Societe Atochem

Michel Bergougnan

Sylvain Perdrieux

Yves Correia

Jean Lesparre

Jean-Michel Galland

The invention relates to continuous production of 1,1,1-chlorodifluoroethane from 1,1,1-trichloroethane and hydrofluoric acid by reaction in liquid phase in the presence of at least one fluorination catalyst. According to the invention, the process is carried out under an absolute pressure of between 6 and 30 bars and at a temperature of between 50.degree. and 120.degree. C., the content of catalyst(s) in the reaction mixture, expressed as a percentage by weight of metal, being between 0.05 and 10% and the content of organohalogenated by-products not belonging to series 140 in the reaction mixture being controlled at a value below 40% by weight. This process makes it possible, at the same time, to obtain a high degree of conversion of hydrofluoric acid, to minimize the coproduction of 1,1,1-trifluoroethane and organohalogenated by-products and to facilitate the recovery of the hydrochloric acid formed.

Process for the production of 1,1,1-chlorodifluoroethane

This invention relates to a process for the purification of 1,1-dichloro-1-fluorethane. To remove unsaturated impurities such as 1,1-dichloroethylene and dichloracetylene the crude 1,1-dichloro-1-fluoroethane is subjected to the action of chlorine and/or of a hydracid. This treatment is carried out in the presence of a Lewis acid, or, only in the case of chlorine, by photochemical catalysis.

Growing community of inventors

Pierre Benite, France

Michel Bergougnan