment manufacturing cost is high, the operation is complicated, the reaction time is long (the residence time of the material is several hours or even longer), and the production efficiency is low