A method of preparing trifluorochloroethene through gas-phase catalytic dehydrochlorination

Abstract

The invention relates to a method of preparing trifluorochloroethene through gas-phase catalytic dehydrochlorination. 1,2-dichloro-1,1,2-trifluoroethane after being vaporized reacts with existence of a nitrogen-containing activated carbon catalyst under atmospheric pressure at 400-650 DEG C, and a reaction product is collected and subjected to quenching, washing with water, drying, compression and rectification purification to obtain a high-purity trifluorochloroethene product. The nitrogen-containing activated carbon catalyst is activated carbon modified with aniline, and is prepared by activated carbon pretreatment, modification with aniline and auxiliary agent loading. The activated carbon which is cheap is adopted as the catalyst, and is low in cost, simple, convenient and efficient in preparation and good in catalytic performance. The method has advantages of a simple process, easily available raw materials, easy industrialization and environment protection.

Description

technical field [0001] The invention belongs to the technical field of fluorochloroalkene preparation, and specifically relates to a method for preparing chlorotrifluoroethylene by gas-phase catalytic dehydrochlorination. Background technique [0002] Chlorotrifluoroethylene is one of the important monomers for the synthesis of fluorine-containing materials. Through its homopolymerization or copolymerization, a series of fluororesins, fluororubbers, fluorine coatings and chlorofluorocarbon lubricating oils can be prepared. Because these fluorine-containing materials have excellent chemical inertness and high and low temperature resistance, they have attracted widespread attention. [0003] The reductive dechlorination method of trifluorotrichloroethane metal zinc powder is a commonly used method for the preparation of chlorotrifluoroethylene in industry. Utilizing the dechlorination function of Zn, one molecule of zinc must be consumed for every two chlorine atoms removed f...

AI Technical Summary

Problems solved by technology

The reaction conditions of this method are relatively mild (80~110 ℃), and the operation method is relatively simple and mature, but there are also the following disadvantages: almost all are intermittent operations, the production equipment is huge, and the efficiency is low; the actual amount of zinc powder used is much larger than that of Theoretical amount (usually 113 to 115 times the theoretical amount); a large amount of methanol or ethanol solvent must be consumed; the amount of by-product zinc chloride is large and difficult to handle, resulting in environmental pollution; a small amount of by-product trifluoroethylene, difluoroethylene, Chlorodifluoroethylene, etc. are difficult to collect and separate; the production cost is high

The disadvantage is that the conversion rate of trifluorotrichloroethane is too low, so that the energy consumption of the process is high, and the reaction conditions have higher requirements than catalytic hydrogenation

Catalyst active components use expensive palladium chloride and platinum chloride, the cost is high

Due to the presence of H in the system 2 , Cl 2 etc., the equipment requirements are high, and it is difficult to prolong the service life of the catalyst