METHOD FOR TREATING A CATALYST BEFORE UNLOADING

Abstract

The present invention relates to a process for treating, in a reactor containing a catalytic bed, a solid catalyst, said process comprising the steps of: a) implementing, in said reactor, a gas-phase catalytic reaction at a catalytic bed temperature T1 in the presence of a hydrogen halide or giving rise to the formation of a hydrogen halide, b) causing an inert gas to flow through the catalytic bed at a catalytic bed temperature T2 that is lower than T1, the temperature T2 being greater than 30 C.

Claims

1-14. (canceled)

15. A process for treating, in a reactor containing a catalytic bed, a solid catalyst, said process comprising the steps of: a) implementing, in said reactor, a gas-phase catalytic reaction at a catalytic bed temperature T1 in the presence of a hydrogen halide or giving rise to the formation of a hydrogen halide, and b) causing an inert gas to flow through the catalytic bed at a catalytic bed temperature T2 that is lower than T1, the temperature T2 being greater than 30 C.

16. The process as claimed in claim 15, characterized in that the inert gas introduced into the reactor is at a temperature of between ambient temperature and the temperature T2.

17. The process as claimed in claim 15, characterized in that the inert gas introduced into the reactor is at ambient temperature.

18. The process as claimed in claim 15, characterized in that the hydrogen halide is hydrogen fluoride or hydrogen chloride.

19. The process as claimed in claim 15, characterized in that the hydrogen halide is in anhydrous form.

20. The process as claimed in claim 15, characterized in that the temperature T2 decreases during the implementation of step b).

21. The process as claimed in claim 15, characterized in that the temperature T2 decreases at a rate of less than 1 C./min during the implementation of step b).

22. The process as claimed in claim 15, characterized in that the inert gas flows at a flow rate of greater than 0.1 ml/min per ml of catalyst.

23. The process as claimed in claim 15, characterized in that the catalyst is based on carbon or based on a metal selected from the group consisting of Cr, Fe, Sb, Ni, Co, Zn, Al and Mn.

24. The process as claimed in claim 15, characterized in that step a) implements a gas-phase reaction between HF and a C.sub.1-C.sub.4 halohydrocarbon compound A or step a) implements a gas-phase dehydrohalogenation reaction of a saturated C.sub.1-C.sub.4 hydrocarbon compound B comprising at least one halogen atom to form an unsaturated C.sub.1-C.sub.4 hydrocarbon compound and a hydrogen halide.

25. The process as claimed in claim 15, characterized in that the compound A is selected from the group consisting of 1,1,2-trichloroethane, 2-chloro-1,1,1-trifluoroethane, 1-chloro-1,1,2-trifluoroethane, 1-chloro-1,2,2-trifluoroethane, 1,1,1,3,3,3-hexachlorodifluoropropane, 1,1,1,3,3,3-hexachloropropane, 1,1,1,3,3-pentachloropropane, 2,2,3-trichloro-1,1,1,3,3-pentafluoropropane, 1,1,1,3,3,3-hexachlorodifluoropropane, 1,1-dichloro-2,2,3,3,3-pentafluoropropane, 1,3-dichloro-1,2,2,3,3-pentafluoropropane, 1,1,1,2,3-pentachloropropane, 1,1,2,2,3-pentachloropropane, 1,1,1,3,3-pentachloropropane, 1,2-dichloroethylene, 1,1,2-trichloroethylene, 1,1,2,2-tetrachloroethylene, 1,1,2-trichloro-3,3,3-trifluoropropene, hexafluoropropene, 1,1,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2-chloro-3,3,3-trifluoropropene, 1,1,2,3-tetrachloropropene, 2,3,3,3-tetrachloropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,3,3-tetrachloropropene, 1,3,3,3-tetrachloropropene, 2,3-dichloro-1,1,1-trifluoropropane, and 2-chloro-1,1,1,2-tetrafluoropropane; or the compound B is selected from the group consisting of 1,1-difluoroethane, 1,1,1-trifluoroethane, 2-chloro-1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2,2-pentafluoroethane, 1,1,1,2-tetrafluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,2,3-hexafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 2,3-dichloro-1,1,1-trifluoropropane, and 2-chloro-1,1,1,2-tetrafluoropropane.

26. The process as claimed in claim 15, characterized in that the process comprises a step c) of unloading the catalyst from said reactor.

27. The process as claimed in claim 15, characterized in that step b) comprises a step b1) of cooling the catalytic bed from the temperature T1 to T2, and then a step b2) of causing said inert gas to flow through the catalytic bed.

28. A process for treating, in a reactor containing a catalytic bed, a solid catalyst, said process comprising the steps of: a) implementing, in said reactor, a gas-phase catalytic reaction at a catalytic bed temperature T1 in the presence of a hydrogen halide or giving rise to the formation of a hydrogen halide, and b) causing an inert gas to flow through the catalytic bed at a catalytic bed temperature T2 that is lower than T1, the temperature T2 decreasing during the implementation of step b).

Description

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0023] The present invention relates to a process for treating a catalyst. In particular, the present invention relates to a process for treating a solid catalyst. Thus, the present invention relates to a process for treating, in a reactor containing a catalytic bed, a solid catalyst.

[0024] Preferably, the present process comprises the steps of: [0025] a) implementing, in said reactor, a gas-phase catalytic reaction at a catalytic bed temperature T1 in the presence of a hydrogen halide or giving rise to the formation of a hydrogen halide, [0026] b) causing an inert gas to flow through the catalytic bed at a catalytic bed temperature T2 that is lower than T1, the temperature T2 being greater than 30 C.

[0027] The process according to the present invention is typically conducted in a reactor provided with a fixed catalytic bed. The reactor and its associated feed lines, effluent lines and associated devices have to be constructed from materials which are resistant to hydrogen halides such as hydrogen fluoride or hydrogen chloride. Typical construction materials, well known in the state of the art of fluorination, include stainless steels, in particular of austenitic type, well-known alloys having a high nickel content, such as Monel nickel/copper alloys, Hastelloy nickel-based alloys and Inconel nickel/chromium alloys.

[0028] According to a preferred embodiment, in step a) the hydrogen halide is in anhydrous form. Preferably, the compound A and the compound B described above can also be in anhydrous form.

[0029] According to a preferred embodiment, in step b) the inert gas is in anhydrous form.

[0030] The term anhydrous refers to a content by mass of water of less than 1000 ppm, advantageously 500 ppm, preferably of less than 200 ppm, in particular of less than 100 ppm, more particularly of less than 50 ppm and favorably of less than 25 ppm, in the compound under consideration.

[0031] Catalyst

[0032] According to a preferred embodiment, the catalyst is based on carbon or on a metal selected from the group consisting of Cr, Ti, Al, Mn, Ni, Co, Fe, Cu, Zn, Sn, Au, Ag, Pt, Pd, Ru, Rh, Mo, Zr, Ge, Nb, Ta, Ir, Hf, V, Mg, Li, Na, K, Ca, Cs, Ru and Sb; preferably, the catalyst is based on a metal selected from the group consisting of Cr, Fe, Sb, Ni, Co, Zn, Al et Mn. The carbon-based catalyst may be activated carbon, charcoal or graphite. The metal-based catalyst may be in the oxide, halide, or oxyhalide form of said metal. In particular, the catalyst is based on Cr, Al, Fe or Sb. The catalyst may be an antimony, iron or aluminum halide, such as SbCl.sub.5, FeCl.sub.3, or AlCl.sub.3. The catalyst may be a chromium oxide, a chromium oxyfluoride or a chromium fluoride. When the catalyst is based on chromium, it may contain a cocatalyst selected from the group consisting of Co, Zn, Mn, Ni or a mixture thereof, in a content by mass of from 1% to 10% based on the total weight of said catalyst.

[0033] Said catalyst may be a bulk or supported catalyst. The support may be selected from the group consisting of activated carbon, alumina and aluminum fluoride. For example, catalysts such as Cr.sub.2O.sub.3, MgF.sub.2, SbCl.sub.5 or FeCl.sub.3 may be supported on activated carbon.

[0034] Said catalyst may be activated before implementing the step a) detailed below. The catalyst may be activated according to the methods known to those skilled in the art. For example, the catalyst may be activated in the presence of oxygen, of HF or of nitrogen, or a mixture thereof, at a temperature of between 100 C. and 500 C.

[0035] Step a)

[0036] Said step a) comprises implementing, in said reactor, a gas-phase catalytic reaction at a catalytic bed temperature T1. Said catalytic reaction may either be implemented in the presence of a hydrogen halide or give rise to the formation of a hydrogen halide.

[0037] The hydrogen halide may be selected from the group consisting of HF, HCl, HBr and HI. Preferably, the hydrogen halide is hydrogen fluoride (HF) or hydrogen chloride (HCl).

[0038] According to a preferred embodiment, step a) may implement a gas-phase reaction between HF and a C.sub.1-C.sub.4 halohydrocarbon compound A. Preferably, step a) implements a reaction between hydrogen fluoride and a compound A to form a halohydrocarbon compound comprising at least one fluorine atom. Said compound A may be a saturated compound of the formula CH.sub.2Cl.sub.2, CH.sub.2Br.sub.2, CHCl.sub.3, CCl.sub.4, C.sub.2Cl.sub.6, C.sub.2BrCl.sub.5, C.sub.2Cl.sub.5F, C.sub.2Cl.sub.4F.sub.2, C.sub.2Cl.sub.3F.sub.3, C.sub.2Cl.sub.2F.sub.4, C.sub.2ClF.sub.5, C.sub.2HCl.sub.5, C.sub.2HCl.sub.4F, C.sub.2HCl.sub.3F.sub.2, C.sub.2HCl.sub.2F.sub.3, C.sub.2HClF.sub.4, C.sub.2HBrF.sub.4, C.sub.2H.sub.2Cl.sub.4, C.sub.2H.sub.2Cl.sub.3F, C.sub.2H.sub.2Cl.sub.2F.sub.2, C.sub.2H.sub.2ClF.sub.3, C.sub.2H.sub.3Cl.sub.3, C.sub.2H.sub.3Cl.sub.2F, C.sub.2H.sub.3ClF.sub.2, C.sub.2H.sub.4Cl.sub.2, C.sub.2H.sub.4ClF, C.sub.3Cl.sub.6F.sub.2, C.sub.3Cl.sub.5F.sub.3, C.sub.3Cl.sub.4F.sub.4, C.sub.3Cl.sub.3F.sub.5, C.sub.3HCl.sub.7, C.sub.3HCl.sub.6F, C.sub.3HCl.sub.5F.sub.2, C.sub.3HCl.sub.4F.sub.3, C.sub.3HCl.sub.3F.sub.4, C.sub.3HCl.sub.2F.sub.5, C.sub.3Cl.sub.2F.sub.6, C.sub.3H.sub.2Cl.sub.6, C.sub.3H.sub.2BrCl.sub.5, C.sub.3H.sub.2Cl.sub.5F, C.sub.3Cl.sub.4F.sub.2, C.sub.3H.sub.2Cl.sub.3F.sub.3, C.sub.3H.sub.2Cl.sub.2F.sub.4, C.sub.3H.sub.2ClF.sub.5, C.sub.3H.sub.3Cl.sub.5, C.sub.3H.sub.3Cl.sub.4F, C.sub.3H.sub.3Cl.sub.3F.sub.2, C.sub.3H.sub.3Cl.sub.2F.sub.3, C.sub.3H.sub.3ClF.sub.4, C.sub.3H.sub.4Cl.sub.4, C.sub.4H.sub.4Cl.sub.4, C.sub.4H.sub.4Cl.sub.6, C.sub.4H.sub.6Cl.sub.6, C.sub.4H.sub.5Cl.sub.4F.sub.1 or C.sub.6H.sub.4Cl.sub.8, or an unsaturated compound of the formula C.sub.2Cl.sub.4, C.sub.2BrCl.sub.3, C.sub.2Cl.sub.3F, C.sub.2Cl.sub.2F.sub.2, C.sub.2ClF.sub.3, C.sub.2F.sub.4, C.sub.2HCl.sub.3, C.sub.2HBrCl.sub.2, C.sub.2HCl.sub.2F, C.sub.2HClF.sub.2, C.sub.2HF.sub.3, C.sub.2H.sub.2Cl.sub.2, C.sub.2H.sub.2ClF, C.sub.2H.sub.2F.sub.2, C.sub.2H.sub.3Cl, C.sub.2H.sub.3F, C.sub.2H.sub.4, C.sub.3H.sub.6, C.sub.3H.sub.5Cl, C.sub.3H.sub.4C.sub.2, C.sub.3H.sub.3Cl.sub.3, C.sub.3H.sub.2Cl.sub.4, C.sub.3HCl.sub.5, C.sub.3H.sub.2ClF.sub.3, C.sub.3F.sub.3HCl.sub.2, C.sub.3F.sub.2H.sub.2Cl.sub.2, C.sub.3F.sub.4H, ClC.sub.3Cl.sub.6, C.sub.3Cl.sub.5F, C.sub.3Cl.sub.4F.sub.2, C.sub.3Cl.sub.3F.sub.3, C.sub.3Cl.sub.2F.sub.4, C.sub.3ClF.sub.5, C.sub.3HF.sub.5, C.sub.3H.sub.2F.sub.4, C.sub.3F.sub.6, C.sub.4Cl.sub.8, C.sub.4Cl.sub.2F.sub.6, C.sub.4ClF.sub.7, C.sub.4H.sub.2F.sub.6, or C.sub.4HClF.sub.6.

[0039] Preferably, said compound A may be selected from the group consisting of 1,1,2-trichloroethane, 2-chloro-1,1,1-trifluoroethane, 1-chloro-1,1,2-trifluoroethane, 1-chloro-1,2,2-trifluoroethane, 1,1,1,3,3,3-hexachlorodifluoropropane, 1,1,1,3,3,3-hexachloropropane, 1,1,1,3,3-pentachloropropane, 2,2,3-trichloro-1,1,1,3,3-pentafluoropropane, 1,1,1,3,3,3-hexachlorodifluoropropane, 1,1-dichloro-2,2,3,3,3-pentafluoropropane, 1,3-dichloro-1,2,2,3,3-pentafluoropropane, 1,1,1,2,3-pentachloropropane, 1,1,2,2,3-pentachloropropane, 1,1,1,3,3-pentachloropropane, 1,2-dichloroethylene, 1,1,2-trichloroethylene, 1,1,2,2-tetrachloroethylene, 1,1,2-trichloro-3,3,3-trifluoropropene, hexafluoropropene, 1,1,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2-chloro-3,3,3-trifluoropropene, 1,1,2,3-tetrachloropropene, 2,3,3,3-tetrachloropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,3,3-tetrachloropropene, 1,3,3,3-tetrachloropropene, 2,3-dichloro-1,1,1-trifluoropropane, 2-chloro-1,1,1,2-tetrafluoropropane.

[0040] More preferentially, said compound A may be selected from the group consisting of 1,1,2-trichloroethane, 2-chloro-1,1,1-trifluoroethane, 1-chloro-1,1,2-trifluoroethane, 1-chloro-1,2,2-trifluoroethane, 2-chloro-3,3,3-trifluoropropene, 1,1,1,2,3-pentachloropropane, 1,1,2,2,3-pentachloropropane, 1,1,2,3-tetrachloropropene, 2,3,3,3-tetrachloropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,3,3-pentachloropropane, 1,1,3,3-tetrachloropropene, 1,3,3,3-tetrachloropropene, 2,3-dichloro-1,1,1-trifluoropropane, 2-chloro-1,1,1,2-tetrafluoropropane, or mixtures thereof.

[0041] In particular, specific examples of reaction between HF and the compound A include the conversion of 1,1,2-trichloroethane (CHCl.sub.2CH.sub.2Cl or HCC-140) into 1-chloro-2,2-difluoroethane (CH.sub.2ClCF.sub.2H or HCFC-142), the conversion of 1,1,1,3,3,3-hexachlorodifluoropropane (CCl.sub.3CF.sub.2CCl.sub.3 or CFC-212ca) into a mixture of 1,1,3-trichloro-1,2,2,3,3-pentafluoropropane (CCl.sub.2FCF.sub.2CClF.sub.2 or CFC-215ca) and 1,3-dichloro-1,1,2,2,3,3-hexafluoropropane (CClF.sub.2CF.sub.2CClF.sub.2 or CFC-216ca), the conversion of 1,1,1,3,3,3-hexachloropropane (CCl.sub.3CH.sub.2CCl.sub.3 or HCC-230fa) into 1-chloro-1,1,3,3,3-pentafluoropropane (CF.sub.3CH.sub.2CClF.sub.2 or HCFC-235fa) and 1,1,1,3,3,3-hexafluoropropane (CF.sub.3CH.sub.2CF.sub.3 or HFC-236fa), the conversion of 1,1,1,3,3-pentachloropropane (CCl.sub.3CH.sub.2CHCl.sub.2 or HCC-240fa) into a mixture of 1,1,1,3,3-pentafluoropropane (CHF.sub.2CH.sub.2CF.sub.3 or HFC-245fa), 1-chloro-3,3,3-trifluoro-1-propene (CHClCHCF.sub.3 or HCFO-1233zd) and 1,3,3,3-tetrafluoropropene (CHFCHCF.sub.3 or HFO-1234ze), the conversion of 2,2,3-trichloro-1,1,1,3,3-pentafluoropropane (CF.sub.3CCl.sub.2CClF.sub.2 or CFC-215aa) into a mixture of 1,1,1,3,3,3-hexachlorodifluoropropane (CF.sub.3CCl.sub.2CF.sub.3 or CFC-212ca) and 2-chloro-1,1,1,2,3,3,3-heptafluoropropane (CF.sub.3CClFCF.sub.3 or CFC-217ba), the conversion of 1,1,1,3,3,3-hexachlorodifluoropropane (CF.sub.3CCl.sub.2CF.sub.3 or CFC-212ca) into 2-chloro-1,1,1,2,3,3,3-heptafluoropropane (CF.sub.3ClFCF.sub.3 or CFC-217ba), the conversion of a mixture containing 1,1-dichloro-2,2,3,3,3-pentafluoropropane (CF.sub.3CF.sub.2CHCl.sub.2 or HCFC-225ca) and 1,3-dichloro-1,2,2,3,3-pentafluoropropane (CClF.sub.2CF.sub.2CHClF or HCFC-225cb) into a mixture of 1-chloro-1,2,2,3,3,3-hexafluoropropane (CF.sub.3CF.sub.2CHClF or HCFC-226ca) and 1,1,1,2,2,3,3-heptafluoropropane (CF.sub.3CF.sub.2CHF.sub.2 or HFC-227ca), the conversion of 1,1,1,2,3-pentachloropropane (CCl.sub.3CHClCH.sub.2Cl or HCC-240db) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf), the conversion of 1,1,2,2,3-pentachloropropane (CHCl.sub.2CCl.sub.2CH.sub.2Cl or HCC-240aa) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf), the conversion of 1,1,1,2,3-pentachloropropane (CCl.sub.3CHClCH.sub.2Cl or HCC-240db) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1,1,2,2,3-pentachloropropane (CHCl.sub.2CCl.sub.2CH.sub.2Cl or HCC-240aa) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1,1,1,3,3-pentachloropropane (CCl.sub.3CH.sub.2CHCl.sub.2 or HCC-240fa) into 1,3,3,3-tetrafluoropropene (CF.sub.3CHCHF or HFO-1234ze), the conversion of 1,2-dichloroethylene (CHClCClH or HCO-1130) into 1-chloro-2,2-difluoroethane (CH.sub.2ClCF.sub.2H or HCFC-142).sub.2, the conversion of 1,1,2-trichloro-3,3,3-trifluoro-1-propene (CCl.sub.2CClCF.sub.3 or CFC-1213xa) into a mixture of 2,3-dichloro-1,1,1,3,3-pentafluoropropane (CF.sub.3CHClCClF.sub.2 or HCFC-225da), of 2-chloro-1,1,1,3,3,3-hexafluoropropane (CF.sub.3CHClCF.sub.3 or HCFC-226da) and/or of 2-chloro-1,1,3,3,3-pentafluoro-1-propene (CF.sub.3CClCF.sub.2 or CFC-1215xc), the conversion of hexafluoropropene (CF.sub.3CFCF.sub.2 or CFC-1216yc) into 1,1,1,2,3,3,3-heptafluoropropane (CF.sub.3CHFCF.sub.3 or HFC-227ea), the conversion of 1,1,3,3,3-pentafluoropropene (CF.sub.3CHCF.sub.2 or HFO-1225zc) into 1,1,1,3,3,3-hexafluoropropane (CF.sub.3CH.sub.2CF.sub.3 or HFC-236fa), the conversion of 1,3,3,3-tetrafluoropropene (CF.sub.3CHCHF or HFO-1234ze) into 1,1,1,3,3-pentafluoropropane (CF.sub.3CH.sub.2CHF.sub.2 or HFC-245fa), the conversion of 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1,1,2,3-tetrachloro-1-propene (CCl.sub.2CClCH.sub.2Cl or HCO-1230xa) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf) or 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 2,3,3,3-tetrachloro-1-propene (CCl.sub.3CClCH.sub.2 or HCO-1230xf) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf) or into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CHCHCl or HCFO-1233zd) or of 1,1,3,3-tetrachloro-1-propene (CCl.sub.2CHCHCl.sub.2 or HCO-1230za) or of 1,3,3,3-tetrachloroprop-1-ene (CCl.sub.3CHCHCl or HCO-1230zd) into 1,3,3,3-tetrafluoropropene (CF.sub.3CHCHF or HFO-1234ze), the conversion of 2,3-dichloro-1,1,1-trifluoropropane (CF.sub.3CHClCH.sub.2Cl or HCFC-243db) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 2-chloro-1,1,1,2-tetrafluoropropane (CF.sub.3CFClCH.sub.3 or HCFC-244bb) into 1,1,1,2,2-pentafluoropropane (CF.sub.3CF.sub.2CH.sub.3 or HFC-245cb), the conversion of 1,1,2,2-tetrachloroethylene (Cl.sub.2CCCl.sub.2 or PER) into 1,1,1,2,2-pentafluoroethane (CF.sub.3CF.sub.2H or HFC-125), the conversion of 2-chloro-1,1,1-trifluoroethane (CF.sub.3CH.sub.2Cl or R-133a) into 1,1,1,2-tetrafluoroethane (CF.sub.3CCH.sub.2F or R-134a), the conversion of 1,1,2,2-tetrachloroethylene (Cl.sub.2CCCl.sub.2 or PER) into 1,1,1,2-tetrafluoroethane (CF.sub.3CCH.sub.2F or R-134a), the conversion of 1,1,2-trichloroethylene (ClHCCCl.sub.2) into 1,1,1,2-tetrafluoroethane (CF.sub.3CCH.sub.2F or R-134a) and/or 1,1,1,2,2-pentafluoroethane (CF.sub.3CF.sub.2H or HFC-125).

[0042] More particularly, specific examples of fluorination reactions of compounds A include the conversion of 1,1,1,2,3-pentachloropropane (CCl.sub.3CHClCH.sub.2Cl or HCC-240db) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf), the conversion of 1,1,2,2,3-pentachloropropane (CHCl.sub.2CCl.sub.2CH.sub.2Cl or HCC-240aa) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf), the conversion of 1,1,1,2,3-pentachloropropane (CCl.sub.3CHClCH.sub.2Cl or HCC-240db) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1,1,2,2,3-pentachloropropane (CHCl.sub.2CCl.sub.2CH.sub.2Cl or HCC-240aa) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1,1,1,3,3-pentachloropropane (CCl.sub.3CH.sub.2CHCl.sub.2 or HCC-240fa) into 1,3,3,3-tetrafluoropropene (CF.sub.3CHCHF or HFO-1234ze), the conversion of 1,1,2-trichloroethane (CHCl.sub.2CH.sub.2Cl or HCC-140) into 1-chloro-2,2-difluoroethane (CH.sub.2ClCF.sub.2H or HCFC-142), the conversion of 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1,1,2,3-tetrachloro-1-propene (CCl.sub.2CClCH.sub.2Cl or HCO-1230xa) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf) or into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 2,3,3,3-tetrachloro-1-propene (CCl.sub.3ClCH.sub.2 or HCO-1230xf) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf) or into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 1-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CHCHCl or HCFO-1233zd) or of 1,1,3,3-tetrachloro-1-propene (CCl.sub.2CHCHCl.sub.2 or HCO-1230za) or of 1,3,3,3-tetrachloroprop-1-ene (CCl.sub.3CHCHCl or HCO-1230zd) into 1,3,3,3-tetrafluoropropene (CF.sub.3CHCHF or HFO-1234ze), the conversion of 1,2-dichloroethylene (CHClCClH or HCO-1130) into 1-chloro-2,2-difluoroethane (CH.sub.2ClCF.sub.2H or HCFC-142), the conversion of 2,3-dichloro-1,1,1-trifluoropropane (CF.sub.3CHClCH.sub.2Cl or HCFC-243db) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of 2-chloro-1,1,1,2-tetrafluoropropane (CF.sub.3CFClCH.sub.3 or HCFC-244bb) into 1,1,1,2,2-pentafluoropropane (CF.sub.3CF.sub.2CH.sub.3 or HFC-245cb), the conversion of 1,1,2,2-tetrachloroethylene (Cl.sub.2CCCl.sub.2 or PER) into 1,1,1,2,2-pentafluoroethane (CF.sub.3CF.sub.2H or HFC-125), the conversion of 2-chloro-1,1,1-trifluoroethane (CF.sub.3CH.sub.2Cl or R-133a) into 1,1,1,2-tetrafluoroethane (CF.sub.3CCH.sub.2F or R-134a), the conversion of 1,1,2,2-tetrachloroethylene (Cl.sub.2CCCl.sub.2 or PER) into 1,1,1,2-tetrafluoroethane (CF.sub.3CCH.sub.2F or R-134a), the conversion of 1,1,2-trichloroethylene (ClHCCCl.sub.2) into 1,1,1,2-tetrafluoroethane (CF.sub.3CCH.sub.2F or R-134a) and/or 1,1,1,2,2-pentafluoroethane (CF.sub.3CF.sub.2H or HFC-125).

[0043] According to another preferred embodiment, step a) may implement a gas-phase dehydrohalogenation reaction of a saturated C.sub.1-C.sub.4 hydrocarbon compound B comprising at least one halogen atom to form an unsaturated C.sub.1-C.sub.4 hydrocarbon compound and a hydrogen halide. Preferably, the compound B is selected from the group consisting of 1,1-difluoroethane, 1,1,1-trifluoroethane, 2-chloro-1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2,2-pentafluoroethane, 1,1,1,2-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,2,3-hexafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1,2,3-pentafluoropropane, 2,3-dichloro-1,1,1-trifluoropropane and 2-chloro-1,1,1,2-tetrafluoropropane. In particular, the compound B is selected from the group consisting of 1,1,1,2,2-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 2,3-dichloro-1,1,1-trifluoropropane and 2-chloro-1,1,1,2-tetrafluoropropane. Preferably, the hydrogen halide is HF or HCl.

[0044] Specific examples of gas-phase dehydrohalogenation of the compound B include the conversion of 1,1-difluoroethane (CHF.sub.2CH.sub.3 or HFC-152a) into vinyl chloride (CHFCH.sub.2 or HFO-1141), the conversion of 1,1,1-trifluoroethane (CF.sub.3CH.sub.3 or HFC-143a) into vinylidene fluoride (CF.sub.2CH.sub.2 or HFO-1132a), the conversion of 2-chloro-1,1,1-trifluoroethane (CF.sub.3CH.sub.2Cl or HCFC-133a) into 2-chloro-1,1-difluoroethylene (CF.sub.2CHCl or HCFO-1122), the conversion of 1,1,1,2-tetrafluoroethane (CF.sub.3CH.sub.2F or HFC-134a) into trifluoroethylene (CF.sub.2CHF or HFO-1123), the conversion of 1,1,2,2-tetrafluoroethane (CHF.sub.2CHF.sub.2 or HFC-134) into trifluoroethylene (CF.sub.2CHF or HFO-1123), the conversion of 1,1,1,2-tetrafluoropropane (CH.sub.3CHFCF.sub.3 or HFC-254eb) into 1,1,1-trifluoropropene (CH.sub.2CHCF.sub.3 or HFO-1243zf), the conversion of 1,1,1,3,3-pentafluoropropane (CHF.sub.2CH.sub.2CF.sub.3 or HFC-245fa) into 1,3,3,3-tetrafluoropropene (CHFCHCF.sub.3 or HFO-1234ze), the conversion of 1,1,1,2,3,3-hexafluoropropane (CHF.sub.2CHFCF.sub.3 or HFC-236ea) into 1,2,3,3,3-pentafluoropropene (CHFCFCF.sub.3 or HFO-1225ye), the conversion of 1,1,1,3,3,3-hexafluoropropane (CF.sub.3CH.sub.2CF.sub.3 or HFC-236fa) into 1,1,3,3,3-pentafluoropropene (CF.sub.3CHCF.sub.2 or HFO-1225zc), the conversion of 1,1,1,2,2,3-hexafluoropropane (CF.sub.3CF.sub.2CFH.sub.2 or HFC-236cb) into 1,2,3,3,3-pentafluoropropene (CHFCFCF.sub.3 or HFO-1225ye), the conversion of 1,1,1,2,2-pentafluoropropane (CF.sub.3CF.sub.2CH.sub.3 or HFC-245cb) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf) and the conversion of 1,1,1,2,3-pentafluoropropane (CF.sub.3CHFCH.sub.2F or HFC-245eb) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf), the conversion of (CF.sub.3CHClCH.sub.2Cl or HCFC-243db) into 2-chloro-3,3,3-trifluoro-1-propene (CF.sub.3CClCH.sub.2 or HCFO-1233xf), the conversion of 2-chloro-1,1,1,2-tetrafluoropropane (CF.sub.3CFClCH.sub.3 or HCFC-244bb) into 2,3,3,3-tetrafluoropropene (CF.sub.3CFCH.sub.2 or HFO-1234yf).

[0045] The catalytic bed temperature T1 may be between 100 C. and 500 C., advantageously between 150 C. and 450 C., preferably between 200 C. and 400 C., more preferentially between 250 C. and 380 C.

[0046] Step a) may also be implemented according to the following operating conditions: [0047] an HF/hydrocarbon compound molar ratio between 1:1 and 150:1, preferably between 2:1 and 125:1, more preferentially between 3:1 and 100:1; [0048] a contact time between 1 and 100 s, preferably between 2 and 75 s, in particular between 3 and 50 s; [0049] a pressure between atmospheric pressure and 20 bar, preferably between 2 and 18 bar, more preferentially between 3 and 15 bar.

[0050] Those skilled in the art will adapt the operating conditions above according to the reaction to be carried out in step a).

[0051] Step a) may be implemented over a duration of between 2000 and 25 000 h, preferably between 2500 and 24 000 h, more preferentially between 3000 and 20 000 h.

[0052] An oxidant, such as oxygen or chlorine, may be added during step a). The molar ratio of the oxidant to the compound A or B may be between 0.005 and 2, preferably between 0.01 and 1.5. The oxidant may be pure oxygen, air or a mixture of oxygen and nitrogen.

[0053] Step a) may optionally comprise a step of regeneration of the catalyst in alternation with said catalytic reaction. The regeneration step is generally implemented in the presence of a stream comprising oxygen at a temperature of between 100 C. and 500 C.

[0054] At the end of the implementation of step a), the catalyst is subjected to step b) according to the process of the present invention.

[0055] Step b)

[0056] According to the present process, step b) comprises causing an inert gas to flow through the catalytic bed. Preferably, step b) is implemented at a catalytic bed temperature T2 that is lower than T1. Thus, it is not necessary to heat the catalytic bed to remove the hydrogen halide present in the reactor or the catalyst. In order to maximize the removal of the hydrogen halide, the catalytic bed temperature T2 is greater than 30 C. Thus, at the start of implementation of step b), the temperature T2 is greater than 30 C.

[0057] After the implementation of step a), the stream of reactants is stopped, the temperature of the catalytic bed decreases from the temperature T1 to the temperature T2, which is lower than T1, and the inert gas is introduced into the reactor.

[0058] Preferably, the catalytic bed temperature T2 is greater than 40 C., advantageously greater than 50 C., preferably greater than 60 C., more preferentially greater than 70 C., in particular greater than 80 C., more particularly greater than 90 C., favorably greater than 100 C.

[0059] Preferably, the catalytic bed temperature T2 is lower than 380 C., advantageously lower than 360 C., preferably lower than 340 C., more preferentially lower than 320 C., in particular lower than 300 C., favorably lower than 250 C.

[0060] According to a preferred embodiment, the inert gas is introduced into the reactor at a temperature of between ambient temperature and T2, advantageously of between ambient temperature and 50 C., and in particular the inert gas is introduced into the reactor at ambient temperature.

[0061] The passage of the inert gas through the catalytic bed leads to a decrease in the catalytic bed temperature T2 during the implementation of step b). Preferably, the temperature T2 decreases at a rate of less than 5 C./min during the implementation of step b), in particular of less than 1 C./min, during the implementation of step b).

[0062] According to a preferred embodiment, the inert gas flows at a flow rate of greater than 0.1 ml/min per ml of catalyst, advantageously of greater than 0.2 ml/min per ml of catalyst, preferably of greater than 0.3 ml/min per ml of catalyst, more preferentially of greater than 0.4 ml/min per ml of catalyst, in particular of greater than 0.5 ml/min per ml of catalyst, favorably of greater than 0.6 ml/min per ml of catalyst, advantageously favorably of greater than 0.7 ml/min per ml of catalyst, preferentially favorably of greater than 0.8 ml/min per ml of catalyst, particularly favorably of greater than 0.9 ml/min per ml of catalyst.

[0063] According to a preferred embodiment, step b) comprises a step b1) of cooling the catalytic bed from the temperature T1 to T2, and then a step b2) of causing said inert gas to flow through the catalytic bed.

[0064] Preferably, the inert gas is nitrogen or argon. In particular nitrogen.

[0065] Preferably, at the outlet of the reactor, the inert gas contains a content by mass of CO and CO2 of less than 100 ppm.

Examples

[0066] The apparatus used comprises a tubular reactor made from INCONEL 600 (internal diameter of 28 mmlength=600 mm), placed vertically in an electric tube furnace. The reactor is equipped with indicators for pressure and temperature (movable thermocouple in an Inconel sleeve placed coaxially at the center of the tube). The fixed catalytic bed consists of a lower layer of corundum followed by a 180 ml layer of catalyst and an upper layer of corundum. The catalyst used is an NiCr/AlF.sub.3 catalyst. Before use, it is dried and then activated in the presence of a mixture of hydrofluoric acid and nitrogen, at a temperature of between T=320 C. and T=350 C.

[0067] The characteristics of the catalyst after activation are as follows: [0068] BET surface area: 38.78 m.sup.2/g; [0069] chemical composition: Al: 19.0%, F: 61.2%, Cr: 4.5%, Ni: 4.4%

[0070] The reactants are introduced continuously at the upper end of the reactor and preheated to the furnace temperature through the upper layer of corundum, the gaseous products of the reaction exit at the lower end of the reactor through a pressure-regulating valve; the gas stream exiting from the valve is analyzed by gas chromatography.

[0071] Test 1 (Invention)

[0072] The reaction is conducted at atmospheric pressure and at a temperature of T=350 C. by continuously supplying anhydrous HF (137.6 g.Math.h.sup.1) and perchloroethylene (28.3 g.Math.h.sup.1). The GHSV (gas hourly space velocity) is 2000 h.sup.1. The HF:organic molar ratio is 40.3.

[0073] After 19 h of reaction, the composition of the organic stream exiting the reactor is given in table 1 below.

TABLE-US-00001 TABLE 1 Composition PER F125 F124 F123 F121 + F122 Others mol % 29.39 21.68 25.33 13.55 4.77 5.28

[0074] After 98 h of reaction, the introduction of the reactants and the heating of the electric furnace are stopped. Nitrogen is introduced into the reactor at a flow rate of 10 l.Math.h.sup.1 (0.9 ml.Math.min.sup.1 per ml of catalyst).

[0075] After flushing for 17 h, the temperature in the reactor is T=140 C. (i.e. a decrease at an average rate of 12 C. per hour).

[0076] Test 2 (Comparative)

[0077] A test identical to test 1 (same batch of activated catalyst) is carried out until the stopping of the reactants. After 98 h of reaction, the introduction of the reactants is stopped and the heating of the electric furnace is increased until a temperature of 360 C. is reached. Nitrogen is introduced into the reactor at a flow rate of 10 l.Math.h.sup.1 (0.9 ml.Math.min.sup.1 per ml of catalyst). The temperature of the furnace is maintained at a temperature of T=360 C. for 8 hours.

Example 1

[0078] The catalyst of test 1 and the catalyst of test 2 are regenerated in identical fashion at atmospheric pressure, by treatment in air (1.5 l.Math.h.sup.1) at a temperature of T=350 C. for 72 hours.

[0079] After regeneration, the catalysts are analyzed (table 2).

TABLE-US-00002 TABLE 2 BET surface area (m.sup.2/g) Catalyst of test 1 Catalyst of test 2 (after regeneration) (after regeneration) 25.79 20.03

[0080] The catalysts of test 1 and of test 2 thus regenerated are tested in the fluorination reaction of perchloroethylene. The reaction is conducted at atmospheric pressure and at a temperature of T=350 C. by continuously supplying anhydrous HF (137.6 g.Math.h.sup.1) and perchloroethylene (28.3 g.Math.h.sup.1). The GHSV (gas hourly space velocity) is 2000 h.sup.1. The HF:organic molar ratio is 40.3. The analysis of the composition of the organic stream exiting the reactor is also conducted after 19 h and 43 h of reaction. The comparative results are presented in table 3 below.

TABLE-US-00003 TABLE 3 F121 + Composition (mol %) PER F125 F124 F123 F122 Others Catalyst of 19 h 37.97 10.08 23.56 16.05 5.59 6.75 test 1 43 h 40.45 13.03 21.99 12.96 5.94 5.63 Catalyst of 19 h 45.89 8.04 17.19 14.95 6.48 7.45 test 2 43 h 48.2 8.62 15.19 13.99 6.5 7.5

[0081] These results clearly show that the treatment conducted on the catalyst of test 2 is harmful to it (lower BET surface area and catalytic activity). In contrast, the nitrogen treatment conducted on the catalyst of the test 1 makes it possible to obtain a better catalytic activity thereof after regeneration. Step b) according to the present invention makes it possible to avoid the premature degradation of the catalyst and to thus obtain a catalyst that is more effective later on when it is reused, for example after regeneration.