Method for synthesizing 2,3,3,3-tetrafluoropropene

Abstract

The invention relates to a method for synthesizing 2,3,3,3-tetrafluoropropene, and belongs to the field of fluorine-containing refrigerants. The method comprises the following steps of: performing telomerization on carbon tetrachloride (CCl4) and ethylene serving as raw materials to generate CCl3CH2CH2Cl, chlorinating to obtain CCl3CHClCH2Cl, and performing fluorine-chlorine exchange and HF removal under the catalytic condition to obtain a final product HFO-1234yf. The raw materials are low-cost and readily available, so raw material cost in the process of producing the HFO-1234yf is reduced; the previous two steps in the method are liquid phase reaction, the reaction temperature is low, and reaction pressure is close to normal pressure; the subsequent two steps are gas phase continuous reaction, pressure and temperature are relatively low, and reaction conditions are easy to control, so equipment is relatively simple; in addition, the conversion rate in each step of the preparation method is high, a few byproducts are generated, and the yield of the target product is high, so the method has a wide industrial application prospect.

Description

technical field [0001] The invention belongs to the field of environment-friendly fluorine-containing refrigerants, and in particular relates to a new synthesis method of 2,3,3,3-tetrafluoropropene. Background technique [0002] Fluorinated refrigerants for industrial applications require short atmospheric survival time (ALT), low atmospheric ozone depletion potential (ODP) and greenhouse effect potential (GWP), non-toxic, non-flammable, non-explosive, chemical and thermal stability Better, it can adapt to different working temperature ranges. 2,3,3,3-Tetrafluoropropene (HFO-1234yf), as a single working refrigerant, has excellent environmental parameters and good cooling effect, and if HFO-1234yf is used as an automobile refrigerant, the original vehicle refrigerant can continue to be used Air-conditioning systems, so HFO-1234yf is considered to be a potential new-generation automotive refrigerant substitute, and has been accepted by automakers in Western Europe. [0003] ...

AI Technical Summary

Problems solved by technology

Doulas A et al. with CX 3 CF 2 CH 3 (HCFC-242) as raw material to synthesize HFO-1234yf (see US 2996555 for details), CX 3 CF 2 CH 3 X in (HCFC-242) is F, Cl, Br, and the transformation rate of this preparation method raw material is 60%, but this process catalyst preparation is relatively difficult

[0004] In summary, the process of preparing HFO-1234yf is a systematic process. Among the various process routes for preparing HFO-1234yf, CX 3 CCl=CClX (X=F, Cl), CCl 2 =CClCH 2 Cl, CX 3 CF 2 CH and CF 3 CF 2 CH 2 The process route starting from Cl as the raw material has more commercial advantages, but these synthesis patents are mainly controlled by some international fluorine chemical giants. Domestic research institutions have also begun to study the preparation of HFO-1234yf, but there is almost no such aspect report