Preparation method of 1,1,1,3-tetrachloropropane

Abstract

The invention discloses a preparation method of 1,1,1,3-tetrachloropropane, which comprises the following steps: mixing carbon tetrachloride with an assistant, preheating, carrying out forced circulation for a period of time, carrying out forced circulation reaction with ethylene in an enhanced reactor to obtain a 1,1,1,3-tetrachloropropane crude product, and carrying out vacuum distillation separation to obtain 1,1,1,3-tetrachloropropane. The method is simple in process and low in energy consumption; the reaction process is easy to control; ethylene, carbon tetrachloride and the assistant obtained at the tower top of the first rectifying tower and 75-95% of residual liquid in the tower bottom of the second rectifying tower can be recycled, the material utilization rate is high, less wasteis generated, the purity of the prepared target product is high, meanwhile, ammonia-nitrogen-free and phosphorus-free catalysts are used, the pollution problem of nitrogen-containing and phosphorus-containing three wastes is solved, and high efficiency and environmental protection are achieved.

Description

technical field [0001] The invention relates to a method for preparing 1,1,1,3-tetrachloropropane, in particular to a method for preparing 1,1,1,3-tetrachloropropane by using carbon tetrachloride and ethylene as raw materials. Background technique [0002] 1,1,1,3-Tetrachloropropane, referred to as HCC-250fb, is an important fine chemical, which can be used as a paint remover, degreasing agent and organic synthesis raw material, such as for the preparation of 1-chloro-3, 3,3-trifluoropropane, 3,3,3-trifluoropropene or HCC-240db. [0003] At present, there are many methods for preparing 1,1,1,3-tetrachloropropane, including the preparation method using ethylene and carbon tetrachloride as raw materials. For example, T. Asahara et al. discovered in 1971 that 1,1,1,3-tetrachloropropane could be prepared from ethylene and carbon tetrachloride under the catalysis of triethyl phosphite-ferric chloride hexahydrate. U.S. Patent No. 4,243,607 improved the preparation method of T.As...

AI Technical Summary

Problems solved by technology

In U.S. Patent US2004225166, a kind of technology that adopts iron and tributyl phosphate as catalyst to prepare 1,1,1,3-tetrachloropropane is reported, adopting this technology is easy to produce phosphorus-containing waste water, pollutes environment, in addition, solid iron powder is in It cannot be effectively dispersed in the raw materials during the reaction process, so it cannot be added quantitatively, which will easily lead to excessive local catalysts during the reaction process and cause polymerization reactions, resulting in an increase in high polymers

Therefore, the traditional 1,1,1,3-tetrachloropropane synthesis process uses iron powder, ferric chloride and phosphate ester system catalysts to telomerize carbon tetrachloride and vinyl chloride to prepare, but the use of phosphorus-containing catalysts is easy to produce phosphorus-containing The three wastes cause great environmental pollution and difficult post-treatment; in addition, the iron powder used is easy to agglomerate on the surface of the reactor after the reaction, making it difficult to clean up, and the fine iron powder is dispersed in the organic high-boiler, resulting in high consumption and separation Difficult to reuse

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