Method for preparing pentafluoroethane

Abstract

The invention discloses a method of preparing Pentafluoroethane. Chlorylene and chlorine gas act addition reaction under the ultraviolet light catalysis to prepare pentachloroethane; the pentachloroethane reacts with fluorine hydride through the catalysis of a catalyst to prepare trifluoro dichloroethane; the trifluoro dichloroethane reacts with the fluorine hydride through the catalysis of the catalyst to generate the Pentafluoroethane. The method of preparing Pentafluoroethane is that the chlorylene is adopted to generate the pentachloroethane which enters into gas phase for fluorizating toobtain the Pentafluoroethane, thereby preventing olefins from directly entering into the gas phase for fluorizating to cause harmful effects, fundamentally solving the difficult problems that the material cost and the operation cost are on high side in the original Pentafluoroethane technology, and providing a new technology route to the preparation of the Pentafluoroethane.

Description

technical field [0001] The invention relates to a preparation method of chemical products, in particular to a preparation method of pentafluoroethane (HFC125). Background technique [0002] Pentafluoroethane (HFC125) has an ozone destruction coefficient of 0 and is currently used as a substitute for chlorodifluoromethane (HCFC22) and is widely used in the field of refrigeration. At present, the global annual output is about 60,000 tons, and the main production route uses tetrafluoroethylene or tetrachloroethylene as the main raw material. Such as document US5399549, CN1035812, CN1308596, CN1273577, US5300711, US5300710 etc. all are the processing route with tetrachloroethylene or tetrafluoroethylene as main raw material. Due to the high manufacturing cost of tetrafluoroethylene, pentafluoroethane produced by the tetrafluoroethylene route has almost no competitive advantage in the market, but unfortunately, this process is almost always used in China. The process route of d...

AI Technical Summary

Problems solved by technology

Due to the high manufacturing cost of tetrafluoroethylene, pentafluoroethane produced by the tetrafluoroethylene route has almost no competitive advantage in the market, but unfortunately, this process route is almost always used in China

The process route of direct gas-phase fluorination of tetrachloroethylene as raw material to produce pentafluoroethane, because olefins directly enter the gas-phase catalyst, the catalyst is prone to failure, and at the temperature of gas-phase fluorination, tetrachloroethylene is easy to form carbon, so further accelerated catalyst failure

Therefore, although the raw material cost of tetrachlorethylene is low, its operating cost is high, and the equipment is seriously corroded.