CN115803308A - Method for preparing 1-chloro-2,3,3-trifluoropropene - Google Patents

Abstract

The present invention provides a method for producing 1233yd in a gas phase, which has a high conversion of raw materials, can obtain 1233yd with a high selectivity, and produces a small amount of impurities. A process for producing 1-chloro-2,3,3-trifluoropropene, which comprises subjecting 3-chloro-1,1,2,2-tetrafluoropropane to a dehydrofluorination reaction in a gas phase in the presence of a catalyst, wherein a metal compound catalyst activated with a fluorine compound containing no chlorine atom in the gas phase is used as the catalyst.

Description

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

Technical Field

The invention relates to a preparation method for preparing 1-chloro-2,3,3-trifluoropropene.

Background

1-chloro-2,3,3-trifluoropropene (hereinafter also referred to as 1233 yd) is a compound which has a small Global Warming Potential (GWP) in place of 3,3-dichloro-1,1,1,2,2-pentafluoropropane (hereinafter also referred to as 225 ca) and 1,3-dichloro-1,1,2,2,3-pentafluoropropane (hereinafter also referred to as 225 cb) and is useful for cleaning agent, refrigerant, blowing agent, solvent, and aerosol applications.

In the present specification, the abbreviation of the compound of the halogenated hydrocarbon is described in parentheses after the compound name, and the abbreviation is used in the present specification in place of the compound name as necessary.

1233yd exists as geometric isomers of Z and E depending on the position of the substituents on the double bond. In the present specification, unless otherwise specified, the compound name or the compound abbreviation means at least 1 selected from the Z isomer and the E isomer, and when the compound name or the compound abbreviation is referred to by (E) or (Z), the (E) isomer or the (Z) isomer of each compound is indicated. For example, 1233yd (Z) and 1233yd (E) represent Z and E entities of 1233yd, respectively.

As an example of 1233yd production, for example, in an example of patent document 1, it is described that a small amount of 1233yd is produced when 3-chloro-1,1,2,2-tetrafluoropropane (hereinafter, also referred to as 244 ca) is introduced in a gaseous state under a nitrogen stream in a vertical fixed bed reactor packed with activated carbon or alumina activated with chlorodifluoromethane as a catalyst.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2017/018412

Disclosure of Invention

Technical problem to be solved by the invention

However, the method for producing 1233yd by a dehydrofluorination reaction in a gas phase described in patent document 1 has problems that the conversion of the raw material is low and the amount of impurities such as 1-chloro-3,3-difluoropropylene produced is large, and is not suitable for mass production on an industrial scale.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for producing 1233yd in a gas phase, which has a high conversion rate of raw materials, can produce 1233yd with a high selectivity, and produces a small amount of impurities.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following means.

[1] A process for producing 1-chloro-2,3,3-trifluoropropene, which comprises subjecting 3-chloro-1,1,2,2-tetrafluoropropane to a dehydrofluorination reaction in a gas phase in the presence of a catalyst to produce 1-chloro-2,3,3-trifluoropropene,

among them, a metal compound catalyst activated with a fluorine compound containing no chlorine atom in a gas phase is used as the catalyst.

[2] The production process according to [1], wherein the metal compound catalyst is a metal compound catalyst containing at least one metal element selected from Cr, al, zn, ti and Ni.

[3] The production process according to any one of [1] to [2], wherein the metal compound catalyst is an oxide of a metal, a fluoride of a metal, or an oxidized fluoride of a metal.

[4] The production process according to any one of [1] to [3], wherein the metal compound catalyst is alumina or chromia.

[5] The production process according to any one of [1] to [4], wherein the activation of the metal compound catalyst is carried out by bringing the fluorine compound containing no chlorine atom into contact with the metal compound catalyst in a gas phase.

[6] The production method according to any one of [1] to [5], wherein the fluorine compound containing no chlorine atom is hydrogen fluoride or a fluorine compound containing 1 to 3 carbon atoms and no chlorine atom.

[7] The production process according to any one of [1] to [6], wherein the fluorine compound containing no chlorine atom is hydrogen fluoride, trifluoromethane or difluoromethane.

[8] The production process according to any one of [1] to [7], wherein the activation treatment temperature for activating the metal compound catalyst is 100 to 400 ℃.

[9] The production process according to any one of [1] to [8], wherein the contact time of the fluorine compound containing no chlorine atom with the catalyst in activating the metal compound catalyst is 0.1 to 100 seconds.

[10] The production process according to any one of [1] to [9], wherein the reaction temperature of the dehydrofluorination reaction is 200 to 400 ℃.

[11] The production process according to any one of [1] to [10], wherein the contact time of the catalyst with 3-chloro-1,1,2,2-tetrafluoropropane 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-difluoropropene in the reaction crude liquid after the dehydrofluorination reaction is 10% by mass or less based on the total amount of the reaction crude liquid.

[13] The production process 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 then fed to a reactor.

[14] The production process 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 production process according to [14], wherein the contents of chloride and fluoride in the purified 1-chloro-2,3,3-trifluoropropene are respectively less than 10 mass ppm relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene,

a water concentration of less than 2000 mass ppm relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene,

the oxygen concentration is 1000 mass ppm or less relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a method for producing 1233yd in a gas phase, which has a high conversion of raw materials, can obtain 1233yd with a high selectivity, and produces a small amount of impurities, can be provided.

Detailed Description

The method for producing 1233yd of the present invention is a method for producing 1233yd using 244ca as a raw material.

The 244ca dehydrofluorination reaction (hereinafter also simply referred to as "dehydrofluorination reaction") according to the production method of the present invention is a reaction represented by the following formula (1).

In the production method of the present invention, the conversion of the raw material 244ca is high, and the amount of 1-chloro-3,3-difluoropropene produced as an impurity is small.

The dehydrofluorination reaction in the production method of the present invention is carried out in a gas phase from the viewpoint of reducing the amount of waste after production and improving the productivity. The dehydrofluorination reaction in the gas phase means that 244ca in the gaseous state is subjected to a dehydrofluorination reaction.

The production method of the present invention is characterized in that 244ca is subjected to a dehydrofluorination reaction in a gas phase in the presence of a metal compound catalyst activated with a fluorine compound containing no chlorine atom in the gas phase.

(244ca)

The method for producing 1233yd of the present invention uses 244ca as a raw material. 244ca is a compound known as a starting material or intermediate for the preparation of fluorine-containing compounds and is readily available.

244ca can be obtained by, for example, a method represented by the formula (2) using thionyl chloride (SOCl) in the presence of N, N-Dimethylformamide (DMF) ₂ ) 2,2,3,3-Tetrafluoropropanol (TFPO) by chlorination. The process can be carried out in the liquid phase or in the gas phase.

In the reaction of the formula (2), a conventional reactor such as a glass flask, SUS autoclave, and glass-lined reactor can be used as the reactor. In the case of using a glass flask, it is preferable to form and separate 244ca while providing a glass distillation column filled with Raschig rings.

The amount of DMF added is about 0.001 to 0.2mol and the amount of thionyl chloride added is about 0.5 to 1.5mol based on 1mol of TFPO. DMF has a catalytic function to allow the reaction to proceed. The reaction of formula (2) is quantitatively performed in equimolar amounts, so that an excess of either one is not required.

If the addition rate of thionyl chloride is too high relative to 1mol of TFPO, the rate of hydrogen chloride generation increases, and TFPO or products may be discharged together with hydrogen chloride to the outside of the system to cause loss. Therefore, thionyl chloride is preferably added dropwise at a rate such that the temperature fluctuation due to the progress of the reaction is within 30 ℃. In addition, in the presence of water, thionyl chloride reacts with water to hydrolyze and decompose into SO ₂ And HCl. Further 2,2,3,3-tetrafluoropropane sulfonyl chloride is also hydrolyzed and decomposed into TFPO and SO ₂ And HCl. To prevent these conditions, it is preferable that the atmosphere in the reactor be replaced with dry nitrogen gas.

In the reaction of formula (2), TFPO is reacted with thionyl chloride by adding thionyl chloride to produce 2,2,3,3-tetrafluoropropane sulfonyl chloride. 2,2,3,3-tetrafluoropropane sulfonyl chloride is heated to generate a sulfur dioxide removal reaction to generate 244ca. The temperature during heating is 70 ℃ to 150 ℃, preferably 90 ℃ to 130 ℃. The temperature raising rate is arbitrary, but in order to avoid insufficient treatment of the generated sulfur dioxide or insufficient recovery of the generated 244ca, the temperature is raised at a slow rate of about 1 to 2 ℃/min to adjust the generation rate.

2,2,3,3-tetrafluoropropane sulfonyl chloride, when the rate of temperature rise is difficult to adjust, a method of heating 2,2,3,3-tetrafluoropropane sulfonyl chloride in a solvent (liquid phase reaction) is preferably used. The solvent is a solvent having a boiling point higher than the reaction temperature of the decomposition reaction of 2,2,3,3-tetrafluoropropane sulfonyl chloride and hardly reacting with the compound participating in the reaction represented by formula (2), and an aprotic solvent is preferably used. Specific examples include dimethyl sulfoxide, DMF and the like. The amount of the solvent to be used is preferably about 0.5 to 3mol based on 1mol of 2,2,3,3-tetrafluoropropane sulfonyl chloride.

5363 the desulfurization reaction of 2,2,3,3-tetrafluoropropane sulfonyl chloride is preferably carried out by a liquid phase reaction in the same reactor as described above. Namely, 244ca was produced by adding a solvent to the reactor and then heating to a temperature for sulfur dioxide removal reaction while adding 2,2,3,3-tetrafluoropropane sulfonyl chloride dropwise. The reaction temperature of the reaction for removing sulfur dioxide is 70-150 ℃, and preferably 90-130 ℃. Preferably, the atmosphere in the reaction vessel is replaced with dry nitrogen.

The 244ca crude product produced by the reaction of formula (2) is usually a gaseous crude product, and the 244 ca-containing composition can be recovered by removing impurities by treatment such as washing with water to remove hydrochloric acid and sulfur dioxide, drying with a drying agent such as calcium chloride or molecular sieve, and then feeding to a cold trap. The obtained 244 ca-containing composition can be used as it is in the production process of the present invention, or can be further purified to, for example, a 244 ca-containing composition having a purity of 99.5 mass% or more.

As 244ca used in the production method of the present invention, a composition of high purity 244ca subjected to a purification step may be used in addition to 244ca having a purity of 100%, and a 244 ca-containing composition containing components (for example, impurities) other than 244ca and 244ca may be used. However, when the latter 244 ca-containing composition is used, it is preferable to remove the impurities in advance when the impurities are impurities which are active in the dehydrofluorination reaction of the present invention. For example, in the case of 244ca produced by the method of formula (2), if TFPO remains together with the produced 244ca, it may react with the production target 1233yd of the present invention, and therefore it is preferable to remove TFPO from the product as much as possible.

In the production method of the present invention, 244ca is subjected to a dehydrofluorination reaction in the presence of a metal compound catalyst activated with a fluorine compound containing no chlorine atom. The dehydrofluorination reaction is carried out by contacting the starting material 244ca with an activated metal compound catalyst in a gas phase.

(Metal Compound catalyst)

Examples of the metal compound catalyst before activation in the present invention include metal oxides, metal fluorides, metal oxyfluorides, and the like. The metal compound catalyst may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

The metal element contained in the metal compound catalyst may be 1 kind or 2 or more kinds. When the metal compound catalyst contains 2 or more metal elements, the metal compound may be a mixture of 2 or more metal compounds having different metal elements, or may be a metal compound containing 2 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 the metal oxide include chromium oxide, aluminum oxide, zinc oxide, titanium oxide, and nickel oxide.

The metal fluoride may be a hydrate, and examples thereof include chromium fluoride, aluminum fluoride, titanium fluoride, zinc fluoride, titanium fluoride, nickel fluoride, and the like.

Examples of the metal oxide fluoride include metal compounds in which a part of chromium oxide, aluminum oxide, zinc oxide, titanium oxide, nickel oxide, and the like is fluorinated.

The metal compound catalyst is preferably an oxide of a metal, and more preferably alumina or chromium oxide, from the viewpoint of conversion and selectivity.

The metal compound catalyst may also be supported on a carrier. Examples of the carrier include an alumina carrier, a silica carrier, and a silica alumina carrier. The support may also have catalytic activity to promote the dehydrofluorination reaction. The carrier is preferably a metal compound containing at least one metal element selected from the group consisting of Cr, al, zn, ti and Ni, similar to the metal compound catalyst.

(activation of catalyst)

In the production method of the present invention, an activated metal compound catalyst is used. The activation herein means that a fluorine compound containing no chlorine atom is brought into contact with a metal compound catalyst in a gas phase. The activated metal compound catalyst is preferably partially fluorinated. As the chlorine atom-free fluorine compounds, 1 kind may be used alone, or 2 or more kinds may be used in combination.

The fluorine compound containing no chlorine atom is preferably hydrogen fluoride, fluoroalkane or fluoroalkene, and more preferably hydrogen fluoride or fluoroalkane.

The fluorine compound containing no chlorine atom is preferably hydrogen fluoride and a fluorine compound containing no chlorine atom having 1 to 3 carbon atoms, more preferably hydrogen fluoride and a fluorine compound containing no chlorine atom having 1 to 2 carbon atoms, and most preferably hydrogen fluoride and a fluorine compound containing no chlorine atom having 1 carbon atom.

Examples of the fluorine compound having 1 carbon atoms and not containing a chlorine atom include trifluoromethane and difluoromethane.

Examples of the fluorine compound having 2 carbon atoms and not containing a chlorine atom include pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1-trifluoroethane, and the like.

Examples of the fluorine compound having 3 carbon atoms and containing no chlorine atom include hexafluoropropane and 1,2,3,3-tetrafluoropropene.

As the fluorine compound containing no chlorine atom, hydrogen fluoride, trifluoromethane, and difluoromethane are preferable, and hydrogen fluoride and trifluoromethane are more preferable from the viewpoint of conversion of the raw material and suppression of impurities.

As a method of bringing a fluorine compound containing no chlorine atom into contact with a metal compound catalyst in a gas phase, there is a method of introducing a fluorine compound containing no chlorine atom in a gaseous state into a metal compound catalyst in a solid state filled in a reactor and bringing the fluorine compound into contact. In this catalyst activation method, after the metal compound catalyst is activated, the raw material 244ca is introduced into the reactor to perform a dehydrofluorination reaction.

Further, a method may be employed in which a mixed gas of the raw material 244ca and a fluorine compound containing no chlorine atom is introduced into a reactor filled with a solid metal compound catalyst, and activation of the metal compound catalyst and a dehydrofluorination reaction are simultaneously carried out.

As the catalyst activation method, the former method is preferable from the viewpoint of sufficiently activating the metal compound catalyst. In some cases, the metal compound catalyst may be activated with a gas of a fluorine compound containing no chlorine atom outside the reactor, and then the activated metal catalyst may be charged into the reactor, and the raw material 244ca may be introduced to perform the dehydrofluorination reaction.

The temperature of the catalyst activation treatment in the present invention (hereinafter also referred to as activation treatment temperature) is preferably 100 to 400 ℃, more preferably 150 to 400 ℃, still more preferably 200 to 400 ℃, particularly preferably 250 to 400 ℃, and most preferably 250 to 350 ℃. Within the above range, the metal compound catalyst can be sufficiently activated. If the activation treatment temperature is less than the above range, the activity of the metal compound catalyst may be insufficient, and the conversion rate of the raw material may be decreased. When the activation treatment temperature exceeds the above range, the activity and the lifetime of the metal compound catalyst may be reduced.

In the activation treatment, the reaction time (which is the contact time of the chlorine atom-free fluorine compound with the metal compound catalyst) is preferably 0.1 to 100 seconds, more preferably 1 to 80 seconds, most preferably 5 to 60 seconds. Within the above range, the metal compound catalyst can be sufficiently activated. The higher the reaction temperature, the shorter the reaction time, and the lower the reaction temperature, the longer the adjustment. The pressure in the reactor in which the dehydrofluorination reaction is carried out is preferably 0 to 2MPa.

(dehydrofluorination reaction)

In the production method of the present invention, the dehydrofluorination reaction is carried out by introducing the raw material 244ca in a gaseous state into the activated metal compound catalyst filled in the reactor and bringing them into contact with each other.

The dehydrofluorination reaction may be carried out batchwise or continuously (including semicontinuous or continuous flow type), but is preferably carried out continuously from the viewpoint of production efficiency. In the case of the continuous type, it is preferable that the steps of supplying 244ca to the reactor, contacting 244ca in the reactor with the activated metal compound catalyst, reacting, and discharging 1233yd produced from the reactor are continuously performed.

The material of the reactor is not particularly limited as long as it is inert to the raw materials, the solvent, the reaction product, and the like and resistant to corrosion. Examples of the material of the reactor include glass, iron, nickel, and alloys such as stainless steel containing iron as a main component.

In the dehydrofluorination reaction in the gas phase, the temperature of the dehydrofluorination reaction (hereinafter also referred to as the reaction temperature) is preferably 200 to 400 ℃, more preferably 250 to 400 ℃, and most preferably 275 to 400 ℃. In the above range, production of impurities can be suppressed, and 1233yd can be obtained with high selectivity. If the reaction temperature is lower than the above range, the reaction rate and the reaction yield may be lowered, and if the unreacted 244ca remains in excess, the separation from 1233yd may become difficult. If the reaction temperature exceeds the above range, the amount of 1-chloro-3,3-difluoropropene produced may be increased by further dehydrofluorination of 1233yd, and the selectivity of 1233yd may be decreased.

In the dehydrofluorination reaction in the gas phase, the reaction time (which is 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 suppressing the conversion of the raw material and the generation of impurities. The higher the reaction temperature, the shorter the reaction time, and the lower the reaction temperature, the longer the adjustment. The pressure in the reactor in which the dehydrofluorination reaction is carried out is preferably 0 to 2MPa.

In the gas-phase dehydrofluorination reaction of the present invention, the content of 1-chloro-3,3-difluoropropene is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 1% by mass or less, relative to the total amount of the reaction crude liquid, from the viewpoint of the selectivity of 1233yd. The reaction crude liquid in the present invention is a crude liquid containing unreacted raw materials and reaction products.

When unreacted 244ca remains, 244ca can be concentrated by distillation and recycled as a raw material of the present invention.

The production method of the present invention may contain, in addition to the target 1233yd, 1-chloro-3,3-difluoropropene produced by further dehydrofluorination of unreacted 244ca and 1233yd. When 1233yd is recovered from the reaction crude liquid containing these substances, a separation and purification method by ordinary distillation or the like is preferably employed. On the other hand, when 1233yd (Z) is contained in the product, it is preferable to perform distillation with high precision because the boiling points of 244ca and 1233yd (Z) are close to each other.

In order to increase the yield of 1233yd (Z), separation of 1233yd (E) and 1233yd (Z) may be performed by a separation and purification method such as evaporation.

By recovering 1233yd produced by the production method of the present invention by the above separation and purification, purified 1233yd containing 1233yd at high purity can be obtained. When the purified 1233yd thus obtained contains an acid component such as HCl, water, or oxygen, it may corrode facilities or deteriorate the stability of 1233yd during use. Therefore, the contents of the acid components, i.e., chloride ion and fluoride ion, are preferably less than 10 mass ppm, more preferably less than 1 mass ppm, and most preferably less than 0.1 mass ppm, respectively, with respect to the total amount of purified 1233yd. The water concentration in the purified 1233yd is preferably less than 2000 mass ppm, more preferably less than 1500 mass ppm, still more preferably less than 1000 mass ppm, and most preferably less than 100 mass ppm. The oxygen concentration in the purified 1233yd is preferably 1000 mass ppm or less, more preferably 500 mass ppm or less. Outside the above range, 1233yd may be decomposed or degreasing and cleaning performance may be impaired.

The 1233yd purified to contain 1233yd at high purity may be 1233yd (Z) or 1233yd (E) alone, but in view of productivity, it is preferable that the proportion of 1233yd (Z) is high. In the 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.

In the dehydrofluorination reaction in the gas phase, it is preferable to preheat 244ca and supply it to the reactor after it is vaporized. The preheating temperature in this case is preferably from 244ca to 200 ℃. In this specification, the boiling point of the compound is 1.013X 10 ⁵ Pa (absolute pressure).

In the dehydrofluorination reaction in the gas phase, it is preferable to mix 244ca with a diluent gas and supply the mixture to the reactor in order to suppress the formation of by-products. As the diluent gas, an inert gas such as nitrogen, helium, or argon can be used. The amount of the diluent gas is preferably 0.1 to 10mol based on 1mol of 244ca supplied to the reactor.

In the case of using the diluent gas, when preheating 244ca, 244ca may be preheated before mixing with the diluent gas or may be preheated after mixing.

Examples

The present invention will be described in more detail 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.

(conditions of gas chromatography)

In the following production of each compound, the composition of the obtained reaction product was analyzed by Gas Chromatography (GC). The column was DB-1301 (length 60m, inner diameter 250 μm, thickness 1 μm, available from Agilent technologies, アジレント, テクノロジー K.K.).

(example of 244 ca)

244ca is manufactured by the following method. The following method is a method of obtaining 244ca by chlorinating TFPO with thionyl chloride as shown in the above formula (2).

A2 liter four-necked flask equipped with a stirrer, a pipe of dimu Luo Lengning, a cooler, and a glass distillation column packed with Raschig rings (5 stages measured in the number of plates) was charged with 1204g (9.12 mol) of TFPO and 12g (0.17 g) of N, N-Dimethylformamide (DMF). 1078g (0.12 mol) of thionyl chloride was added dropwise thereto, and stirred at room temperature for 12 hours. Then, the reactor was heated to 100 ℃ and reactive distillation was carried out according to a reflux timer at a reflux time/distillation time ratio of 5/1. The distilled 244ca was neutralized with a 20 mass% aqueous potassium hydroxide solution. The 244ca (purity 100%) recovered was 979g (6.50 mol).

(example 1)

An insertion tube (material: SUS316, diameter: 3 mm) was introduced into the center of a vertical fixed-bed reactor (material: SUS316, inner diameter: 22.6 mm. Times. Height: 200 mm), and a K-type thermocouple was inserted into the insertion tube to measure the inner temperature. The reactor was filled with alumina (manufactured by Nissan catalytic conversion Co., ltd., N612N) at the center thereof as a catalyst layer. The catalyst layer with 300mL/min nitrogen gas while heating to 300 degrees C for drying. Trifluoromethane (R-23) was then fed at 300mL/min and the catalyst was activated for about 10 hours until the outlet gas composition stabilized. The raw material preheating mixing line connecting the gas feeding line and the raw material feeding line was heated to 70 c and connected to the upper portion of the reactor.

The nitrogen gas was supplied from the gas supply line to the raw material preheating and mixing line by adjusting the gas flow rate using a mass flow controller. The raw material 244ca was supplied to the raw material preheating and mixing line heated to 70 ℃ through the raw material supply line with the liquid flow rate adjusted by a plunger pump. The product was continuously discharged from the lower part of the reactor. A part of the product discharged from the lower portion of the reactor was collected and subjected to composition analysis by Gas Chromatography (GC). Hereinafter, the product discharged from the lower portion of the reactor is referred to as an outlet gas.

Nitrogen and the raw materials were introduced into the reactor under the conditions shown in Table 1, and the reaction was continued for 10 hours. A portion of the outlet gas was collected immediately before the end of the reaction and analyzed for composition by Gas Chromatography (GC). The results are shown in Table 1.

(examples 2 to 4)

Using a vertical fixed bed reactor (material: SUS316, inner diameter 22.6 mm. Times. Height 200 mm) as a reactor and alumina (N612N, manufactured by Nikkiso Kagaku Co., ltd.) as a catalyst, the catalyst was dried at 300 ℃ in the same manner as in example 1. Chlorodifluoromethane (R-22) was then fed at 300mL/min and the catalyst was activated for about 10 hours until the outlet gas composition stabilized. The reaction was carried out in the same manner 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.

TABLE 1

The reaction was carried out in the same manner as in example 1 except that hydrogen fluoride or difluoromethane was used instead of trifluoromethane to activate the catalyst, and the same results as in example 1 were obtained. As examples of this, (example 5) and (example 6) are shown below.

(example 5)

A vertical fixed-bed reactor (material: SUS316, inner diameter 22.6 mm. Times. Height 200 mm) was used as a reactor, and alumina (N612N, manufactured by Nikkaido chemical Co., ltd.) was used as a catalyst, and the catalyst was dried at 300 ℃ in the same manner as in example 1. Then, hydrogen fluoride was supplied at 100mL/min to activate the catalyst for about 10 hours. The reaction was carried out in the same manner 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.

(example 6)

Using a vertical fixed bed reactor (material: SUS316, inner diameter 22.6 mm. Times. Height 200 mm) as a reactor and alumina (N612N, manufactured by Nikkiso Kagaku Co., ltd.) as a catalyst, the catalyst was dried at 300 ℃ in the same manner as in example 1. Difluoromethane (R-32) was then supplied at 300mL/min to activate the catalyst for about 10 hours. The reaction was carried out in the same manner 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.

[ TABLE 2]

Industrial applicability of the invention

By the production method of the present invention, 1233yd can be produced at a high reaction rate and a high selectivity by performing the reaction using 244ca, which is easily available and can be stably supplied, without using a special operation or a reaction apparatus, and thus, the production method can be applied to mass production on an industrial scale.

The entire contents of the specification, claims, drawings and abstract of japanese patent application No. 2019-121380 filed on 7/15/2020, are hereby incorporated by reference as disclosure of the present specification.

Claims (15)

1. A process for producing 1-chloro-2,3,3-trifluoropropene, which comprises subjecting 3-chloro-1,1,2,2-tetrafluoropropane to a dehydrofluorination reaction in a gas phase in the presence of a catalyst to produce 1-chloro-2,3,3-trifluoropropene,

among them, a metal compound catalyst activated with a fluorine compound containing no chlorine atom in a gas phase is used as the catalyst.

2. The production method according to claim 1, wherein the metal compound catalyst is a metal compound catalyst containing at least one metal element selected from the group consisting of Cr, al, zn, ti and Ni.

3. The production process according to any one of claims 1 to 2, wherein the metal compound catalyst is an oxide of a metal, a fluoride of a metal, or an oxide fluoride of a metal.

4. The production process according to any one of claims 1 to 3, wherein the metal compound catalyst is alumina or chromia.

5. The production process according to any one of claims 1 to 4, wherein the activation of the metal compound catalyst is carried out by contacting the fluorine compound containing no chlorine atom with the metal compound catalyst in a gas phase.

6. The production method according to any one of claims 1 to 5, wherein the fluorine compound containing no chlorine atom is hydrogen fluoride or a fluorine compound containing no chlorine atom and having 1 to 3 carbon atoms.

7. The production method according to any one of claims 1 to 6, wherein the chlorine atom-free fluorine compound is hydrogen fluoride, trifluoromethane or difluoromethane.

8. The production process according to any one of claims 1 to 7, wherein the activation treatment temperature in the activation of the metal compound catalyst is 100 to 400 ℃.

9. The production process according to any one of claims 1 to 8, wherein the contact time of the fluorine compound containing no chlorine atom with the catalyst in the activation of the metal compound catalyst is 0.1 to 100 seconds.

10. The production process according to any one of claims 1 to 9, wherein the reaction temperature of the dehydrofluorination reaction is 200 to 400 ℃.

11. The production process according to any one of claims 1 to 10, wherein the contact time of 3-chloro-1,1,2,2-tetrafluoropropane with the catalyst in the dehydrofluorination reaction is from 0.1 to 100 seconds.

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

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

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

15. The production process according to claim 14, wherein the contents of chloride and fluoride in the purified 1-chloro-2,3,3-trifluoropropene are each less than 10 mass ppm relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene,

a water concentration of less than 2000 mass ppm relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene,

the oxygen concentration is 1000 mass ppm or less relative to the total amount of the purified 1-chloro-2,3,3-trifluoropropene.