Method for producing 1,1-dichloro-3,3,3-trifluoropropene

Abstract

To prevent sedimentation of polymers in piping and a reactor downstream of an evaporator in a high-temperature gas phase reaction of HCP.SOLUTION: A method of producing 1,1-dichloro-3,3,3-trifluoropropene by reacting 1,1,1,3,3,3-hexachloropropane with hydrogen fluoride is provided, the method including: reacting 1,1,1,3,3,3-hexachloropropane with hydrogen fluoride in a reactor whose contact face with 1,1,1,3,3,3-hexachloropropane comprises an alloy mainly composed of nickel, or nickel.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing 1,1-dichloro-3,3,3-trifluoropropene (hereinafter sometimes referred to as HCFO-1223za). [Background technology]

[0002] 1,1,1,3,3,3-Hexachloropropane (hereinafter sometimes referred to as HCP) is useful as a raw material for the synthesis of halogenated hydrocarbons by dehydrochlorination reaction. Patent Document 1 describes the production of 1,1,1,3,3,3-hexafluoropropane (hereinafter sometimes referred to as HFC-236fa) by reacting HCP with hydrogen fluoride (HF) in the gas phase in the presence of a catalyst to fluorinate the HCP. Since the normal boiling point of HCP is about 200°C, the gas phase reaction described in Patent Document 1 is carried out at a temperature of about 200 to 400°C. Patent Document 1 also describes the production of CF, a halo precursor of HFC-236fa, as the reaction product. 3 CH=CCl 2 However, it is described that these halo precursors of HFC-236fa are separated from the reaction product and returned to the reactor so as to be converted to HFC-236fa. 3 When HCP and HF were reacted using a carbon catalyst, 95% of the unsaturated product C was 3 HCl 2 F 3 It is reported that a mixture of isomers and 4.4% HFC-236fa was obtained, but the unsaturated product C 3 HCl 2 F 3 It is described that the HCFO-1223za is recycled and used for the production of HFC-236fa. Patent Document 1 describes HCFO-1223za as a by-product, but does not describe the conditions for efficiently producing HCFO-1223za.

[0003] Patent Document 2 discloses a method for producing HCFO-1223za by gas-phase fluorination of 1,1,3,3,3-pentachloropropene (1220za) with hydrogen fluoride. Example 7-1 of Patent Document 2 describes that gas-phase fluorination of 1220za was performed using a stainless steel reactor (SUS316) packed with stainless steel Raschig rings (SUS316L), and HCFO-1223za was obtained in a yield (GC yield) of 90% or more. However, to the knowledge of the present inventor, there is no prior art document that discloses the production of HCFO-1223za as a final product by a gas-phase reaction from HCP and hydrogen fluoride.

[0004] On the other hand, HCFO-1223za is a useful compound as a solvent, a raw material for the production of halogen compounds, etc., and in consideration of production efficiency, it needs to be produced on a scale of at least several tons per year (tons / year scale) using a single production device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 10-503518 [Patent Document 2] Republished WO2018 / 193884 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the study by the present inventors, when HCP is introduced as a liquid into a catalyst tower filled with a catalyst, local overheating occurs in the catalyst tower, making it impossible to continue the reaction. Also, when HCP is introduced into an evaporator made of SUS304 heated to 250°C, polymers gradually accumulate and block the evaporator, making it impossible to supply HCP to the reactor and making it impossible to continue the reaction. Considering the normal boiling point of HCP, it is necessary to heat HCP to a temperature of at least 200°C in the evaporator in order to form HCP vapor. In addition, in order to mass-produce 1223za, it is necessary to efficiently react a large amount of HCP with HF using a catalyst. In addition, considering the disadvantage of the complicated structure of the apparatus, it is not realistic to perform the reaction by lowering the boiling point of HCP under reduced pressure conditions. Therefore, the object of the present invention is to provide a method for mass-producing 1223za by preventing the accumulation of polymers in the piping and reactor downstream of the evaporator when HCP is supplied as a gas in a high-temperature gas-phase reaction of HCP, stably carrying out the reaction, and mass-producing 1223za. [Means for solving the problem]

[0007] The present invention provides the following: [1] A method for producing 1,1-dichloro-3,3,3-trifluoropropene by reacting 1,1,1,3,3,3-hexachloropropane with hydrogen fluoride, comprising reacting 1,1,1,3,3,3-hexachloropropane with hydrogen fluoride in a reactor whose surface in contact with the 1,1,1,3,3,3-hexachloropropane is made of an alloy mainly composed of nickel or nickel. [2] The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to [1], wherein the alloy contains 56% by weight or more of nickel. [3] The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to [1] or [2], wherein the temperature of the reactor is 190°C to 250°C. [4] The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to any one of [1] to [3], wherein the surface of the reactor that comes into contact with 1,1,1,3,3,3-hexachloropropane is made of nickel. [5] The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to any one of [1] to [4], wherein 1,1,1,3,3,3-hexachloropropane is vaporized in an evaporator having a surface that comes into contact with 1,1,1,3,3,3-hexachloropropane made of the alloy or nickel, and then introduced into the reactor. [6] The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to [5], wherein the temperature of the evaporator is 200°C to 250°C. [7] The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to [5] or [6], wherein the surface of the evaporator that comes into contact with 1,1,1,3,3,3-hexachloropropane is made of nickel. [8] A method for preventing deposition of polymerized matter in an evaporator for vaporizing 1,1,1,3,3,3-hexachloropropane in a high-temperature gas-phase reaction of 1,1,1,3,3,3-hexachloropropane, and in piping and a reactor downstream of the evaporator, the method comprising providing an evaporator, piping and a reactor whose surfaces in contact with 1,1,1,3,3,3-hexachloropropane are composed of an alloy mainly composed of nickel or nickel. [9] Use of an evaporator for vaporizing 1,1,1,3,3,3-hexachloropropane in a high-temperature gas-phase reaction of 1,1,1,3,3,3-hexachloropropane and a piping and a reactor downstream of the evaporator, the evaporator, the piping and the reactor having a surface in contact with 1,1,1,3,3,3-hexachloropropane made of an alloy mainly composed of nickel or nickel. Effect of the Invention

[0008] According to the present invention, deposition of polymers in the evaporator and downstream piping and reactor during the high-temperature gas-phase reaction of HCP can be prevented, the reaction can be carried out stably, and 1223za can be mass-produced. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a reaction apparatus used in Example 1 and Comparative Example 1. [Diagram 2] FIG. 1 is a schematic diagram of a reaction apparatus used in Comparative Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Effect] The present inventors believed that the polymerization of HCP occurs because the inner wall of the reactor functions as a catalyst, and investigated various materials for the inner wall of the reactor. As a result, they found that when a reactor whose surface in contact with HCP is made of an alloy mainly composed of nickel or nickel is used, polymerization of HCP does not occur and no accumulation of polymerized products is observed.

[0011] [Contact surface with HCP] In the present invention, the contact surface with the HCP must be made of nickel or an alloy mainly composed of nickel, and is preferably made of nickel alone. Only the contact surface may be coated with these metals, or the member may be made of these metals in part or in whole. In the alloy mainly composed of nickel, the proportion of nickel is preferably 56% by weight or more, and more preferably 69% by weight or more, based on the weight of the entire alloy.

[0012] Examples of alloys include Hastelloy (registered trademark) B-2, Hastelloy B-3, Hastelloy C-4, Hastelloy C-2000, Hastelloy C-22, Hastelloy C-276, Hastelloy N, Hastelloy W, Monel (registered trademark) 400, Monel K500, INCONEL (registered trademark) 600, INCONEL 625, INCONEL X750, and the like.

[0013] [HCFO-1223za manufacturing conditions] In the present invention, HCFO-1223za is produced by a gas phase reaction between HCP and hydrogen fluoride. The reaction is usually carried out by vaporizing HCP at normal pressure at a temperature of 200°C or higher, preferably 200°C to 300°C, more preferably 210°C to 250°C, and then mixing with hydrogen fluoride vapor. The temperature of the reactor may be lower than the temperature of the evaporator, and is preferably 190°C to 250°C, more preferably 190°C to 230°C. The supply ratio of HCP to hydrogen fluoride is preferably 1:1 to 1:10, more preferably 1:1 to 1:7, and even more preferably 1:1 to 1:5 in terms of molar ratio (equivalent ratio, gas flow rate ratio). In contrast to hydrogen fluoride, the molecular weight of HCP is relatively large at 251, and therefore it is easy to liquefy at normal pressure. For this reason, it is not desirable to supply a large amount of HCP, and the supply amount of HCP varies depending on the size of the reactor. For example, when the reactor is 40A×150cm, it is preferably 930 to 1740sccm, more preferably 1200 to 1470sccm. On the other hand, hydrogen fluoride can be supplied in excess, but since the surplus hydrogen fluoride must be detoxified, it is usually supplied at a flow rate of preferably 930 to 17400sccm, more preferably 1200 to 7350sccm, in consideration of reaction efficiency. In this specification, "sccm" is defined as the flow rate (cc) of gas per minute converted to a value at 1 atmospheric pressure and 25°C.

[0014] The HCP and hydrogen fluoride may be supplied together with an inert gas. Examples of the inert gas include nitrogen and noble gases such as helium, neon, argon, and xenon. The inert gas is usually supplied at a flow rate of preferably 0 to 1340 sccm, more preferably 0 to 670 sccm. The inert gas is also used to temporarily purge the inside of the piping to prevent accumulation of substances.

[0015] HCP and hydrogen fluoride are supplied to the reactor in a gaseous state, and a catalyst may be present in the reactor to improve the reaction efficiency. Examples of the catalyst include halides, oxyhalides, and oxides of metals such as chromium, titanium, manganese, cobalt, nickel, copper, zinc, niobium, and tantalum. The catalyst may be supported on a carrier such as activated carbon, alumina, or zeolite, and the concentration of the supported catalyst is preferably 5 to 30%, more preferably 10 to 25%, based on the weight of the entire catalyst.

[0016] [HCFO-1223za manufacturing equipment] In FIG. 1, which shows a manufacturing apparatus for HCFO-1223za, liquid HCP, which is a reaction substrate, is pumped from an HCP storage tank 1 through a pipe 2 to an evaporator 3. Although not shown, when HCP is supplied to the evaporator 3, nitrogen gas (N 2 ) to adjust the concentration and flow rate of HCP. Meanwhile, hydrogen fluoride (HF) is supplied from a HF storage tank 4 through a pipe 5 to the evaporator 3. When hydrogen fluoride is supplied to the evaporator 3, nitrogen gas (N 2 ) to adjust the concentration and flow rate. In the evaporator of FIG. 1, hydrogen fluoride vapor flows horizontally from one end of the cylindrical evaporator to the other end, and liquid HCP is supplied from the side wall of the evaporator perpendicular to the flow of hydrogen fluoride. The side wall of the evaporator is at 200° C. or higher, and the liquid HCP vaporizes when it enters the evaporator. The gaseous HCP mixes with hydrogen fluoride, moves horizontally to the other end of the evaporator, and exits the evaporator. The mixture of HCP, hydrogen fluoride, and possibly an inert gas that exits the evaporator end is sent through the pipe 6 to the top end of a cylindrical catalyst tower 7 that is vertically erected. The catalyst tower 7 is formed by filling a cylindrical reactor with a catalyst, and has a structure in which substrate gas flows in from the top end and product gas flows out from the bottom end. The temperature of the catalyst tower 7 (i.e., the reactor) can be set lower than the temperature of the evaporator. The reaction product leaving the bottom end of the catalyst tower 7 passes through a pipe 8 and a buffer tank (empty trap) 9, and is collected as a liquid in a collection tank 10 filled with water.

[0017] The inventors' research has revealed that by supplying gaseous HCP and HF to a reactor filled with a catalyst, the reaction substrates can be uniformly supplied, localized heat generation in the reactor can be prevented, and the reaction can be stably carried out. However, the high-temperature HCP gas obtained by vaporizing HCP causes the problem of HCP polymers accumulating in the evaporator and the downstream piping and components leading to the reactor. In the present invention, this problem is solved by making the parts of these components that come into contact with HCP out of an alloy mainly composed of nickel or nickel.

[0018] [Method to prevent accumulation of polymers] Another aspect of the present invention is a method for preventing deposition of polymers in an evaporator for vaporizing HCPs in a high-temperature gas-phase reaction of HCPs and in a piping and reactor downstream of the evaporator, the method comprising providing an evaporator, piping and reactor whose contact surfaces with HCPs are made of nickel-based alloy or nickel. Research by the present inventors has revealed that an evaporator, piping and reactor whose contact surfaces with HCPs are made of nickel-based alloy or nickel prevents the formation of polymers derived from HCPs. The gas flow rate, temperature and other conditions for carrying out this method are as described above for the production conditions of HCFO-1223za.

[0019] [Use of evaporators, piping and reactors to prevent polymer build-up] Another aspect of the present invention is the use of an evaporator, piping, and reactor having a contact surface with HCP made of nickel-based alloy or nickel as an evaporator for vaporizing HCP in a high-temperature gas-phase reaction of HCP and a piping and reactor downstream of the evaporator. According to the research of the present inventors, it has been found that an evaporator, piping, and reactor having a contact surface with HCP made of nickel-based alloy or nickel prevents the formation of polymers derived from HCP. The conditions such as gas flow rate and temperature for using such an evaporator, piping, and reactor are the same as those described above for the production conditions of HCFO-1223za. EXAMPLES

[0020] The present invention will be described with reference to the following examples, but the scope of the present invention should not be construed as being limited to these examples. (Reference Example 1 (Nickel (Ni) piece)) 7.00g of 1,1,1,3,3,3-hexachloropropane (HCP) and 0.88g of Ni chips were placed in a 20ml test tube equipped with a Dimroth condenser and heated to reflux at 250°C under a nitrogen blanket. After 2 hours, the heating was stopped and the mixture was cooled. The recovered contents were a yellow liquid consisting of 23.0% by weight of 1,1,3,3,3-pentachloropropene (PCP) and 76.9% by weight of 1,1,1,3,3,3-hexachloropropane (HCP). The amount of by-products, including polymerized products, was less than 0.1% by weight.

[0021] (Reference example 2 (SUS piece)) 7.00g of 1,1,1,3,3,3-hexachloropropane and 0.78g of SUS304 pieces were placed in a 20ml test tube equipped with a Dimroth condenser and heated to 250℃ under a nitrogen blanket. After 2 hours, the heating was stopped and the tube was cooled. The recovered contents were a black solid consisting of 0.5% by weight of 1,1,3,3,3-pentachloropropene, 0.1% by weight of 1,1,1,3,3,3-hexachloropropane, and 99.4% by weight of polymers.

[0022] (Reference Example 3 (Hastelloy C-22 piece)) 7.03g of 1,1,1,3,3,3-hexachloropropane and 1.84g of Hastelloy C-22 pieces were placed in a 20ml test tube equipped with a Dimroth condenser and heated to 250°C under a nitrogen blanket. After 2 hours, the heating was stopped and the tube was cooled. The recovered contents were a brown liquid consisting of 94.1% by weight of 1,1,3,3,3-pentachloropropene, 3.4% of 1,1,1,3,3,3-hexachloropropane, and 2.4% of polymers.

[0023] (Reference Example 4 (Hastelloy B-2 piece)) 10.06 g of 1,1,1,3,3,3-hexachloropropane and 3.71 g of Hastelloy B-2 pieces were placed in a 20 ml test tube equipped with a Dimroth condenser and heated to 250°C under a nitrogen blanket. After 2 hours, the heating was stopped and the tube was cooled. The recovered contents were a yellow liquid consisting of 43.1% by weight of 1,1,3,3,3-pentachloropropene (PCP), 56.7% of 1,1,1,3,3,3-hexachloropropane (HCP), and 0.2% of polymerized products.

[0024] The results of Reference Examples 1 to 4 are summarized in Table 1. [Table 1]

[0025] From Table 1, it was found that the higher the nickel content, the less polymerized products were produced, and that in order to prevent the production of polymerized products and prevent clogging of the reactor, it was necessary to use an alloy having a nickel content of 56% by weight or more (e.g., Hastelloy C-22). It was found that the production of polymerized products could be further suppressed by using an alloy having a nickel content of 69% by weight or more (e.g., Hastelloy B-2), and that the polymerized products could be suppressed to less than 0.1% by weight if nickel was used alone. The nickel used in Reference Example 1 had a purity of 99% by weight or more, and the remainder other than nickel was impurities, so it could be said that the nickel was essentially composed of only nickel.

[0026] Example 1 Nickel evaporator (40A x 20cm) and 17wt% CrF 3-The apparatus was made of a nickel catalyst tower (40A x 150cm) packed with 1.1kg of activated carbon catalyst. The evaporator was heated to 250℃ and the catalyst tower was heated to an internal temperature of 190℃, and HF was flowed at 3.90SLM (indicated value) for 30 minutes. After that, while HF was flowed at 0.24kg / h (11.8mol / h, 3.6eq), 1,1,1,3,3,3-hexachloropropane (HCP) was supplied to the evaporator at a setting of 9.03ml / min (=0.84kg / h (3.35mol / h)) and vaporized in the evaporator, and the mixture of HCP and HF was passed through the catalyst tower to react. After passing 64.3kg of 1,1,1,3,3,3-hexachloropropane through the water trap, 38.8kg of an organic layer containing HCFO-1223za at a ratio of 93.2% by weight was obtained from the water trap, with a yield of 85%. After that, 369.6 kg of 1,1,1,3,3,3-hexachloropropane (HCP) was fed and the evaporator was opened and inspected, but no polymerized products were found.

[0027] Comparative Example 1 The reactor shown in FIG. 1 is equipped with a SUS304 evaporator (40A×20cm) and a 17% by weight CrF 3 -In an apparatus equipped with a SUS304 catalyst tower (40A x 150cm) filled with 1.1kg of activated carbon catalyst, the evaporator was heated to 250℃ and the catalyst tower was heated to an internal temperature of 190℃, and hydrogen fluoride (HF) was passed through for 30 minutes at 580SCCM (indicated value). After that, while passing HF at 0.22kg / h (10.99mol / h, 3.6eq), 1,1,1,3,3,3-hexachloropropane (HCP) was supplied to the evaporator at a flow rate of 8.45ml / min (=0.76kg / h (3.03mol / h)) and vaporized in the evaporator, and the mixture of HCP and HF was passed through the catalyst tower to react. After passing 1,1,1,3,3,3-hexachloropropane through the catalyst tower for 150 hours, the evaporator was clogged, and 1,1,1,3,3,3-hexachloropropane and HF could no longer be supplied. Upon opening and inspecting, it was found that the evaporator was clogged with a black solid.

[0028] Comparative Example 2 The reactor shown in FIG. 2 is a 17 wt. % CrF 3-In an apparatus equipped with a SUS304 catalyst tower (40A x 150cm) packed with 1.1kg of activated carbon catalyst, the catalyst tower was heated to an internal temperature of 190°C and HF was passed through it at 580SCCM (indicated value) for 30 minutes. After that, while passing HF at 0.22kg / h (10.99mol / h, 3.6eq), 1,1,1,3,3,3-hexachloropropane (HCP) was supplied directly to the catalyst tower without passing through an evaporator at a setting of 8.45ml / min (=0.76kg / h (3.03mol / h)), and the catalyst tower was aerated and reacted. Shortly after starting the supply of 1,1,1,3,3,3-hexachloropropane (HCP), a temperature rise was observed in part of the catalyst tower. After 30 minutes of supply and aeration, the temperature rose to over 300°C and showed a tendency to continue to rise. Therefore, the supply of 1,1,1,3,3,3-hexachloropropane was stopped and the reaction was interrupted.

[0029] According to Example 1, which satisfies the requirements of the present invention, it was found that by using a metal mainly composed of nickel as the surface inside the reactor, HCFO-1223za can be obtained at a yield of over 80% without clogging the reactor with polymers. In Comparative Example 2, in which the surface inside the reactor is made of SUS304, an evaporator was used to adjust the flow rate of the raw material gas in an attempt to achieve stable production, but the evaporator was clogged after 150 hours of HCP aeration. In Comparative Example 4, in which an evaporator was not used, the catalyst tower was heated to over 300°C after 30 minutes of raw material aeration, and a tendency for the temperature to further increase was observed, so the reaction was stopped. Thus, according to the present invention, HCFO-1223za can be obtained at a high yield without generating polymers. According to the present invention, a large amount of HCFO-1223za can be produced stably for a long period of time, which is very advantageous when mass-producing HCFO-1223za.

Claims

1. A method for producing 1,1-dichloro-3,3,3-trifluoropropene by reacting 1,1,1,3,3,3-hexachloropropane with hydrogen fluoride, comprising the steps of: The method includes reacting 1,1,1,3,3,3-hexachloropropane with hydrogen fluoride in a reactor having a surface in contact with the 1,1,1,3,3,3-hexachloropropane that is made of an alloy mainly composed of nickel or nickel, 1,1,1,3,3,3-hexachloropropane is vaporized in an evaporator whose contact surface with 1,1,1,3,3,3-hexachloropropane is made of the alloy or nickel, and a mixture of 1,1,1,3,3,3-hexachloropropane and hydrogen fluoride or a mixture of 1,1,1,3,3,3-hexachloropropane, hydrogen fluoride and an inert gas is introduced into the reactor; The temperature of the evaporator is 200°C to 250°C. Method for producing 1,1-dichloro-3,3,3-trifluoropropene.

2. The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to claim 1, wherein the alloy contains 56% by weight or more of nickel.

3. The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to claim 1 or 2, wherein the temperature of the reactor is 190°C to 250°C.

4. The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to any one of claims 1 to 3, wherein the surface of the reactor that comes into contact with 1,1,1,3,3,3-hexachloropropane is made of nickel.

5. The method for producing 1,1-dichloro-3,3,3-trifluoropropene according to any one of claims 1 to 4, wherein the surface of the evaporator that comes into contact with 1,1,1,3,3,3-hexachloropropane is made of nickel.

6. A method for preventing deposition of polymers in an evaporator for vaporizing 1,1,1,3,3,3-hexachloropropane and in piping and a reactor downstream of the evaporator in a method for producing 1,1-dichloro-3,3,3-trifluoropropene by a high-temperature gas-phase reaction of 1,1,1,3,3,3-hexachloropropane, comprising: providing an evaporator, a piping, and a reactor, the surfaces of which in contact with 1,1,1,3,3,3-hexachloropropane are made of a nickel-based alloy or nickel; 1,1,1,3,3,3-hexachloropropane is vaporized in the evaporator, and a mixture of 1,1,1,3,3,3-hexachloropropane and hydrogen fluoride or a mixture of 1,1,1,3,3,3-hexachloropropane, hydrogen fluoride and an inert gas is introduced into the reactor; The temperature of the evaporator is 200°C to 250°C. method.

7. A method for producing 1,1-dichloro-3,3,3-trifluoropropene by subjecting 1,1,1,3,3,3-hexachloropropane to a high-temperature gas-phase reaction with hydrogen fluoride, comprising the steps of: an evaporator for vaporizing 1,1,1,3,3,3-hexachloropropane; and a piping and reactor downstream of the evaporator, the evaporator, piping and reactor having a surface in contact with 1,1,1,3,3,3-hexachloropropane that is made of an alloy mainly composed of nickel or nickel, 1,1,1,3,3,3-hexachloropropane is vaporized in the evaporator, and a mixture of 1,1,1,3,3,3-hexachloropropane and hydrogen fluoride or a mixture of 1,1,1,3,3,3-hexachloropropane, hydrogen fluoride and an inert gas is introduced into the reactor; The temperature of the evaporator is 200°C to 250°C. use.

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