Method for preparing 2-chlorine-1,1,1,4,4,4-hexafluoro-2-butene by adopting micro-channel reactor

Abstract

The invention discloses a method for preparing 2-chlorine-1,1,1,4,4,4-hexafluoro-2-butene by adopting a micro-channel reactor. The method comprises the following steps: (1) activating the catalyst: introducing a liquid fluorination catalyst and anhydrous HF into a micro-channel reactor to obtain an activated catalyst-HF mixture; and (2) carrying out a fluorination reaction: returning the activatedcatalyst-HF mixture prepared in the step (1) into the micro-channel reactor in the step (1), meanwhile, respectively introducing anhydrous HF and hexachlorobutadiene into the micro-channel reactor from a second path and a third path, conveying a mixture obtained after a reaction to a rectifying tower through a pump, extracting a mixture of 2-chlorine-1,1,1,4,4,4-hexafluoro-2-butene and HF from the top of the rectifying tower, and carrying out layering, wherein the lower layer is 2-chlorine-1,1,1,4,4,4-hexafluoro-2-butene, and the upper layer is HF. The method for preparing 2-chlorine-1,1,1,4,4,4-hexafluoro-2-butene has a high conversion rate, high selectivity and few impurities, and activity of the catalyst is greatly prolonged. The silicon carbide micro-channel reactor is adopted, so that the reaction time is short, superacid corrosion resistance is achieved, reaction mass transfer and heat transfer performance is excellent, and therefore, high activity of the catalyst can be kept for a long time.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for preparing 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene by using a microchannel reactor. Background technique [0002] The present invention relates to the first step reaction on the preparation of the fourth generation blowing agent 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz) by using hexachlorobutadiene as the basic raw material Improvement of the process for the preparation of 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene by liquid-phase fluorination of chloroprene. [0003] 1,1,1,4,4,4-hexafluoro-2-butene, its ODP is 0, GWP is 5, non-flammable, thermal conductivity close to HFC-365mfc and HFC-245fa. 1,1,1,4,4,4-hexafluoro-2-butene has two isomers, cis and trans, of which cis-hexafluoro-2-butene (Type Z) has a boiling point of 33-34°C, mainly Used to replace HCFC-141b as a blowing agent. Trans-hexafluoro-2-butene (Type E) has a boiling point of 6-8°C and is...

AI Technical Summary

Problems solved by technology

Obviously, this kind of reactor has poor mass transfer and heat transfer in some strongly exothermic liquid-phase fluorination reactions, and there are local hot spots in the reaction materials, which cause the polymers of the materials to form wrapped catalysts and fluorinated catalysts such as SbCl x f 5-x Thermal decomposition makes Sb 5+ Reduced to inactive Sb 3+ , resulting in poor catalyst stability