Method for producing 1-chloro-2,3,3-trifluoropropene

Abstract

The present invention provides a method for producing 1233yd in a vapor phase, said method having a high conversion rate of a starting material and enabling the achievement of 1233yd with high selectivity, while suppressing the production amount of impurities.　A method for producing 1-chloro-2, 3, 3-trifluoropropene by subjecting 3-chloro-1, 1, 2, 2-tetrafluoropropane to a hydrogen fluoride elimination reaction in a vapor phase in the presence of a catalyst, said method being characterized in that a metal compound catalyst, which is activated in a vapor phase by a fluorine compound that does not contain a chlorine atom, is used as the catalyst.

Description

[Technical Field]

[0001] The present invention relates to a method for producing 1-chloro-2,3,3-trifluoropropene. [Background technology]

[0002] 1-Chloro-2,3,3-trifluoropropene (hereinafter referred to as 1233yd) is a new low global warming potential (GWP) alternative to 3,3-dichloro-1,1,1,2,2-pentafluoropropane (hereinafter referred to as 225ca) and 1,3-dichloro-1,1,2,2,3-pentafluoropropane (hereinafter referred to as 225cb) and is used in cleaning agents, refrigerants, blowing agents, solvents, and aerosols. In this specification, for halogenated hydrocarbons, the abbreviation of the compound is written in parentheses after the compound name, but in this specification, the abbreviation will be used instead of the compound name as necessary.

[0003] 1233yd exists as geometric isomers, Z isomer and E isomer, depending on the position of the substituent on the double bond. Unless otherwise specified, when a compound name or abbreviation is used in this specification, it refers to at least one selected from the Z isomer and the E isomer. When a compound name or abbreviation is followed by (Z) or (E), it indicates the Z isomer or the E isomer of the respective compound. For example, 1233yd(Z) indicates the Z isomer, and 1233yd(E) indicates the E isomer.

[0004] As an example of the production of 1233yd, the examples of Patent Document 1 state that when 3-chloro-1,1,2,2-tetrafluoropropane (hereinafter also referred to as 244ca) is introduced in a gaseous state into a vertical fixed-bed reactor packed with activated carbon or alumina activated with chlorodifluoromethane as a catalyst under a nitrogen stream, a trace amount of 1233yd is produced. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 018412 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method for producing 1233yd by a gas-phase dehydrofluorination reaction described in Patent Document 1 has problems such as a low conversion rate of the raw material and a large amount of impurities such as 1-chloro-3,3-difluoropropyne being produced, making it unsuitable for industrial-scale mass production. An object of the present invention is to provide a method for producing 1233yd in the vapor phase, which has a high conversion rate of raw materials, can produce 1233yd with high selectivity, and produces only a small amount of impurities. [Means for solving the problem]

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration. [1] A method for producing 1-chloro-2,3,3-trifluoropropene by dehydrofluorinating 3-chloro-1,1,2,2-tetrafluoropropane in the presence of a catalyst in a gas phase, comprising: A method for producing 1-chloro-2,3,3-trifluoropropene, characterized in that the catalyst used is a metal compound catalyst activated in a gas phase with a fluorine compound that does not contain chlorine atoms. [2] The method according to [1], wherein the metal compound catalyst contains at least one metal element selected from the group consisting of Cr, Al, Zn, Ti, and Ni. [3] The method according to any one of [1] to [2], wherein the metal compound catalyst is a metal oxide, a metal fluoride, or a metal oxyfluoride. [4] The method according to any one of [1] to [3], wherein the metal compound catalyst is aluminum oxide or chromium oxide. [5] The method according to any one of [1] to [4], wherein the activation of the metal compound catalyst is carried out by contacting the chlorine-free fluorine compound with the metal compound catalyst in a gas phase. [6] The method according to any one of [1] to [5], wherein the fluorine compound containing no chlorine atoms is hydrogen fluoride or a fluorine compound containing no chlorine atoms and having 1 to 3 carbon atoms. [7] The method according to any one of [1] to [6], wherein the fluorine compound not containing a chlorine atom is hydrogen fluoride, trifluoromethane, or difluoromethane. [8] The method according to any one of [1] to [7], wherein the activation treatment temperature in the activation of the metal compound catalyst is 100 to 400°C. [9] The method according to any one of [1] to [8], wherein the contact time between the fluorine compound not containing chlorine atoms and the catalyst during activation of the metal compound catalyst is 0.1 to 100 seconds.

[10] The method according to any one of [1] to [9], wherein the dehydrofluorination reaction is carried out at a reaction temperature of 200 to 400°C.

[11] The method according to any one of [1] to

[10] , wherein the contact time between 3-chloro-1,1,2,2-tetrafluoropropane and the catalyst in the dehydrofluorination reaction is 0.1 to 100 seconds.

[12] The production method according to any one of [1] to

[11] , wherein the content of 1-chloro-3,3-difluoropropyne in the reaction crude liquid after the dehydrofluorination reaction is 10 mass % or less based on the total amount of the reaction crude liquid.

[13] The production method according to any one of [1] to

[12] , wherein in the dehydrofluorination reaction, 3-chloro-1,1,2,2-tetrafluoropropane is mixed with a diluent gas and supplied to a reactor.

[14] The production method according to any one of [1] to

[13] , wherein purified 1-chloro-2,3,3-trifluoropropene is recovered from the reaction crude liquid after the dehydrofluorination reaction.

[15] The content of chloride ions and fluorine ions in the purified 1-chloro-2,3,3-trifluoropropene is each less than 10 ppm by mass relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene; the water concentration is less than 2000 ppm by mass based on the total amount of the purified 1-chloro-2,3,3-trifluoropropene;

[14] The production method according to

[14] , wherein the oxygen concentration is 1000 mass ppm or less based on the total amount of the purified 1-chloro-2,3,3-trifluoropropene. [Effects of the Invention]

[0008] According to the present invention, a method for producing 1233yd in the vapor phase can be provided, which has a high conversion rate of the raw material, can produce 1233yd with high selectivity, and produces a small amount of impurities. DETAILED DESCRIPTION OF THE INVENTION

[0009] The method for producing 1233yd of the present invention is a method for obtaining 1233yd using 244ca as a raw material. The dehydrofluorination reaction of 244ca according to the production method of the present invention (hereinafter also simply referred to as "dehydrofluorination reaction") is a reaction represented by the following formula (1).

[0010] [ka]

[0011] In the production method of the present invention, the conversion rate of the raw material 244ca is high, and the amount of the impurity 1-chloro-3,3-difluoropropyne produced is small. In the production method of the present invention, the dehydrofluorination reaction is carried out in a gas phase from the viewpoint of reducing waste after production and increasing productivity. Dehydrofluorination in a gas phase means dehydrofluorinating 244ca in a gaseous state.

[0012] The production method of the present invention is characterized in that 244ca is dehydrofluorinated in the gas phase in the presence of a metal compound catalyst activated with a fluorine compound containing no chlorine atoms.

[0013] (244ca) The method for producing 1233yd of the present invention uses 244ca as a raw material. 244ca is a compound known as a raw material or intermediate for the production of fluorine-containing compounds and is readily available.

[0014] There are no particular limitations on the method for obtaining 244ca, and it can be produced, for example, by chlorinating 2,2,3,3-tetrafluoropropanol (TFPO) with thionyl chloride (SOCl2) in the presence of N,N-dimethylformamide (DMF), as shown in formula (2). This method can be carried out in either the liquid or gas phase.

[0015] [ka]

[0016] In the reaction of formula (2), a general reactor such as a glass flask, a stainless steel autoclave, a glass-lined reactor, etc. When a glass flask is used, it is preferable to install a glass distillation column packed with Raschig rings to simultaneously produce and separate 244ca.

[0017] The amount of DMF added per mole of TFPO is preferably 0.001 to 0.2 moles, and the amount of thionyl chloride added is preferably about 0.5 to 1.5 moles. DMF acts as a catalyst to promote the reaction. The reaction of formula (2) proceeds quantitatively with equimolar amounts, so there is no need for either to be in excess.

[0018] If the rate of addition of thionyl chloride per mole of TFPO is too fast, the rate of hydrogen chloride production will increase, and TFPO and other products may be lost as they are discharged outside the system along with the hydrogen chloride. Therefore, it is preferable to add thionyl chloride dropwise at a rate that keeps the temperature fluctuation caused by the reaction within 30°C. In addition, if water is present, thionyl chloride reacts with the water and is hydrolyzed, decomposing into SO2 and HCl. Furthermore, 2,2,3,3-tetrafluoropropanesulfonic acid chloride is also hydrolyzed, decomposing into TFPO, SO2, and HCl. To prevent this, it is preferable to replace the atmosphere inside the reactor with dry nitrogen gas.

[0019] In the reaction of formula (2), the addition of thionyl chloride causes a reaction between TFPO and thionyl chloride to produce 2,2,3,3-tetrafluoropropanesulfonic acid chloride. When 2,2,3,3-tetrafluoropropanesulfonic acid chloride is heated, it undergoes a sulfur dioxide removal reaction to produce 244ca. The heating temperature is 70°C to 150°C, preferably 90°C to 130°C. The temperature can be raised at any rate, but it is desirable to raise the temperature slowly at a rate of about 1 to 2°C / min to control the production rate in order to avoid insufficient treatment of the produced sulfur dioxide or insufficient recovery of the produced 244ca. When it is difficult to adjust the temperature rise rate during heating of 2,2,3,3-tetrafluoropropanesulfonic acid chloride, it is preferable to employ a method of heating 2,2,3,3-tetrafluoropropanesulfonic acid chloride in a solvent (liquid phase reaction). The solvent has a boiling point higher than the reaction temperature of the decomposition reaction of 2,2,3,3-tetrafluoropropanesulfonic acid chloride and is preferably an aprotic solvent that does not easily react with the compounds involved in the reaction represented by formula (2). Specific examples include dimethyl sulfoxide and DMF. The amount of solvent used is preferably about 0.5 to 3 moles per mole of 2,2,3,3-tetrafluoropropanesulfonic acid chloride. The sulfur dioxide removal reaction of 2,2,3,3-tetrafluoropropanesulfonyl chloride is preferably carried out as a liquid-phase reaction using a reactor similar to that described above. That is, a solvent is added to the reactor, heated to a temperature at which the sulfur dioxide removal reaction occurs, and then 2,2,3,3-tetrafluoropropanesulfonyl chloride is added dropwise to produce 244ca. The reaction temperature for the sulfur dioxide removal reaction is 70°C to 150°C, preferably 90°C to 130°C. The atmosphere inside the reaction vessel is preferably replaced with dry nitrogen gas.

[0020] The crude 244ca product produced via the reaction of formula (2) is usually a crude gaseous product, and can be treated by methods such as water washing to remove hydrochloric acid and sulfur dioxide, dried with a desiccant such as calcium chloride or a molecular sieve, and subjected to methods such as cold trapping to remove impurities, resulting in the recovery of a composition containing 244ca. The resulting composition containing 244ca can be used in the production method of the present invention as is, or after further purification, as a composition containing 244ca with a purity of, for example, 99.5% by mass or higher. The 244ca used in the production method of the present invention may be 100% pure 244ca, or a composition of high-purity 244ca that has undergone a purification process. Alternatively, a 244ca-containing composition that contains 244ca and components other than 244ca (e.g., impurities) may also be used. However, when using the latter 244ca-containing composition, if the impurities are active in the dehydrofluorination reaction of the present invention, it is preferable to remove them in advance. For example, when producing 244ca by the method of formula (2), if TFPO remains with the produced 244ca, it may react with 1233yd, the target product of the present invention. Therefore, it is preferable to remove as much TFPO as possible from the product.

[0021] In the production method of the present invention, 244ca is dehydrofluorinated in the presence of a metal compound catalyst activated with a chlorine-free fluorine compound. This dehydrofluorination reaction is carried out by contacting the raw material 244ca with the activated metal compound catalyst in the gas phase.

[0022] (metal compound catalyst) In the present invention, examples of the metal compound catalyst before activation include metal oxides, metal fluorides, metal oxyfluorides, etc. The metal compound catalyst may be used alone or in combination of two or more kinds. The metal compound catalyst may contain one metal element or two or more metal elements. When the metal compound catalyst contains two or more metal elements, the metal compound may be a mixture of two or more metal compounds having different metal elements, or may be a metal compound containing two or more metal elements. The metal compound catalyst before activation is preferably a metal compound containing at least one metal element selected from the group consisting of Co, Fe, Pd, Sn, Mg, La, Cr, Al, Zn, Ti, and Ni, and more preferably a metal compound containing at least one metal element selected from the group consisting of Cr, Al, Zn, Ti, and Ni. Examples of metal oxides include chromium oxide, aluminum oxide, zinc oxide, titanium oxide, and nickel oxide. The metal fluorides may be hydrates, and examples thereof include chromium fluoride, aluminum fluoride, titanium fluoride, zinc fluoride, titanium fluoride, and nickel fluoride. Examples of metal oxyfluorides include partially fluorinated chromium oxide, aluminum oxide, zinc oxide, titanium oxide, nickel oxide, and the like. As the metal compound catalyst, from the viewpoints of conversion rate and selectivity, metal oxides are preferred, and aluminum oxide and chromium oxide are more preferred.

[0023] The metal compound catalyst may be supported on a carrier. Examples of the carrier include an alumina carrier, a silica carrier, and a silica-alumina carrier. The carrier may have catalytic activity that promotes the dehydrofluorination reaction. As with the above-mentioned metal compound catalyst, the carrier is preferably a metal compound carrier containing at least one metal element selected from the group consisting of Cr, Al, Zn, Ti, and Ni.

[0024] (Catalyst activation) In the production method of the present invention, an activated metal compound catalyst is used. Here, activation refers to contacting a chlorine-free fluorine compound with the metal compound catalyst in a gas phase. The activated metal compound catalyst is preferably partially fluorinated. The chlorine-free fluorine compound may be used alone or in combination of two or more. As the fluorine compound not containing a chlorine atom, hydrogen fluoride, a fluorinated alkane, or a fluorinated alkene is preferred, and hydrogen fluoride or a fluorinated alkane is more preferred. As the fluorine compound not containing a chlorine atom, hydrogen fluoride and a fluorine compound having 1 to 3 carbon atoms not containing a chlorine atom are preferred, hydrogen fluoride and a fluorine compound having 1 to 2 carbon atoms not containing a chlorine atom are more preferred, and hydrogen fluoride and a fluorine compound having 1 carbon atom not containing a chlorine atom are most preferred. Examples of fluorine compounds having one carbon atom and not containing a chlorine atom include trifluoromethane and difluoromethane. Examples of fluorine compounds having two carbon atoms and not containing a chlorine atom include pentafluoroethane, 1,1,2,2-tetrafluoroethane, and 1,1,1-trifluoroethane. Examples of fluorine compounds having 3 carbon atoms and not containing a chlorine atom include hexafluoropropane and 1,2,3,3-tetrafluoropropene. As the fluorine compound not containing a chlorine atom, hydrogen fluoride, trifluoromethane, and difluoromethane are preferred, and from the viewpoint of the conversion rate of the raw materials and the suppression of impurities, hydrogen fluoride and trifluoromethane are more preferred.

[0025] As a method for contacting a fluorine compound not containing chlorine atoms with a metal compound catalyst in the gas phase, a method of introducing a fluorine compound not containing chlorine atoms in a gaseous state into a solid metal compound catalyst packed in a reactor and contacting the catalyst can be mentioned. In this catalyst activation method, after activating the metal compound catalyst, the raw material 244ca is introduced into the reactor and subjected to the dehydrofluorination reaction. Alternatively, a method may be used in which a mixed gas of the raw material 244ca and a fluorine compound not containing chlorine atoms is introduced into a reactor filled with a solid metal compound catalyst, and activation of the metal compound catalyst and dehydrofluorination reaction are carried out simultaneously. As a catalyst activation method, the former method is preferred from the viewpoint of sufficiently activating the metal compound catalyst. In some cases, the metal compound catalyst can be activated outside the reactor with a fluorine compound gas that does not contain chlorine atoms, and then the activated metal catalyst can be filled into the reactor, and the raw material 244ca can be introduced to carry out the dehydrofluorination reaction.

[0026] The temperature for the activation treatment of the catalyst in the present invention (hereinafter also referred to as the activation treatment temperature) is preferably 100 to 400°C, more preferably 150 to 400°C, even more preferably 200 to 400°C, particularly preferably 250 to 400°C, and most preferably 250 to 350°C. By setting the temperature within the above range, the metal compound catalyst can be sufficiently activated. If the activation treatment temperature does not reach the above range, the activity of the metal compound catalyst may be insufficient, and the conversion rate of the raw material may decrease. If the activation treatment temperature exceeds the above range, the activity and life of the metal compound catalyst may decrease.

[0027] In the activation treatment, the reaction time (this time refers to the contact time between the fluorine compound not containing chlorine atoms and the metal compound catalyst) is preferably 0.1 to 100 seconds, more preferably 1 to 80 seconds, and most preferably 5 to 60 seconds. By setting the time within the above range, the metal compound catalyst can be sufficiently activated. It is preferable to adjust the reaction time to be shorter when the reaction temperature is high, and longer when the reaction temperature is low. In addition, the pressure inside the reactor where the dehydrofluorination reaction is carried out is preferably 0 to 2 MPa.

[0028] (Dehydrofluorination reaction) In the production method of the present invention, the gaseous raw material 244ca is introduced into an activated metal compound catalyst packed in a reactor, and the two are brought into contact with each other to cause a dehydrofluorination reaction.

[0029] The dehydrofluorination reaction may be carried out batchwise or continuously (including semi-continuously or continuously flowing), with continuous operation being preferred from the viewpoint of production efficiency. In the case of a continuous operation, it is preferable that the supply of 244ca to the reactor, the contact and reaction of 244ca with the activated metal compound catalyst in the reactor, and the removal of the produced 1233 yd from the reactor are all carried out continuously. The material of the reactor is not particularly limited as long as it is inert to the raw materials, solvent, reaction products, etc. and is corrosion-resistant. Examples of the material for the reactor include glass, iron, nickel, and alloys such as stainless steel containing iron as a main component.

[0030] In the gas-phase dehydrofluorination reaction, the temperature of the dehydrofluorination reaction (hereinafter also referred to as the reaction temperature) is preferably 200 to 400°C, more preferably 250 to 400°C, and most preferably 275 to 400°C. By setting the temperature within the above range, the generation of impurities can be suppressed and 1233yd can be obtained with high selectivity. If the reaction temperature does not reach the above range, the reaction rate and reaction yield may decrease, and if an excess of unreacted 244ca remains, it may be difficult to separate it from 1233yd. Furthermore, if the reaction temperature exceeds the above range, the amount of 1-chloro-3,3-difluoropropyne produced by further dehydrofluorination of 1233yd may increase, or the selectivity to 1233yd may decrease.

[0031] In the gas-phase dehydrofluorination reaction, the reaction time (this time refers to the contact time between the raw material and the activated metal compound catalyst) is preferably 0.1 to 100 seconds, more preferably 1 to 80 seconds, and most preferably 5 to 60 seconds, from the viewpoint of raw material conversion rate and suppressing the generation of impurities. It is preferable to adjust the reaction time to be shorter when the reaction temperature is high, and longer when the reaction temperature is low. The pressure inside the reactor where the dehydrofluorination reaction is carried out is preferably 0 to 2 MPa.

[0032] In the gas-phase dehydrofluorination reaction of the present invention, from the viewpoint of the selectivity for 1233yd, the content of 1-chloro-3,3-difluoropropyne relative to the total amount of the reaction crude liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 1% by mass or less. The reaction crude liquid in the present invention is a crude liquid containing unreacted raw materials and reaction products. If unreacted 244ca remains, it can be concentrated by distillation and recycled as a raw material for the present invention.

[0033] In the production method of the present invention, in addition to the target product 1233yd, unreacted 244ca and 1-chloro-3,3-difluoropropyne, which is produced by further dehydrofluorination of 1233yd, may be contained. When recovering 1233yd from the reaction crude liquid containing these, it is preferable to adopt a separation and purification method such as general distillation. Here, if the product contains 1233yd(Z), it is preferable to perform high-precision distillation because the boiling points of 244ca and 1233yd(Z) are close. In addition, in order to increase the yield of 1233yd(Z), 1233yd(E) and 1233yd(Z) may be separated by a separation and purification method such as distillation.

[0034] By separating, purifying, and recovering the 1233yd obtained by the production method of the present invention as described above, purified 1233yd containing high-purity 1233yd can be obtained. If the purified 1233yd thus obtained contains acids such as HCl, water, or oxygen, it may corrode equipment during use or reduce the stability of the 1233yd. Therefore, the acid content, i.e., the chloride ion and fluoride ion content, is preferably less than 10 ppm by mass, more preferably less than 1 ppm by mass, and most preferably less than 0.1 ppm by mass, based on the total amount of purified 1233yd. Furthermore, the water concentration in the purified 1233yd is preferably less than 2000 ppm by mass, more preferably less than 1500 ppm by mass, even more preferably less than 1000 ppm by mass, and most preferably less than 100 ppm by mass. The oxygen concentration in the purified 1233yd is preferably 1000 ppm by mass or less, more preferably 500 ppm by mass or less. If the concentration is outside the above range, decomposition of 1233yd may occur, or the degreasing and cleaning performance may be impaired.

[0035] Although purified 1233yd containing 1233yd at high purity may consist of only 1233yd(Z) or 1233yd(E), a higher proportion of 1233yd(Z) is preferred in terms of productivity. In purified 1233yd, the content of 1233yd(Z) is preferably 50% by mass or more, more preferably 75 to 98% by mass, and particularly preferably 90 to 98% by mass.

[0036] In the gas-phase dehydrofluorination reaction, it is preferable to preheat and vaporize 244ca before supplying it to the reactor. In this case, the preheating temperature is preferably equal to or higher than the boiling point of 244ca and equal to or lower than 200°C. In this specification, the boiling point of the compound is expressed as a temperature at a pressure of 1.013 × 10 5 The value is in Pa (absolute pressure).

[0037] In the gas-phase dehydrofluorination reaction, in order to suppress the formation of by-products, it is preferable to mix 244ca with a diluent gas and supply it to the reactor. As the diluent gas, an inert gas such as nitrogen gas, helium gas, or argon gas can be used. The amount of diluent gas is preferably 0.1 to 10 mol per 1 mol of 244ca supplied to the reactor. When a diluent gas is used, the 244ca may be preheated before or after mixing with the diluent gas. [Example]

[0038] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples. Examples 1, 5 and 6 are examples of the present invention, and Examples 2 to 4 are comparative examples.

[0039] (Gas chromatography conditions) In the synthesis of the following compounds, the composition of the reaction products was analyzed by gas chromatography (GC) using a DB-1301 column (length 60 m × inner diameter 250 μm × thickness 1 μm, manufactured by Agilent Technologies).

[0040] (244ca manufacturing example) 244ca was produced by the following method, which involves chlorinating TFPO with thionyl chloride to obtain 244ca, as shown in the above formula (2). A 2-liter four-neck flask equipped with a glass distillation column (measured five plates) packed with a stirrer, Dimroth filter, condenser, and Raschig rings was charged with 1204 g (9.12 mol) of TFPO and 12 g (0.17 g) of N,N-dimethylformamide (DMF). 1078 g (0.12 mol) of thionyl chloride was added dropwise, and the mixture was stirred at room temperature for 12 hours. The reactor was then heated to 100°C, and reactive distillation was carried out with a reflux time / distillation time ratio of 5 / 1, using a reflux timer. The distilled 244ca was neutralized with a 20% by weight potassium hydroxide aqueous solution. 979 g (6.50 mol) of 244ca (100% purity) was recovered.

[0041] (Example 1) A bayonet tube (material: SUS316, diameter: 3 mm) was placed in the center of a vertical fixed-bed reactor (material: SUS316, inner diameter 22.6 mm × height 200 mm), and a K-type thermocouple was inserted into it to measure the internal temperature. Alumina (N612N, manufactured by JGC Catalysts and Chemicals Co., Ltd.) was packed in the center of the reactor, forming the catalyst layer. The catalyst layer was heated to 300°C in an electric furnace while supplying nitrogen gas at 300 mL / min to dry. Trifluoromethane (R-23) was then supplied at 300 mL / min, and the catalyst was activated for approximately 10 hours until the composition of the outlet gas stabilized. A raw material preheating and mixing line heated to 70°C, connected to the gas feed line and raw material supply line, was connected to the top of the reactor. The nitrogen gas flow rate was adjusted using a mass flow controller and supplied from the gas feed line to the raw material preheating and mixing line. The raw material 244ca was supplied through the raw material feed line to the raw material preheating and mixing line heated to 70°C, with the liquid flow rate adjusted using a plunger pump. The product was continuously removed from the bottom of the reactor. A portion of the product removed from the bottom of the reactor was sampled and its composition analyzed by gas chromatography (GC). Hereinafter, the product removed from the bottom of the reactor is referred to as the outlet gas. Nitrogen and raw materials were introduced into the reactor under the conditions shown in Table 1, and the reaction was carried out continuously for 10 hours. Just before the end of the reaction, a portion of the outlet gas was sampled and its composition was analyzed by gas chromatography (GC). The results are shown in Table 1.

[0042] (Examples 2-4) A vertical fixed-bed reactor (material: SUS316, inner diameter 22.6 mm × height 200 mm) was used as the reactor, and alumina (N612N, manufactured by JGC Catalysts and Chemicals Co., Ltd.) was used as the catalyst. The catalyst was dried at 300°C using the same procedure as in Example 1. Chlorodifluoromethane (R-22) was then supplied at 300 mL / min to activate the catalyst for approximately 10 hours until the composition of the outlet gas stabilized. The reaction was carried out using the same procedure as in Example 1, except that the reaction temperature and other reaction conditions were changed to those shown in Table 1. The reaction conditions and results are shown in Table 1.

[0043] [Table 1]

[0044] When the reaction is carried out in the same manner as in Example 1 except that the catalyst is activated with hydrogen fluoride or difluoromethane instead of trifluoromethane, the same results as in Example 1 are obtained. Examples 5 and 6 are shown below.

[0045] (Example 5) A vertical fixed-bed reactor (material: SUS316, inner diameter 22.6 mm x height 200 mm) was used as the reactor, and alumina (N612N, manufactured by JGC Catalysts and Chemicals Co., Ltd.) was used as the catalyst. The catalyst was dried at 300°C using the same procedure as in Example 1. Hydrogen fluoride was then supplied at 100 mL / min to activate the catalyst for approximately 10 hours. The reaction was carried out using the same procedure as in Example 1, except that the reaction temperature and other reaction conditions were changed to those shown in Table 2. The reaction conditions and results are shown in Table 2.

[0046] (Example 6) A vertical fixed-bed reactor (material: SUS316, inner diameter 22.6 mm × height 200 mm) was used as the reactor, and alumina (N612N, manufactured by JGC Catalysts and Chemicals Co., Ltd.) was used as the catalyst. The catalyst was dried at 300°C using the same procedure as in Example 1. Difluoromethane (R-32) was then supplied at 300 mL / min to activate the catalyst for approximately 10 hours. The reaction was carried out using the same procedure as in Example 1, except that the reaction temperature and other reaction conditions were changed to those shown in Table 2. The reaction conditions and results are shown in Table 2.

[0047] [Table 2] [Industrial Applicability]

[0048] According to the manufacturing method of the present invention, 244ca, which is easily available and can be supplied stably, can be used to carry out the reaction without using any special operations or reaction equipment, thereby enabling the production of 1233yd with high reaction rate and high selectivity, making it possible to apply it to mass production on an industrial scale.

[0049] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2019-121380, filed on July 15, 2020, are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

1. A method for producing 1-chloro-2,3,3-trifluoropropene by dehydrofluorinating 3-chloro-1,1,2,2-tetrafluoropropane in the presence of a catalyst in a gas phase, comprising: As the catalyst, a metal compound catalyst activated with a fluorine compound that does not contain chlorine atoms in a gas phase is used, the fluorine compound not containing a chlorine atom is a fluorinated alkane or a fluorinated alkene, The method for producing 1-chloro-2,3,3-trifluoropropene, wherein the metal compound catalyst is a metal compound catalyst containing Al or Cr.

2. The method according to claim 1 , wherein the metal compound catalyst is a metal oxide, a metal fluoride, or a metal oxyfluoride.

3. 3. The method according to claim 1, wherein the metal compound catalyst is aluminum oxide or chromium oxide.

4. The production method according to any one of claims 1 to 3, wherein the activation of the metal compound catalyst is carried out by contacting the chlorine atom-free fluorine compound with the metal compound catalyst in a gas phase.

5. The method according to any one of claims 1 to 4, wherein the fluorine compound containing no chlorine atoms is a fluorine compound containing no chlorine atoms and having 1 to 3 carbon atoms.

6. The method according to any one of claims 1 to 5, wherein the fluorine compound containing no chlorine atoms is trifluoromethane or difluoromethane.

7. The method according to any one of claims 1 to 6, wherein the activation treatment temperature in the activation of the metal compound catalyst is 100 to 400°C.

8. The method according to any one of claims 1 to 7, wherein the contact time between the fluorine compound containing no chlorine atoms and the catalyst during activation of the metal compound catalyst is 0.1 to 100 seconds.

9. The method according to any one of claims 1 to 8, wherein the dehydrofluorination reaction is carried out at a reaction temperature of 200 to 400°C.

10. The method according to any one of claims 1 to 9, wherein the contact time between 3-chloro-1,1,2,2-tetrafluoropropane and the catalyst in the dehydrofluorination reaction is 0.1 to 100 seconds.

11. The production method according to any one of claims 1 to 10, wherein the content of 1-chloro-3,3-difluoropropyne in the reaction crude liquid after the dehydrofluorination reaction is 10 mass% or less based on the total amount of the reaction crude liquid.

12. The production method according to any one of claims 1 to 11, wherein in the dehydrofluorination reaction, 3-chloro-1,1,2,2-tetrafluoropropane is mixed with a diluent gas and supplied to a reactor.

13. The production method according to any one of claims 1 to 12, wherein purified 1-chloro-2,3,3-trifluoropropene is recovered from the reaction crude liquid after the dehydrofluorination reaction.

14. the purified 1-chloro-2,3,3-trifluoropropene has a chloride ion content and a fluoride ion content of less than 10 ppm by mass, based on the total amount of the purified 1-chloro-2,3,3-trifluoropropene; the water concentration is less than 2000 ppm by mass based on the total amount of the purified 1-chloro-2,3,3-trifluoropropene; The method according to claim 13, wherein the oxygen concentration is 1000 ppm by mass or less based on the total amount of the purified 1-chloro-2,3,3-trifluoropropene.

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