Method for producing reaction gas containing fluorinated organic compound

Abstract

A novel method for producing a fluorinated organic compound is provided. The present production method is a method for producing a reaction gas containing at least one fluorinated organic compound selected from the group consisting of a fluoroethylene compound and a fluoroethane compound, and includes a coupling reaction step for supplying a raw material gas containing a fluoromethane compound to a Group 8 to Group 11 transition metal catalyst.

Description

Method for producing reaction gases containing fluorinated organic compounds

[0001] This disclosure relates to a method for producing a reaction gas containing a fluorinated organic compound.

[0002] (E)-1,2-difluoroethylene (hereinafter also referred to as "R-1132(E)") is attracting attention as a refrigerant that can replace the greenhouse gases difluoromethane (R-32) and 1,1,1,2,2-pentafluoroethane (R-125) because of its low global warming potential (GWP).

[0003] Patent Document 1 contains the following formula (1): CH ２ A method for producing 1,2-difluoroethylene is disclosed, characterized by producing 1,2-difluoroethylene from a compound represented by formula FX (1) (wherein X is a halogen atom) by a synthesis reaction involving thermal decomposition.

[0004] Japanese Patent Application Publication No. 2013-241348

[0005] This disclosure aims to provide a novel method for producing fluorinated organic compounds.

[0006] This disclosure includes, for example, the inventions described in the following sections.

[0007] Item 1. A method for producing a reaction gas containing at least one fluorinated organic compound selected from the group consisting of fluoroethylene compounds and fluoroethane compounds, comprising a coupling reaction step of supplying a raw material gas containing a fluoromethane compound to a group 8 to 11 transition metal catalyst.

[0008] Item 2. The method for producing according to Item 1, wherein the reaction gas comprises at least one fluorinated organic compound selected from the group consisting of 1,2-difluoroethylene (R-1132), 1,1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143).

[0009] Item 3. The method for producing according to item 1 or 2, wherein the raw material gas comprises at least one fluoromethane compound selected from the group consisting of fluoromethane (R-41), chlorofluoromethane (R-31), difluoromethane (R-32), and chlorodifluoromethane (R-22).

[0010] Item 4. The manufacturing method according to any one of items 1 to 3, wherein the Group 8 to 11 transition metal catalyst comprises at least one precious metal selected from the group consisting of palladium (Pd), ruthenium (Ru), platinum (Pt), rhodium (Rh), iridium (Ir), gold (Au), and silver (Ag).

[0011] Item 5. The manufacturing method according to any one of items 1 to 4, wherein the Group 8 to 11 transition metal catalyst includes a noble metal alloy.

[0012] Item 6. The manufacturing method according to any one of items 1 to 5, wherein the group 8 to 11 transition metal catalyst is supported on a carrier.

[0013] Item 7. The method for producing a product according to any one of items 1 to 6, wherein the reaction gas comprises at least one fluorinated organic compound selected from the group consisting of 1,2-difluoroethylene (R-1132) and 1,1,2-trifluoroethane (R-143), the raw material gas comprises at least one fluoromethane compound selected from the group consisting of fluoromethane (R-41), chlorofluoromethane (R-31), difluoromethane (R-32), and chlorodifluoromethane (R-22), and the group 8 to group 11 transition metal catalyst comprises at least one precious metal selected from the group consisting of palladium (Pd), ruthenium (Ru), platinum (Pt), rhodium (Rh), iridium (Ir), gold (Au), and silver (Ag).

[0014] Item 8. The manufacturing method according to any one of items 1 to 7, wherein the coupling reaction step is carried out at a temperature of less than 750°C.

[0015] Item 9-1. The manufacturing method according to any one of items 1 to 8, wherein the coupling reaction step is carried out at a temperature of 0°C or higher and less than 200°C.

[0016] Item 9-2. The manufacturing method according to any one of items 1 to 8, wherein the coupling reaction step is carried out at a temperature of 200°C or higher and less than 400°C.

[0017] Item 9-3. The manufacturing method according to any one of items 1 to 8, wherein the coupling reaction step is carried out at a temperature of 400°C or higher and 700°C or lower.

[0018] Item 10-1. The manufacturing method according to any one of items 1 to 9-3, comprising a pretreatment step of pretreating the group 8 to 11 transition metal catalyst with the source gas before the coupling reaction step.

[0019] Item 10-2. The manufacturing method according to any one of items 1 to 9-3, further comprising a recycling step of resupplying part or all of the reaction gas to the Group 8 to 11 transition metal catalyst after the coupling reaction step.

[0020] Item 10-3. The manufacturing method according to any one of items 1 to 9-3, wherein the coupling reaction step is carried out in a batch manner.

[0021] Item 11. A Group 8 to Group 11 transition metal catalyst used in the manufacturing method described in any one of Items 1 to 10-3.

[0022] Item 12. A catalytic reactor for use in the manufacturing method described in any one of Items 1 to 10-3, comprising: a reactor containing the Group 8 to 11 transition metal catalyst; a supply port for supplying the raw material gas to the reactor; and a discharge port for discharging the reaction gas from the reactor.

[0023] Item 13. The catalytic reactor according to item 12, further comprising a circulation path for resupplying all or part of the reaction gas discharged from the outlet to the supply port.

[0024] Item 14. A method for producing an activated catalyst, comprising an activation step of treating a Group 8 to Group 11 transition metal catalyst with a gas containing a fluoromethane compound, a reducing gas, or a reducing liquid.

[0025] Item 15. An activated catalyst, wherein a group 8 to group 11 transition metal catalyst is obtained by treating it with a gas containing a fluoromethane compound, a reducing gas, or a reducing liquid.

[0026] This disclosure provides a novel method for producing fluorinated organic compounds.

[0027] This is a schematic diagram showing an example of a catalytic reactor used in the manufacturing method of the present disclosure. This is a graph showing the selectivity of fluorinated organic compounds in Example 1-1 (circle), Example 1-2 (triangle), Example 1-3 (diamond), and Example 1-4 (square) (vertical axis: total selectivity (%) for trans-1,2-difluoroethylene (R-1132(E)), cis-1,2-difluoroethylene (R-1132(Z)), 1,1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143), horizontal axis: temperature inside the reaction tube (°C)). This is a schematic diagram showing another example of a catalytic reactor used in the manufacturing method of the present disclosure. This is a graph showing the amount of fluorinated organic compounds produced in Example 2-1 (circle: R-1132(E), triangle: R-1132(Z)) (vertical axis: GCMS area value, horizontal axis: circulation reaction time (minutes)).

[0028] In this specification, "contains" is a concept that encompasses all of the following: "contains," "consist essentially of," and "consist of." Furthermore, in this specification, when a numerical range is indicated as "A to B," it means A or greater and B or less.

[0029] In this specification, "conversion rate" means the ratio (mol %) of the total molar amount of compounds other than fluoromethane compounds contained in the effluent gas from the reactor outlet (= reaction gas) to the molar amount of fluoromethane compounds supplied to the reactor.

[0030] As used herein, the term "selectivity" means the ratio (mol%) of the molar amount of the target compound (fluorinated organic compound) contained in the effluent gas from the reactor outlet to the total molar amount obtained by excluding the total molar amount of the fluoromethane compounds contained in the raw material gas from the total molar amount of compounds contained in the effluent gas (=reaction gas) from the reactor outlet, wherein the total molar amount of the fluoromethane compounds contained in the raw material gas is calculated in advance.

[0031] As used herein, "room temperature" can mean a temperature within the range of 10°C to 40°C.

[0032] As used herein, the term "fluoroethylene compound" is a general term for fluoroethylene in a broad sense, that is, ethylene compounds having one or more fluorine atoms.

[0033] As used herein, the term "fluoroethane compound" is a general term for fluoroethane in a broad sense, that is, ethane compounds having one or more fluorine atoms.

[0034] As used herein, the term "fluoromethane compound" is a general term for fluoromethane in a broad sense, that is, methane compounds having one or more fluorine atoms.

[0035] Unless otherwise specified, olefins herein include both E-isomers and Z-isomers.

[0036] 1. Method for producing reaction gas containing fluorinated organic compound The method for producing reaction gas containing fluorinated organic compound of the present disclosure comprises a coupling reaction step of supplying a raw material gas containing a fluoromethane compound to a group 8 to 11 transition metal catalyst.

[0037] 1-1. Reaction gas The reaction gas contains at least one fluorinated organic compound selected from the group consisting of fluoroethylene compounds and fluoroethane compounds.

[0038] The fluoroethylene compounds are not particularly limited as long as they can be synthesized by a coupling reaction using the source gas described later. Examples include fluoroethylene (R-1141), 1-chloro-1-fluoroethylene, (E)-1-chloro-2-fluoroethylene, (Z)-1-chloro-2-fluoroethylene, 1,1-difluoroethylene (R-1132a), (E)-1,2-difluoroethylene (R-1132(E)), (Z)-1,2-difluoroethylene (R-1132(Z)), 1-chloro-1,2-difluoroethylene, trifluoroethylene (R-1123), chlorotrifluoroethylene (R-1113), and tetrafluoroethylene (R-1114). In particular, as fluoroethylene compounds, 1,2-difluoroethylene (R-1132), i.e., (E)-1,2-difluoroethylene (R-1132(E)) and / or (Z)-1,2-difluoroethylene (R-1132(Z)), is preferred from the viewpoint of suppressing the formation of by-products, and (E)-1,2-difluoroethylene (R-1132(E)) is more preferred.

[0039] The fluoroethane compound is not particularly limited as long as it can be synthesized by a coupling reaction using the raw material gas described below. Examples thereof include fluoroethane (R-161), 1,1-difluoroethane (R-152a), 1,2-difluoroethane (R-152), 1-chloro-1,1-difluoroethane (R-142b), 1,1,2,2-tetrachloro-1,2-difluoroethane (R-112), 1,1,1-trifluoroethane (R-143a), 1,1,2-trifluoroethane (R-143), 1,1,2-trichloro-1,2,2-trifluoroethane (R-113), 1,1,1,2-tetrafluoroethane (R-134a), 1,2-dichloro-1,1,2,2-tetrafluoroethane (R-114), pentafluoroethane (R-125), chloropentafluoroethane (R-115), and the like. Among these, from the viewpoint of suppressing the generation of by-products, 1,1,1-trifluoroethane (R-143a), 1,1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143) are preferable as the fluoroethane compound, and 1,1,2,2-tetrafluoroethane (R-134) and 1,1,2-trifluoroethane (R-143) are more preferable.

[0040] In the first embodiment, the reaction gas preferably contains a fluoroethylene compound as the fluorinated organic compound, more preferably contains 1,2-difluoroethylene (R-1132), that is, (E)-1,2-difluoroethylene (R-1132 (E)) and / or (Z)-1,2-difluoroethylene (R-1132 (Z)), and even more preferably contains (E)-1,2-difluoroethylene (R-1132 (E)).

[0041] In the above embodiment, the reaction gas may contain a fluoroethane compound as the fluorinated organic compound in addition to the fluoroethylene compound. Specifically, the reaction gas may contain, as the fluorinated organic compound, 1,2-difluoroethylene (R-1132) and 1,1,2,2-tetrafluoroethane (R-134) and / or 1,1,2-trifluoroethane (R-143).

[0042] In the above embodiment, the reaction gas may further contain, in addition to the fluorinated organic compound, fluorinated organic compounds such as 1,1-difluoroethylene (R-1132a), 1,1,2-trifluoroethylene (R-1123), and 1,1,1-trifluoroethane (R-143a); and hydrocarbons such as n-hexane and cyclohexane.

[0043] In the second embodiment, the reaction gas preferably contains a fluoroethane compound as a fluorinated organic compound, and more preferably contains 1,1,2,2-tetrafluoroethane (R-134).

[0044] In the third embodiment, the reaction gas preferably contains a fluoroethane compound as the fluorinated organic compound, and more preferably contains 1,1,2-trifluoroethane (R-143).

[0045] The reaction gas may contain some of the source gas containing fluoromethane compounds.

[0046] The reaction gas in this disclosure may be used as a refrigerant as is, or the fluorinated organic compound may be diluted or concentrated before use. Alternatively, by increasing the content of (E)-1,2-difluoroethylene (R-1132(E)) and / or (Z)-1,2-difluoroethylene (R-1132(Z)) in the reaction gas in this disclosure, a composition with a higher content of (E)-1,2-difluoroethylene (R-1132(E)) and / or (Z)-1,2-difluoroethylene (R-1132(Z)) that is promising as a refrigerant can be obtained.

[0047] 1-2. The raw material gas used in the raw material gas coupling reaction process contains a fluoromethane compound.

[0048] The fluoromethane compound is not particularly limited as long as it can synthesize a reaction gas containing the above-mentioned fluorinated organic compound by coupling reaction. For example, at least one fluoromethane compound selected from the group consisting of fluoromethane (R-41), chlorofluoromethane (R-31), difluoromethane (R-32), and chlorodifluoromethane (R-22) can be mentioned. Among these, difluoromethane (R-32) is preferred as the fluoromethane compound from the viewpoint of suppressing the generation of by-products.

[0049] There are no particular limitations on the method for obtaining the raw material gas for the coupling reaction process, and a wide range of known methods can be employed.

[0050] The raw material gas may consist solely of a fluoromethane compound, or it may be a mixture of a fluoromethane compound and a gas other than a fluoromethane compound. Examples of gases other than fluoromethane compounds include the reaction gases mentioned above.

[0051] Furthermore, the raw material gas may be supplied to the reactor as is, or it may be diluted with an inert gas such as nitrogen, argon, or carbon dioxide before being supplied.

[0052] The content of the fluoromethane compound in the raw material gas is preferably 90% to 100% by volume, more preferably 95% to 100% by volume, and even more preferably 99% to 100% by volume. If the content of the fluoromethane compound in the raw material gas is within this range, the conversion rate of the fluoromethane compound and the selectivity of the desired fluorinated organic compound can be improved, and the selectivity of carbon in the reaction gas can be suppressed.

[0053] The raw material gas is particularly preferably 100% by volume of difluoromethane (R-32). This makes it possible to improve both the conversion rate of R-32 and the selectivity of R-1132(E) while suppressing the generation of by-products associated with the thermal decomposition reaction, and also suppressing the selectivity of carbon in the reaction gas.

[0054] When the raw material gas contains an inert gas, the inert gas content is preferably 1% to 99% by volume relative to 100% by volume of the raw material gas.

[0055] The raw material gas preferably contains substantially no water vapor, and more preferably contains no water vapor. The water vapor content in the raw material gas is preferably 1 volume% or less, more preferably 0.1 volume% or less, even more preferably 0.01 volume%, and particularly preferably 0 volume%. The lower the water vapor content in the raw material gas, the better; no lower limit is particularly set, but for example, it can be less than 0.1 volume ppm or less than 1 volume ppm.

[0056] 1-3. Group 8 to Group 11 Transition Metal Catalysts In the method for producing a reaction gas containing a fluorinated organic compound according to the present disclosure, the above-mentioned raw material gas is supplied to a Group 8 to Group 11 transition metal catalyst (hereinafter sometimes simply referred to as "catalyst").

[0057] The Group 8 to Group 11 transition metal catalyst is not particularly limited as long as it can synthesize a reaction gas containing the above-mentioned fluorinated organic compound by coupling reaction, and can broadly include transition metals from Group 8 to Group 11. From the viewpoint of improving the yield of the above-mentioned fluorinated organic compound, the catalyst preferably contains at least one noble metal selected from the group consisting of palladium (Pd), ruthenium (Ru), platinum (Pt), rhodium (Rh), iridium (Ir), gold (Au), and silver (Ag).

[0058] From the viewpoint of improving the yield of the fluorinated organic compound, the catalyst (especially the precious metal catalyst) preferably contains a precious metal alloy including the above-mentioned precious metal, i.e., at least one precious metal alloy selected from the group consisting of palladium alloy, ruthenium alloy, platinum alloy, rhodium alloy, iridium alloy, gold alloy, and silver alloy. Among these, a palladium alloy is more preferable from the viewpoint of improving the yield of the fluorinated organic compound.

[0059] Catalysts (especially precious metal catalysts) may contain metals other than precious metals. These non-precious metals are not particularly limited and include, for example, iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu).

[0060] A precious metal alloy may be an alloy composed of two or more precious metals, or an alloy composed of one or more precious metals and a non-precious metal. Examples of precious metal alloys, though not particularly limited, include PdPt alloys, PdCo alloys, PdNi alloys, PdFe alloys, PdAu alloys, PdAg alloys, PdZr alloys, PdRu alloys, PtRu alloys, RuCo alloys, RuNi alloys, RuFe alloys, RuRh alloys, RuPt alloys, etc.

[0061] From the viewpoint of improving the yield of the above-mentioned fluorinated organic compound, the catalyst is preferably a supported catalyst that is supported on a carrier.

[0062] Examples of support materials include carbon supports such as activated carbon, amorphous carbon, graphite, and diamond; and alumina (Al ２ O ３ ), Zirconia (ZrO ２ ), silica (SiO ２ ), Titania (TiO ２ ), Celia (CeO ２ Examples include ceramic supports such as zinc (ZnO) and polydimethylsilane.

[0063] From the viewpoint of mixing efficiency when used in the reaction, the amount of catalyst supported on the support is preferably 0.05% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to the mass of the support. Furthermore, from the viewpoint of the size of the supported nanoparticles, the amount of catalyst supported is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the mass of the support.

[0064] The catalyst can be used individually or in combination of two or more types.

[0065] Catalysts (especially precious metal catalysts) can be prepared, for example, by impregnation. An example of a method for preparing the Group 8 to Group 11 transition metal catalysts of this disclosure is shown below.

[0066] (Metal-supported) A test tube containing a magnetic stirring bar is placed in a magnetic stirrer (manufactured by Tokyo Rikakikai Co., Ltd.). Alumina (0.8 g) (manufactured by Merck) and PdCl2 (41.7 g) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) are added to the test tube, and then 10 ml of 0.08 mol / L hydrochloric acid (manufactured by Kanto Chemical Co., Ltd.) is added dropwise, and the mixture is stirred for 72 hours. After decanting the stirred solution, the precipitate (A) is washed three times with water (10 mL). (Methanol reduction) 50 ml of methanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) is added to the washed precipitate (A), and reflux is performed for 45 minutes using a magnetic stirrer (manufactured by Tokyo Rikakikai Co., Ltd.). After that, the precipitate is collected and dried in a vacuum. (Hydrazine Reduction) Prepare a hydrazine aqueous solution by diluting 0.5 ml of 80% hydrazine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in 25 ml of distilled water in a test tube, and add the washed precipitate (A) to it. Place the test tube in a magnetic stirrer (manufactured by Tokyo Rikakikai Co., Ltd.) and heat at 60°C for 10 minutes while stirring. After that, collect the precipitate and dry it in a vacuum.

[0067] The particle size of the catalyst is preferably 10 nm or less.

[0068] From the viewpoint of improving the yield of fluorinated organic compounds, it is preferable to subject the catalyst to an activation treatment before the coupling reaction step. The activation treatment may involve pre-treating the catalyst with a reducing agent, or pre-treating the catalyst with the above-mentioned raw material gas. Known methods can be used for the treatment method when subjecting the catalyst to the activation treatment. The temperature at which the catalyst is subjected to the activation treatment (activation temperature) is not particularly limited and may be, for example, room temperature or a high temperature. The activation temperature is not general and depends on the type of catalyst and treatment agent, pressure, etc., but is preferably 200°C to 450°C, and more preferably 300°C to 400°C.

[0069] Reducing agents include reducing gases such as hydrogen gas, alcohol gases (e.g., methanol, ethanol, isopropanol, etc.), carbon monoxide gas, methane gas, ethane gas, halogenated methane gas, halogenated ethane gas, and ammonia gas; and reducing liquids such as sodium borohydride, lithium aluminum hydride, hydrazine, hydroxylamine, catechol, hydroquinone, ascorbic acid, and oxalic acid.

[0070] 1-4. Coupling Reaction Process In the method for producing a reaction gas containing a fluorinated organic compound according to this disclosure (hereinafter sometimes simply referred to as the "production method"), a solid-phase catalyst mediates a coupling reaction involving the formation of carbon-carbon bonds in a gaseous substrate. In the coupling reaction, a reaction gas containing the fluorinated organic compound is generated on the catalyst surface from a raw material gas containing the fluoromethane compound via dehydrofluoric acid, dehydrogenation, hydrogenation, carbon-carbon bond formation reactions, etc.

[0071] In the manufacturing method of this disclosure, by subjecting the raw material gas to the coupling reaction at a temperature of less than 750°C (reaction temperature), it is possible to produce a reaction gas containing a fluorinated organic compound with good selectivity while suppressing thermal decomposition. Preferably, the manufacturing method of this disclosure can produce a reaction gas containing a fluorinated organic compound with good selectivity without substantially involving thermal decomposition. Conventional techniques that utilize thermal decomposition reactions are industrially disadvantageous because the by-products generated by thermal decomposition lead to a decrease in yield, and the costs of constructing and repairing equipment that can withstand harsh conditions, as well as the manufacturing costs for heating, are high. In contrast, the manufacturing method of this disclosure is industrially advantageous because it can produce a reaction gas containing a fluorinated organic compound at a relatively low cost.

[0072] In the manufacturing method of this disclosure, the reaction temperature is preferably less than 750°C. By setting the reaction temperature within this range, it is possible to produce a reaction gas containing a fluorinated organic compound with good selectivity while suppressing the thermal decomposition reaction.

[0073] In the manufacturing method of the present disclosure according to the first embodiment, the reaction temperature is preferably 0°C or higher and less than 700°C, more preferably 200°C to 600°C, and even more preferably 300°C to 500°C. By setting the reaction temperature within this range, it is easy to produce a reaction gas containing a fluorinated organic compound with good selectivity while suppressing the thermal decomposition reaction.

[0074] In the manufacturing method of the present disclosure according to the second embodiment, the reaction temperature is preferably 200°C or more and less than 400°C, more preferably 210°C to 350°C, and even more preferably 220°C to 330°C. By setting the reaction temperature within this range, it is easy to produce a reaction gas containing a fluorinated organic compound with good selectivity while suppressing the thermal decomposition reaction.

[0075] In the third embodiment of the present invention, the reaction temperature is preferably 400°C to 700°C, more preferably 410°C to 600°C, and even more preferably 420°C to 550°C. By setting the reaction temperature within this range, it is easy to produce a reaction gas containing a fluorinated organic compound with good selectivity while suppressing the thermal decomposition reaction.

[0076] Known methods can be used to heat the raw material gas when supplying it to the above reaction. These include heating the reactor (reaction vessel) in an electric furnace, heating the reactor with an electric heater or a jacket through which a heat transfer medium flows, heating the reactor with microwaves, and heating the inert gas as a diluent and then mixing it with fluoromethanes. If necessary, the raw material gas may be preheated to an arbitrary temperature before supplying it.

[0077] The pressure at which the raw material gas is supplied to the above reaction (reaction pressure) is preferably 0 MPaG to 1.0 MPaG (gauge pressure). By setting the pressure within this range, both the conversion rate of fluoromethane compounds and the selectivity of fluorinated organic compounds can be improved.

[0078] The time (residence time) during which the raw material gas is subjected to the above reaction can be appropriately adjusted depending on the type of fluoromethane compound, reaction temperature, reaction pressure, etc.

[0079] The form of the reactor used to supply the raw material gas to the above reaction is not particularly limited, and any known reactor capable of withstanding the above reaction temperature and pressure can be widely used.

[0080] In one embodiment, the coupling reaction step is preferably carried out in a continuous gas-phase flow manner using a (tubular) reactor containing a catalyst. Carrying the reaction in a continuous gas-phase flow manner is economically advantageous because it simplifies the equipment and operation. When carrying out the reaction in a continuous manner, it is more preferable, for example, to supply the raw material gas to a reactor filled with catalyst, set the heater or cooler to an appropriate reaction temperature, and allow the reaction to proceed for a certain period of time. As the reactor, a multi-tube reactor or the like, which uses a heat transfer medium to remove heat and / or equalize the temperature distribution inside the reactor, can be used as needed.

[0081] Furthermore, when carrying out the reaction in a continuous manner, it is preferable to connect the reactor to a deoxidation tower filled with alkali (e.g., soda lime) and a dehydration tower filled with a dehydrating agent (e.g., calcium chloride), and to supply the reaction gas to the deoxidation tower and dehydration tower after the reaction. In this case, hydrofluoric acid and water can be continuously removed from the reaction gas after the coupling reaction step.

[0082] In the above embodiment, the coupling reaction step can be carried out in a continuous reactor to produce a reaction gas containing a fluorinated organic compound with good selectivity. The coupling reaction step can also be carried out in a flow-through manner, in which raw materials are continuously fed into a catalyst-filled reactor and the target compound is continuously withdrawn from the reactor. By using a continuous reactor, the purification process can also be made continuous, thereby improving the efficiency of the production equipment. For example, by using a distillation column together with a continuous reactor in the purification process, it becomes possible to carry out the reaction and purification continuously.

[0083] Specifically, it is preferable to use a reactor made of a material that is resistant to corrosion, such as Hastelloy®, Inconel, Monel, Incoloy, or stainless steel (SUS316, etc.).

[0084] In another embodiment, the coupling reaction step can be carried out in a batch manner using a pressure-resistant reaction vessel containing a catalyst. When carrying out the reaction in a batch manner, it is preferable to supply the raw material gas to a reactor (such as an autoclave) filled with a catalyst, supply alkali and / or a dehydrating agent as needed, set the heater or cooler to an appropriate reaction temperature, and react for a certain period of time under stirring. It is preferable to use a reactor made of a material resistant to the corrosive action described above.

[0085] The catalyst-filled reactor can be a fixed-bed or fluidized-bed reactor filled with catalyst, and catalysts in the form of pellets, powder, or fluid can be used.

[0086] 1-5. The reaction gas in the purification process can be subjected to a purification process as appropriate to increase the purity of the desired fluorinated organic compound and extract it.

[0087] As for purification methods, well-known purification methods such as distillation and extractive distillation can be widely used.

[0088] 1-6. Recycling Process In the manufacturing method disclosed herein, it is preferable to have a recycling process 1 (recycling process) in which part or all of the reaction gas obtained in the above process is resupplied (recycled) to the reactor (catalyst) in order to recover the reaction gas in which the proportion of fluorinated organic compounds is increased.

[0089] The manufacturing method of the present disclosure preferably includes a step of recycling part or all of the reaction gas containing the fluorinated organic compound into the coupling reaction after the coupling reaction step or after the purification step. Specifically, the reaction gas containing the fluorinated organic compound can be produced by supplying the fluoromethane compound and / or the fluorinated organic compound to the reactor (catalyst) again. By recycling the reaction gas in this way, a reaction gas with a higher content of the fluorinated organic compound (particularly 1,2-difluoroethylene (R-1132)) can be obtained.

[0090] Furthermore, in the manufacturing method of the present disclosure, it is preferable to have a circulation step 2 (pretreatment step) in which part or all of the raw material gas is pre-supplied to the reactor (catalyst) before the above step in order to recover a reaction gas in which the proportion of fluorinated organic compounds is higher.

[0091] In the manufacturing method of the present disclosure, preferably, a step is included in which the catalyst is pretreated with part or all of the raw material gas containing a fluoromethane compound before the coupling reaction step. Specifically, the catalyst can be activated by supplying the fluoromethane compound to the reactor (catalyst) in advance, and then the coupling reaction step can be carried out. By using the catalyst in this activated state, a reaction gas with a higher content of fluorinated organic compounds (particularly 1,2-difluoroethylene (R-1132)) can be obtained.

[0092] 2. Catalytic Reactor In one embodiment, the catalytic reactor of the present disclosure (particularly the automated catalytic reactor) preferably comprises: a reactor containing the above-mentioned Group 8 to Group 11 transition metal catalyst; a supply port for supplying the above-mentioned raw material gas to the reactor; and an outlet for discharging the above-mentioned reaction gas from the reactor. The catalytic reactor of the present disclosure is useful as a device for coupling reactions of fluoromethane compounds and is preferably used in the above-described manufacturing method.

[0093] An example of the catalytic reaction apparatus in the above embodiment is shown in Figure 1.

[0094] In Figure 1, the catalytic reactor comprises a reactor containing a transition metal catalyst from Group 8 to Group 11. The reactor includes a supply port for raw material gas and an outlet for discharge of reaction gas. The catalytic reactor may optionally include an electric furnace (heater) for appropriately adjusting the reactor temperature, a ball valve and back pressure valve for adjusting the flow rate and reaction pressure, and a deoxidation tower and a dehydration tower. The deoxidation tower and dehydration tower are connected to the supply port.

[0095] Furthermore, the catalytic reactor of the present disclosure preferably further includes a circulation path for resupplying part or all of the reaction gas to the Group 8 to 11 transition metal catalyst. Specifically, the catalytic reactor preferably includes a reactor containing the Group 8 to 11 transition metal catalyst, a supply port for supplying the raw material gas to the reactor, an outlet for discharging the reaction gas from the reactor, and a circulation path for resupplying all or part of the reaction gas discharged from the outlet to the supply port.

[0096] An example of the catalytic reaction apparatus in the above embodiment is shown in Figure 3.

[0097] In Figure 3, the catalytic reactor, in addition to the configuration shown in Figure 1, includes a circulation path that resupplies all or part of the reaction gas to the reactor (supply port).

[0098] In the above embodiment, the circulation path may also pre-supply part or all of the raw material gas to the reactor (catalyst) before the coupling reaction step in order to recover a reaction gas with a higher proportion of fluorinated organic compounds.

[0099] 3. Activated Catalyst The Group 8 to Group 11 transition metal catalysts of this disclosure are preferably activated catalysts. The activated catalysts of this disclosure are useful as catalysts for coupling reactions of fluoromethane compounds and are preferably used in the above-described manufacturing method.

[0100] As Group 8 to Group 11 transition metal catalysts, the catalysts exemplified in "1-3. Group 8 to Group 11 Transition Metal Catalysts" can be used. In particular, noble metal alloy catalysts are preferred as Group 8 to Group 11 transition metal catalysts to be used in the activation treatment.

[0101] An activated catalyst according to the first embodiment of the present disclosure can be obtained by treating a group 8 to 11 transition metal catalyst with a gas containing a fluoromethane compound.

[0102] The activated catalyst of the present disclosure according to a second embodiment can be obtained by treating a group 8 to 11 transition metal catalyst with a reducing gas other than a fluoromethane compound. Examples of reducing gases include hydrogen gas, alcohol gas (e.g., methanol, ethanol, isopropanol, etc.), carbon monoxide gas, methane gas, ethane gas, halogenated methane gas, halogenated ethane gas, ammonia gas, and the like.

[0103] An activated catalyst according to a third aspect of the present disclosure can be obtained by treating a group 8 to 11 transition metal catalyst with a reducing liquid. Examples of reducing liquids include sodium borohydride, lithium aluminum hydride, hydrazine, hydroxylamine, catechol, hydroquinone, ascorbic acid, and oxalic acid.

[0104] The method for producing the activated catalyst (Group 8-11 transition metal catalyst) according to this disclosure is not particularly limited, as long as it includes an activation step of treating the Group 8-11 transition metal catalyst with a gas containing a fluoromethane compound, a reducing gas, or a reducing liquid. Known methods can be used to treat the catalyst using these treatment agents.

[0105] The temperature at which the catalyst is subjected to the activation treatment (activation temperature) is not particularly limited and may be, for example, room temperature or a high temperature. The activation temperature is not uniform and depends on the type of catalyst and treatment agent, pressure, etc., but is preferably 200°C to 450°C, and more preferably 300°C to 400°C.

[0106] While embodiments of this disclosure have been described above, this disclosure is not limited to these examples and can be implemented in various forms without departing from the gist of this disclosure.

[0107] The embodiments of this disclosure will be described in more detail below based on the examples, but this disclosure is not limited to these examples.

[0108] [Production Examples 1 to 4 (Procedure for Preparing Catalyst)] Production Example 1 (PdNi / alumina) The catalyst of Production Example 1 was produced by the following method. A test tube containing a magnetic stirring bar was placed on a magnetic stirrer (manufactured by Tokyo Rikakikai Co., Ltd.). Alumina (0.8 g) (manufactured by Merck KGaA), PdCl ２ (41.7 g) (manufactured by Fujifilm Wako Pure Chemical Corporation), NiCl ２ (57.1 g) (manufactured by Fujifilm Wako Pure Chemical Corporation) were added, then 10 mL of hydrochloric acid with a concentration of 0.08 mol / L (manufactured by Kanto Chemical Co., Inc.) was added dropwise, and the mixture was stirred for 72 hours. After decantation of the stirred solution, the precipitate was washed 3 times with water (10 mL). 50 mL of methanol (manufactured by Fujifilm Wako Pure Chemical Corporation) was added to the washed precipitate, and the mixture was refluxed for 45 minutes using a magnetic stirrer (manufactured by Tokyo Rikakikai Co., Ltd.). Thereafter, the precipitate was collected and dried in vacuum to obtain the catalyst PdNi / alumina.

[0109] Production Example 2 (PdCo / alumina) Except that NiCl ２ was changed to CoCl ２ (57.1 g), the catalyst PdCo / alumina was produced in the same manner as in Production Example 1.

[0110] Production Example 3 (PdFe / alumina) Except that NiCl ２ was changed to FeCl ２ (30.4 g), the catalyst PdFe / alumina was produced in the same manner as in Production Example 1.

[0111] Production Example 4 (PtAu / alumina) Except that PdCl ２ and NiCl ２ were changed to PtCl ２ (63.8 g) and HAuCl ４ (98.8 g), the catalyst PtAu / alumina was produced in the same manner as in Production Example 1.

[0112] In addition to the above catalysts, a 2% Pd / alumina spherical catalyst (NE Chemcat Corporation), a 2% Pd / carbon catalyst (NE Chemcat Corporation), a 0.5% Ru / alumina pellet catalyst (NE Chemcat Corporation), and a 0.5% Rh / alumina pellet catalyst (NE Chemcat Corporation) were purchased and used.

[0113] (Gas Chromatography GCMS) In the following Examples 1 to 3, the composition of the reaction gas was analyzed using a gas chromatograph NEXIS GC-2030 (Shimadzu Corporation). A GCMS-QP2020NX (Shimadzu Corporation) MS detector was used to detect each component. A PoraPLOT Q column (length: 50 m, inner diameter: 0.32 mm, film thickness: 10 μm; Agilent Technologies) was used as the column.

[0114] [Example 1 (Embodiment 1: Continuous type with pretreatment)] Example 1-1 Figure 1 shows the automatic catalyst reactor used in this experiment. An F-201CL (Bronkost Corporation) was used as a flow meter, a PGI-50M-MG5.0 (Swagelok Corporation) as a pressure gauge, an ARF20KC (Asahi Rika Seisakusho Co., Ltd.) as an electric furnace, a stainless steel pipe with an outer diameter of 1 / 8 inch as piping, and difluoromethane (R-32) (manufactured by Daikin Industries, Ltd.) as the fluoromethane compound used as the raw material. For the reactor (reaction tube), the material was Hastelloy® C276, the inner diameter was 7.53 mm, and the catalyst installed inside the reaction tube was heated by covering the outside with an electric furnace. The reaction gas after the coupling reaction was to pass through a deoxidation tower filled with soda lime (medium granular; Fujifilm Wako Pure Chemical Corporation) and a dehydration tower filled with calcium chloride (Fujifilm Wako Pure Chemical Corporation) to remove hydrofluoric acid and water.

[0115] 1.5 g of a 2% Pd / alumina ball catalyst was used as the catalyst. Difluoromethane (R-32), the raw material, was supplied to the reactor at a flow rate of 10 ml / min. The pressure was adjusted to 0.6 MPa by operating the back pressure valve, and the catalyst in the reaction tube was pretreated by heating it at a reaction tube temperature of 450°C for more than 3 hours. After that, the heating was stopped and the temperature in the reaction tube was lowered to room temperature (approximately 20°C). The temperature in the reaction tube was heated again to 360°C, and the raw material gas, difluoromethane (R-32), was passed through for 1 hour. The reaction gas was then collected from the exhaust port using a 2 ml glass syringe. The same procedure was performed at 20°C intervals from 380°C to 520°C, and the changes in the reaction products were investigated.

[0116] The reaction gas contained fluorinated organic compounds: trans-1,2-difluoroethylene (R-1132(E)), cis-1,2-difluoroethylene (R-1132(Z)), 1,1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143). The selectivity of these fluorinated organic compounds in the reaction gas increased with increasing catalyst temperature (Figure 2).

[0117] In addition to the compounds mentioned above, the reaction gas also contained by-products such as chlorodifluoromethane (R-22), trifluoromethane (R-23), chlorofluoromethane (R-31), chloromethane (R-40), fluoromethane (R-41), 1-fluoroethane (R-161), 1,1,1-trifluoroethane (R-143a), 1,1-difluoroethane (R-152a), and dimethyl ether.

[0118] Example 1-2 A reaction gas containing 1,2,2-tetrafluoroethane (R-134) and 1,1,2-trifluoroethane (R-143) was produced in the same manner as in Example 1-1, except that the catalyst was replaced with a 2% Pd / carbon catalyst (Figure 2). Although the formation of trans-1,2-difluoroethylene (R-1132(E)) and cis-1,2-difluoroethylene (R-1132(Z)) was not observed in the temperature range of this experiment, the coupling reaction was able to occur by using a Pd / carbon catalyst.

[0119] In Example 1-3, a reaction gas containing trans-1,2-difluoroethylene (R-1132(E)), cis-1,2-difluoroethylene (R-1132(Z)), 1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143) was produced in the same manner as in Example 1-1, except that the catalyst was replaced with a 0.5% Ru / alumina catalyst (Figure 2).

[0120] In Example 1-4, a reaction gas containing trans-1,2-difluoroethylene (R-1132(E)), cis-1,2-difluoroethylene (R-1132(Z)), 1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143) was produced in the same manner as in Example 1-1, except that the catalyst was replaced with a 0.5% Rh / alumina catalyst (Figure 2).

[0121] [Example 2 (Embodiment 2: Continuous type with recycling)] Example 2-1 Figure 3 shows the catalytic automatic reaction apparatus used in this experiment. This apparatus is the same as the apparatus shown in Figure 1, but with the addition of a circulation path N86 pump (flow rate: maximum 6.5 l / min, operating pressure: maximum 2.5 bar; KNF Corporation) that resupplies (recycles) the reaction gas back into the reaction tube.

[0122] 1.5 g of 2% Pd alumina ball catalyst was used as the catalyst. Difluoromethane (R-32), the raw material, was flowed into the reactor at a flow rate of 200 ml / min. The pressure was adjusted to a range of 0.1 MPa to 0.2 MPa by operating the back pressure valve, and the temperature inside the reaction tube was set to 325°C. Then, the pump in the circulation path was operated in a range of 200 ml / min to 300 ml / min, and the reaction gas that had come out of the reaction tube was circulated back into the reaction tube by adjusting the valves near the supply port and exhaust port. The discharged reaction gas was collected at predetermined time intervals starting immediately after the start of circulation.

[0123] The reaction gas contained the fluorinated organic compounds trans-1,2-difluoroethylene (R-1132(E)) and cis-1,2-difluoroethylene (R-1132(Z)). Figure 4 shows the amount of fluorinated organic compounds produced in the reaction gas.

[0124] [Example 3 (Embodiment 3: Batch Method)] Example 3-1 Using PdNi / alumina (Production Example 1) as a catalyst, a reaction gas containing a fluorinated organic compound was obtained by supplying a raw material gas containing a fluoromethane compound to the catalyst in a batch manner at room temperature. Specifically, 0.5 g of catalyst and 3 g of soda lime were placed inside a 100 cc portable reactor (Pressure Glass Industry) equipped with a pressure gauge, and after closing the reactor, degassing was performed using a vacuum pump. Then, 100% difluoromethane (R-32) raw material gas was filled into the reactor at a pressure of 0.6 MPa, and the reaction was started at room temperature (approximately 20°C). After a predetermined time had elapsed, the reaction gas was collected from the exhaust port using a 2 ml glass syringe.

[0125] The reaction gas contained trifluoroethane (R-143), a fluorinated organic compound (Table 1).

[0126] Example 3-2 A reaction gas containing cis-1,2-difluoroethylene (R-1132(Z)) and trifluoroethane (R-143) was prepared in the same manner as in Example 3-1, except that the catalyst was replaced with PdCo / alumina (Production Example 2) (Table 1).

[0127] Example 3-3 A reaction gas containing trifluoroethane (R-143) was prepared in the same manner as in Example 3-1, except that the catalyst was replaced with PdFe / alumina (Production Example 3) (Table 1).

[0128] Example 3-4 A reaction gas containing trifluoroethane (R-143) was prepared in the same manner as in Example 3-1, except that the catalyst was replaced with PtAu / alumina (Production Example 4) (Table 1).

[0129]

[0130] Comparative Example 1: The catalytic reactor was operated in the same manner as in Example 1-1, except that no catalyst was used and the reaction temperature range was set to 400°C to 520°C. However, without a catalyst, neither the coupling reaction nor the thermal decomposition reaction proceeded, and no fluorinated organic compound was obtained (Table 2).

[0131]

Claims

1. A method for producing a reaction gas containing at least one fluorinated organic compound selected from the group consisting of fluoroethylene compounds and fluoroethane compounds, comprising a coupling reaction step of supplying a raw material gas containing a fluoromethane compound to a group 8 to 11 transition metal catalyst.

2. The production method according to claim 1, wherein the reaction gas comprises at least one fluorinated organic compound selected from the group consisting of 1,2-difluoroethylene (R-1132), 1,1,2,2-tetrafluoroethane (R-134), and 1,1,2-trifluoroethane (R-143).

3. The production method according to claim 1 or 2, wherein the raw material gas comprises at least one fluoromethane compound selected from the group consisting of fluoromethane (R-41), chlorofluoromethane (R-31), difluoromethane (R-32), and chlorodifluoromethane (R-22).

4. The manufacturing method according to any one of claims 1 to 3, wherein the Group 8 to Group 11 transition metal catalyst comprises at least one precious metal selected from the group consisting of palladium (Pd), ruthenium (Ru), platinum (Pt), rhodium (Rh), iridium (Ir), gold (Au), and silver (Ag).

5. The manufacturing method according to any one of claims 1 to 4, wherein the Group 8 to 11 transition metal catalyst includes a noble metal alloy.

6. The manufacturing method according to any one of claims 1 to 5, wherein the group 8 to 11 transition metal catalyst is supported on a carrier.

7. The method for producing a product according to any one of claims 1 to 6, wherein the reaction gas comprises at least one fluorinated organic compound selected from the group consisting of 1,2-difluoroethylene (R-1132) and 1,1,2-trifluoroethane (R-143), the raw material gas comprises at least one fluoromethane compound selected from the group consisting of fluoromethane (R-41), chlorofluoromethane (R-31), difluoromethane (R-32), and chlorodifluoromethane (R-22), and the group 8 to group 11 transition metal catalyst comprises at least one precious metal selected from the group consisting of palladium (Pd), ruthenium (Ru), platinum (Pt), rhodium (Rh), iridium (Ir), gold (Au), and silver (Ag).

8. The manufacturing method according to any one of claims 1 to 7, wherein the coupling reaction step is carried out at a temperature of less than 750°C.

9. The manufacturing method according to any one of claims 1 to 8, wherein the coupling reaction step is carried out at a temperature of 200°C or higher and less than 400°C.

10. The manufacturing method according to any one of claims 1 to 8, wherein the coupling reaction step is carried out at a temperature of 400°C or higher and 700°C or lower.

11. A group 8 to 11 transition metal catalyst used in the manufacturing method described in any one of claims 1 to 10.

12. A catalytic reactor for use in the manufacturing method described in any one of claims 1 to 10, comprising: a reactor containing the Group 8 to 11 transition metal catalyst; a supply port for supplying the raw material gas to the reactor; and a discharge port for discharging the reaction gas from the reactor.

13. The catalytic reaction apparatus according to claim 12, further comprising a circulation path for resupplying all or part of the reaction gas discharged from the outlet to the supply port.

14. A method for producing an activated catalyst, comprising an activation step of treating a Group 8 to Group 11 transition metal catalyst with a gas containing a fluoromethane compound, a reducing gas, or a reducing liquid.

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