Elf Atochem S.a.

Societe Atochem

Atochem

Produits Chimiques Ugine Kuhlmann

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Atofina

D'elf Atochem S.a.

P C U K Produits Chimiques Ugine Kuhlmann

Andre Lantz

Bernard Cheminal

Eric Lacroix

Rene Bertocchio

Eric LaCroix

Louis Foulletier

Sylvain Perdrieux

Benoit Requieme

Jean-Pierre Schirmann

Pascal Michaud

Serge Hub

Pierre Durual

Aime Cambon

Brigitte Bertaina

Laurent Wendlinger

Bertrand Collier

Bernard Boutevin

Jean G Riess

Henri Mathais

Auguste Andre Commeyras

Gilles Drivon

Bernard Jean Gurtner

Hubert Blancou

Yves Pietrasanta

Charles Laviron

Maurice Le Blanc

Francois Jeanneaux

Patrick Lambert

Dominique Garrait

Pierre Chabert

Mohamed Taha

Francois Garcia

Daniel Roland

Gerard Dupuis

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 subject of the invention is the manufacture of 1,1,1-trifluoroethane by fluorination or 1-chloro-1,1-difluoroethane with anhydrous hydrofluoric acid. The reaction is carried out in the liquid phase and in the presence of a fluorination catalyst.

Synthesis of 1,1,1-trifluoroethane by fluorination of 1-chloro-1, 1-difluoroethane

In order to purify a crude pentafluoroethane (F125) containing chloropentafluoroethane (F115), it is subjected to a heat treatment in the presence of hydrogen, the treatment being carried out at a temperature at least equal to 550.degree. C. and with an H.sub.2 /F115 molar ratio of at least 10.

Purification of pentafluoroethane

To remove the olefinic impurities from a hydrochlorofluoroethane of formula: CF.sub.3 --CHClX (X=H, F, or Cl), it is subjected to a photochlorination stage.

Process for purification of hydrochlorofluoroethanes

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

1,1,1,3,3-Pentachlorobutane, whose fluorination leads to 1,1,1,3,3-pentafluorobutane, is prepared with high yield and selectivity by addition of carbon tetrachloride to 2-chloropropene in the presence of a copper salt and an amine.

Preparation of 1,1,1,3,3-pentachlorobutane and

The invention relates to the manufacture of difluoromethane by catalytic gas-phase fluorination of methylene chloride. The operation is carried out in the presence of oxygen at a temperature of between 330 and 450.degree. C. and with a bulk or supported chromium catalyst.

Synthesis of difluoromethane

To remove the traces of chlorotrifluoroethylene (F1113) which are present in a pentafluoroethane (F125), the F125 is passed through a bed of active carbon.

Purification of pentafluroethane

Method for coproducing difluoromethane and 1,1,1,2-tetrafluoroethane

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 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.

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Vernaison, France

Andre Lantz