GAS-PHASE CATALYTIC FLUORATION WITH CHROMIUM-BASED CATALYSTS

Abstract

Gas-phase catalytic fluorination with chromium-based catalysts. The present invention relates to a process for fluorinating a chlorinated compound comprising the steps of (a) contacting said chlorinated compound with hydrogen fluoride in the gas phase in a reactor in the presence of a fluorination catalyst to produce a fluorinated compound, and (b) regeneration of the fluorination catalyst used in step a), the regeneration step of the fluorination catalyst comprising (c) treating said fluorination catalyst with an oxidant to form an oxidized fluorination catalyst, and (d) treating the oxidized fluorination catalyst obtained in step (c) with a gaseous mixture comprising a reducing agent.

Description

Title of the invention: Gas-phase catalytic fluorination with chromium-based catalysts. Field of the invention

[0001] The present invention relates to a gas-phase catalytic fluorination process. Preferably, the present invention relates to a gas-phase catalytic process for the fluorination of a chlorinated compound to a fluorinated compound in the presence of hydrogen fluoride. In particular, the present invention relates to a process in which the fluorination reaction is carried out in the presence of a catalyst that is regenerated. Background of the present invention

[0002] The Montreal Protocol for the protection of the ozone layer required the phase-out of the use of chlorofluorocarbons (CFCs). More ozone-friendly materials, such as hydrofluorocarbons (HFCs), e.g., HFC-134a, replaced chlorofluorocarbons. These latter compounds have been shown to be greenhouse gases, causing global warming. They were regulated by the Kyoto Protocol on climate change. Ongoing concerns about global climate change are driving a growing need to develop technologies to replace those with a high ozone depletion potential (ODP) and a high global warming potential (GWP).Although hydrofluorocarbons (HFCs), which are not ozone-depleting compounds, have been identified as alternatives to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) as solvents, cleaning agents, and heat transfer fluids, they still tend to exhibit a significant GWP. Hydrofluoroolefins (HFOs) have been identified as potential alternatives with zero ODP and a low GWP.

[0003] Numerous documents therefore describe manufacturing processes for such HFOs, including HFO-1234yf.

[0004] For example, WO 2007 / 079431 describes processes for the production of fluorinated olefins, including hydrofluoropropenes. The processes, which are generally described as a single reaction or two or more reactions, include the fluorination of a compound of formula C(X)mCCl(Y)nC(X)m to at least one compound of formula CF3CF=CHZ, in which X, Y, and Z each independently represent H, F, Cl, I, or Br, and each m independently represents 1, 2, or 3, and n represents 0 or 1. HFO-1234yf is prepared by fluorinating HFCO-1233xf in 1,1,1,2-tetrafluoro-2-chloropropane (HCFC-244bb), followed by dehydrochlorination. HFCO-1233xf is prepared by fluorination of the corresponding chlorinated precursor (CC12=CC1CH2C1).

[0005] EP-A-939071 describes, among many possibilities, phase fluorination gaseous conversion of a halogenated propene (according to a very long list) into a fluorinated propene (including in the HFO-1234yf list).

[0006] WO 2008 / 054781 describes various processes for producing various fluoropropanes and halofluoropropenes by reacting halopropanes or halopropenes with HF, optionally in the presence of a catalyst. It describes a process for manufacturing HFO-1234yf by reacting 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db) in the presence of HF, over a catalyst, in particular Cr / Co (98 / 2). The reaction products include HFO-1234yf and HFCO-1233xf, the latter being the main product; Other products include l-chloro-3,3,3-trifluoro-l-propene (HFCO-1233zd), as well as 1,1,1,2,2-pentafluoropropane (HFC-245cb) and 1,3,3,3-tetrafluoro-1-propene (HFO-1234ze).

[0007] WO 2008 / 002500 describes a process for manufacturing a mixture of HFO-1234yf and HFO-1234ze by catalytic conversion of 1,1,1,2,3-pentafluoropropane (HFC-245eb) on a dehydrofluoration catalyst.

[0008] WO 2008 / 040969 describes a process comprising the dehydrochlorination of HCFC-243db to HFCO-1233 (xf and zd), followed by a reaction comprising the formation of 1,1,1,2-tetrafluoro-2-chloropropane (HCFC-244bb) and the subsequent formation of the desired HFO-1234yf by dehydrochlorination. Example 1 of said document describes a gas-phase reaction at atmospheric pressure of HCFC-243db with HF on a Zn / chromium dioxide catalyst, forming HFO-1234yf and HFCO-1233xf, as well as a small amount of HFC-245cb.

[0009] WO 2009 / 015317 describes the reaction of a chlorinated compound which can be the 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 1,1,1,2,3-pentachloropropane (HCC-240db), or 2,3,3,3-tetrachloro-1-propene (HCO-1230xf) with HF, in the gas phase, over a catalyst and in the presence of at least one stabilizer. This process makes it possible to obtain 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf).

[0010] US 2009 / 0240090 describes a process for manufacturing 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf) from a compound of formula (I) CX2=CC1CH2X, or of formula (II) CX3CC1=CH2, or of formula (III) CX3CHC1CH2X, where X = F, Cl, Br, I. The process comprises three steps, which may be followed by purification. The process includes recycling steps to achieve higher conversions and yields.

[0011] WO 2010 / 123154 relates to a process for producing HFO-1234yf starting from HFCO-1233xf, by reacting the latter with HF in the presence of oxygen and of a catalyst comprising chromium oxide or fluorinated chromium oxide.

[0012] WO2012 / 098421 and WO2012 / 098422 relate to processes for fluorination ca Gas-phase catalytic reaction of 2-chloro-3,3,3-trifluoro-l-propene or 1,1,1,2,3-pentachloropropane to produce 2,2,2,3-tetrafluoropropene. Catalyst regeneration is carried out in the presence of an oxidant.

[0013] There is still a need for an improved process for the manufacture of fluoro-roolefins such as HFO-1234yf, having in particular an improved conversion rate and / or improved selectivity and / or being efficient for a longer period of time. Summary of the invention

[0014] According to a first aspect, the present invention relates to a process for fluorinating a chlorinated compound into a fluorinated compound, comprising the following steps: a. contacting, in a reactor, the chlorinated compound with hydrogen fluoride in the gas phase in the presence of a fluorination catalyst to produce the fluorinated compound, and b. the regeneration of the fluorination catalyst used in step a),

[0015] step (b) of regeneration of the fluorination catalyst comprising (c) the treatment of said fluorination catalyst with a gas stream containing an oxidant to form an oxidized fluorination catalyst, and (d) the treatment of the oxidized fluorination catalyst obtained in step (c) with a gas mixture comprising a reducing agent.

[0016] The present process allows for the improvement of the conversion or selectivity of the reaction. Indeed, it has been observed that by subjecting the fluorination catalyst to a regeneration step as required according to the invention, the presence of by-products is limited or avoided, in particular when the fluorination catalyst thus regenerated is used in step a).

[0017] According to a preferred embodiment, the gas mixture used in step (d) may further comprise an inert gas, preferably selected from nitrogen, helium, argon or HF or mixtures thereof.

[0018] According to a preferred embodiment, the reducing agent may be a gaseous reducing agent. Preferably, the reducing agent may be chosen from the group consisting of hydrogen, carbon monoxide, nitrogen monoxide, formaldehyde, Ci-C6 alkanes and Ci-CiO hydrohalocarbons.

[0019] According to a preferred embodiment, the chlorinated compound may be a linear or branched C2-C6 alkane or C2-C6 alkene bearing at least one chlorine atom; preferably, the chlorinated compound may be selected from the group consisting of 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 2,3,3,3-tetrachloro-1-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,3,3-pentachloropropane (HCC-240fa), 1,1,3,3-tetrachloropropene (HCO-1230za), 1,3,3,3-tetrachloropropene (HCO-1230zd), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,1,1,3-tetrachloropropane (HCC-250fb), 1,1,3-trichloropropene (HCO-1240za), 3,3,3-trichloropropene (HCO-1240zf); Preferably, the chlorinated compound may be chosen from the group consisting of 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-l-propene (HCO-1230xa), 2,3,3,3-tetrachloro-l-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb)..

[0020] According to a preferred embodiment, the fluorinated compound is the 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,2,2-pentafluoropropane (HFC-245cb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3-tetrafluoro-3-chloropropane (HCFC-244fa), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,3,3,3-tetrafluoropropene (HFO-1234ze), 3,3,3-trifluoropropene (HFO-1243zf) and 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf).

[0021] Preferably, the chlorinated compound and the fluorinated compound are different. For example, when 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) is the chlorinated compound, then the fluorinated compound obtained in step a) is different from 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf). Furthermore, when 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) is the fluorinated compound obtained in step a), the chlorinated compound used as the starting material in step a) is different from 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf).

[0022] According to a preferred embodiment, the fluorination of the chlorinated compound to a fluorinated compound is: • 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,1,2,3-pentachloropropane (HCC-240db) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,2,2,3-pentachloropropane (HCC-240aa) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,1,2,3-pentachloropropane (HCC-240db) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,1,2,3-pentachloropropane (HCC-240db) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,1,2,3-pentachloropropane (HCC-240db) to 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 1,1,2,2,3-pentachloropropane (HCC-240aa) to 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) to 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) to 1,1,1,2,2-pentafluoropropane (HFC-245cb).

[0023] According to a preferred embodiment, the fluorination catalyst may comprise chromium oxyfluoride, chromium oxides, chromium halides and their mixtures. Chromium halides refer to chromium fluorides and / or chromium chlorides.

[0024] According to a preferred embodiment, the fluorination catalyst may also contain one or more co-catalysts comprising a salt of a transition metal selected from the group consisting of Co, Zn, Mn, Mg, V, Mo, Te, Nb, Sb, Ta, Ni; or a phosphorus salt.

[0025] According to a preferred embodiment, the process includes an activation step carried out before step (a) which includes a first step of contacting the fluorination catalyst with a gas stream containing an oxidant.

[0026] According to a preferred embodiment, the activation step may also include a second step, after the first step, of treating the fluorination catalyst obtained after the first step with a reducing agent.

[0027] According to a preferred embodiment, the gas mixture of step (d) may comprise from 1 to 10% by volume of reducing agent, preferably from 2 to 9% by volume, more preferably from 3 to 7% by volume, relative to the total volume of the gas mixture.

[0028] According to a preferred embodiment, step d) is carried out at a temperature ranging from 100 °C to 450 °C, with a contact time of 1 to 100 s, preferably from 1 to 75 s, more preferably from 5 to 50 s, for a period of more than 1 hour, preferably from 1 to 50 hours.

[0029] According to a preferred embodiment, steps (a) and (b) can be carried out alternately.

[0030] According to a preferred embodiment, steps (a) and (b) are carried out in a single reactor. Furthermore, the activation step as defined in this document can also be carried out in the same reactor as that used for steps (a) and (b) according to the present process.

[0031] According to a preferred embodiment, the fluorination catalyst obtained after step (b) is reused in step (a) of the present process.

[0032] According to a preferred embodiment, purging of the reactor may be carried out before and / or after step (b), i.e., between the fluorination reaction and the regeneration step and / or between the end of the regeneration step and the fluorination reaction using the fluorination catalyst thus regenerated. This purging may be carried out by maintaining the reactor under vacuum or by introducing a stream of nitrogen into the reactor to replace the gaseous components contained in the reactor before or after step (b). Alternatively, the purging may be carried out by introducing a stream of an oxidant such as air or a mixture of oxygen and nitrogen into the reactor to replace the gaseous components contained in the reactor before or after step (b). The purging may be carried out at a temperature ranging from ambient temperature to 400 °C; preferably at an absolute pressure ranging from atmospheric pressure to 5 bar; and preferably for a duration ranging from 1 hour to 50 hours.

[0033] According to a second aspect, the present invention relates to a process for fluorinating a 2,3,3,3-tetrafluoropropene to 1,1,1,2,2-pentafluoropropane, comprising the following steps: a. the contacting, in a reactor, of 2,3,3,3-tetrafluoropropene with hydrogen fluoride in the gas phase in the presence of a fluorination catalyst to produce 1,1,1,2,2-pentafluoropropane, and b. the regeneration of the fluorination catalyst used in step a),

[0034] step (b) of regeneration of the fluorination catalyst comprising (c) the treatment of said fluorination catalyst with a gas stream containing an oxidant to form an oxidized fluorination catalyst, and (d) the treatment of the oxidized fluorination catalyst obtained in step (c) with a gas mixture comprising a reducing agent.

[0035] The reducing agent, the oxidant, the catalyst, the regeneration step and the activation step are defined previously and / or subsequently with regard to the first aspect of the present invention. Detailed description of the present invention

[0036] The term "Ci-CiO hydrohalocarbure," as used in this document, refers to a Ci-CiO alkane, a C2-CiO alkene, or a C2-CiO alkyne bearing at least one halogen atom, the halogen atom preferably being F or Cl. Preferably, "Ci-CiO hydrohalocarbure" refers to a C2-C6 alkane or a C2-C6 alkene bearing at least one halogen atom, preferably F or Cl. More preferably, the "Ci-CiO hydrohalocarbure" may be a chlorinated compound as defined below, i.e., a C2-C6 alkane or a C2-C6 alkene bearing at least one chlorine atom.

[0037] The present invention relates to a process for fluorinating a compound. It has been surprisingly discovered that by regenerating the fluorination catalyst used in the fluorination process, the presence of by-products can be limited or avoided.

[0038] According to a first aspect, the present invention therefore relates to a process for fluorinating a chlorinated compound to a fluorinated compound. Said process comprises the steps (a) of contacting the chlorinated compound with hydrogen fluoride in the gas phase in the presence of a fluorination catalyst to produce the fluorinated compound, and (b) of regenerating said fluorination catalyst used in step (a). In particular, step (b) of regenerating the fluorination catalyst comprises (c) treating said fluorination catalyst with a gas stream containing an oxidant to form an oxidized fluorination catalyst, and (d) treating the oxidized fluorination catalyst obtained in step (c) with a gas mixture comprising an agent reducer.

[0039] The "chlorinated compound" can be any molecule containing a chlorine atom, and the "fluorinated compound" can be any molecule containing a fluorine atom.

[0040] Preferably, the chlorinated compound is a linear or branched C2-C6 alkane or C2-C6 alkene bearing at least one chlorine atom. The term "C2-C6 alkane" refers to an alkane containing 2, 3, 4, 5, or 6 carbon atoms. The term "C2-C6 alkene" refers to an alkene containing 2, 3, 4, 5, or 6 carbon atoms. The chlorinated compound may be a C2-C5 alkane, preferably a C2-C4 alkane, more preferably a C3-C4 alkane, and most preferably a C3 alkane, bearing at least one chlorine atom. The chlorinated compound may be a C2-C5 alkene, preferably a C2-C4 alkene, more preferably a C3-C4 alkene, and most preferably a C3 alkene, bearing at least one chlorine atom. The chlorinated compound may bear at least one chlorine atom, preferably at least two chlorine atoms. The chlorinated compound may bear one, two, three, four, five, or six chlorine atoms.Therefore, said chlorinated compound may be a linear or branched C2-C6 alkane or C2-C6 alkene bearing from one to six chlorine atoms, preferably from one to five chlorine atoms or from two to five chlorine atoms. The linear or branched C2-C6 alkane or C2-C6 alkene bearing at least one chlorine atom as defined herein may also bear one or more halogen atoms in addition to the chlorine atom(s), said halogen atom being selected from F, I, and Br; preferably F. In a preferred embodiment, the total number of halogen atoms in the chlorinated compound as defined herein may be from two to five halogen atoms, preferably from three to five halogen atoms, more preferably from four to five halogen atoms selected from F, Cl, Br, and I; at least one being a chlorine atom. .

[0041] Preferably, the chlorinated compound may be a C3 alkane compound containing at least one chlorine atom, preferably at least two chlorine atoms; and preferably from 0 to 5 fluorine atoms. The chlorinated compound may be a C3 alkane compound containing one, two, three, four, five, or six chlorine atoms; and preferably no fluorine atoms, one, two, three, four, or five fluorine atoms. Preferably, the chlorinated compound may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F; at least one being a chlorine atom, preferably at least two being a chlorine atom. Preferably, the chlorinated compound may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F, of which at most four halogen atoms are fluorine atoms, and at least one is a chlorine atom, preferably at least two are chlorine atoms.

[0042] Preferably, the chlorinated compound can be a C3 alkene compound containing at minus one chlorine atom, preferably at least two chlorine atoms; and preferably from 0 to 3 fluorine atoms. The chlorinated compound may be a C3 alkene compound containing one, two, three, or four chlorine atoms; and preferably no fluorine atoms, one, two, or three fluorine atoms. Preferably, the chlorinated compound may be a C3 alkene compound containing three or four halogen atoms selected from Cl and F; at least one being a chlorine atom, preferably at least two being chlorine atoms. More preferably, the chlorinated compound may be a C3 alkene compound containing three or four halogen atoms selected from Cl and F, of which at most three halogen atoms are fluorine atoms, and at least one is a chlorine atom.

[0043] Preferably, the chlorinated compound may be selected from the group consisting of 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 2,3,3,3-tetrachloro-1-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,3,3-pentachloropropane (HCC-240fa), 1,1,3,3-tetrachloropropene (HCO-1230za), 1,3,3,3-tetrachloropropene (HCO-1230zd), l-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,1,1,3-tetrachloropropene (HCC-250fb), 1,1,3-trichloropropene (HCO-1240za), 3,3,3-trichloropropene (HCO-1240zf).

[0044] In particular, the chlorinated compound can be chosen from the group consisting of 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-l-propene (HCO-1230xa), 2,3,3,3-tetrachloro-l-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb).

[0045] Preferably, the fluorinated compound is a linear or branched C2-C6 alkane or C2-C6 alkene bearing at least one fluorine atom. The fluorinated compound may be a C2-C5 alkane, preferably a C2-C4 alkane, more preferably a C3-C4 alkane, and most preferably a C3 alkane bearing at least one fluorine atom. The fluorinated compound may be a C2-C5 alkene, preferably a C2-C4 alkene, more preferably a C3-C4 alkene, and most preferably a C3 alkene bearing at least one fluorine atom.

[0046] Said fluorinated compound may be a linear or branched C2-C6 alkane or C2-C6 alkene bearing at least one fluorine atom, preferably at least two fluorine atoms, and more preferably at least three fluorine atoms. The fluorinated compound may bear one, two, three, four, or five fluorine atoms. The fluorinated compound may bear from one to five fluorine atoms, preferably from two to five fluorine atoms or from three to five fluorine atoms. The linear or branched C2-C6 alkane or C2-C6 alkene bearing at least one fluorine atom as defined herein may also bear one or more halogen atoms in addition to the fluorine atom(s), said halogen atom being selected from Cl, I, and Br; preferably Cl. According to a preferred embodiment, the total number of halogen atoms in the fluorinated compound as defined herein may be from 2 to 5 halogen atoms, preferably from 3 to 5 halogen atoms, more preferably from 4 or 5 halogen atoms selected from F, Cl, Br, and I; at least one being a fluorine atom, preferably at least two being a fluorine atom, more preferably at least three being a fluorine atom.

[0047] Preferably, the fluorinated compound may be a C3 alkane containing at least one fluorine atom, preferably at least two fluorine atoms, and more preferably at least three fluorine atoms. The fluorinated compound may be a C3 alkane containing one, two, three, four, or five fluorine atoms; and preferably 0 to 5 chlorine atoms, more preferably 0 to 4 chlorine atoms, and in particular 0 to 3 chlorine atoms. Preferably, the fluorinated compound may be a C3 alkane containing four or five halogen atoms selected from Cl and F; at least one being a fluorine atom.More preferably, the fluorinated compound may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F, of which at most three, preferably at most two, halogen atoms are chlorine atoms; and at least one is a fluorine atom, preferably at least two are fluorine atoms, more preferably at least three are fluorine atoms.

[0048] Preferably, the fluorinated compound may be a C3 alkene compound containing at least one fluorine atom, preferably at least two fluorine atoms, and more preferably at least three fluorine atoms. The fluorinated compound may be a C3 alkene compound containing one, two, three, or four fluorine atoms; and preferably from 0 to 2 chlorine atoms, and more preferably from 0 to 1 chlorine atom. Preferably, the fluorinated compound may be a C3 alkene compound containing four halogen atoms selected from Cl and F; at least one being a fluorine atom. More preferably, the fluorinated compound may be a C3 alkene compound containing four halogen atoms selected from Cl and F, of which at most two, and preferably at most one, halogen atoms are chlorine atoms; and at least one is a fluorine atom, preferably at least two are fluorine atoms, and more preferably at least three are fluorine atoms.In particular, the fluorinated compound can be a C3 alkene containing four halogen atoms, these being fluorine atoms. The fluorinated compound can also be a C3 alkene compound. containing four halogen atoms, three out of four being fluorine atoms, the remaining halogen atoms being chlorine atoms.

[0049] Preferably, the fluorinated compound may be selected from the group consisting of 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,2,2-pentafluoropropane (HFC-245cb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3-tetrafluoro-3-chloropropane (HCFC-244fa), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,3,3,3-tetrafluoropropene (HFO-1234ze-E), 3,3,3-trifluoropropene (HFO-1243zf) and the 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf).

[0050] According to the present process, the fluorination of the chlorinated compound is based on increasing the degree of fluorination, i.e., the number of fluorine atoms in the fluorinated compound is greater than the number of fluorine atoms in the chlorinated compound. Preferably, during the reaction, at least one Cl substituent in the chlorinated compound is replaced by an F substituent. Preferably, the chlorinated compound chosen for the reaction and the fluorinated compound obtained from it by the fluorination reaction have the same number of carbon atoms.

[0051] According to a preferred embodiment, the fluorination of the chlorinated compound to a fluorinated compound is: • 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,1,2,3-pentachloropropane (HCC-240db) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,2,2,3-pentachloropropane (HCC-240aa) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) to 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); • 1,1,1,2,3-pentachloropropane (HCC-240db) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); • 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,1,2,3-pentachloropropane (HCC-240db) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); • 1,1,1,2,3-pentachloropropane (HCC-240db) to 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 1,1,2,2,3-pentachloropropane (HCC-240aa) to 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) to 1,1,1,2,2-pentafluoropropane (HFC-245cb); • 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) to 1,1,1,2,2-pentafluoropropane (HFC-245cb).

[0052] The conversion of the chlorinated compound into the fluorinated compound includes a direct conversion (i.e. in one individual reaction step or according essentially to one set of reaction conditions) and an indirect conversion (i.e. by two or more reaction steps or using more than one individual set of reaction conditions).

[0053] The fluorination reaction can be carried out with:

[0054] - a molar ratio HF generally from 3:1 to 150:1, preferably from 4:1 to 125:1, in a more preferred manner from 5:1 to 100:1;

[0055] - a contact time of 3 to 100 s, preferably 4 to 75 s, in a more preferred from 5 to 50 seconds; and

[0056] - a pressure ranging from atmospheric pressure to 20 bar, preferably from 2 to 18 bar, but more preferably 3 to 15 bar.

[0057] Step a) can be carried out at a temperature of 200 to 450 °C, preferably 250 °C to 400 °C, more preferably 280 °C to 380 °C. Preferably, the temperature of step a) is the temperature of the catalytic bed.

[0058] In order to prevent rapid deactivation of the catalyst during the fluorination reaction, an oxidant (such as oxygen or chlorine) may be added, for example at a rate of 0.05 to 20% by moles, preferably 0.1 to 15% by moles, more preferably 0.5 to 10% by moles, in particular 1 to 8% by moles, compared to the mixture of the oxidant plus the chlorinated compound.

[0059] According to a preferred embodiment, the reactor can be purged before the regeneration of the fluorination catalyst according to step (b) of the present invention. The purge can be carried out by maintaining the reactor under vacuum or by introducing a stream of nitrogen into the reactor after step (a) of the present process.

[0060] According to a preferred embodiment, steps a) and b) can be carried out alternately. When step a) alternates with step b), the duration of each step can be from 50 to 2,000 hours, preferably from 200 to 1,000 hours, and the duration of each regeneration step can be from 10 to 200 hours, preferably from 15 to 60 hours. Catalyst

[0061] This may be, for example, a metal-based catalyst comprising a transition metal oxide or a derivative, halide, or oxyhalide of such a metal. Catalysts that may be used include chromium oxyfluoride, chromium oxides, chromium halides, aluminum fluoride and oxyfluoride, a supported or unsupported catalyst, optionally containing or not containing a metal such as Cr, Ni, Zn, Ti, V, Zr, Mo, Ge, Sn, Pb, Mg. Reference may also be made to the disclosures in WO-A-2007 / 079431, on page 7, lines 1 to 5 and 28 to 32, EP-A-939071, paragraph

[0022] , WO 2008 / 054781 on page 9, line 22 to page 10, line 34, WO 2008 / 040969 in claim 1, all incorporated into this document by reference.

[0062] According to a preferred embodiment, the fluorination catalyst may comprise chromium oxyfluoride, chromium oxides, chromium halides, and mixtures thereof. The fluorination catalyst used in the present invention may be supported or unsupported. According to a preferred embodiment, the chromium oxyfluoride catalyst may have a fluorine content of more than 30% by weight relative to the total weight of the chromium oxyfluoride catalyst, preferably from 30 to 45% by weight. Alternatively, the chromium oxyfluoride catalyst may have a fluorine content of less than 30% by weight relative to the total weight of the chromium oxyfluoride catalyst.

[0063] The fluorination catalyst may be chromium oxyfluoride, chromium oxides, supported or unsupported chromium halides and mixtures thereof, and may or may not contain a transition metal such as Ni, Zn, Ti, V, Zr, Mo, Ge, Sn, Pb, Mg, Mr.

[0064] According to a preferred embodiment, the catalyst is a supported mixed catalyst containing both chromium and nickel. The Cr:Ni molar ratio, relative to the metallic element, is generally between 0.5 and 5, for example between 0.7 and 2, including close to 1. The catalyst may contain from 0.5 to 20% by weight of nickel.

[0065] With regard to supported catalysts, the catalyst support can be chosen from materials known in the field to be compatible with HF at higher temperatures and pressures. For example, fluorinated alumina, pre-fluorinated activated carbon, graphite, or fluorinated graphite are suitable catalyst supports. The support is preferably aluminum. Several possible supports exist, such as alumina, activated alumina, or aluminum derivatives. These derivatives include aluminum halides and aluminum oxyhalides, for example, those described in US 4,902,838, or obtained by the activation process. Reference may be made to WO 2009 / 118628, and in particular to the catalyst disclosure from page 4, line 30 to page 7, line 16, which is incorporated by reference in this document.

[0066] According to another embodiment, the process uses a large surface area Cr-based catalyst that is preferably unsupported. A preferred catalyst is a large surface area unsupported chromium oxide catalyst.

[0067] Any one of the catalysts defined in this document may have a surface area of ​​at least 50 m2 / g, preferably from 50 to 300 m2 / g, more preferably from 70 to 250 m2 / g, in particular from 100 to 200 m2 / g.

[0068] Other possible catalysts are chromium dioxide-based fluorination catalysts comprising zinc or zinc oxide. The total amount of zinc or a zinc compound present in the zinc / chromium dioxide catalysts can be from about 0.01% to about 25%, preferably from 0.1% to 25%, conveniently from 0.01% to 6% zinc, and in some embodiments preferably from 0.5% to 25% by weight of the catalyst, preferably from about 1% to 10% by weight of the catalyst, more preferably from about 2% to 8% by weight of the catalyst, for example, about 4% to 6% by weight of the catalyst. In other embodiments, the catalyst conveniently comprises 0.01% to 1%, more preferably 0.05% to 0.5% zinc. Zinc / chromium dioxide catalysts may include an additional metal or a compound thereof.Generally, the additional metal is a divalent or trivalent metal, preferably selected from nickel, magnesium, aluminum, and mixtures thereof. Typically, the additional metal is present in an amount from 0.01% by weight to about 25% by weight of the catalyst, preferably from about 0.01% to 10% by weight of the catalyst. Other embodiments may include at least about 0.5% by weight or at least about 1% by weight of additional metal. Other catalysts are ca-. Chromium dioxide-based fluorination catalysts consisting of amorphous chromium dioxide; zinc oxide in a total quantity of zinc from 0.5 to 25% by weight of the catalyst; and crystalline chromium oxide in a total quantity from 0.1 to 2.5% by weight of the catalyst; the catalyst being supported or unsupported, as described in EP 1 877 181.

[0069] According to a preferred embodiment, the catalyst may contain, preferably at low levels, one or more co-catalysts such as a salt of Co, Zn, Mn, Mg, V, Mo, Te, Nb, Sb, Ta, P, and Ni. A preferred co-catalyst may be nickel, magnesium, or zinc. The preferred unsupported chromium catalyst may optionally contain low levels of one or more co-catalysts selected from cobalt, nickel, zinc, manganese, magnesium, or a mixture of manganese and magnesium, prepared by processes known in the field, such as impregnation, powder mixing, and the like.

[0070] The amount of co-catalyst, when present, may vary from 1 to 20% by weight, preferably from 1 to 10% by weight, and more preferably from 1 to 5% by weight. The co-catalyst may be added to the catalyst by processes known in the field, such as adsorption from an aqueous or organic solution, followed by evaporation of the solvent. The preferred catalyst according to this embodiment is pure chromium oxide with nickel or zinc as a co-catalyst. Alternatively, the co-catalyst may be physically mixed with the catalyst by grinding to produce an intimate mixture.

[0071] Before activation, the catalyst may be subjected to a drying step. This drying step may include passing a drying gas, preferably nitrogen, over the catalyst. The drying step may be carried out at a pressure ranging from atmospheric pressure up to 20 bar. The temperature of the catalyst during the drying step may range from ambient temperature up to 400 °C, preferably from about 100 °C to about 300 °C, for a contact time of about 1 to 100 s, preferably from about 10 to 40 s, for approximately 1 to 50 hours, preferably between 5 and 20 hours.

[0072] After the drying step, the catalyst must be activated to obtain the best level of catalyst activity. Catalyst activation

[0073] The present inventors have discovered that activating the previous catalysts using a gas stream containing an oxidant can improve the efficiency of the fluorination process.

[0074] The activation process includes activating the catalyst using one or two activating agents, in two steps or in a single step. One of the activating agents is an oxidant, such as oxygen or an oxygen / nitrogen mixture or air or chlorine. The other activating agent may be a gaseous mixture including a reducing agent.

[0075] According to a first embodiment, the activation process includes a step of contacting the fluorination catalyst with a gas stream containing an oxidant. The fluorination catalyst is treated with the oxidant. The oxidant may be an oxygen-containing agent, preferably selected from air, oxygen, chlorine, or a mixture of oxygen and nitrogen. The temperature during treatment with the oxidant may range from 250 to 500 °C, preferably from 300 to 450 °C, more preferably from 350 to 400 °C; preferably with a contact time of approximately 1 to approximately 200 s, preferably from 1 to 150 s, more preferably from 5 to 100 s; and preferably for a period of at least 1 hour, preferably at least 2 hours, more preferably at least 4 hours, preferably of at least 10 hours, in particular at least 15 hours.Therefore, treatment with the oxidant can be carried out for a period of 1 to approximately 1,500 hours, preferably 2 to 1,000 hours, more preferably 4 to 500 hours, preferably of all 10 to 200 hours, especially 15 to 150 hours.

[0076] According to another embodiment, the activation step comprises a first step (i) of contacting the fluorination catalyst with a gas stream containing an oxidant, as defined previously, and a second step (ii) of treating the fluorination catalyst obtained after step (i) with a gas mixture comprising a reducing agent.

[0077] The gas mixture comprising the reducing agent may also include an inert gas. The inert gas may be nitrogen, helium, argon, HF, or mixtures thereof. The gas mixture may comprise from 1 to 10% by volume of reducing agent, preferably from 2 to 9% by volume, and more preferably from 3 to 7% by volume, relative to the total volume of the gas mixture.

[0078] The reducing agent may be selected from the group consisting of hydrogen, carbon monoxide, nitrogen monoxide, formaldehyde, Ci-C6 alkanes, and CrClO hydrohalocarbons. Preferably, the reducing agent may be hydrogen, formaldehyde, a Ci-C6 alkane, or a CiClO hydrohalocarbon. In particular, the reducing agent may be a CiClO hydrohalocarbon, preferably a chlorinated compound as defined above. When the reducing agent is a chlorinated compound, it may be the same as, or different from, the chlorinated compound used in step a) of the present process, preferably the same as that used in step a) of the present process. When the reducing agent is a Ci-Cio hydrohalocarbide, preferably a chlorinated compound, the gas mixture includes an inert gas such as nitrogen, helium, argon, HF or mixtures thereof.

[0079] Therefore, the reducing agent may be a C3 alkane compound containing at least one chlorine atom, preferably at least two chlorine atoms; and preferably from 0 to 5 fluorine atoms. The reducing agent may be a C3 alkane compound containing one, two, three, four, five, or six chlorine atoms; and preferably no fluorine atoms, one, two, three, four, or five fluorine atoms. Preferably, the reducing agent may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F; at least one being a chlorine atom, preferably at least two being a chlorine atom. Even more preferably, the reducing agent may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F; among which at most four halogen atoms are fluorine atoms, and at least one is a chlorine atom, preferably at least two are a chlorine atom.

[0080] Preferably, the reducing agent may be a C3 alkene compound containing at least one chlorine atom, preferably at least two chlorine atoms; and preferably from 0 to 3 fluorine atoms. The reducing agent may be a C3 alkene compound containing one, two, three, or four chlorine atoms; and preferably no fluorine atoms, one, two, or three fluorine atoms. Preferably, the reducing agent may be a C3 alkene compound containing four halogen atoms selected from Cl and F; at least one being a chlorine atom, preferably at least two being chlorine atoms. Even more preferably, the reducing agent may be a C3 alkene compound containing four halogen atoms selected from Cl and F; of which at most three halogen atoms are fluorine atoms, and at least one is a chlorine atom.

[0081] Preferably, the reducing agent may be chosen from the group consisting of 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 2,3,3,3-tetrachloro-1-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,3,3-pentachloropropane (HCC-240fa), 1,1,3,3-tetrachloropropene (HCO-1230za), 1,3,3,3-tetrachloropropene (HCO-1230zd), l-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,1,1,3-tetrachloropropene (HCC-250fb), 1,1,3-trichloropropene (HCO-1240za), 3,3,3-trichloropropene (HCO-1240zf).

[0082] In particular, the reducing agent may be chosen from the group consisting of 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 2,3,3,3-tetrachloro-l-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb).

[0083] The temperature of the second stage (ii) can be from approximately 100 °C to approximately 450 °C. The second stage (ii) can be carried out with a contact time of approximately 1 to approximately 100 s, preferably from 1 to 75 s, more preferably from 5 to 50 s; for a duration of more than 1 hour, preferably from 1 to 50 hours. Preferably, the temperature of the second stage (ii) can be from approximately 300 to approximately 400 °C, with a contact time of approximately 1 to approximately 100 s, preferably from 1 to 75 s, more preferably from 5 to 50 s; for a duration of more than 1 hour, preferably from 1 to 50 hours. Alternatively, the second stage (ii) can be carried out for a duration of less than 1 hour. Alternatively, the second step (ii) can be carried out at a temperature ranging from 200 to 300 °C. The second step (ii) can be carried out at a pressure ranging from atmospheric pressure to 5 bar.

[0084] Steps (i) and (ii) can both be repeated until the catalyst activity reaches its best level.

[0085] According to a particular embodiment, before the activation process as defined above, the catalyst can be contacted with a mixture comprising HF and a chlorinated compound as defined in this document. The contact can be carried out for approximately 6 to approximately 100 hours (e.g., for less than 50 hours). The HF:chlorinated compound molar ratio can be from approximately 2 to approximately 40. The chlorinated compound can be the same as that used subsequently in the fluorination reaction in step a). Alternatively, the chlorinated compound can be different from the chlorinated compound that is used subsequently in the fluorination reaction. Therefore, according to this particular embodiment, the activation step can be carried out by:

[0086] (i') contacting the fluorination catalyst with a mixture comprising HF and a chlorinated compound,

[0087] (ii') contacting the fluorination catalyst obtained in step (i') with a a gaseous stream containing an oxidant, and

[0088] (iii') possibly or not, the treatment of the fluorination catalyst obtained after step (ii') with the reducing agent.

[0089] Each step can be repeated until the catalyst activity reaches its best level.

[0090] According to another embodiment, the activation process can be carried out by:

[0091] (i) bringing the fluorination catalyst into contact with a gaseous mixture comprising HF, a gas stream containing an oxidant and a chlorinated compound, and

[0092] (ii”) optionally or not, contacting the fluorination catalyst obtained at step (i”) with a reducing agent.

[0093] The oxidant, the chlorinated compound, and the reducing agent are as defined previously. The proportion of oxidant in the mixture of HF, the chlorinated compound, and the oxidant can be from approximately 2 to approximately 98 mole percent. The proportion of HF in the mixture of HF, the chlorinated compound, and the oxidant can be from approximately 2 to approximately 98 mole percent. The proportion of HF in the mixture of HF, the chlorinated compound, and the oxidant can be from approximately 2 to approximately 98 mole percent. The process conditions of the activation step are defined previously. Each step can be repeated until the catalyst activity reaches its optimal level.

[0094] Steps (i), (ii), or (i'), (ii'), (iü'), or (i”), (ii”) can be repeated once, twice or more alternately. Catalyst regeneration

[0095] The present inventors have also discovered that the presence of by-products can be limited by subjecting the catalyst to regeneration steps during which it is brought into contact with a gas stream containing an oxidant, and then with a reducing agent.

[0096] According to a preferred embodiment, the regeneration of the fluorination catalyst (step b) of the present process comprises:

[0097] c) treating said fluorination catalyst with a gas stream containing an oxidant to form an oxidized fluorination catalyst; and

[0098] d) the treatment of said oxidized fluorination catalyst obtained in step c) with a gaseous mixture comprising a reducing agent.

[0099] According to one embodiment, the oxidant used in step c) is oxygen, air, an oxygen / nitrogen mixture, or chlorine. When step c) is carried out with air or an oxygen / nitrogen mixture, the proportion of oxygen can be from 20 to about 100 mole percent relative to the oxygen-nitrogen mixture.

[0100] According to another embodiment, step c) can be carried out with oxygen or air or an oxygen / nitrogen mixture or chlorine and HF. The proportion of oxygen can be from about 2 to about 98 mole percent relative to the oxygen plus HF mixture, and from about 20 to about 100 mole percent relative to the oxygen plus nitrogen mixture.

[0101] The temperature during step c) can range from 250 to 500 °C, preferably from 300 to 450 °C, more preferably from 350 to 400 °C; with a contact time of 1 to 200 s, preferably from 1 to 150 s, more preferably from 5 to 100 s; and for a duration of 1 to approximately 1,500 hours, preferably from 2 to 1,000 hours, more preferably from 4 to 500 hours, most preferably from 10 to 200 hours, in particular from 15 to 150 hours. Step c) can be carried out at a pressure ranging from atmospheric pressure up to 20 bar. According to a preferred embodiment, the temperature during step c) can be approximately 250 to 500 °C, with a contact time of approximately 1 to 200 s, for a duration of 10 to 200 hours and at a pressure ranging from atmospheric pressure to 20 bar.

[0102] The gas mixture used in step (d) may include an inert gas, particularly when the reducing agent is a CrCl₂ hydrohalocarbon, preferably a chlorinated compound. The inert gas may be nitrogen, helium, argon, HF, or mixtures thereof. In particular, the inert gas may be a mixture of HF and nitrogen.

[0103] According to a preferred embodiment, the gas mixture of step (d) comprises 1 to 10% by volume of reducing agent, preferably 2 to 9% by volume, more preferably 3 to 7% by volume, relative to the total volume of the gas mixture.

[0104] According to a preferred embodiment, step d) is carried out with a reducing agent selected from the group consisting of hydrogen, carbon monoxide, nitrogen monoxide, formaldehyde, Ci-C6 alkanes, and CrClO hydrohalocarbons. Preferably, the reducing agent may be hydrogen, formaldehyde, a Ci-C6 alkane, or a Ci-CiO hydrohalocarbon. More preferably, the reducing agent may be a Ci-CiO hydrohalocarbon. In particular, the reducing agent may be a chlorinated compound as defined above.

[0105] Therefore, the reducing agent may be a C3 alkane compound containing at least one chlorine atom, preferably at least two chlorine atoms; and preferably from 0 to 5 fluorine atoms. The reducing agent may be a C3 alkane compound containing one, two, three, four, five, or six chlorine atoms; and preferably no fluorine atoms, one, two, three, four, or five fluorine atoms. Preferably, the reducing agent may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F; at least one being a chlorine atom, preferably at least two being a chlorine atom. Preferably, the reducing agent may be a C3 alkane compound containing four or five halogen atoms selected from Cl and F, of which at most four halogen atoms are fluorine atoms, and at least one is a chlorine atom, preferably at least two are chlorine atoms.

[0106] Preferably, the reducing agent may be a C3 alkene compound containing at least one chlorine atom, preferably at least two chlorine atoms; and preferably from 0 to 3 fluorine atoms. The reducing agent may be a C3 alkene compound containing one, two, three, or four chlorine atoms; and preferably no fluorine atoms, one, two, or three fluorine atoms. Preferably, the reducing agent may be a C3 alkene compound containing four halogen atoms selected from Cl and F; at least one being a chlorine atom, preferably at least two being chlorine atoms. More preferably, the reducing agent may be a C3 alkene compound containing four halogen atoms selected from Cl and F, of which at most three halogen atoms are fluorine atoms, and at least one is a chlorine atom.

[0107] Preferably, the reducing agent may be selected from the group consisting of 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 2,3,3,3-tetrachloro-1-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,3,3-pentachloropropane (HCC-240fa), 1,1,3,3-tetrachloropropene (HCO-1230za), 1,3,3,3-tetrachloropropene (HCO-1230zd), l-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,1,1,3-tetrachloropropene (HCC-250fb), 1,1,3-trichloropropene (HCO-1240za), 3,3,3-trichloropropene (HCO-1240zf).

[0108] In particular, the reducing agent may be chosen from the group consisting of 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-l-propene (HCO-1230xa), 2,3,3,3-tetrachloro-l-propene (HCO-1230xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb).

[0109] Step d) can be carried out at a temperature ranging from about 100 °C to about 450 °C. Preferably, step d) can be carried out at a temperature of 300 to 400 °C. Step d) can be carried out for a contact time of about 1 to about 100 s, preferably from 1 to 75 s, more preferably from 5 to 50 s. Preferably, step d) can be carried out for a duration of more than 1 hour, preferably from 1 to 50 hours. More preferably, step d) can be carried out at a temperature of about 300 to about 400 °C, with a contact time of about 1 to about 100 s, preferably from 1 to 75 s, more preferably from 5 to 50 s; for a duration of more than 1 hour, preferably from 1 to 50 hours. Alternatively, step d) can be carried out in less than 1 hour. Alternatively, step d) can be carried out at a temperature ranging from 200 to 300 °C.Step d) can be carried out at a pressure ranging from atmospheric pressure to 5 bar.

[0110] Steps c) and d) can both be repeated once, twice, or more alternately. In particular, step d) can be repeated independently once, twice, or more; that is, each step d) can be repeated with different reducing agents. For example, step d) can be carried out with hydrogen and can be repeated with 2-chloro-3,3,3-trifluoro-l-propene. Examples

[0111] The following examples illustrate the invention without limiting it.

[0112] The equipment comprises an INCONEL® 600 alloy tubular reactor with an internal diameter of 21 mm and a 12 m resistance preheating device with an internal diameter of 6 mm. The system is immersed in a fluidized sand bath. The reactor is equipped with pressure and temperature control devices. The pre-mixed reagents are introduced at the bottom of the reactor.

[0113] The gas stream exiting the reactor passes through a water scrubber before being dried, sampled, and analyzed by gas chromatography. A model 5890 HP GC is used for all experiments. The chromatograph is equipped with an RTX®-200 column and a ShinCarbon column (Restek), both connected to a thermal conductivity detector (TCD).

[0114] Comparative example 1: Fluorination of HFCO-1233xf: regeneration of the fluorination catalyst without treatment with a gas mixture comprising a reducing agent.

[0115] The equipment described above is used to carry out the catalytic vapor-phase fluorination of HFCO-1233xf. The reactor is loaded with approximately 130 cm³ of a pre-activated commercial bulk chromium catalyst.

[0116] The reaction is carried out at a constant absolute pressure of P = 5 bar and the temperature is maintained at T = 380 °C. Anhydrous hydrogen fluoride (HF), HFCO-1233xf, and air are continuously introduced into the reactor. The molar ratio of HF to HFCO-1233xf is 20. The molar ratio of oxygen (O2) to HFCO-1233xf is 0.04. The contact time is calculated to be 20 seconds under the reaction conditions.

[0117] After 70 hours of reaction, when the conversion of HFCO-1233xf is about 20%, the reaction is stopped and a regeneration step is carried out with air treatment for 72 hours at 13 l / h, T = 380 °C and at atmospheric pressure.

[0118] The reaction is then restarted using the same conditions.

[0119] The major product obtained other than HFO-1234yf is HFC-245cb. This compound can be recycled and reused, and is considered a useful substance. The by-products obtained and their selectivities are shown in Table 1 below:

[0120] Table 1 Selectivities Temp s (h) CO F143 a F1234y f + F245 cb F1234z eZ + F245fa F1233z dE Others 6 2.26 0.56 86.17 2.78 2.16 2.24 12 2.13 0.54 87.22 2.53 1.89 2.09 24 2.00 0.46 89.61 1.83 1.47 1.58 30 2.30 0.45 89.05 1.74 1.34 1.72 36 2.06 0.45 89.90 1.60 1.15 1.67

[0121] Example 2 according to the present invention: Fluorination of HFCO-1233xf: regeneration of the fluorination catalyst with treatment with a gas mixture comprising a reducing agent.

[0122] The equipment described above is used to carry out the catalytic vapor-phase fluorination of HFCO-1233xf. The reactor is loaded with approximately 130 cm³ of a pre-activated commercial bulk chromium catalyst.

[0123] The reaction is carried out at a constant absolute pressure of P = 5 bar and the temperature is maintained at T = 380 °C. Anhydrous hydrogen fluoride (HF), HFCO-1233xf, and air are continuously introduced into the reactor. The molar ratio of HF to HFCO-1233xf is 20. The molar ratio of oxygen (O2) to HFCO-1233xf is 0.04. The contact time is calculated to be 20 seconds under the reaction conditions.

[0124] After 76 hours of reaction, when the conversion of HFCO-1233xf is approximately 35%, the reaction is stopped and a regeneration step is carried out - with air treatment for 72 hours at 5 l / h, T = 380 °C and at atmospheric pressure, - with a treatment using a mixture of HFCO-1233xf: HF: nitrogen (14.1 g / h, 43.1 g / h; 511 / h) for 5 hours at T = 350 °C.

[0125] The reaction is then restarted using the same conditions.

[0126] The major product obtained other than HFO-1234yf is HFC-245cb. This compound can be recycled and reused, and is considered a useful substance. The by-products obtained and their selectivities are shown in Table 2 below:

[0127] Table 2 Selectivities Temp s (h) CO F143 a F1234y f + F245 cb F1234z eZ + F245fa F1233z dE Others 6 2.05 0.45 89.32 1.69 1.53 0.26 12 1.99 0.45 89.70 1.60 1.40 0.27 24 1.90 0.40 90.66 1.39 1.21 0.31 30 2.01 0.42 90.23 1.46 1.15 0.35 36 2.02 0.42 90.28 1.41 1.11 0.36

[0128] Comparative example 3: Fluorination of HFCO-1233xf: regeneration of the fluorination catalyst without treatment with a gas mixture comprising a reducing agent.

[0129] The equipment described above is used to carry out the catalytic vapor-phase fluorination of HFCO-1233xf. The reactor is loaded with approximately 130 cm³ of a pre-activated commercial bulk chromium catalyst.

[0130] The reaction is carried out at a constant absolute pressure of P = 5 bar and the temperature is maintained at T = 350°C. Anhydrous hydrogen fluoride (HF), HFCO-1233xf, and air are continuously introduced into the reactor. The molar ratio of HF to HFCO-1233xf is 20. The molar ratio of oxygen (O2) to HFCO-1233xf is 0.04. The contact time is calculated to be 34 seconds under the reaction conditions.

[0131] After 48 hours of reaction, the reactant flow rates are increased and the new contact time is calculated to be 20 seconds under the reaction conditions. After a further 24 hours of reaction, when the conversion of HFCO-1233xf is approximately 45%, the reaction is stopped and a regeneration step is carried out with air treatment for 72 hours at 7.5 l / h, T = 350 °C and atmospheric pressure.

[0132] The reaction is then restarted using the same conditions (contact time calculated as being 20 seconds under the reaction conditions).

[0133] The major product obtained other than HFO-1234yf is HFC-245cb. This compound can be recycled and reused, and is considered a useful substance. The by-products obtained and their selectivities are shown in Table 3 below:

[0134] Table 3 Selectivities Temp s (h) F1234y f + F245 cb F1234z eE + F1243 zf F1234z eZ + F245fa F1224 xe F1233z dE 6 92.41 0.95 1.25 0.33 0.89 12 93.04 0.99 1.40 0.13 1.08 18 94.18 0.80 1.16 0.08 0.80

[0135] Example 4 according to the present invention: Fluorination of HFCO-1233xf: regeneration of the fluorination catalyst with treatment with a gas mixture comprising a reducing agent.

[0136] The equipment described above is used to carry out the catalytic vapor-phase fluorination of HFCO-1233xf. The reactor is loaded with approximately 130 cm³ of a pre-activated commercial bulk chromium catalyst.

[0137] The reaction is carried out at a constant absolute pressure of P = 5 bar and the temperature is maintained at T = 350 °C. Anhydrous hydrogen fluoride (HF), HFCO-1233xf, and air are continuously introduced into the reactor. The molar ratio of HF to HFCO-1233xf is 20. The molar ratio of oxygen (O2) to HFCO-1233xf is 0.04. The contact time is calculated to be 20 seconds under the reaction conditions.

[0138] After 48 hours of reaction, when the conversion of HFCO-1233xf is approximately 61%, the reaction is stopped and a regeneration step is carried out - with air treatment for 48 hours at 5 l / h, T = 350 °C and at atmospheric pressure, - with a treatment using a mixture of hydrogen: nitrogen (1.25 1 / h; 25 1 / h) for 5 hours at T = 325 °C. - with nitrogen treatment for 24 hours at 10 l / h, T = 350 °C and at an absolute pressure P = 1.6 bar.

[0139] The reaction is then restarted using the same conditions.

[0140] The major product obtained other than HFO-1234yf is HFC-245cb. This compound can be recycled and reused, and is considered a useful substance. The by-products obtained and their selectivities are shown in Table 4 below:

[0141] Table 4 Selectivities Temp s (h) F1234y f + F245 cb F1234z eE + F1243 zf F1234z eZ + F245fa F1224 xe F1233z dE 6 95.63 0.51 0.67 0.07 0.44 18 95.01 0.57 0.78 0.07 0.47

Claims

Demands

1. A process for fluorinating a C3 alkane or alkene chlorinated compound containing at least one chlorine atom into a C3 alkane or alkene fluorinated compound containing at least one fluorine atom, comprising the following steps: a. contacting the chlorinated compound with hydrogen fluoride in the gas phase in a reactor in the presence of a fluorination catalyst to produce a fluorinated compound, and b. regenerating the fluorination catalyst used in step a), step (b) of regenerating the fluorination catalyst comprising (c) treating said fluorination catalyst with a gas stream containing an oxidant to form an oxidized fluorination catalyst, and (d) treating the oxidized fluorination catalyst obtained in step (c) with a gas mixture comprising a reducing agent selected from the group consisting of CrCl₂O hydrohalocarbons; the catalyst regenerated in step b) is reused in step a).

2. A method according to any one of the preceding claims, wherein the gas mixture used in step (d) further comprises an inert gas, preferably selected from nitrogen, helium, argon or HF or mixtures thereof.

3. A process according to any one of the preceding claims, wherein the gas mixture of step (d) comprises 1 to 10% by volume of reducing agent, preferably 2 to 9% by volume, more preferably 3 to 7% by volume, relative to the total volume of the gas mixture.

4. A method according to any one of the preceding claims, wherein step d) is carried out at a temperature from 100 °C to 450 °C, with a contact time of 1 to 100 s, preferably from 1 to 75 s, more preferably from 5 to 50 s, for a period of more than 1 hour, preferably from 1 to 50 hours.

5. A process according to any one of the preceding claims, wherein the chlorinated compound is 2-chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-l-propene (HCO-1230xa), 2,3,3,3-tetrachloro-l-propene (HCO-1230xf), 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb), 1,1,1,3,3-pentachloropropane (HCC-240fa), 1,1,3,3-tetrachloropropene (HCO-1230za), 1,3,3,3-tetrachloropropene (HCO-1230zd), l-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,1,1,3-tetrachloropropane (HCC-250fb), 1,1,3-trichloropropene (HCO-1240za), 3,3,3-trichloropropene (HCO-1240zf); more preferably, the chlorinated compound is chosen from the group consisting of 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db), 1,1,2,3-tetrachloro-l-propene (HCO-1230xa), 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) or 2-chloro-1,1,1,2-tetrafluorocarbons (HCFC-244bb).

6. A process according to any one of the preceding claims, wherein the fluorinated compound is 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,2,2-pentafluoropropane (HFC-245cb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3-tetrafluoro-3-chloropropane (HCFC-244fa), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 1,3,3,3-tetrafluoropropene (HFO-1234ze), 3,3,3-trifluoropropene (HFO-1243zf), or the 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf).

7. A process according to any one of the preceding claims, wherein the fluorination of the chlorinated compound to a fluorinated compound is: - 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) into 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); - 1,1,1,2,3-pentachloropropane (HCC-240db) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); - 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); - 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); - 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 2,3,3,3-tetrafluoro-l-propene (HFO-1234yf); 1,1,1,2,3-pentachloropropane (HCC-240db) to 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) into 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf); 2-chloro-3,3,3-trifluoro-l-propene (HFCO-1233xf) to 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); 1,1,1,2,3-pentachloropropane (HCC-240db) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); 1,1,2,2,3-pentachloropropane (HCC-240aa) in 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) into 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) to 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) to 2-chloro-l,l,l,2-tetrafluoropropane (HCFC-244bb); 1,1,1,2,3-pentachloropropane (HCC-240db) in 1,1,1,2,2-pentafluoropropane (HFC-245cb); 1,1,2,2,3-pentachloropropane (HCC-240aa) in 1,1,1,2,2-pentafluoropropane (HFC-245cb); 2,3-dichloro-l,l,l-trifluoropropane (HCFC-243db) in 1,1,1,2,2-pentafluoropropane (HFC-245cb); 1,1,2,3-tetrachloro-l-propene (HCO-1230xa) in 1,1,1,2,2-pentafluoropropane (HFC-245cb); 2,3,3,3-tetrachloro-l-propene (HCO-1230xf) in 1,1,1,2,2-pentafluoropropane (HFC-245cb).

8. A method according to any one of the preceding claims, wherein the fluorination catalyst comprises chromium oxyfluoride, chromium oxides, chromium halides and mixtures thereof.

9. A process according to the preceding claims, wherein the fluorination catalyst contains one or more co-catalysts comprising a salt of a transition metal selected from the group consisting of Co, Zn, Mn, Mg, V, Mo, Te, Nb, Sb, Ta, Ni; or a phosphorus salt.

10. A method according to any one of the preceding claims, comprising an activation step carried out before step (a) which includes a first step of bringing the fluorination catalyst into contact with a gas stream containing an oxidant.

11. A process according to the preceding claim, wherein the activation step comprises a second step, after the first step, of treating the fluorination catalyst obtained after the first step with a reducing agent.

12. A method according to any one of the preceding claims, wherein steps (a) and (b) are carried out alternately.

13. A method according to any one of the preceding claims, wherein a purge of the reactor is carried out before and / or after step (b), the purge being preferably carried out by introducing a stream of nitrogen into the reactor or by maintaining the reactor under vacuum.

14. A process for fluorinating 2,3,3,3-tetrafluoropropene to 1,1,1,2,2-pentafluoropropane, comprising the following steps: a. contacting 2,3,3,3-tetrafluoropropene with hydrogen fluoride in the gas phase in a reactor in the presence of a fluorination catalyst to produce 1,1,1,2,2-pentafluoropropane, and b. regenerating the fluorination catalyst used in step a), step (b) of regenerating the fluorination catalyst comprising (c) treating said fluorination catalyst with a gas stream containing an oxidant to form an oxidized fluorination catalyst, and (d) treating the oxidized fluorination catalyst obtained in step (c) with a gas mixture comprising a reducing agent selected from the group consisting of hydrogen and the hydrohalocarbons in Ci-Cio; the catalyst regenerated in step b) is reused in step a).