Preparation method of 1,3,3,3-tetrafluoropropylene

Abstract

The invention relates to a preparation method of 1,3,3,3-tetrafluoropropylene, and belongs to the field of refrigerants. Carbon tetrachloride, vinyl chloride and hydrogen fluoride are used as raw materials in the preparation method. The preparation method comprises the following steps of: performing telomerization on CC14 and chloroalkene to generate CCl3CH2CHCl2, performing fluorine-chlorine exchange and hydrogen chloride removal to obtain CF3CH=CHCl, and performing fluorine-chlorine exchange to obtain a final product HFO-1234ze. The raw materials are low in price and easily obtained in the method, so the raw material cost in the HFO-1234ze production process is reduced; and the reaction temperature is low, the reaction pressure is low, the whole reaction process is operated in a tubularreactor in a continuous phase mode, and the reaction conditions are easily controlled, so the method has great industrialized application prospect.

Description

technical field [0001] The invention belongs to the field of refrigerants, and in particular relates to a preparation method of 1,3,3,3-tetrafluoropropene. Background technique [0002] 1,3,3,3-Tetrafluoropropene (HFO-1234ze) not only has zero atmospheric ozone depletion potential (ODP), but also has low greenhouse effect potential (GWP), so it is considered to be the third most potential application potential. ODS substitute products; According to public reports, HFO-1234ze can be used in refrigerants, fire extinguishing agents, heat transfer media, propellants, foam agents, blowing agents, gaseous dielectrics, disinfectant carriers, polymerization reaction media, etc. For example, U.S. Patent No.11474887 has studied the performance of HFO-1234ze as a foaming agent, and the resulting foam has excellent quality, uniform pore size distribution, and no defects on the surface; U.S. Patent No.696970 has reported HFO-1234ze and CF 3 I can form an azeotrope, which has good physic...

AI Technical Summary

Problems solved by technology

Chinese patent (CN200810000765.X) reports a method for preparing HFO-1234ze by gas-phase fluorination using 1,1,1,3,3-pentachloropropane (HCC-240fa) as a raw material, but the method prepares HFO -1234ze is less selective, only about 50%

For the telomerization method, U.S. Patent (UA 20050245773) and U.S. Patent (UA 20050245774) have reported using methyl halides and vinyl halides as raw materials to obtain HFO-1234ze through continuous fluorination after telomerization, but this synthesis method route Complicated, the catalyst is expensive and prone to coking and deactivation, and there are many by-products and low conversion

For the preparation method of carbene reaction, U.S. Patent 20050245774 reported that above the cracking temperature of difluorocarbene precursor, HFO-1234ze was prepared by high-temperature reaction of difluorocarbene and vinylidene fluoride monomer in the same reactor. The reaction temperature of this synthesis method is High, low yield, no industrial application value