Preparation method for chlorotrifluoropropylene

Abstract

A monochloro-fluoropropene preparation belongs to the intermediate preparation technical field of coolant, foaming agent and fluorine compounds, which comprises that under catalyst condition, the telomeric reaction on chloromethane and chloroalkene is processed to prepare pentachloro-propane, which is fluorinated with hydrogen fluoride via the catalysis of composite catalyst to prepare trifluoro-dichloropropane, and hydrogen chloride is removed via the alkali alcohol liquid catalysis to obtain monochloro-fluoropropene as final product. The invention has the advantages that the preparation fluorinates pentachloro-propane into trifluoro-dichloropropane, to remove hydrogen chloride to obtain monochloro-fluoropropene, thereby avoiding azeotropic material and sub isomer generated in the fluorination from pentachloro-propane to monochloro-fluoropropene, while the whole process has low reaction temperature to save energy, and the monochloro-fluoropropene product has reach 99.0-99.6% purity and 80.70-88.05% yield, to meet industrial batch production.

Description

technical field [0001] The invention belongs to the technical field of preparation of intermediates of refrigerants, blowing agents and fluorine compounds, and in particular relates to a preparation method of chlorotrifluoropropene. Background technique [0002] Chlorotrifluoropropene (HCFC-1233zd) is a high-efficiency refrigerant, foaming agent and intermediate of fluorine compounds, and it is mainly an intermediate raw material for the preparation of pentafluoropropane (HFC-245fa). Since pentafluoropropane is the main substitute of monofluorodichloroethane (141b), with the acceleration of the process of monofluorodichloroethane being replaced, the amount of pentafluoropropane will increase accordingly, so that as pentafluoropropane Chlorotrifluoropropene, an intermediate of fluoropropane, has a good industrial application background. [0003] The traditional method of preparing chlorotrifluoropropene is: firstly, pentachloropropane is prepared by telomerization reaction o...

AI Technical Summary

Problems solved by technology

Since the reaction needs to be carried out under high temperature conditions, that is, fluorination into chlorotrifluoropropene in the next step at high temperature, the reaction products are more complicated, for example, there are about six azeotropic products (pentafluoropropane) between 15.8-20.8 °C , tetrafluoropropene, chlorotetrafluoropropane, dichlorotrifluoropropane, 1-chloro-3,3,3-trifluoropropene and 2-chloro-3,3,3-trifluoropropene, etc.), where 1- Chloro-3,3,3-trifluoropropene and 2-chloro-3,3,3-trifluoropropene are isomers of each other, which makes it almost impossible to obtain monochlorine with ideal purity under ordinary rectification purification conditions. Trifluoropropene, and the yield of chlorotrifluoropropene prepared by traditional method is low (obtaining a purity of 98% chlorotrifluoropropene with pentachloropropane as a benchmark, its yield is only about 60%) energy consumption is high, output is low

Not suitable for industrial scale-up production