Abstract: The invention relates to the synthesis of difluoromethane by gas-phase catalytic fluorination of methylene chloride. To lengthen the lifetime of the catalyst the operation is carried out in the presence of chlorine.

Abstract: 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° C. and under a pressure between atmospheric pressure and 2.5 MPa, the HF/F134a molar ratio being between 0.05 and 0.5.

Abstract: 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.

Abstract: The invention relates to the synthesis of difluoromethane by gas-phase catalytic fluorination of methylene chloride.

Abstract: The invention relates to the synthesis of difluoromethane by gas-phase catalytic fluorination of methylene chloride. To lengthen the lifetime of the catalyst the operation is carried out in the presence of chlorine.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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

Abstract: The present invention relates to the simultaneous manufacture of difluoromethane (F32) and 1,1,1,2-tetrafluoroethane (F134a) by pyrolysis of chlorodifluoromethane in the presence of hydrogen, working at a temperature above 500.degree. C. in the absence of any catalyst or metal surface. Depending on the operating conditions chosen, this process also makes it possible predominantly to manufacture either F134a or F32.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In order to stabilize 1,1-dichloro-1-fluoroethane containing traces of vinylidene chloride, at least one ethylenic hydrocarbon containing at least 4 carbon atoms is added thereto.

Abstract: The invention relates to the synthesis of hydrogenperfluoroalkanes R.sub.F H, R.sub.F denoting a perfluoroalkyl radical containing 2 to 20 carbon atoms, by reaction of the corresponding perfluoroalkyl iodide R.sub.F I with an alkali metal hydroxide.The use of methanol as solvent allows the formation of tars to be avoided, an almost total conversion of R.sub.F I and an R.sub.F H of excellent purity to be obtained, and the alkali metal iodide by-product to be recovered easily.

Abstract: 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.