Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
  • B01J21/02—Boron or aluminium; Oxides or hydroxides thereof
  • B01J21/04—Alumina
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J35/64—Pore diameter
  • B01J35/647—2-50 nm
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
  • C07B61/00—Other general methods
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/25—Preparation of halogenated hydrocarbons by splitting-off hydrogen halides from halogenated hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C21/00—Acyclic unsaturated compounds containing halogen atoms
  • C07C21/02—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds
  • C07C21/18—Acyclic unsaturated compounds containing halogen atoms containing carbon-to-carbon double bonds containing fluorine

Definitions

• the present disclosure relates to compositions, systems, containers containing the compositions, and methods for producing the compositions.
• Patent Document 1 describes a composition comprising trifluoroethylene and at least one first compound selected from the group consisting of E-1,2-difluoroethylene, Z-1,2-difluoroethylene, 1,1-difluoroethylene, chlorotrifluoroethylene, 1-chloro-2,2-difluoroethylene, E-1-chloro-1,2-difluoroethylene, Z-1-chloro-1,2-difluoroethylene, 1,1,2-trifluoroethane, and methane.
• first compound selected from the group consisting of E-1,2-difluoroethylene, Z-1,2-difluoroethylene, 1,1-difluoroethylene, chlorotrifluoroethylene, 1-chloro-2,2-difluoroethylene, E-1-chloro-1,2-difluoroethylene, Z-1-chloro-1,2-difluoroethylene, 1,1,2-trifluoroethane, and methane.
• Patent Document 2 describes a method for producing trifluoroethylene, which comprises contacting 1,1,1,2-tetrafluoroethane gas or 1,1,1,2-tetrafluoroethane gas diluted with a diluent gas (wherein the ratio of 1,1,1,2-tetrafluoroethane to the total amount of the diluent gas and 1,1,1,2-tetrafluoroethane is 50 mol % or more) with a first dehydrofluorination catalyst to convert a portion of the 1,1,1,2-tetrafluoroethane to trifluoroethylene, removing hydrogen fluoride from a reaction product gas obtained by the reaction, and then contacting the reaction product gas from which hydrogen fluoride has been removed with a second dehydrofluorination catalyst to convert at least a portion of the 1,1,1,2-tetrafluoroethane to trifluoroethylene.
• compositions containing trifluoroethylene (HFO-1123), there are cases where it is required to reduce the content of the impurity 1,1,1-trifluoroethane (HFC-143a) and suppress the generation of acid.
• An object of one embodiment of the present invention is to provide a composition containing HFO-1123, which has a low content of HFC-143a contained as an impurity and in which generation of acid is suppressed, and a method for producing the composition.
• Another object of the present invention is to provide a system including the composition, and a container containing the composition.
• a composition comprising trifluoroethylene the composition further comprises 1,1,1-trifluoroethane and 1,1,3,3,3-pentafluoropropene; Does not contain 1-chloro-2,2-difluoroethylene, (E)-1-chloro-1,2-difluoroethylene, or (Z)-1-chloro-1,2-difluoroethylene;
• the content of 1,1,1-trifluoroethane is 0.1% by mass or less based on the total amount of the composition
• the content of 1,1,3,3,3-pentafluoropropene is 0.5 mass% or less based on the total amount of the composition.
• composition according to ⁇ 1> further comprising at least one selected from the group consisting of trifluoromethane, vinylidene fluoride, (E)-1,2-difluoroethylene, difluoromethane, (E)-1,3,3,3-tetrafluoropropene, and 1,1,2,2-tetrafluoroethane.
• composition according to ⁇ 1> further comprising trifluoromethane, vinylidene fluoride, (E)-1,2-difluoroethylene, difluoromethane, and 1,1,2,2-tetrafluoroethane.
• ⁇ 7> ⁇ 6> A system comprising the composition according to any one of ⁇ 1> to ⁇ 6> and a contact member having at least a part of a surface that comes into contact with the composition and is made of a metal.
• ⁇ 8> ⁇ 6> A container including the composition according to any one of ⁇ 1> to ⁇ 6> and a contact member having at least a part of a surface thereof that comes into contact with the composition and is made of a metal; A container containing the composition, the container being sealed in a state in which the composition is contained.
• a method for producing a composition comprising contacting 1,1,1,2-tetrafluoroethane with a catalyst containing ⁇ -alumina to produce the composition according to any one of ⁇ 1> to ⁇ 6>.
• a composition containing HFO-1123 which has a low content of HFC-143a contained as an impurity and suppresses the generation of acid, and a method for producing the composition.
• a system comprising the composition, and a container containing the composition.
• a numerical range indicated using “to” means a range that includes the numerical values before and after “to” as the minimum and maximum values, respectively.
• the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in the present disclosure.
• the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.
• a combination of two or more preferred aspects is a more preferred aspect.
• the amount of each component means the total amount of multiple substances, unless otherwise specified.
• the statement that "the composition does not contain a specific component” means that the content of the specific component in the composition is less than 1.0 ppm when the content of the specific component is measured using gas chromatography.
• the measurement is performed by the following method: All samples to be analyzed are in a gaseous state.
• a gas chromatograph product name "Gas Chromatograph 6890 Series", manufactured by Agilent
• a column product name "DB-1", length 60 m, diameter 250 ⁇ m, filter thickness 1 ⁇ m)
• a data system product name "OpenLab”, manufactured by Agilent
• the measurement conditions are as follows.
• Carrier gas Helium Injection temperature: 240°C Sample injection volume: 0.5 mL Split ratio: 60/1 Linear velocity: 35.9 cm/sec. Start of measurement: Temperature -30°C, holding time 10 minutes. Heating rate: 10°C/min. End of measurement: Temperature 240°C, holding time 20 minutes. Detection temperature: 250°C.
• composition of the present disclosure is a composition comprising HFO-1123, the composition further comprising HFC-143a and 1,1,3,3,3-pentafluoropropene (HFO-1225zc), and does not comprise 1-chloro-2,2-difluoroethylene (HCFO-1122), (E)-1-chloro-1,2-difluoroethylene (HCFO-1122a(E)), and (Z)-1-chloro-1,2-difluoroethylene (HCFO-1122a(Z)), the content of HFC-143a being 0.1 mass% or less, based on the total amount of the composition, and the content of HFO-1225zc being 0.5 mass% or less, based on the total amount of the composition.
• the content of the impurity HFC-143a is low, at 0.1 mass% or less relative to the total amount of the composition.
• HFC-143a has a high 100-year Global Warming Potential (GWP) of 5810, as described in the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC). Therefore, a low content of the impurity HFC-143a can, for example, lower the GWP.
• GWP Global Warming Potential
• AR6 Sixth Assessment Report
• IPCC Intergovernmental Panel on climate Change
• a low content of the impurity HFC-143a can, for example, lower the GWP.
• HFC-143a and HFO-1123 have similar boiling points, it is difficult to completely separate HFC-143a and HFO-1123 by refining, and a low content of the impurity HFC-143a is advantageous for subsequent use.
• composition of the present disclosure does not contain HCFO-1122, HCFO-1122a(E), or HCFO-1122a(Z), it is possible to suppress the generation of acids that accompany the elimination of chlorine atoms. In addition, by suppressing the generation of acids, corrosion is less likely to occur when the composition of the present disclosure is in contact with metals for a long period of time.
• HFO-1225zc is produced as an impurity.
• HFO-1225zc forms an azeotropic composition with hydrogen fluoride, so if the content of HFO-1225zc is high, for example, it becomes difficult to separate hydrogen fluoride produced due to the production of HFO-1123 from the composition, and the hydrogen fluoride content also increases.
• the acid content in the composition increases.
• the content of HFO-1225zc is 0.5 mass% or less with respect to the total amount of the composition, so that the content of hydrogen fluoride that may be contained in association with HFO-1225zc can be reduced.
• Patent Document 1 describes a method for producing HFO-1123 by hydrogen reduction of chlorotrifluoroethylene (CTFE).
• CTFE chlorotrifluoroethylene
• the crude product and distillate 2 obtained by this production method contain any of HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z).
• the crude product and distillate 2 obtained by this production method do not contain HFO-1225zc.
• Patent Document 1 also describes a method for producing HFO-1123 by thermal decomposition of a mixture of chlorodifluoromethane (HCFC-22) and chlorofluoromethane (HCFC-31).
• the crude product obtained by this production method contains any of HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z).
• the crude product and distillate 2 obtained by this production method do not contain HFO-1225zc.
• Patent Document 1 since HFO-1225zc is not produced, an increase in the acid content due to HFO-1225zc is not expected, and therefore Patent Document 1 does not focus on the content of HFO-1225zc.
• ⁇ -alumina is used as a catalyst, which makes the dehydrofluorination reaction highly reactive and also makes the reverse reaction likely to proceed, so that vinylidene fluoride (VdF) is likely to be produced as a by-product.
• An addition reaction of hydrogen fluoride to VdF is likely to occur, resulting in a high content of HFC-143a.
• Patent Document 2 does not mention the fact that the content of HFC-143a is 0.1 mass% or less.
• the composition of the present disclosure includes HFO-1123.
• the composition of the present disclosure includes a method for producing the composition ( Hereinafter, it is also referred to as "Production Method A"), in which HFC-134a is brought into contact with ⁇ -alumina to obtain HFO-1123.
• composition of the present disclosure may be a crude product (a product before purification such as distillation) obtained by the method for producing HFO-1123, or a purified product obtained after purification such as distillation of the crude product.
• the amount of HFO-1123 is not particularly limited, but is preferably 3% by mass or more, more preferably 4% by mass or more, and even more preferably 5% by mass or more, based on the total amount of the composition.
• the upper limit of the amount of HFO-1123 is, for example, 99.9% by mass.
• the content of HFO-1123 is preferably 3 to 15 mass%, more preferably 4 to 15 mass%, and even more preferably 5 to 15 mass%, from the viewpoint of carrying out the reaction within an appropriate temperature range in order to maintain the selectivity of HFO-1123.
• the content of HFO-1123 is preferably 99.0 mass % or more, and more preferably 99.5 mass % or more.
• the HFO-1123 content In order to achieve a HFO-1123 content of 3 mass% or more, a certain degree of conversion rate is necessary in manufacturing method A. For example, if the conversion rate is 1.5% or more, the HFO-1123 content can be set to 3 mass% or more.
• HFC-143a The composition of the present disclosure contains HFC-143a.
• HFC-143a is obtained as a by-product.
• the content of HFC-143a is 0.1 mass% or less based on the total amount of the composition. Since the content of HFC-143a is 0.1 mass% or less, the GWP of the entire composition can be reduced.
• the content of HFC-143a is more than 0 mass %, and is preferably 0.001 mass % or more. Furthermore, the content of HFC-143a is preferably 0.1% by mass or less, more preferably 0.09% by mass or less, and even more preferably 0.08% by mass or less.
• HFC-143a is a by-product in the production method of HFO-1123, but since HFC-143a and HFO-1123 have similar boiling points, it is difficult to completely separate HFC-143a and HFO-1123 by purification, and a huge purification facility is required. Therefore, it is preferable from the viewpoint of production efficiency that the content of HFC-143a is 0.001 mass% or more.
• HFO-1225zc The compositions of the present disclosure include HFO-1225zc.
• HFO-1225zc is obtained as a by-product.
• the content of HFO-1225zc is 0.5 mass% or less based on the total amount of the composition. Since the content of HFO-1225zc is 0.5 mass% or less, an increase in the acid content can be suppressed.
• the content of HFO-1225zc is more than 0 mass %, and is preferably 0.0001 mass % or more.
• the content of HFO-1225zc is preferably 0.5 mass% or less, more preferably 0.25 mass% or less, even more preferably 0.1 mass% or less, and particularly preferably 0.05 mass% or less.
• HFC-134a In the production method A, HFC-134a is used as a raw material. In addition to the forward reaction in which HFC-134a produces HFO-1123, a reverse reaction in which HFO-1123 returns to HFC-134a also occurs. Therefore, the composition of the present disclosure is It is preferred that it comprises HFC-134a.
• the total content of HFO-1123 and HFC-134a is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more, based on the total amount of the composition.
• the upper limit of the total content is, for example, 99.9% by mass.
• the content of HFC-134a is preferably 65 mass% or more, more preferably 75 mass% or more, even more preferably 80 mass% or more, and particularly preferably 85 mass% or more.
• the content of HFC-134a is preferably 10.0 mass% or less, more preferably 5.0 mass% or less, even more preferably 1.0 mass% or less, and particularly preferably 0.1 mass% or less.
• compositions of the present disclosure include trifluoromethane (HFC-23), vinylidene fluoride (VdF), (E)-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (HFC-32), ( E) At least one selected from the group consisting of 1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and 1,1,2,2-tetrafluoroethane (HFC-134) It may further include.
• compositions of the present disclosure may further contain HFC-23, VdF, HFO-1132(E), HFC-32, and HFC-134.
• HFC-23, VdF, HFO-1132(E), HFC-32, and HFC-134 are obtained as by-products. If no purification process is performed, the crude product contains HFC-23, VdF, HFO-1132(E), HFC-32, and HFC-134 along with HFO-1123 and HFC-143a.
• the total content of at least one selected from the group consisting of trifluoromethane (HFC-23), vinylidene fluoride (VdF), (E)-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (HFC-32), and 1,1,2,2-tetrafluoroethane (HFC-134) is preferably 0.0001 to 20% by mass based on the total amount of the composition.
• the total content of HFC-23, VdF, HFO-1132(E), HFC-32, and HFC-134 is preferably 0.01 to 20% by mass based on the total amount of the composition.
• CTFE The compositions of the present disclosure may include CTFE.
• HFC-134a is used as a raw material.
• HFC-134a can be obtained, for example, by subjecting CTFE to a hydrogenation reaction, a dehydrochlorination reaction, and a hydrogen fluoride addition reaction.
• the raw material used in Production Method A may contain, in addition to HFC-134a, CTFE that may be contained in the production process of HFC-134a.
• the CTFE will not be converted into other compounds and will be included as is in the reaction product.
• the CTFE content is preferably 0.0001 to 20 mass% based on the total amount of the composition.
• composition of the present disclosure does not contain HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z).
• HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z) have a CCl bond.
• the CCl bond is more easily dissociated than a CF bond.
• acid may be generated due to the elimination of chlorine atoms.
• the composition of the present disclosure does not contain HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z)
• the generation of acid due to the elimination of chlorine atoms can be suppressed.
• corrosion since the generation of acid is suppressed, corrosion is unlikely to occur when the composition of the present disclosure is in contact with a metal member for a long period of time.
• composition of the present disclosure does not contain HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z).
• compositions of the present disclosure preferably do not contain olefin compounds having 2 carbon atoms and containing chlorine atoms and 2 or less fluorine atoms.
• HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z) are examples of olefin compounds having 2 carbon atoms and containing chlorine atoms and 2 or less fluorine atoms.
• olefin compounds having two carbon atoms and two or less fluorine atoms that contain a chlorine atom include 1,2-dichloro-1,2-difluoroethylene (CFO-1112(E), CFO-1112(Z)) and 1-chloro-2-fluoroethylene (HCFO-1131(E), HCFO-1131(Z)).
• the system of the present disclosure preferably comprises the composition of the present disclosure and a contact member having at least a portion of a surface that comes into contact with the composition of the present disclosure, the surface being made of metal.
• Examples of the system include piping through which the composition passes, a container for containing the composition, and a thermal cycle system.
• the surface of the contact member that comes into contact with the composition of the present disclosure may be at least partially composed of a metal, and may be composed of only a metal, an alloy containing a metal, or a compound containing a metal.
• the metal is preferably at least one selected from the group of metals consisting of iron, copper, aluminum, stainless steel, titanium, nickel, zinc, tin, brass, magnesium, chromium, lead, silver, tungsten, and tantalum.
• the alloy is preferably an alloy containing at least one metal selected from the above group of metals.
• alloys include nickel-chrome plating, solder, and tin plating.
• the metal-containing compound is preferably a compound containing at least one metal selected from the above group of metals.
• metal-containing compounds include anodized aluminum sulfate, zinc phosphate, and iron phosphate.
• composition of the present disclosure does not contain HCFO-1122, HCFO-1122a(E), or HCFO-1122a(Z), and therefore can suppress the generation of acids that accompany the elimination of chlorine atoms.
• contact members at least part of whose surface that comes into contact with the composition of the present disclosure is made of metal are less susceptible to corrosion.
• a container containing the composition of the present disclosure comprises the composition of the present disclosure and a container having a contact member, at least a portion of whose surface that comes into contact with the composition is made of metal, and is sealed with the composition contained therein.
• the container containing the composition of the present disclosure may be, for example, a container whose entirety is made of metal, a container having a multi-layer structure with the innermost layer made of metal, or a container having a metal coating on the surface that comes into contact with the composition of the present disclosure.
• the composition of the present disclosure does not contain HCFO-1122, HCFO-1122a(E), or HCFO-1122a(Z), and therefore can suppress the generation of acids that accompany the elimination of chlorine atoms.
• containers in which at least a portion of the surface that comes into contact with the composition of the present disclosure is made of metal are less susceptible to corrosion, making it possible to store the composition of the present disclosure for long periods of time.
• the method for producing the composition of the present disclosure preferably comprises contacting HFC-134a with a catalyst containing ⁇ -alumina to produce the composition of the present disclosure.
• the catalyst comprises alpha-alumina.
• the presence of ⁇ -alumina in the catalyst can be confirmed by a diffraction pattern obtained by X-ray diffraction, in other words, XRD (X-Ray Diffractometer).
• XRD X-Ray Diffractometer
• the catalyst may contain compounds other than ⁇ -alumina.
• compounds other than ⁇ -alumina include alumina with a different crystal structure from ⁇ -alumina, and oxides other than alumina.
• oxides other than alumina include ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, boehmite, and gibbsite.
• oxides other than alumina include chromium oxide, copper oxide, iron oxide, nickel oxide, magnesium oxide, zinc oxide, and zirconium oxide.
• the catalyst may also contain compounds other than ⁇ -alumina, such as aluminum oxide fluoride, which is ⁇ -alumina fluorinated.
• ⁇ -alumina is the main component of the catalyst.
• ⁇ -alumina may function not only as a catalyst, but also as a support while functioning as a catalyst. ⁇ -alumina may also be supported on a support other than ⁇ -alumina.
• Examples of carriers include carbon, ⁇ -alumina, ⁇ -alumina, zirconia, silica, and titania.
• the form of the catalyst is not particularly limited, and it may be in the form of a powder, pellets, or spheres.
• ⁇ -alumina is preferably in the form of a molded body such as a sphere or pellet from the viewpoint of handling when used for about 10 hours.
• a molded body is different from a powder and can be obtained, for example, by putting a powder into a mold and compressing it.
• Nitrogen can be used as a common adsorption gas to analyze pores in the micro (less than 2 nm) and mesoporous (2-200 nm) ranges. From the adsorption and desorption isotherms, the parameters of the specific surface area, average pore diameter, and pore volume can be obtained.
• the specific surface area of a catalyst can be calculated from the adsorption of a single layer of nitrogen based on the BET (Brunauer-Emmett-Teller) theory.
• the average pore size can be calculated based on the BJH (Barrett-Joyner-Halenda) theory.
• the average pore diameter of the catalyst is measured by the following method.
• the average pore diameter of the catalyst is 2 to 200 nm, it can be determined by the BET method and the BJH method based on the nitrogen adsorption method.
• a measuring device for example, "3Flex" manufactured by Micrometrics can be used.
• the average pore diameter is calculated based on the following formula using the specific surface area (S) determined by the BET method from the adsorption isotherm obtained by the nitrogen adsorption method and the pore volume (V) determined by the BJH method.
• V is the pore volume (m 3 /g) of the sample
• S is the specific surface area (m 2 /g) of the sample.
• the average pore diameter of the catalyst is less than 2 nm, the calculation is performed by the HK method using the Lennard-Jones function.
• This measurement is to be carried out immediately before the catalyst is brought into contact with HFC-134a.
• the average pore size of the catalyst is 5 nm or more, and preferably 5 to 200 nm.
• the average pore diameter of the catalyst is preferably 6 nm or more, more preferably 10 nm or more, more preferably 12 nm or more, and particularly preferably 15 nm or more.
• the average pore diameter of the catalyst is more preferably 150 nm or less, even more preferably 100 nm or less, particularly preferably 50 nm or less, and most preferably 30 nm or less.
• the pore volume can be calculated based on the BJH (Barrett-Joyner-Halenda) theory.
• Pore volume affects the diffusibility of the substrate into the catalyst pores and the strength of the catalyst.
• the pore volume becomes too large, the strength of the catalyst decreases, and there is a tendency for the strength of the catalyst to decrease.
• the pore volume of the catalyst is preferably 0.002 to 1.20 cm 3 /g.
• the pore volume of the catalyst is more preferably 0.005 cm 3 /g or more, further preferably 0.01 cm 3 /g or more, and particularly preferably 0.02 cm 3 /g or more.
• the pore volume of the catalyst is more preferably 1 cm 3 /g or less, further preferably 0.90 cm 3 /g or less, and particularly preferably 0.80 cm 3 /g or less.
• the bulk density of the catalyst is not particularly limited, if the bulk density of the catalyst is low, the volume per mass is large, the reactor becomes large, and the efficiency is reduced, whereas if the bulk density of the catalyst is high, the specific surface area and pore volume of the catalyst are reduced. From the above viewpoint, the bulk density of the catalyst is preferably 0.4 to 1.5 g/mL.
• the bulk density of the catalyst is more preferably 0.5 g/mL or more, even more preferably 0.6 g/mL or more, and particularly preferably 0.7 g/mL or more.
• the bulk density of the catalyst is more preferably 1.4 g/mL or less, even more preferably 1.3 g/mL or less, and particularly preferably 1.2 g/mL or less.
• the raw material gas only needs to contain HFC-134a, and may contain components other than HFC-134a.
• the raw material gas may consist of only HFC-134a, or may contain isomers, disproportionation products, impurities, and the like obtained during the production of HFC-134a.
• the raw material gas preferably contains an inert gas such as nitrogen, argon, helium, carbon dioxide, or octafluorocyclobutane in addition to HFC-134a.
• the inert gas can dilute the target product and the by-product hydrogen fluoride.
• the content of HFC-134a is preferably 60 mol % or more, more preferably 70 mol % or more, even more preferably 75 mol % or more, and particularly preferably 80 mol % or more, based on the total amount of the raw material gas.
• the method for producing the composition of the present disclosure may be carried out in either the gas phase or the liquid phase. Since HFC-134a is a gas at room temperature, it is preferable to contact HFC-134a with the catalyst in the gas phase.
• the reactor in which HFC-134a is brought into contact with the catalyst may be one that can withstand the temperature and pressure described below, and there are no particular limitations on its shape or structure.
• An example of the reactor is a cylindrical vertical reactor. Examples of materials for the reactor include glass, stainless steel, iron, nickel, and alloys mainly composed of iron or nickel.
• the reactor may be equipped with a heating means, such as an electric heater, for heating the inside of the reactor.
• the catalyst may be housed in any of the following formats: fixed bed, fluidized bed, or moving bed. If it is a fixed bed, it may be either a horizontal fixed bed or a vertical fixed bed.
• the reaction system may be either a flow system or a batch system.
• a moving bed reactor In a fixed bed reactor, various molded bodies of catalyst-supporting carriers are filled to reduce pressure loss of the reaction fluid.
• the catalyst layer In a fluidized bed reactor, the catalyst layer is operated so that it exhibits fluid-like properties due to the reaction fluid, so the catalyst particles are suspended in the reaction fluid and move inside the reactor.
• Fixed bed reactors are preferred because they offer a wide range of catalyst shape options and can suppress catalyst wear. Fixed bed reactors include tubular reactors and tank reactors, and tubular reactors are preferred because of the ease of controlling the reaction temperature.
• a multi-tube heat exchange reaction in which a large number of reaction tubes with small diameters are arranged in parallel and a heat medium is circulated on the outside can be used.
• multiple catalyst layers are installed. There should be at least one catalyst layer, but there may be two or more.
• the method for producing the composition of the present disclosure is preferably carried out in a flow-through manner using a fixed-bed reactor (particularly a vertical fixed-bed type reactor).
• the HFC-134a it is preferable to contact the HFC-134a with the catalyst at a temperature of 300 to 800°C, more preferably at a temperature of 400 to 700°C, and even more preferably at a temperature of 400 to 600°C. If the contact temperature is 300°C or higher, the conversion rate of HFC-134a is improved. On the other hand, if the contact temperature is 800°C or lower, the decomposition of HFC-134a can be suppressed.
• the contact temperature here refers to the temperature of the catalyst layer.
• the dehydrofluorination reaction is generally an endothermic reaction
• the decrease in the conversion rate can be suppressed by appropriately maintaining the reaction temperature.
• the reaction temperature in the catalyst layer increases, the conversion rate of the raw material increases. Therefore, it is preferable to maintain the reaction temperature in the catalyst layer at a desired temperature so that a high conversion rate can be maintained.
• a method of heating the catalyst layer from the outside with a heat medium or the like can be mentioned. The catalyst usually deteriorates over time as the reaction progresses.
• the decrease in the conversion rate can be suppressed by heating the catalyst layer with a heat medium or the like and appropriately maintaining or increasing the reaction temperature.
• the reaction zone starts from the inlet of the raw material gas.
• the catalyst at the inlet of the raw material gas deteriorates over time as the reaction progresses, the reaction zone moves downstream in the gas flow direction. Since the low-temperature product gas generated in the reaction zone flows into the vicinity of the downstream side of the reaction zone, the vicinity of the downstream side is usually the coldest in the catalyst layer.
• the temperature of this region of the catalyst layer that is at the coldest temperature is referred to as the "minimum temperature of the catalyst layer.”
• the temperature from the vicinity of the downstream side further downstream usually increases from the minimum temperature of the catalyst layer as it moves away from the reaction zone.
• the raw material gas containing HFC-134a may be supplied to the reactor at room temperature. However, it is preferable to properly heat (preheat) the raw material gas before supplying it to the reactor. When preheating is performed, it is preferable to heat the raw material gas to a temperature of 80 to 600°C before supplying it to the reactor. Preheating to 80°C or higher makes it difficult for the internal temperature of the reactor to decrease, making it easier to achieve the set conversion rate. Preheating to 600°C or lower also makes it difficult for the internal temperature of the reactor to increase, suppressing undesirable reactions and improving the selectivity.
• the pressure when contacting HFC-134a with the catalyst is not particularly limited, but from the viewpoint of improving the conversion rate, it is preferably from -0.05 to 2 MPa, more preferably from -0.01 to 1 MPa, and even more preferably from normal pressure to 0.5 MPa.
• pressure means gauge pressure.
• the contact time between HFC-134a and the catalyst is preferably 0.5 to 100.0 seconds, more preferably 1.0 to 50.0 seconds, and even more preferably 2.0 to 20.0 seconds.
• the linear velocity means the speed at which the feed gas containing HFC-134a passes through the catalyst per unit time.
• the contact time (g ⁇ sec/mL) between HFC-134a and the catalyst is preferably 1 to 200 g ⁇ sec/mL, more preferably 5 to 175 g ⁇ sec/mL, even more preferably 7 to 150 g ⁇ sec/mL, and particularly preferably 10 to 125 g ⁇ sec/mL. If the contact time (g ⁇ sec/mL) is 1 g ⁇ sec/mL or more, the conversion rate is improved. If the contact time (g ⁇ sec/mL) is 200 g ⁇ sec/mL or less, equipment costs can be reduced.
• the inert gas is preferably at least one selected from the group consisting of nitrogen, helium, argon, octafluorocyclobutane, and carbon dioxide. Of these, the inert gas is preferably nitrogen.
• the molar ratio of HFC-134a to the inert gas in the gas phase is preferably 0.1 to 30, and more preferably 0.5 to 25.
• Example 1 ⁇ Preparation of Gas A> A stainless steel (SUS304) reaction tube having an inner diameter of 3.57 cm and a length of 35 cm was filled with 14 mL of ⁇ -alumina (product name "C500", manufactured by Nippon Light Metals Co., Ltd., average pore size 19 nm) as a catalyst.
• the reaction tube filled with the catalyst was placed in a tubular electric furnace, and the catalyst was dehydrated by passing nitrogen through it and heating it to 450°C. Thereafter, a 0.1/1 (mol/mol) mixed gas of nitrogen/HFC-134a was passed through the reactor for a contact time of 4.4 seconds to carry out a HF removal reaction to produce HFO-1123.
• the gas from the outlet of the reaction tube was passed through a KOH alkaline trap, and then the composition (Gas A) was recovered in a stainless steel container.
• the obtained composition contained HFO-1123, HFC-134a, HFC-143a, and HFO-1225zc in the amounts shown in Table 1.
• the obtained composition also contained HFC-23, VdF, HFO-1132(E), HFC-32, HFO-1234ze(E), and HFC-134.
• the resulting composition was free of HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z). Furthermore, the obtained composition did not contain any olefin compound having a carbon number of 2 and having a chlorine atom and two or less fluorine atoms.
• Example 2 A composition was obtained in the same manner as in Example 1, except that ⁇ -alumina (product name "SA52124", manufactured by Saint-Gobain, average pore diameter 25 nm) was used as the catalyst.
• the obtained composition contained HFO-1123, HFC-134a, HFC-143a, and HFO-1225zc in the amounts shown in Table 1.
• the obtained composition also contained HFC-23, VdF, HFO-1132(E), HFC-32, HFO-1234ze(E), and HFC-134.
• the resulting composition was free of HCFO-1122, HCFO-1122a(E), and HCFO-1122a(Z). Furthermore, the obtained composition did not contain any olefin compound having a carbon number of 2 and having a chlorine atom and two or less fluorine atoms.
• Examples 3 to 5 Gas A prepared in Example 1 was mixed with HCFO-1122 (manufactured by Synquest Corporation) to prepare a composition having the content of each component shown in Table 1.
• Example 6 A stainless steel (SUS304) reaction tube having an inner diameter of 2.27 cm and a length of 30 cm was filled with 40 mL of ⁇ -alumina (product name "N612N", manufactured by JGC Catalysts and Chemicals Co., Ltd.) as a catalyst.
• the reaction tube filled with the catalyst was placed in a tubular electric furnace, and the catalyst was dehydrated by passing nitrogen through it and heating it to 450°C. Thereafter, a 4/1 (mol/mol) mixed gas of nitrogen/HFC-134a was passed through the reactor for a contact time of 10 seconds to carry out a HF removal reaction to produce HFO-1123.
• the gas from the outlet of the reaction tube was passed through a KOH alkali trap, and the composition was then recovered in a stainless steel container.
• the obtained composition contained HFO-1123, HFC-134a, and HFC-143a in the amounts shown in Table 1.
• the obtained composition also contained HFC-23, HFC-134, VdF, and HFO-1132(E).
• the obtained composition did not contain HFO-1225zc (shown as "0" in Table 1).
• the resulting composition was subjected to a stability test.
• the test method was as follows.
• the pH of the resulting aqueous layer was measured using a pH meter (model number "D-51", manufactured by HORIBA) and a pH electrode (model number "9615-10D", manufactured by HORIBA). Furthermore, the wall surface of the cylinder in which the gas was sealed was visually observed, and the change in appearance before and after the test was evaluated according to the following criteria. A: No change before and after the test. B: The gloss disappeared after the test. C: Corrosion was observed after the test.
• Table 1 shows the results of pH and appearance. In Example 6, the test was not performed, so "-" is entered. In Examples 1, 2, and 6, HCFO-1122 was not added, and therefore was not detected, so "-" is entered.
• Examples 1-2 are working examples, and Examples 3-6 are comparative examples.
• the compositions of Examples 1 and 2 are compositions containing HFO-1123, and further contain HFC-143a and HFO-1225zc, and do not contain HCFO-1122, HCFO-1122a(E), or HCFO-1122a(Z).
• the content of HFC-143a is 0.1 mass% or less, based on the total amount of the composition, and the content of HFO-1225zc is 0.5 mass% or less, based on the total amount of the composition. It was therefore found that generation of acid was suppressed.
• the compositions of Examples 3 to 5 contained HCFO-1122, and generation of acid was confirmed.
• the composition of Example 6 has a high content of HFC-143a and tends to have a high GWP.

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