Atochem

Elf Atochem S.a.

Societe Atochem

Other

Atofina

D'elf Atochem S.a.

Bernard Cheminal

Andre Lantz

Henri Mathais

Eric Lacroix

Eric LaCroix

Benoit Requieme

Marc Thomarat

Sylvain Perdrieux

Jean-Marie Cognion

Dominique Guillet

Andr E Lantz

Robert Azerad

Francois Garcia

Process for the manufacture of difluoromethane

In order to remove the impurities (in particular 1-chloro-2,2-difluoroethylene) present in crude 1,1,1,2-tetrafluoroethane (F134a), a gaseous mixture of crude F134a and hydrofluoric acid is treated in the gas phase, in the presence of a fluorination catalyst, at a temperature of between 200 and 380&deg; C. and under a pressure between atmospheric pressure and 2.5 MPa, the HF/F134a molar ratio being between 0.05 and 0.5.

Process for the purification of 1,1,1,2-tetrafluoroethane

The invention relates to catalytic fluorination of perchloroethylene or of pentachloroethane in the gas phase by means of hydrofluoric acid. A mixed catalyst is employed, made up of nickel and chromium oxides, halides and/or oxyhalides deposited on a support consisting of aluminium fluoride or of a mixture of aluminium fluoride and alumina.

Process for fluorination of perchloroethylene or of pentachloroethane

In order to regenerate the activity of a catalyst for gas phase fluorination the spent catalyst is treated with chlorine and hydrogen fluoride, at a temperature of between 250.degree. and 450.degree. C.

Regeneration of catalysts for gas phase fluorination

The invention relates to the manufacture of 1,1,1,2-tetrafluoroethane (F134a) by gas-phase catalytic fluorination of 1-chloro-2,2,2-trifluoroethane (F133a). A mixed catalyst is employed, composed of nickel and chromium oxides, halides and/or oxyhalides deposited on a support consisting of aluminium fluoride or of a mixture of aluminium fluoride and alumina. This mixed catalyst makes it possible to obtain an excellent selectivity for F134a with a high production efficiency.

Process for the manufacture of 1,1,1,2-Tetrafluoroethane

To remove the unsaturated impurities (in particular 1-chloro-2,2-difluoroethylene and polyfluoropropenes) present in crude 1,1,1,2-tetrafluoroethane (F134a), a gaseous mixture of crude F134a, of hydrofluoric acid and of chlorine is treated in gaseous phase in the presence of a fluorination catalyst at a temperature of between 100.degree. and 300.degree. C. and at a pressure between atmospheric pressure and 2.5 MPa, the molar ratio HF/F134a being between 0.05 and 0.5 and the molar ratio Cl.sub.2 /F134a between 0.0001 and 0.1.

The invention relates to a process for the manufacture of 1,1,1,2-tetrafluoro-2-chloroethane and of pentafluoroethane. The process, which consists of the gas phase catalytic fluorination of at least one pentahaloethane of formula C.sub.2 HX.sub.2-n F.sub.3+n in which X denotes a chlorine or bromine atom and n the number 0 or 1 by means of hydrofluoric acid, is characterized in that there is used a mixed catalyst composed of oxides, halides and/or oxyhalides of nickel and chromium deposited on a support consisting of aluminium fluoride or a mixture of aluminium fluoride and alumina.

Process for the manufacture of 1,1,1,2-tetrafluoro-2-chloroethane and of

The invention relates to mass catalysts based on chromium and nickel oxides, obtained from a sol of chromium and nickel hydroxides. These catalysts, in which the Ni/Cr atomic ratio is between 0.05 and 5, may be used from the fluorination of halogenated hydrocarbons by HF in the gas phase.

Mass catalysts based on chromium and nickel oxides and their application

The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F15). The F-125-F115 mixture to be purified is subjected to a fluorination stage to convert F115 into hexafluoroethane (F116) which is then separated from F125, for example by distillation.

Purification of pentafluoroethane

In order to remove the olefinic impurities (in particular 1-chloro-2,2-difluoroethylene and polyfluoropropenes) present in crude 1,1,1,2-tetrafluoroethane (F134a), a gaseous mixture of crude F134a, hydrofluoric acid and oxygen or air is treated in the gas phase, in the presence of a fluorination catalyst, at a temperature between 200.degree. and 350.degree. C. and at a pressure between atmospheric pressure and 2.5 MPa, the HF/F134a molar ratio being between 0.05 and 0.5 and the O.sub.2 /F134a molar ratio being between 0.001 and 0.1.

The invention relates to a process for the manufacture of 1,1,1,2-tetrafluorochloroethane and of pentafluoroethane. The process which consists of gas phase catalytic fluorination of at least one pentahaloethane of formula C.sub.2 HX.sub.2-n F.sub.3+n in which X denotes a chlorine or bromine atom and n the number 0 or 1, by hydrofluoric acid, is characterized in that a catalyst is employed consisting of a catalytic quantity of chromium in an oxidation state equal to or greater than 3 and of an activated charcoal as support. The selectivity for 1,1,1,2-tetrafluorochloroethane and pentafluoroethane reaches approximately 95% and even more.

Process for the manufacture of 1,1,1,2-tetrafluorochloroethane and of

The invention relates to the selective manufacture of 1,1-dichloro-1,2,2,2-tetrafluoroethane by catalytic fluorination of 1,1,1-trichloro-2,2,2-trifluoroethane with anhydrous hydrofluoric acid. The reaction is carried out in the liquid phase at a temperature of between 70.degree. and 170.degree. C. and under a pressure of between 10 and 80 bars absolute, in the presence of an antimony-containing catalyst.

Synthesis of 1,1-dichloro-1,2,2,2-tetrafluoroethane

The invention relates to the manufacture of chlorofluoroethanes of formula CF.sub.3 --CHF.sub.x Cl.sub.2-x, where x is equal to 0 or 1, by the catalytic hydrogenation of a perhaloethane of formula: CF.sub.3 --CF.sub.x Cl.sub.3-x. The use of a ruthenium-based catalyst deposited on a support enables the selectivity to be improved.

Selective hydrogenolysis of perhalogenated ethane derivatives

The invention relates to a process for the manufacture of 1-chloro-1,1-difluoroethane in the liquid phase by reacting hydrofluoric acid with 1,1,1-trichloroethane and/or 1,1-dichloro-1-fluoroethane. The selectively is improved by using a perfluoroalkanesulphonic acid, in particular trifluoromethanesulphonic acid, as a catalyst.

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Bernard Cheminal