Process for the purification of chlorotrifluoroethylene by extractive distillation

Abstract

The present invention relates to a process for purifying chlorotrifluoroethylene (CTFE) from a first composition comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane (143), said process comprising the steps of: a) extractive distillation of said first composition in the presence of at least one organic extraction agent to form i) a second composition comprising said organic extraction agent and 1,1,2-trifluoroethane; and ii) a first stream comprising chlorotrifluoroethylene, and b) recovery and separation of said second composition to form a second stream comprising said organic extraction agent and a third stream comprising 1,1,2-trifluoroethane, preferably said second stream is recycled to step a).

Description

Title of the invention: Process for purifying chlorotrifluoroethylene by extractive distillation technical field

[0001] The present invention relates to a process for the production and purification of hydrofluoroolefins. In particular, the present invention relates to a process for the purification of chlorotrifluoroethylene. The present invention also relates to a process for the production of trifluoroethylene (VF3) by hydrogenolysis of chlorotrifluoroethylene. Technological background of the invention

[0002] Fluorinated olefins, such as VF3, are known and used as monomers or co-monomers for the manufacture of fluorocarbon polymers exhibiting remarkable characteristics, in particular excellent chemical resistance and good thermal resistance.

[0003] Trifluoroethylene is a gas under normal conditions of pressure and temperature. The main risks associated with the use of this product concern its flammability, its propensity for auto-polymerization when unstabilized, its explosiveness due to its chemical instability, and its presumed susceptibility to peroxidation, by analogy with other halogenated olefins. Trifluoroethylene is particularly flammable, with a lower explosive limit (LEL) of approximately 10% and an upper explosive limit (UEL) of approximately 30%. The major hazard, however, is associated with the propensity of VF3 to decompose violently and explosively under certain pressure conditions in the presence of an energy source, even in the absence of oxygen.

[0004] In view of the main risks mentioned above, the synthesis and storage of VF3 present particular problems and require strict safety rules throughout these processes. A known route for the preparation of trifluoroethylene uses chlorotrifluoroethylene (CTFE) and hydrogen as starting materials in the presence of a catalyst and in the gas phase. A process for the production of trifluoroethylene by hydrogenolysis of CTFE in the gas phase and in the presence of a catalyst based on a Group VIII metal at atmospheric pressure and low temperatures is known from WO 2013 / 128102. It is known from PCT / FR2022 / 051054 that the reaction generates a reaction stream comprising, in addition to trifluoroethylene and unreacted chlorotrifluoroethylene, 1,1,2-trifluoroethane. Chlorotrifluoroethylene and 1,1,2-trifluoroethane form an azeotrope under certain conditions.The recovery of chlorotrifluoroethylene with high purity is the goal. Therefore, its recycling proves complex. A purification process for chlorotrifluoroethylene is thus necessary. Summary of the invention

[0005] According to a first aspect, the present invention provides a process for purifying chlorotrifluoroethylene (CTFE) from a first composition comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane (143), said process comprising the steps of:

[0006] a) Extractive distillation of said first composition in the presence of at least one organic extraction agent to form i. a second composition comprising said organic extraction agent and 1,1,2-trifluoroethane; and ii. a first stream comprising chlorotrifluoroethylene, and

[0007] b) Recovery and separation of said second composition to form a second stream comprising said organic extraction agent and a third stream comprising 1,1,2-trifluoroethane, preferably said second stream is recycled in step a).

[0008] According to a preferred embodiment, said organic extraction agent has a flash point greater than 13°C.

[0009] According to a preferred embodiment, said organic extraction agent is a compound comprising 2 to 12 carbon atoms.

[0010] According to a preferred embodiment, said organic extraction agent has a molecular mass of less than 200 g.mol'.

[0011] According to a preferred embodiment, said organic extraction agent has a separation factor Si>2 greater than or equal to 2.0, said separation factor being calculated by the formula Si>2 = (Yi,s) / (Y2,s) in which

[0012] Yi.s represents the activity coefficient of chlorotrifluoroethylene in said organic extraction agent at infinite dilution,

[0013] Y2,s represents the activity coefficient of 1,1,2-trifluoroethane in said organic extraction agent at infinite dilution,

[0014] Advantageously, the separation factor S[j2 is greater than or equal to 2.1, preferably greater than or equal to 2.2, more preferably greater than or equal to 2.3, in particular greater than or equal to 2.4, more particularly greater than or equal to 2.5.

[0015] According to a preferred embodiment, said organic extraction agent has an absorption capacity C2jS greater than or equal to 0.20, said absorption capacity being calculated by the formula C2jS = 1 / (Y2,s) in which y2,s represents the activity coefficient of 1,1,2-trifluoroethane in said organic extraction agent at infinite dilution.

[0016] According to a preferred embodiment, the first composition is an azeotropic or quasi-azeotropic composition comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane.

[0017] According to a preferred embodiment, said organic extraction agent has a melting point below 0°C.

[0018] According to a preferred embodiment, step b) is carried out at a pressure of 1 to 10 bara, preferably 1 to 7 bara.

[0019] Selon un mode de réalisation préféré, ledit agent d’extraction organique est sélectionné parmi le groupe consistant en beta-propiolactone, gamma-butyrolactone, l-hydroxy-2-propanone, acetonylacetone, trimethylphosphate, acetylacetone, propyle-necarbonate, dimethylmalonate, ethylacetoacetate, 1,2-ethanedioldiacetate, glycol, ethyloxalat, 3-oxobutanoicacid- 1-methylethylester, ethyleneglycolmonomethylethe-racetate, dimethylmaleate, triethylphosphate, triethyleneglycol, diethylmalonate, furfural, diethyleneglycol, t-butylacetoacetate, ethylsuccinate, 1,3-propanediol, cyclo-pentanone, propyleneglycol, 1-cyclopropylethanone, 2-methoxyethanol, 2,3-pentanedione, tripropyleneglycol, cyclohexanone, diethylcarbonate, 1,3-butanediol, 3-methoxy-l-butanol, 4-methyl-3-penten-2-one, l-methoxy2-propanol, phenylacetate, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, citral, 1,5-pentanediol, diethyleneglycohnonobu-tylether, 4-phenyl-2-butanone,ethanol, n-butylacetate, 4-methyl-2-pentanone, 3-hexanone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone and ethylbenzoate. ,

[0020] According to another aspect, the present invention provides a process for producing trifluoroethylene in a reactor equipped with a fixed catalytic bed comprising a catalyst, said process comprising the steps of:

[0021] A') reaction of chlorotrifluoroethylene with hydrogen in the presence of ca alyzer and in gas phase to produce a stream A comprising trifluoroethylene, unreacted chlorotrifluoroethylene and 1,1,2-trifluoroethane;

[0022] B') purification of said current A to form a current B1 comprising trifluoride- roethylene and a B2 stream comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane,

[0023] C') implementation of the purification process according to the present invention from said current B2. Detailed description of the invention: CTFE purification process

[0024] According to a first aspect of the present invention, a method for purifying chlorotrifluoroethylene (CTFE) is provided. In particular, the present invention makes it possible to Separating chlorotrifluoroethylene from 1,1,2-trifluoroethane (143). Mixtures of chlorotrifluoroethylene and 1,1,2-trifluoroethane are obtained during the implementation of trifluoroethylene production processes. Chlorotrifluoroethylene and 1,1,2-trifluoroethane are generally obtained as an azeotropic composition, depending on the operating conditions. In order to recover the chlorotrifluoroethylene, it is necessary to separate the constituents of this azeotropic composition. The applicant has surprisingly found organic extraction agents capable of separating chlorotrifluoroethylene and 1,1,2-trifluoroethane by extractive distillation.

[0025] Said purification process comprises the steps of:

[0026] a) Extractive distillation of said first composition in the presence of at least one organic extraction agent to form i. a second composition comprising said organic extraction agent and 1,1,2-trifluoroethane; and ii. a first stream comprising chlorotrifluoroethylene,

[0027] b) Recovery and separation of said second composition to form a second stream comprising said organic extraction agent and a third stream comprising 1,1,2-trifluoroethane, preferably said second stream is recycled in step a).

[0028] According to a preferred embodiment, said first composition comprises at least 50% by weight of chlorotrifluoroethylene, advantageously at least 60% by weight of chlorotrifluoroethylene, preferably at least 70% by weight of chlorotrifluoroethylene, in particular at least 80% by weight of chlorotrifluoroethylene based on the total weight of the first composition.

[0029] According to a preferred embodiment, said first composition comprises at most 30% by weight of 1,1,2-trifluoroethane, advantageously at most 25% by weight of 1,1,2-trifluoroethane, preferably at most 20% by weight of 1,1,2-trifluoroethane, in particular at most 15% by weight of 1,1,2-trifluoroethane based on the total weight of the first composition.

[0030] According to a preferred embodiment, the first composition is an azeotropic or quasi-azeotropic composition comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane.

[0031] Advantageously, said first composition is azeotropic and comprises from 80% to 99.99% by weight of chlorotrifluoroethylene based on the total weight of said composition. Preferably, said first composition is azeotropic and comprises from 85% to 99.99% by weight of chlorotrifluoroethylene based on the total weight of said composition. In particular, said first composition is azeotropic and comprises from 90% to 99.99% by weight of chlorotrifluoroethylene based on the total weight of said composition.

[0032] Advantageously, said first composition is azeotropic and comprises from 0.01% to 20% by weight of 1,1,2-trifluoroethane based on the total weight of said composition. Preferably, said first composition is azeotropic and comprises from 0.01% to 15% by weight of 1,1,2-trifluoroethane based on the total weight of said composition. In particular, said first composition is azeotropic and comprises from 0.01% to 10% by weight of 1,1,2-trifluoroethane based on the total weight of said composition.

[0033] Preferably, said first composition is azeotropic and has a boiling point between -40°C and 40°C, more preferably between -35°C and 25°C. In particular, said first composition is azeotropic and has a boiling point between -40°C and 40°C at a pressure between 0.5 bar and 8 bar. More particularly, said first composition is azeotropic and has a boiling point between -35°C and 25°C at a pressure between 1 bar and 6 bar.

[0034] Thus, said first composition is azeotropic and may comprise from 80% to 99.99% by weight of chlorotrifluoroethylene and from 0.01% to 20% by weight of 1,1,2-trifluoroethane based on the total weight of said composition; and has a boiling point between -40°C and 40°C at a pressure between 0.5 bar and 8 bar. Advantageously, said first composition is azeotropic and comprises from 85% to 99.99% by weight of chlorotrifluoroethylene and from 0.01% to 15% by weight of 1,1,2-trifluoroethane based on the total weight of said composition; and has a boiling point between -40°C and 40°C at a pressure between 0.5 bar and 8 bar. More specifically, said first composition is azeotropic and comprises from 90% to 99.99% by weight of chlorotrifluoroethylene and from 0.01 to 10% by weight of 1,1,2-trifluoroethane on the basis of the total weight of said composition; and has a boiling point between -30°C and 25°C at a pressure of 1 bar to 6 bar.

[0035] According to a preferred embodiment, said organic extraction agent is a solvent selected from the group consisting of hydrocarbons, hydrohalocarbons, alcohols, ketones, amines, esters, ethers, aldehydes, acids, nitriles, carbonates, thioalkyls, amides, heterocycles, sulfates, and phosphates. Advantageously, said organic extraction agent is a solvent selected from the group consisting of alcohols, ketones, phosphates, esters, and ethers.

[0036] The term "hydrocarbon" as used herein refers to linear or branched compounds of C1-C20 alkanes, C3-C20 cycloalkanes, C5-C20 alkenes, C5-C20 cycloalkenes, and C6-C18 arenes. For example, the term alkane refers to compounds of the formula CnH2n+2 in which n is from 1 to 20. The term C1-C20 alkane includes, for example, pentane, hexane, heptane, octane, nonane, decane, or isomers thereof. The term C5-C20 alkene refers to hydro compounds Carbonate compounds containing one or more carbon-carbon double bonds and from 5 to 20 carbon atoms. The term cycloalkane (C3-C2O) refers to a saturated hydrocarbon ring containing 3 to 20 carbon atoms. The term aryl (C6-Ci8se) refers to cyclic and aromatic hydrocarbon compounds containing 6 to 18 carbon atoms. The term cycloalkene (C5-C2O) refers to cyclic hydrocarbon compounds containing 5 to 20 carbon atoms and one or more carbon-carbon double bonds.

[0037] The term "alkyl" refers to a monovalent radical derived from an alkane, linear or branched, comprising from 1 to 20 carbon atoms. The term "cycloalkyl" refers to a monovalent radical derived from a cycloalkane comprising from 3 to 20 carbon atoms. The term "aryl" refers to a monovalent radical derived from an arene comprising from 6 to 18 carbon atoms. The term "alkenyl" refers to a monovalent radical of 2 to 20 carbon atoms and at least one carbon-carbon double bond. The term "alkynyl" refers to a monovalent radical of 2 to 20 carbon atoms and at least one carbon-carbon triple bond. The term "halogen" refers to a -F, -Cl, -Br, or -I group. The term "cycloalkenyl" refers to a monovalent radical derived from a cycloalkene comprising from 3 to 20 carbon atoms.The alkyl substituents in C1-C20, C2-C20 alkenyl, C2-C20 alkynyl, C3-C20 cycloalkyl, C3-C20 cycloalkenyl, and C6-C18 aryl may or may not be substituted by one or more substituents: -OH, halogen, -NRaC(O)Rb, -C(O)NRaRb, -CN, -NO2, -NRaRb, -ORa, -SRa, -CO2Ra, -OC(O)ORa, -OC(O)Ra, -C(O)H, -C(O)Ra, in which Ra and Rb are independently of each other; unsubstituted alkyl in C1-C20; unsubstituted alkenyl in C2-C20; unsubstituted alkynyl in C3-C20; and unsubstituted cycloalkyl in C3-C20. unsubstituted C3-C20 cycloalkenyl, unsubstituted C6-Ci8 aryl. In the -NRaRb substituents, Ra and Rb can form with the nitrogen atom to which they are attached a saturated or unsaturated heterocycle, aromatic or non-aromatic, comprising 5 to 10 groups.

[0038] The term “hydrohalocarbons” refers to compounds of formula RaX in which Ra is selected from CrC2O alkyl, C2-C2O alkenyl, C2-C2O alkynyl, C3-C2O cycloalkyl, C3-C2O cycloalkenyl, C6-Ci8 aryl and X represents an atom of chlorine, fluorine, bromine or iodine. CrC2O alkyl, C2-C2O alkenyl, C2-C2O alkynyl, C3-C2O cycloalkyl, C3-C2O cycloalkenyl, and C6-Ci8 aryl substituents may or may not be substituted by one or more -OH, halogen, -NRaC(O)Rb, -C(O)NRaRb, -CN, -NO2, -NRaRb, -ORa, -SRa, -CO2Ra, -OC(O)ORa, -OC(O)Ra, -C(O)H, and -C(O)Ra substituents, in which Ra and Rb are as defined above.

[0039] The term "alcohol" refers to hydrocarbons or hydrohalocarbons as defined above in which at least one hydrogen atom is replaced by a hydroxyl group -OH.

[0040] The term "ketone" refers to hydrocarbons comprising at least one or more carbonyl functional groups Rc-C(O)-Rd, in which Rc and Rd are independently of each other, a C1-C20 alkyl, C2-C2O alkenyl, C2-C2O alkynyl, C3-C20 cycloalkyl, C3-C20 cycloalkenyl, or C6-C18 aryl, and may or may not be substituted by one or more substituents -OH, halogen, -NRaC(O)Rb, -C(O)NRaRb, -CN, -NO2, -NRaRb, -ORa, -SRa, -CO2Ra, -OC(O)ORa, -OC(O)Ra, -C(O)H, or -C(O)Ra, in which Ra and Rb are as defined above, Rc and Rd being able to be linked together to to form, with the carbonyl group to which they are attached, a cyclic ketone comprising 4 to 10 carbonyl groups, preferably 4 to 7 carbonyl groups. The cyclic ketone may also contain one or more carbon-carbon double bonds. The cyclic ketone may or may not be substituted by one or more substituents as defined above.

[0041] The term "amine" refers to hydrocarbons comprising at least one or more amine -NRcRd functional groups in which Rc and Rd are as defined above, Rc and Rd being able to be linked together to form with the nitrogen atom to which they are attached an aromatic or non-aromatic heterocycle comprising 4 to 10 links.

[0042] The term “esters” refers to compounds of formula Rc-C(O)-O-Rd in which Rc and Rd are as defined above, Rc and Rd being able to be linked together to form with the ester group a ring comprising from 4 to 20 carbon atoms.

[0043] The term "ether" refers to compounds of formula Rc-O-Rd in which Rc and Rd are as defined above, Rc and Rd being able to be linked together to form with the oxygen atom to which they are attached a heterocycle comprising from 4 to 20 carbon atoms.

[0044] The term “aldehyde” refers to compounds comprising at least one or more -C(O)-H functional groups.

[0045] The term “nitrile” refers to compounds comprising at least one or more -CN functional groups.

[0046] The term "carbonate" refers to compounds of formula Rc-OC(O)-O-Rd in which Rc and Rd are as defined above.

[0047] The term “thioalkyl” refers to compounds of formula RcSRd in which Rc and Rd are as defined above.

[0048] The term “phosphate” refers to compounds of formula P(ORC)3 in which Rc is, independently for each substituent, as defined above.

[0049] The term “sulfate” refers to compounds of formula SO2(ORC)2 in which Rc is, independently for each substituent, as defined above.

[0050] The term “acid” refers to compounds of formula Rc-CO2H in which Rc is as defined above.

[0051] The term "amide" refers to compounds of the formula RcC(O)NReRd, in which Rc and Rd are as defined above, Re having the same definition as Rc, and Rc and Rd being able to be linked together to form, with the amide group -C(O)N- to which they are attached, a cyclic amide comprising from 4 to 10 members, preferably from 4 to 7 members. The cyclic amide may also include one or more carbon-carbon double bonds. The cyclic amide may also be substituted or not by one or more substituents as defined above.

[0052] The term "heterocycle" refers to a carbon ring comprising 4 to 10 members, at least one of which is a heteroatom selected from the group consisting of O, S, P, and N. The heterocycle may comprise one or more carbon-carbon double bonds, or one or more carbon-heteroatom double bonds, or one or more heteroatom-heteroatom double bonds. Preferably, the heterocycle may comprise 1, 2, 3, 4, or 5 heteroatoms as defined above. In particular, the heterocycle may comprise 1, 2, or 3 heteroatoms selected from oxygen, nitrogen, or sulfur. Preferably, the heterocycle may be a carbon ring comprising 4 to 6 members, of which 1, 2, or 3 are heteroatoms selected from O or N.The heterocycle may or may not be substituted by one or more substituent(s) chosen from -OH, halogen, -NRaC(O)Rb, -C(O)NRaRb, -CN, -NO2, -NRaRb, -ORa, -SRa, -CO2Ra, -OC(O)ORa, -OC(O)Ra, -C(O)H, -C(O)Ra in which Ra and Rb are as defined above.

[0053] The term "azeotropic composition" refers to a liquid mixture of two or more compounds that behaves as a single substance and boils at a fixed temperature while maintaining a liquid-phase composition identical to that of the gas phase. The term "quasi-azeotropic composition" refers to a liquid mixture of two or more compounds that has a constant boiling point or that tends not to separate when subjected to boiling or evaporation.

[0054] The term “organic extraction agent” refers to a compound comprising at least one carbon atom.

[0055] According to a preferred embodiment, said organic extraction agent is a compound comprising from 2 to 12 carbon atoms, advantageously from 2 to 11 carbon atoms, preferably from 2 to 10 carbon atoms, more preferably from 2 to 9 carbon atoms, in particular from 2 to 8 carbon atoms.

[0056] Said organic extraction agent preferably has a molecular mass less than 200 g.mol*, advantageously less than 190 g.mol*, preferably less than 180 g.mol*, more preferably less than 170 g.mol*, in particular less than 160 g.mol*.

[0057] According to a preferred embodiment, said organic extraction agent has a melting point below 50°C, advantageously below 40°C, preferably below 30°C, more preferably below 20°C, in particular below 10°C, more particularly below 0°C.

[0058] According to a preferred embodiment, said organic extraction agent has a separation factor S[j2] greater than or equal to 2.0, said separation factor being calculated by the formula S[j2] = (Yi,s) / (Y2,s) in which

[0059] Yi.s represents the activity coefficient of chlorotrifluoroethylene in said organic extraction agent at infinite dilution,

[0060] Y2,s represents the activity coefficient of 1,1,2-trifluoroethane in said organic extraction agent at infinite dilution,

[0061] Advantageously, the separation factor S[j2 is greater than or equal to 2.1, preferably greater than or equal to 2.2, more preferably greater than or equal to 2.3, in particular greater than or equal to 2.4, more particularly greater than or equal to 2.5.

[0062] According to a preferred embodiment, said organic extraction agent is selected from the group consisting of ethylchloroacetate, ethylmercaptoacetate, phenylacetate, n-butylacetate, b-phenylethylacetate, sec-butylacetate, methyldichlo-roacetate, isoamylacetate, n-pentylacetate, propynol, 3-butyn-l-ol, 2-butyn-l-ol, 3-butyn-2-ol, ethanol, 2-propanol, alpha-methylcyclopropanemethanol, glycidylaldehyde, 2,4-hexadienal, 3-phenyl-2-propenal, benzaldehyde, 4-methylbenzaldehyde, hexanal, heptanal, 3-butenoic acid, propionic acid, 4-pentenoic acid, 5-hexenoic acid, isobutyric acid, butyric acid, 4-ethylnitrobenzene, l,4-dimethyl-2-nitrobenzene, dimethylformamide, n,n-dimethylacetamide, methyl-formamide, n,n-dimethylpropanamide, n,n-dimethylbutanamide, n-butylacetamide, n-nitrosodimethylamine, 1-methylimidazol, n-(2-aminoethyl)-l,2-ethanediamine, tetra-methylurea, 3,3'-iminodipropylamine, 2,2-diethoxyethanamine, tetraethylene-pentamine, furfurylamine, n,n-Dimethyl-1,3-benzenediamine, 4-morpholinepropanamine, 3-chlorobenzeneamine, acetic acid anhydride, propanoic acid anhydride, isobutyric acid anhydride, butanoic acid anhydride, nitromethane, nitroethane, 1,3-dioxane, 4-methyl-1,3-dioxane, beta-propiolactone, gamma-butyrolactone, dimethylmalonate, ethyl acetoacetate, 1,2-ethanedioldiacetate, methyl ester of cyanoacetic acid, 2-propenyl ester of 3-oxobutanoic acid, dimethyl ester of pentanedioic acid, ethyloxalate, methyl ethyl ester of 3-oxobutanoic acid, ethylene glycol monomethyl ether acetate, dimethylmaleate, ester ethyl cyanoacetic acid, ethyl methyl ester of butanedioic acid, diethylmalonate, methyl 2-hydroxypropanoic acid, t-butylacetoacetate, ethylsuccinate, ethyl ester of chloroacetic acid, allylidene diacetate, diethyl ester of adipic acid, ethyl phenylacetate, phenyl methyl ester of acetic acid,dibutyl ester of (z)-2-butenedioic acid, 2-methylpropyl ester of acetic acid, 2-propenyl ester of , butanoic acid, methyl benzoate, tetramethyl ester of silicic acid, butyl ester of 2-propenoic acid, 2-methylpropyl ester of propenoic acid, pentyl ester of formic acid, cyclohexyl ester of acetic acid, ethyl ester of 3-methylbutanoic acid, ethyl benzoate, methyl hexanoate, diglyme, bis(2-chloroethyl)ether, chlorotyl glycol ether, ethylene glycol monobenzyl ether, diethylene glycol monobutyl ether, 2-chloroethylethyl ether, diethylene glycol dibutyl ether, benzylmethyl ether, isoamyl formate, 2,5,8,11-tetraoxadodecane, methyl thiocyanate, ethylthiocyanate, ethylisothiocyanate, l-hydroxy-2-propanone, acetony-lacetone, acetylacetone, 2-oxepanone, chloroacetone, n-methyl-2-pyrrolidinone, 5-ethyldihydro-2(3h)-furanone, l-bromo-2-propanone, 5-methyl-2(3h)-furanone, 2-cyclohexen-1-one, l-(4-methoxyphenyl)-2-propanone, cyclopentanone, 4-oh-4-me-2-pentanone, 4-methylene-2-oxetanone, 1-cyclopropylethanone, l-phenyl-2-propanone, 2,3-pentanedione, isophorone, cyclohexanone, 2-methylcyclopentanone, 4-methyl-3-penten-2-one, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, 4-phenyl-2-butanone, 2-hexanone, l-(3,4-dimethylphenyl)ethanone, 4-methyl-2-pentanone, 3-hexanone, 4-fluoroacetophenone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone, 2-heptanone, 2,4-dimethyl-3-pentanone, 2,2-dimethyl-3-pentanone, 3-heptanone, 4-heptanone, 2-octanone, 2-methyl-l-phenyl-l-propanone, (ethylthio) acetic acid, 1,3-propanedithiol, 1,2-ethanedithiol, 1,3-dithiolane, 1,4-butanedithiol, pentane-dinitrile, 2-methylpentanedinitrile, hydroxyacetonitrile, 3-chloropropanenitrile, 2-hydroxypropanenitrile, dimethylaminopropionitrile, (e)-2-butenenitrile, 3-butenenitrile, butyronitrile, 2-hydroxy-2-methylpropanenitrile, valeronitrile, phenyla-cetonitrile, hexanenitrile, benzenepropanenitrile, benzonitrile, heptanenitrile, 3-methylbenzonitrile, 2-methylbenzonitrile,octanenitrile, 3-fluorobenzonitrile, nona-nonitrile, trimethylphosphate, propylene carbonate, tetramethylorthocarbonate, trie-thylphosphate, dimethylsulfate, tris(2-butoxyethyl)phosphate, diethylsulfate, diethyl-carbonate, 2-(2-ethoxyethoxy)ethanolacetate, 2-ethoxyethanolacetate, 2-(2-butoxyethoxy)ethanolacetate, 2-butoxyethanolacetate, furfural, diethyleneglycol-monoethylether, 2-methoxyethanol, 2-2-(2-butoxyethoxy)ethoxyethanol, 3-methoxy-l-butanol, l-methoxy2-propanol, ethoxyethanol, 2-furanmethanol, te-trahydro-2h-pyran-2-methanol, 3-methoxyphenol, l-propoxy-2-propanol, acide difluo-roacétique, 2-fluoroethanol, 2-bromoethanolacetate, 2-chloroethanol, acide chloro-sulfonique, 2,2-difluoroethanol, 2,2,3,3-tetraflouro-l-propanol, acide 2-chloropropionique, 1 -chloro-2-methyl-2-propanol, 2,2'-oxybis(2,l-ethanediyloxy)bisethanol, 2,2'-(methylimino)bis-ethanol, 2-(2-methoxyethoxy)ethanol, 2-bromoethanol, 3-chloro-l-propanol, , l,3-dichloro-2-propanol, ethylenecyanohydrin, 2-nitroethanol, 2-nitro-l-butanol, 2-amino-l-butanol, 3-pyridinemethanol, 2-(ethylamino)ethanol, 2-(dimethylamino)-ethanol, 3-(dimethylamino)- 1-propanol, l-(dimethylamino)-2-propanol, divinylsulfone, 2,2'-thiobisethanol, 2-(ethylthio)-ethanol, glycol, triethyleneglycol, diethyleneglycol, 1,3-propanediol, pro-pyleneglycol, tripropyleneglycol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethoxyethylacrylate, ethylbutyrate, propylpropionate, ethylvalerate, n-butylpropionate, n-propylbutyrate, isobutylpropionate, isopropylbutyrate, diacetoxydi-methylsilane, (3-chloropropyl)trimethoxy-silane, triethoxysilane, methylhydrazine, py-ridazine, 2-methylpyridinel-oxide, 1-piperidinecarboxaldehyde, (chloromethyl)-oxirane, dimethylcarbamoylchloride, 4-pyridinecarboxaldehyde, 2-nitropropane, 1-acetylpiperidine, 1-nitropropane, 4-methoxybenzaldehyde, 1,1 '-oxybis-2-ethoxy-ethane, trimethylphosphite, tetrahydrofurfurylalcohol, 4-(2-hydroxyethyl)morpholine,1,3-butanediol, 1,2-ethanedioldinitrate, 3-oxiranyl-7-oxabicyclo[4,l,0]heptane, dibutyloxalate, morpholine, ((l,l-dimethylethoxy)methyl)oxirane, 1,4-oxathiane, dimethoxytetrahydrofuran, trie-thylorthoformate, 3-chloropropanoylchloride, citral, pyrrole, allylacrylate, 3-methoxyaniline, 2-methylpyrazine, methylaminoacetaldehydedimethylacetal, (c-chloroethoxy)ethane, butyllactate, nitrocyclohexane, 4-fluorobenzaldehyde, me-thoxyacetylchloride, 2-propen-l-ol, 2-ethylbutyraldehyde, 2-fluorobenzaldehyde, 1,6-heptadiyne, 2-nitrotoluene, methyl-2-chloroacrylate, 2-furancarbonylchloride, sali-cylicaldehyde, 4,5-dihydro-2-methylthiazole, l,4-difluoro-2-nitrobenzene, benzi-soxazole, thiazole, m-fluoroaniline, l,4-dichloro-2-butyne, aniline, p-fluoroaniline, 1-methyl-lh-pyrrole, pyridine, 2,4-dimethylbenzaldehyde, methacrylalcohol, 2,3-dichlorobutane, chloroacetylchloride, 1,3-dichloropropane, 1,5-dichloro-pentane, 2,6-dimethylmorpholine, myristicin, 2,3-dimethylpyrazine, 2-butanoneoxime,2-Ethylnitrobenzene.

[0063] Advantageously, said organic extraction agent is selected from the group consisting of phenylacetate, n-butylacetate, b-phenylethylacetate, sec-butylacetate, isoamylacetate, n-pentylacetate, ethanol, 2-propanol, alpha-methylcyclopropanemethanol, dimethylformamide, n,n-dimethylacetamide, methyl-formamide, n,n-dimethylpropanamide, n,n-dimethylbutanamide, n-butylacetamide, 1,3-dioxane, 4-methyl-1,3-dioxane, beta-propiolactone, gamma-butyrolactone, dimethylmalonate, ethyl acetoacetate, 1,2-ethanedioldiacetate, methyl ester of cyanoacetic acid, 2-propenyl ester of 3-oxobutanoic acid, dimethyl ester of pentanedioic acid, ethyloxalate, methyl ethyl ester of 3-oxobutanoic acid, ethylene glycol monomethyl ether acetate, dimethyl maleate, ethyl ester of cyanoacetic acid, ethyl methyl ester of butanedioic acid, diethylmalonate, acid methyl of 2-hydroxypropanoic acid, t-butylacetoacetate, ethylsuccinate, ethyl ester of chloroacetic acid, allylidene diacetate, diethyl ester of adipic acid, ethyl phenylacetate, phenylmethyl ester of acetic acid, dibutyl ester of (z)-2-butenedioic acid, 2-methylpropyl ester of acetic acid, 2-propenyl ester of butanoic acid, methyl benzoate, tetramethyl ester of silicic acid, butyl ester of 2-propenoic acid, 2-methylpropyl ester of propenoic acid, pentyl ester of formic acid, cyclohexyl ester of acetic acid, ethyl ester of 3-methylbutanoic acid, benzoate ethyl, methyl hexanoate, diglyme, bis(2-chloroethyl)ether, crotyl glycol ether, ethylene glycol monobenzylether, diethyl-neglycol monobutylether, 2-chloroethylethylether, diethyleneglycol dibutylether, ben-zylmethylether, isoamylformate, 2,5,8,11-tetraoxadodecane, l-hydroxy-2-propanone, acetonylacetone,acetylacetone, 2-oxepanone, chloroacetone, n-methyl-2-pyrrolidinone, 5-ethyldihydro-2(3h)-furanone, l-bromo-2-propanone, 5-methyl-2(3h)-furanone, 2-cyclohexen-l-one, l-(4-methoxyphenyl)-2-propanone, cy-clopentanone, 4-oh-4-me-2-pentanone, 4-methylene-2-oxetanone, 1-cyclopropylethanone, l-phenyl-2-propanone, 2,3-pentanedione, isophorone, cyclo-hexanone, 2-methylcyclopentanone, 4-methyl-3-penten-2-one, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, 4-phenyl-2-butanone, 2-hexanone, l-(3,4-dimethylphenyl)ethanone, 4-methyl-2-pentanone, 3-hexanone, 4-fluoroacetophenone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone, 2-heptanone, 2,4-dimethyl-3-pentanone, 2,2-dimethyl-3-pentanone, ,

[0064] 3-heptanone, 4-heptanone, 2-octanone, 2-methyl-l-phenyl-l-propanone, pentane-dinitrile, 2-methylpentanedinitrile, hydroxyacetonitrile, 2-hydroxypropanenitrile, dime-thylaminopropionitrile, (e)-2-butenenitrile, 3-butenenitrile, butyronitrile, 2-hydroxy-2-methylpropanenitrile, valeronitrile, phenylacetonitrile, hexanenitrile, hep-tanenitrile, octanenitrile, 3-fluorobenzonitrile, nonanonitrile, trimethylphosphate, propylene carbonate, tetramethylorthocarbonate, triethylphosphate, dimethylsulfate, tris(2-butoxyethyl)phosphate, diethylsulfate, diethylcarbonate, 2-(2-ethoxyethoxy)ethanolacetate, 2-ethoxyethanolacetate, 2-(2-butoxyethoxy)ethanolacetate, 2-butoxyethanolacetate, furfural, diethyleneglycol-monoethylether, 2-methoxyethanol, 2-2-(2-butoxyethoxy)ethoxyethanol, 3-methoxy-l-butanol, l-methoxy2-propanol, ethoxyethanol, 2-furanmethanol, te-trahydro-2h-pyran-2-methanol, 3-methoxyphenol, l-propoxy-2-propanol, 2,2'-oxybis(2,l-ethanediyloxy)bisethanol, 2,2'-(methylimino)bis-ethanol,2-(2-methoxyethoxy)ethanol, glycol, triethyleneglycol, diethyleneglycol, 1,3-propanediol, propyleneglycol, tripropyleneglycol, 1,5-pentanediol, , 2-methyl-2,4-pentanediol, 2-ethoxyethylacrylate, ethylbutyrate, propylpropionate, ethylvalerate, n-butylpropionate, n-propylbutyrate, isobutylpropionate, isopropyl-butyrate, l,l'-oxybis-2-ethoxy-ethane, trimethylphosphite, tetrahydrofurfurylalcohol, 4-(2-hydroxyethyl)morpholine, 1,3-butanediol, 1,2-ethanedioldinitrate, 3-oxiranyl-7-oxabicyclo[4,l,0]heptane, dibutyloxalate, morpholine, ((1,1 -dimethylethoxy )methyl)oxirane, dimethoxy tetrahydrofuran, triethylorthoformate, citral, allylacrylate, butyllactate, nitrocyclohexane, 2-propen-l-ol, methacrylalcohol, 2,6-dimethylmorpholine, 2-butanoneoxime.

[0065] Preferably, said organic extraction agent is selected from the group consisting of phenylacetate, n-butylacetate, b-phenylethylacetate, sec-butylacetate, isoamylacetate, n-pentylacetate, ethanol, 2-propanol, alpha-methylcyclopropanemethanol, dimethylformamide, n,n-dimethylacetamide, methyl-formamide, n,n-dimethylpropanamide, n,n-dimethylbutanamide, n-butylacetamide, 1,3-dioxane, 4-methyl-1,3-dioxane, beta-propiolactone, gamma-butyrolactone, dimethylmalonate, ethyl acetoacetate, 1,2-ethanedioldiacetate, methyl ester of cyanoacetic acid, 2-propenyl ester of 3-oxobutanoic acid, dimethyl ester of pentanedioic acid, ethyloxalate, methyl ethyl ester of 3-oxobutanoic acid, ethylene glycol monomethyl ether acetate, dimethyl maleate, ethyl ester of cyanoacetic acid, ethyl methyl ester of butanedioic acid, diethylmalonate, methyl acid of 2-hydroxypropanoic acid, t-butylacetoacetate, ethylsuccinate, al-lylidene diacetate,adipic acid diethyl ester, ethyl phenylacetate, phenyl methyl ester of acetic acid, (z)-2-butenedioic acid dibutyl ester, 2-methylpropyl ester of acetic acid, tetramethyl ester of silicic acid, butyl ester of 2-propenoic acid, 2-methylpropyl ester of propenoic acid, pentyl ester of formic acid, cyclohexyl ester of acetic acid, ethyl ester of 3-methylbutanoic acid, methyl hexanoate, diglyme, crotyl glycol ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, isoamyl formate, 2,5,8,11-tetraoxadodecane, l-hydroxy-2-propanone, acetonyl-lacetone, acetylacetone, 2-oxepanone, n-methyl-2-pyrrolidinone, 5-ethyldihydro-2(3h)-furanone, 5-methyl-2(3h)-furanone, 2-cyclohexen-1-one, l-(4-methoxyphenyl)-2-propanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, 4-methylene-2-oxetanone, 1-cyclopropylethanone, 2,3-pentanedione, isophorone, cy-clohexanone, 2-methylcyclopentanone,4-methyl-3-penten-2-one, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, 4-phenyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-hexanone, 4-fluoroacetophenone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone, 2-heptanone, 2,4-dimethyl-3-pentanone, 2,2-dimethyl-3-pentanone, 3-heptanone, 4-heptanone, 2-octanone, , 2-methyl-l-phenyl-l-propanone, pentanedinitrile, 2-methylpentanedinitrile, hydroxy-acetonitrile, 2-hydroxypropanenitrile, dimethylaminopropionitrile, (e)-2-butenenitrile, 3-butenenitrile, butyronitrile, 2-hydroxy-2-methylpropanenitrile, valeronitrile, phenyla-cetonitrile, hexanenitrile, heptanenitrile, octanenitrile, nonanonitrile, trimethyl-phosphate, propylene carbonate, tetramethylorthocarbonate, triethylphosphate, tris(2-butoxyethyl)phosphate, diethylcarbonate, 2-(2-ethoxyethoxy)ethanolacetate, 2-ethoxyethanolacetate, 2-(2-butoxyethoxy)ethanolacetate, 2-butoxyethanolacetate, furfural, diethyleneglycolmonoethylether, 2-methoxyethanol, 2-2-(2-butoxyethoxy)ethoxyethanol, 3-methoxy-l-butanol, l-methoxy2-propanol, ethoxyethanol, 2-furanmethanol, tetrahydro-2h-pyran-2-methanol, 3-methoxyphenol, l-propoxy-2-propanol, 2,2'-oxybis(2,l-ethanediyloxy)bisethanol, 2-(2-methoxyethoxy)ethanol, glycol, triethyleneglycol, diethyleneglycol, 1,3-propanediol, propyleneglycol, tripropyleneglycol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethoxyethylacrylate, ethylbutyrate, propylpropionate, ethylvalerate, n-butylpropionate, n-propylbutyrate, isobutylpropionate, isopropyl-butyrate, 1,1 '-oxybis-2-ethoxy-ethane, tetrahydrofurfurylalcohol, 4-(2-hydroxyethyl)morpholine, 1,3-butanediol, 1,2-ethanedioldinitrate, 3-oxiranyl-7-oxabicyclo[4,l,0]heptane, dibutyloxalate, , ((1,1 -dimethylethoxy )methyl)oxirane, dimethoxy tetrahydrofuran, triethylorthoformate, citral, allylacrylate, butyllactate, 2-propen-l-ol, methacrylalcohol, 2-butanoneoxime.

[0066] Plus préférentiellement, ledit agent d’extraction organique est sélectionné parmi le groupe consistant en beta-propiolactone, gamma-butyrolactone, l-hydroxy-2-propanone, acetonylacetone, trimethylphosphate, acetylacetone, propyle-necarbonate, dimethylmalonate, ethylacetoacetate, 1,2-ethanedioldiacetate, glycol, ethyloxalat, 3-oxobutanoicacid- 1-methylethylester, ethyleneglycolmonomethylethe-racetate, dimethylmaleate, triethylphosphate, triethyleneglycol, diethylmalonate, furfural, diethylene glycol, t-butylacetoacetate, ethylsuccinate, 1,3-propanediol, cyclo-pentanone, propylene glycol, 1-cyclopropylethanone, 2-methoxyethanol, 2,3-pentanedione, tripropylene glycol, cyclohexanone, diethylcarbonate, 1,3-butanediol, 3-methoxy-l-butanol, 4-methyl-3-penten-2-one, l-methoxy2-propanol, phenylacetate, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, citral, 1,5-pentanediol, diethylene glycol monobu-tylether, 4-phenyl-2-butanone, éthanol,n-butylacetate, 4-methyl-2-pentanone, 3-hexanone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone and ethylbenzoate. ,

[0067] In particular, said organic extraction agent is selected from the group consisting of trimethylphosphate, ethylacetoacetate, glycol, ethyl oxalate, triethylene glycol, diethylmalonate, diethylene glycol, 1,3-propanediol, propylene glycol, 2-methoxyethanol, ethanol and ethylbenzoate.

[0068] According to a preferred embodiment, step b) is carried out at a pressure of 1 to 10 bara, preferably 1 to 7 bara.

[0069] According to a preferred embodiment, said organic extraction agent has a melting point below 0°C, advantageously below -5°C, preferably below -10°C, in particular below -20°C.

[0070] According to a preferred embodiment, when step b) is carried out at a pressure of 3 to 6 bar, the organic extraction agent has a melting point below 0°C. This prevents the solidification of the extraction agent at the top of the distillation column. In this preferred embodiment, the organic extraction agent is as described above.

[0071] According to another preferred embodiment, when step b) is carried out at a pressure of 1 to 3 bara, said organic extraction agent has a melting point below -10°C, preferably -20°C, in particular -40°C. According to this alternative embodiment, said organic extraction agent is preferably selected from the group consisting of beta-propiolactone, gamma-butyrolactone, l-hydroxy-2-propanone, tri-methylphosphate, acetylacetone, propylenecarbonate, dimethylmalonate, ethylacetate, 1,2-ethanedioldiacetate, glycol, ethyloxalate, 3-oxobutanoic acid-1-methylethyl ester, ethyleneglycol monomethyletheracetate, dimethylmaleate, triethylphosphate, diethylmalonate, furfural, diethyleneglycol, t-butylacetoacetate, ethylsuccinate, 1,3-propanediol, cyclopentanone, propyleneglycol, 1-cyclopropylethanone, 2-methoxyethanol, 2,3-pentanedione, tripropyleneglycol, cyclohexanone, diethylcarbonate, 1,3-butanediol, 3-methoxy-l-butanol, 4-methyl-3-penten-2-one,l-methoxy-2-propanol, phenylacetate, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, citral, 1,5-pentanediol, diethyleneglycolmonobutylether, 4-phenyl-2-butanone, éthanol, n-butylacetate, 4-methyl-2-pentanone, 3-hexanone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone et ethylbenzoate ; de préférence ledit agent d’extraction organique est sélectionné parmi le groupe consistant en beta-propiolactone, gamma-butyrolactone, trimethylphosphate, acetylacetone, propylenecarbonate, dimethylmalonate, ethylacetoacetate, 1,2-ethanedioldiacetate, ethyloxalate, 3-oxobutanoicacid- 1-methylethylester, ethyleneglycolmonomethyletheracetate, triethylphosphate, diethylmalonate, furfural, t-butylacetoacetate, ethylsuccinate, 1,3-propanediol, cyclopentanone, propyleneglycol, 1-cyclopropylethanone, 2-methoxyethanol, 2,3-pentanedione, tripropyleneglycol, cyclohexanone, diethylcarbonate, 1,3-butanediol, 3-methoxy-l-butanol,4-methyl-3-penten-2-one, l-methoxy2-propanol, phenylacetate, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, diethyleneglycolmonobutylether, éthanol, , n-butylacetate, 4-methyl-2-pentanone, 3-hexanone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone et ethylbenzoate ; en particulier ledit agent d’extraction organique est sélectionné parmi le groupe consistant en gamma-butyrolactone, trimethylphosphate, propylene carbonate, dimethylmalonate, ethylacetoacetate, ethyloxalate, ethylene glycol monomethylether acetate, triethyl-phosphate, diethylmalonate, cyclopentanone, propylene glycol, 1-cyclopropylethanone, 2-methoxyethanol, 2,3-pentanedione, diethylcarbonate, 1,3-butanediol, 3-methoxy-l-butanol, 4-methyl-3-penten-2-one, l-methoxy2-propanol, 3-methylcyclohexanone, 4-methylcyclohexanone, diethylene glycol monobutylether, éthanol, n-butylacetate, 4-methyl-2-pentanone, 3-hexanone, 4,4-dimethyl-2-pentanone et 5-methyl-2-hexanone. Procédé de production du trifluoroéthylène

[0072] According to a second aspect of the present invention, a process for producing trifluoroethylene is provided. Said process is carried out in a reactor equipped with a fixed catalytic bed comprising a catalyst.

[0073] Said process comprises the steps of:

[0074] A') reaction of chlorotrifluoroethylene with hydrogen in the presence of ca alyzer and in gas phase to produce a stream A comprising trifluoroethylene, unreacted chlorotrifluoroethylene and 1,1,2-trifluoroethane;

[0075] B') purification of said current A to form a current B1 comprising trifluoride roethylene and a B2 stream comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane,

[0076] C') implementation of the purification process according to the present invention from said current B2.

[0077] In a preferred embodiment, the process is carried out continuously. In a preferred embodiment, the hydrogen is in anhydrous form. In a preferred embodiment, the chlorotrifluoroethylene is in anhydrous form. Carrying out the processes according to the invention in the presence of hydrogen and / or anhydrous chlorotrifluoroethylene makes it possible to effectively increase the lifetime of the catalyst and thus the overall productivity of the process. The term anhydrous refers to a water content by mass of less than 1000 ppm, advantageously 500 ppm, preferably less than 200 ppm, and in particular less than 100 ppm based on the total weight of the compound considered.

[0078] Catalyst

[0079] Preferably, the catalyst is based on a metal from columns 8 to 10 of the periodic table of elements. In particular, the catalyst is based on a metal selected from the group consisting of Pd, Pt, Rh, and Ru; preferably palladium.

[0080] Preferably, the catalyst is supported. The support is preferably selected Among the group consisting of activated carbon, an aluminum-based support, calcium carbonate, and graphite. Preferably, the support is aluminum-based. In particular, the support is alumina. The alumina may be alpha alumina. Preferably, the alumina comprises at least 90% alpha alumina. It has been observed that the conversion of the hydrogenolysis reaction is improved when the alumina is alpha alumina. Thus, the catalyst is more particularly palladium supported on alumina, advantageously palladium supported on alumina comprising at least 90% alpha alumina, preferably palladium supported on alpha alumina.

[0081] Preferably, palladium represents from 0.01% to 5% by weight based on the total weight of the catalyst, preferably from 0.1% to 2% by weight based on the total weight of the catalyst.

[0082] In particular, said catalyst comprises from 0.01% to 5% by weight of palladium supported on alumina, preferably the alumina comprises at least 90% alpha alumina, more preferably the alumina is an alpha alumina.

[0083] Catalyst activation

[0084] Said catalyst is preferably activated before its use in step A'). Preferably, the activation of the catalyst is carried out at high temperature and in the presence of a reducing agent, an inert gas or a mixture of these.

[0085] According to a particular embodiment, the reducing agent is chosen from the group consisting of hydrogen, carbon monoxide, nitrogen monoxide, formaldehyde, Ci-C6 alkanes and Ci-Cio hydrohalocarbons, or a mixture thereof; preferably hydrogen or a Ci-Cio hydrohalocarbon, or a mixture thereof; in particular hydrogen, chlorotrifluoroethylene, trifluoroethylene, chlorotrifluoroethane, trifluoroethane or difluoroethane or a mixture thereof.

[0086] The inert gas can be nitrogen or argon; preferably nitrogen.

[0087] Preferably, the catalyst activation is carried out at a temperature between 100°C and 400°C, in particular at a temperature between 150°C and 350°C. In particular, the catalyst activation is carried out at a temperature between 100°C and 400°C, in particular at a temperature between 150°C and 350°C, in the presence of hydrogen as a reducing agent.

[0088] Preferably, the temperature of the catalytic bed is increased during activation from a temperature T1 to a temperature T2. In particular, the temperature of the catalytic bed is increased from a temperature T1 to a temperature T2 higher than T1 with a temperature gradient of less than 0.5°C / min. The temperature gradient implemented prevents premature degradation of the catalyst and thus allows for a better yield or productivity of the hydrogenolysis reaction. In particular, the temperature is increased with a gradient ofThe temperature must be less than 0.45°C / min, 0.40°C / min, 0.35°C / min, 0.30°C / min, 0.25°C / min, 0.20°C / min, 0.15°C / min, 0.10°C / min, or 0.05°C / min. The temperature Tl represents the initial temperature of the activation step. This temperature Tl can be the ambient temperature. Alternatively, the temperature T1 can be between 0°C and 150°C, advantageously between 0°C and 120°C, preferably between 0°C and 100°C, more preferably between 10°C and 100°C, in particular between 20°C and 100°C, more particularly between 20°C and 75°C, and preferably between 20°C and 50°C. The temperature T2 represents the temperature to be reached during the activation phase.The temperature T2 is advantageously between 150°C and 400°C, preferably between 155°C and 375°C, more preferably between 160°C and 350°C, in particular between 165°C and 325°C, more particularly between 170°C and 320°C, preferably between 175°C and 310°C, and more preferably between 180°C and 300°C. According to a preferred embodiment, the temperature T2 is advantageously between 185°C and 290°C, preferably between 190°C and 280°C, more preferably between 195°C and 270°C, and in particular between 200°C and 260°C. Temperature T2 can be maintained from 5 min to 200 h, preferably from 10 min to 100 h, in particular from 15 min to 75 h, more particularly from 30 min to 50 h, preferably from 1 h to 25 h. Temperature T2 can be maintained from 5 min to 24 h, preferably from 10 min to 20 h, in particular from 15 min to 15 h, more particularly from 30 min to 100 h, preferably from 1 h to 100 h.

[0089] Preferably, the gas stream used during the activation step does not contain oxygen. Preferably, the activation step can be carried out with an amount of reducing agent greater than 0.01 mol per gram of catalyst, preferably greater than 0.05 mol per gram of catalyst. In particular, the activation step can be carried out with an amount of reducing agent between 0.01 and 10 mol per gram of catalyst, preferably between 0.05 and 5 mol per gram of catalyst.

[0090] According to another embodiment, during the activation step, the temperature of the catalytic bed is increased from a temperature T1 to a temperature T2 in steps. Stepwise activation of the catalyst makes it more efficient. The use of steps prevents degradation of the catalyst. It has also been observed that the properties of the catalyst are further improved if the temperature increase between steps is gradual and relatively slow compared to the usual activation conditions of a catalyst. Thus, preferably, during the activation step, between two steps, the temperature is increased with a temperature gradient of less than 0.5°C / min. The temperature gradient used between two steps prevents premature degradation of the The catalyst is used to improve the yield or productivity of the hydrogenolysis reaction. Specifically, the temperature is increased with a temperature gradient less than 0.45°C / min, 0.40°C / min, 0.35°C / min, 0.30°C / min, 0.25°C / min, 0.20°C / min, 0.15°C / min, 0.10°C / min, or 0.05°C / min. The temperature Tl represents the initial temperature of the activation step. This temperature Tl can be ambient temperature. Alternatively, the temperature T1 can be between 0°C and 150°C, advantageously between 0°C and 120°C, preferably between 0°C and 100°C, more preferably between 10°C and 100°C, in particular between 20°C and 100°C, more particularly between 20°C and 75°C, and preferably between 20°C and 50°C. The temperature T2 represents the temperature to be reached during the activation phase.The temperature T2 is advantageously between 150°C and 400°C, preferably between 155°C and 375°C, more preferably between 160°C and 350°C, in particular between 165°C and 325°C, more particularly between 170°C and 320°C, preferably between 175°C and 310°C, and more preferably between 180°C and 300°C. According to a preferred embodiment, the temperature T2 is advantageously between 185°C and 290°C, preferably between 190°C and 280°C, more preferably between 195°C and 270°C, and in particular between 200°C and 260°C. Temperature T2 can be maintained from 5 minutes to 200 hours, preferably from 10 minutes to 100 hours, in particular from 15 minutes to 75 hours, more particularly from 30 minutes to 50 hours, and preferably from 1 hour to 25 hours. Temperature T2 can be maintained from 5 minutes to 24 hours, preferably from 10 minutes to 20 hours, in particular from 15 minutes to 15 hours, more particularly from 30 minutes to 100 hours, and preferably from 1 hour to 100 hours.The catalyst activation step (i') contains at least one plateau between temperature T1 and temperature T2. This step may include several plateaus between temperatures T1 and T2. Preferably, the activation step includes at least one plateau at a temperature T1 between 90 and 120°C. The presence of a plateau between 90°C and 120°C is recommended to increase catalyst lifespan. The activation step may also include one or more plateaus between temperatures T1 and T1 and / or between temperatures T1 and T2. Preferably, each plateau between temperatures T1 and T2 can last between 5 minutes and 200 hours, preferably between 10 minutes and 100 hours, in particular between 15 minutes and 75 hours, and more specifically between 30 minutes and 50 hours.In particular, each plateau between temperature T1 and temperature T2 can last between 5 minutes and 24 hours, preferably between 10 minutes and 20 hours, especially between 15 minutes and 15 hours, and more particularly between 30 minutes and 100 hours. In particular, the plateau at temperature T1 can last between 5 minutes and 200 hours, preferably between 10 minutes and 100 hours, especially between 15 minutes and 75 hours, and more particularly between 30 minutes and 50 hours. Preferably, the plateau at temperature T1... can last between 5 min and 24h, preferably between 10 min and 20h, especially between 15 min and 15h, more particularly between 30 min and 10h.

[0091] The gas flow used during the activation step may vary over time. For example, the gas flow may include an inert gas between two plateaus and, for example, a reducing agent between two other plateaus. In particular, the gas flow includes an inert gas when the activation step is carried out between temperatures T1 and T1a, and the gas flow includes a reducing agent, preferably hydrogen or Ci-ClO hydrohalocarbons as defined above, when the activation step is carried out between temperatures T1 and T2. Thus, the gas flow used during the activation step is modified during the plateau carried out at temperature T1a. Alternatively, the gas flow may include a reducing agent such as hydrogen or Ci-ClO hydrohalocarbons as defined above throughout the activation step, optionally mixed with an inert gas such as nitrogen.It has been observed that the use of a reducing agent such as hydrogen or Ci-ClO hydrohalocarbons as defined above, optionally mixed with an inert gas such as nitrogen, during the temperature ramp-up between temperature T1 and temperature T2, provides an additional productivity advantage. As mentioned above, temperature T2 is maintained for a certain duration. During this hold at temperature T2, the gas flow can be modified. Thus, the gas flow during the hold at temperature T2 can include hydrogen or a Ci-ClO hydrohalocarbon as defined above; in particular, the gas flow during the hold at temperature T2 can include hydrogen, chlorotrifluoroethylene, trifluoroethane, trifluoroethylene, chlorotrifluoroethane, or difluoroethane.Preferably, the activation step can be carried out with an amount of reducing agent greater than 0.01 per gram of catalyst, preferably greater than 0.05 per gram of catalyst. In particular, the activation step can be carried out with an amount of reducing agent between 0.01 and 10 mol per gram of catalyst, preferably between 0.05 and 5 mol per gram of catalyst.

[0092] According to another embodiment, the activation step comprises contacting said catalyst with a gas stream that includes chlorotrifluoroethylene, and optionally hydrogen. It has been observed that chlorotrifluoroethylene (CTFE) activates the catalyst, particularly when hydrogen is also present. This improves the trifluoroethylene production process. Activation in the presence of CTFE allows the catalyst to be activated at a lower temperature and thus provides a less energy-intensive process. The process is further simplified since the reducing agent during activation is also one of the reactants for the subsequent reaction. Preferably, in this embodiment, The activation step is carried out at a temperature T2' below 100°C. This temperature T2' can be reached from a temperature Tl' using a shallow temperature gradient. Thus, during the activation step, the temperature of the catalytic bed is increased from a temperature Tl' to a temperature T2' above Tl', preferably with a temperature gradient of less than 0.5°C / min. The temperature gradient used prevents premature degradation of the catalyst and thus allows for a better yield or productivity of the hydrogenolysis reaction.In particular, the temperature is increased with a temperature gradient of less than 0.45°C / min or less than 0.40°C / min, or less than 0.35°C / min, or less than 0.30°C / min, or less than 0.25°C / min, or less than 0.20°C / min, or less than 0.15°C / min, or less than 0.10°C / min, or less than 0.05°C / min.

[0093] Preferably, the temperature of the catalytic bed is increased by increasing the contact time, calculated as the ratio of the volume of catalyst, in liters, to the total flow rate of said gas stream, in normal liters per second, at the reactor inlet. The contact time is between 1 and 60 seconds, preferably between 5 and 45 seconds, particularly between 10 and 30 seconds, and more particularly between 15 and 25 seconds. The temperature T1' can be between 0°C and 50°C, advantageously between 10°C and 50°C, and preferably between 20°C and 50°C. Preferably, the temperature T2' is lower than the temperature T3 of the implementation of step A'). The T3 temperature is preferably between 100°C and 180°C, more preferably between 100°C and 160°C, in particular between 120°C and 160°C.

[0094] Catalyst regeneration

[0095] The catalyst used in the present process can be regenerated. This regeneration step can be carried out within a catalytic bed temperature range of 90°C to 450°C. Preferably, the regeneration step is carried out in the presence of hydrogen. Implementing the regeneration step improves the reaction yield compared to the initial yield before regeneration.

[0096] According to a preferred embodiment, the regeneration step can be carried out at a catalytic bed temperature of 90°C to 300°C, preferably at a catalytic bed temperature of 90°C to 250°C, more preferably from 90°C to 200°C, in particular from 90°C to 175°C, and more particularly at a catalytic bed temperature of 90°C to 150°C. In particular, carrying out the regeneration step at a low temperature, for example from 90°C to 200°C or from 90°C to 175°C or from 90°C to 150°C, allows the desorption of compounds detrimental to the activity of the catalyst and / or limits phase transitions that modify the structure of the catalyst.

[0097] According to another preferred embodiment, the regeneration step can be carried out at a catalytic bed temperature above 200°C, advantageously above 230°C, preferably above 250°C, and in particular above 300°C. The regeneration step can be carried out periodically depending on the productivity or conversion achieved in step a). The regeneration step can advantageously be carried out at a catalytic bed temperature between 200°C and 300°C, preferably between 205°C and 295°C, more preferably between 210°C and 290°C, particularly between 215°C and 290°C, more particularly between 220°C and 285°C, preferably between 225°C and 280°C, and most preferably between 230°C and 280°C. Alternatively, the regeneration step can be carried out at a temperature between 300°C and 450°C, preferably between 300°C and 400°C.The regenerated catalyst can be reused in step A') of this process.

[0098] Hydrogenolysis reaction

[0099] The process includes, as mentioned above, a step of hydrogenolysis of chlorotrifluoroethylene with hydrogen to produce a stream comprising trifluoroethylene. The hydrogenolysis step is carried out in the presence of a catalyst and in the gas phase. Preferably, the hydrogenolysis step is carried out in the presence of a pre-activated catalyst and in the gas phase. The hydrogenolysis step consists of simultaneously introducing hydrogen, CTFE, and optionally an inert gas, such as nitrogen, in the gas phase and in the presence of said catalyst, preferably activated.

[0100] Preferably, said step A') is carried out at a fixed catalytic bed temperature between 50°C and 250°C. Said step A') can be carried out at a fixed catalytic bed temperature between 50°C and 240°C, advantageously between 50°C and 230°C, preferably between 50°C and 220°C, more preferably between 50°C and 210°C, in particular between 50°C and 200°C. Said step a) can also be implemented at a fixed catalytic bed temperature between 60°C and 250°C, advantageously between 70°C and 250°C, preferably between 80°C and 250°C, more preferably between 90°C and 250°C, in particular between 100°C and 250°C, more particularly between 120°C and 250°C.Said step A') can also be implemented at a fixed catalytic bed temperature between 60°C and 240°C, advantageously between 70°C and 230°C, preferably between 80°C and 220°C, more preferably between 90°C and 210°C, in particular between 100°C and 200°C, more particularly between 100°C and 180°C, preferably between 100°C and 160°C, particularly preferably between 120°C and 160°C. .

[0101] The H2 / CTFE molar ratio is between 0.5 / 1 and 2 / 1 and preferably between 1 / 1 and 1.2 / 1. If an inert gas such as nitrogen is present in step A'), the nitrogen / H2 molar ratio is between 0 / 1 and 2 / 1 and preferably between 0 / 1 and 1 / 1.

[0102] Step A') is preferably carried out at a pressure of 0.05 MPa to 1.1 MPa, more preferably from 0.05 MPa to 0.5 MPa, in particular at atmospheric pressure.

[0103] The contact time, calculated as the ratio between the volume, in liters, of catalyst and the total flow rate of the gas mixture, in normal liters per second, at the reactor inlet, is between 1 and 60 seconds, preferably between 5 and 45 seconds, in particular between 10 and 30 seconds, and more particularly between 15 and 25 seconds. Examples

[0104] Method for selecting the organic extraction agent

[0105] The selection of the organic extraction agent is determined using the Cosmo-RS model implemented in the COSMOTHERM software. For this selected binary pair, a separation factor is calculated for each of the solvents studied using the following equation:

[0106] Sjj2 = (Yi,s) / (Y2,s) in which

[0107] Yi.s represents the activity coefficient of the first compound 1 in the organic extraction agent considered at infinite dilution,

[0108] Y2,s represents the activity coefficient of the second compound 2 of the binary pair in the organic extraction agent considered at infinite dilution,

[0109] An absorption capacity is also calculated for each of the solvents studied and for a given (1,2) binary pair. The absorption capacity is calculated using the formula C2jS = 1 / (Y2,s) where Y2,s represents the activity coefficient of the second compound of the binary pair considered in the organic extraction agent studied at infinite dilution.

[0110] The calculations are repeated for each organic extraction agent studied. Minimum values ​​for separation factor and absorption capacity are identified to allow sufficient separation between the first and second compounds of the binary pair (1,2) considered. [YES] Example 1

[0112] In this example, the separation between chlorotrifluoroethylene (CTFE) and 1,1,2-trifluoroethane is considered. Organic extraction agents having a separation factor Si>2 greater than 2 are suitable for separating a mixture comprising chlorotrifluoroethylene (CTFE) and 1,1,2-trifluoroethane.

[0113] [Table 1]

[0114] Table 1 - Capacity and Separation Factor of the Organic Extraction Agent Organic extraction agent Separation factor Si>2 Absorption capacity C2,s beta-propiolactone 18.637 1.020 gamma-butyrolactone 18,152 1,518 1 -hydroxy-2-propanone 16,833 1,153 acetonylacetone 14,051 1,654 trimethy Ipho sphate 13,656 1,794 acetylacetone 11,908 1,377 Propylene carbonate 11,813 0,907 dimethylmalonate 11,810 1,275 ethylacetoacetate 11,780 1,465 1,2-ethanedioldiacetate 11,219 1,386 glycol 10,029 0,254 ethyloxalate 8,921 1,787 3-oxobutanoicacid-l-methylethylester 8,491 1,502 Ethylene glycol monomethyl ether acetate 8,447 1,590 dimethylmaleate 8,125 1,173 triethy Ipho sphate 7,383 2,165 Triethylene glycol 7,378 0,797 diethylmalonate 7,191 1,552 furfural 6,755 0,934 diethyleneglycol 6,581 0,587 t-butylacetoacetate 6,235 1,412 ethylsuccinate 6,062 1,453 1,3-propanediol 5,844 0,520 cyclopentanone 5,576 1,593 Propylene glycol 5,499 0,390 1 -cyclopropylethanone 5,047 1,372 2-methoxyethanol 4,605 0,746 2,3-pentanedione 4,572 1,138 tripropyleneglycol 4,251 1,407 cyclohexanone 4,105 1,349 diethy le arbonate 4,057 1,282 1,3-butanediol 3,890 0,524 3-methoxy- 1-butanol 3,621 1,298 4-methyl-3-penten-2-one 3,603 1,219 1 -methoxy2-propanol 3,495 0,964 phenylacetate 3,406 0,959 cycloheptanone 3,360 1,296 3-methylcyclohexanone 3,330 1,326 4-methylcyclohexanone 3,284 1,302 2,3-hexanedione 3,191 1,060 3,4-hexanedione 3,173 1,028 citral 3,115 1,239 1,5-pentanediol 3,006 0,289 Diethylene glycol monobutyl ether 2,989 1,027 4-phenyl-2-butanone 2,974 0,955 éthanol 2,874 0,383 n-butylacetate 2,838 1,275 4-methyl-2-pentanone 2,760 1,091 3-hexanone 2,699 1,122 4,4-dimethyl-2-pentanone 2,623 1,179 5-methyl-2-hexanone 2,541 1,057 2,2-dimethylcyclohexanone 2,512 1,124 ethylbenzoate 2,148 0,829

[0115] The results are confirmed using a mixture comprising 90-95% by weight of chlorotrifluoroethylene and 5-10% by weight of 1,1,2-trifluoroethane, based on the total weight of the mixture. This mixture is distilled under 1 bar with one of the following extraction agents: glycol, 1,3-propanediol, propylene glycol, or ethanol. The mixture to be separated is introduced into a distillation column at atmospheric pressure. The extraction agent is continuously introduced at the top of the distillation column. The chlorotrifluoroethylene is recovered at the top of the distillation column. The 1,1,2-trifluoroethane and the extraction agent are recovered at the bottom of the distillation column.

Claims

Demands

1. Process for purifying chlorotrifluoroethylene (CTFE) from a first composition comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane (143), said process comprising the steps of: a) Extractive distillation of said first composition in the presence of at least one organic extraction agent to form i. a second composition comprising said organic extraction agent and 1,1,2-trifluoroethane; and ii. a first stream comprising chlorotrifluoroethylene, b) Recovery and separation of said second composition to form a second stream comprising said organic extraction agent and a third stream comprising 1,1,2-trifluoroethane, preferably said second stream is recycled to step a).

2. A process according to the preceding claim characterized in that said organic extraction agent has a flash point greater than 13°C.

3. A process according to any one of the preceding claims characterized in that said organic extraction agent is a compound comprising from 2 to 12 carbon atoms.

4. A process according to any one of the preceding claims characterized in that said organic extraction agent has a molecular mass of less than 200 g.mol*.

5. A process according to any one of the preceding claims characterized in that said organic extraction agent has a separation factor Si>2 greater than or equal to 2.0, said separation factor being calculated by the formula Si>2 = (Yi,s) / (Y2,s) in which Yi,s represents the activity coefficient of chlorotrifluoroethylene in said organic extraction agent at infinite dilution, Y2,s represents the activity coefficient of 1,1,2-trifluoroethane in said organic extraction agent at infinite dilution, advantageously the separation factor Si>2 is greater than or equal to 2.1, preferably greater than or equal to 2.2, more preferably greater than or equal to 2.3, in particular greater than or equal to 2.4, more particularly greater than or equal to 2.

5.

6. A process according to any one of the preceding claims, characterized in that said organic extraction agent has a capacity absorption C2jS greater than or equal to 0.20, said absorption capacity being calculated by the formula C2jS = 1 / (Y2,s) in which y2>s represents the activity coefficient of 1,1,2-trifluoroethane in said organic extraction agent at infinite dilution.

7. A process according to any one of the preceding claims characterized in that the first composition is an azeotropic or quasi-azeotropic composition comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane.

8. A process according to any one of the preceding claims characterized in that said organic extraction agent has a melting point below 0°C.

9. A method according to any one of the preceding claims characterized in that step b) is carried out at a pressure of 1 to 10 bara, preferably 1 to 7 bara. [Revendication 10] Procédé selon l’une quelconque des revendications précédentes caractérisé en ce que ledit agent d’extraction organique est sélectionné parmi le groupe consistant en H2O, beta-propiolactone, gamma-butyrolactone, l-hydroxy-2-propanone, acetonylacetone, trimethyl-phosphate, acetylacetone, propylenecarbonate, dimethylmalonate, ethy-lacetoacetate, 1,2-ethanedioldiacetate, glycol, ethyloxalat, 3-oxobutanoicacid-1 -methylethylester, ethyleneglycolmonomethylethe-racetate, dimethylmaleate, triethylphosphate, triethyleneglycol, diethyl-malonate, furfural, diethyleneglycol, t-butylacetoacetate, ethylsuccinate, 1,3-propanediol, cyclopentanone, propyleneglycol, 1-cyclopropylethanone, 2-methoxyethanol, 2,3-pentanedione, tripropy-leneglycol, cyclohexanone, diethylcarbonate, 1,3-butanediol, 3-methoxy-l-butanol, 4-methyl-3-penten-2-one, l-methoxy2-propanol, phenylacetate, cycloheptanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2,3-hexanedione, 3,4-hexanedione, citral, 1,5-pentanediol, diethyleneglycolmonobutylether, 4-phenyl-2-butanone, ethanol, n-butylacetate, 4-methyl-2-pentanone, 3-hexanone, 4,4-dimethyl-2-pentanone, 5-methyl-2-hexanone, 2,2-dimethylcyclohexanone and ethylbenzoate.,

11. A process for producing trifluoroethylene in a reactor equipped with a fixed catalytic bed comprising a catalyst, said process comprising the steps of: A') reacting chlorotrifluoroethylene with hydrogen in the presence of the catalyst and in the gas phase to produce a current A including trifluoroethylene, unreacted chlorotrifluoroethylene and 1,1,2-trifluoroethane; B') purification of said stream A to form a stream B1 comprising trifluoroethylene and a stream B2 comprising chlorotrifluoroethylene and 1,1,2-trifluoroethane, (c) implementation of the purification process according to any one of the preceding claims 1 to 10 from said current B2.