JP6119388B2 - Parallel production method of trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane - Google Patents

Description

  The present invention relates to a parallel production method of trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane. Trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane are propellers that are aerosol propellants in intermediate raw materials such as medical pesticides or functional materials, sprays, etc. It is useful as a protective gas used in manufacturing a magnesium alloy, an etching gas used in manufacturing a semiconductor, a foaming agent, a fire extinguishing agent, a heat medium or a refrigerant.

  Fluorohydrocarbons have transitioned to alternative chlorofluorocarbons that have a lower ozone depletion potential than the specific chlorofluorocarbons regulated by the international treaty to protect the ozone layer. Trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane, which are alternative fluorocarbons with a low global warming potential, in addition to the ozone depletion potential, convert raw material compounds It has been studied to obtain a reaction efficiently and efficiently.

  Patent Documents 1 to 3 disclose methods for obtaining 1,1,1,3,3-pentafluoropropane using 1-chloro-3,3,3-trifluoropropene as a raw material compound.

  Patent Document 1 discloses a method for liquid-phase fluorination of 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride in the presence of an antimony catalyst.

  Patent Document 2 discloses that 1,1,1,3-tetrafluoro-3-chloropropane is added to 1-chloro-3,3,3-trifluoropropene by adding hydrogen fluoride in the presence of an addition catalyst. And then disproportionating the 1,1,1,3-tetrafluoro-3-chloropropane in the presence of a disproportionation catalyst.

  Patent Document 3 discloses a method for producing 1,1,1,3,3-pentafluoropropane from 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride in the presence of chlorine. , A first reactor set at 150 ° C. or higher from the upstream using a fluorination reactor comprising a reactor (A) and a reactor (B) each filled with antimony pentachloride-supported activated carbon, 20-150 The second reactors set at ° C are arranged in series, and in the first time section, the reactor (A) is the first reactor, the reactor (B) is the second reactor, and the second time section The reaction is carried out using the reactor (B) as the first reactor and the reactor (A) as the second reactor, and then repeating the exchange of the reactor (A) and the reactor (B) in the same manner as described above. A method comprising performing

  On the other hand, in Patent Document 4, 1-chloro-3,3,3-trifluoropropene is fluorinated in the gas phase in the presence of a fluorination catalyst to obtain 1,3,3,3-tetrafluoropropene. An oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride or at least one metal selected from chromium, titanium, aluminum, manganese, nickel or cobalt as the fluorination catalyst The use of activated carbon carrying oxyfluoride chloride has been reported.

In the method described in Patent Document 4, when hydrogen fluoride is excessive or the reaction temperature is low, as shown in the following reaction scheme (1), in addition to 1,3,3,3-tetrafluoropropene, fluorination is performed. Further, 1,1,1,3,3-pentafluoropropane, which is a advanced higher-order fluorination product, is by-produced.

  Patent Document 5 discloses 1, 3, 3, 3 in the presence of a hydrogen halide addition catalyst, which is a halide of at least one metal selected from the group consisting of aluminum, tin, bismuth, antimony and iron. -A method for producing 1,1,1,3,3-pentafluoropropane by adding hydrogen fluoride to tetrafluoropropene is disclosed.

JP-A-9-241188 JP-A-10-72381 JP 2002-105006 A Japanese Patent Laid-Open No. 10-7604 Japanese Patent Laid-Open No. 10-17502

  As described above, a method for obtaining 1,3,3,3-tetrafluoropropene using 1-chloro-3,3,3-trifluoropropene as a starting compound, 1-chloro-3,3,3-trifluoropropene And 1,1,1,3,3-pentafluoropropane to obtain 1,1,1,3,3-pentafluoropropane is known, and the target compound, trans-1,3,3,3-tetrafluoropropene and 1,1,1, 1,3,3-pentafluoropropane can be obtained in good yield. However, 1-chloro-3,3,3-trifluoropropene is used as a raw material compound, and trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane are efficiently produced. There is no known method for producing a common product.

  The present invention provides a method for efficiently producing trans-1,3,3,3-tetrafluoropropene and 1,1,3,3-pentafluoropropane in parallel with a raw material compound.

  As a result of intensive investigations to solve such problems, the inventors of the present invention reacted with hydrogen fluoride using 1-chloro-3,3,3-trifluoropropene as a starting material compound to produce trans-1,3. , 3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane have been reached.

  That is, this invention includes the following inventions 1-7.

[Invention 1]
1-chloro-3,3,3-trifluoropropene and hydrogen fluoride are reacted in the gas phase at a temperature of 200 ° C. or higher and 450 ° C. or lower and a pressure of 0.05 MPa or higher and 0.3 MPa or lower using a fluorination catalyst. Trans-1,3,3,3-tetrafluoropropene, cis-1,3,3,3-tetrafluoropropene, 1,1,1,3,3-pentafluoropropane and hydrogen chloride, A reaction step of obtaining a reaction product A containing 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride as reactants;
A distillation step of distilling reaction product A to return the bottoms containing 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride to the reaction step, and obtaining fraction B;
A hydrogen fluoride separation step in which hydrogen fluoride is separated and recovered from the fraction B after the distillation step and supplied to the reaction step;
A hydrogen chloride separation step of separating and removing hydrogen chloride by bringing water or an aqueous sodium hydroxide solution into contact with the residue C after recovering hydrogen fluoride in the hydrogen fluoride separation step;
A dehydration step of dehydrating the residue D after separating the hydrogen chloride in the hydrogen chloride separation step;
The residue E after dehydration in the dehydration step is rectified to contain a fraction containing trans-1,3,3,3-tetrafluoropropene and cis-1,3,3,3-tetrafluoropropene. A purification step to obtain residue F;
The residue E after dehydration in the dehydration step is rectified to contain trans-1,3,3,3-tetrafluoropropene and cis-1,3,3,3-tetrafluoropropene as fractions. A purification step to obtain residue F;
A conversion step of converting cis-1,3,3,3-tetrafluoropropene in residue F of the purification step into 1,1,1,3,3-pentafluoropropane;
including,
Parallel production method of trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane.
[Invention 2]
Fluorination catalyst is chromium, titanium, aluminum, manganese, nickel, cobalt, iron, copper, zinc, silver, molybdenum, zirconium, niobium, tantalum, iridium, tin, hafnium, vanadium, magnesium, lithium, sodium, potassium, calcium And at least one metal selected from the group consisting of antimony and nitrate, chloride, oxide, sulfate, fluoride, fluoride, oxyfluoride, oxychloride, or oxyfluoride The average production method.

[Invention 3]
The reaction in the reaction step is carried out by using fluorinated alumina supporting chromium chloride as a fluorination catalyst, and representing the supply amount of 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride in molar ratio as 1- The parallel production method of Invention 1 or Invention 2, which is carried out as chloro-3,3,3-trifluoropropene: hydrogen fluoride = 1: 8 to 1:25.

[Invention 4]
The reaction in the reaction step is performed by using activated carbon carrying chromium oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride or oxyfluorinated chloride as a fluorination catalyst, and 1-chloro-3 , 3,3-trifluoropropene and hydrogen fluoride are represented by molar ratio, and 1-chloro-3,3,3-trifluoropropene: hydrogen fluoride = 1: 8 to 1:25. The parallel production method of invention 1 or invention 2.

[Invention 5]
The parallel production method of inventions 1-4, wherein in the hydrogen fluoride separation step, hydrogen fluoride is absorbed and recovered by sulfuric acid.

[Invention 6]
In the dehydration process, the entrained water of the residue D after the hydrogen chloride separation process is dehydrated by freezing and solidifying on the cooling surface of the heat exchanger using a heat exchanger.

[Invention 7]
In the dehydration step, the entrained water of the residue D after the hydrogen chloride separation step is adsorbed by an adsorbent and dehydrated.

  The present invention uses readily available 1-chloro-3,3,3-trifluoropropene as a starting material compound, trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3 -Pentafluoropropane can be efficiently produced in parallel.

It is an example of the flowchart of the manufacturing process using the trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane production method of the present invention.

  Hereinafter, embodiments of the present invention will be described. It is also within the scope of the present invention to appropriately change or improve the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

1. Parallel production method of trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane

The present invention
1-chloro-3,3,3-trifluoropropene and hydrogen fluoride are reacted in the gas phase at a temperature of 200 ° C. or higher and 450 ° C. or lower and a pressure of 0.05 MPa or higher and 0.3 MPa or lower using a fluorination catalyst. Trans-1,3,3,3-tetrafluoropropene, cis-1,3,3,3-tetrafluoropropene, 1,1,1,3,3-pentafluoropropane and hydrogen chloride, A reaction step of obtaining a reaction product A containing 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride as reactants;
A distillation step of distilling the reaction product A, recovering a bottoms containing 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride, supplying to the reaction step, and obtaining a fraction B;
A hydrogen fluoride separation step in which hydrogen fluoride is separated and recovered from the fraction B after the bottoms are collected in the distillation step and supplied to the reaction step;
A hydrogen chloride separation step of separating and removing hydrogen chloride by bringing water or an aqueous sodium hydroxide solution into contact with the residue C after recovering hydrogen fluoride in the hydrogen fluoride separation step;
A dehydration step of dehydrating the residue D after separating the hydrogen chloride in the hydrogen chloride separation step;
The residue E after dehydration in the dehydration step is rectified to contain trans-1,3,3,3-tetrafluoropropene and cis-1,3,3,3-tetrafluoropropene as fractions. A purification step to obtain residue F;
A conversion step of converting cis-1,3,3,3-tetrafluoropropene in residue F of the purification step into 1,1,1,3,3-pentafluoropropane,
This is a parallel production method of trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane.

Specifically, the method of the present invention comprises:
In the “reaction step”, a raw material compound, that is, 1-chloro-3,3,3-trifluoropropene as a reactant is reacted with hydrogen fluoride to obtain trans-1,3, which is a target product. Operation to produce 3,3-tetrafluoropropene,
In the “distillation step”, trans-1,3,3,3-tetrafluoropropene which is the target compound after the “reaction step” and cis-1,3,3,3-tetrafluoropropene which is a by-product, Distilling reaction product A containing 1,1,1,3,3-pentafluoropropane and hydrogen chloride and unreacted 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride, An operation of recovering unreacted 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride as bottoms and supplying them to the “reaction step”;
In the “hydrogen fluoride separation step”, an operation of separating and recovering hydrogen fluoride from the fraction B which is a distillate in the “distillation step” and supplying it to the “reaction step”;
In the “hydrogen chloride separation step”, an operation of separating and removing hydrogen chloride by bringing water or an aqueous sodium hydroxide solution into contact with the residue C after recovering hydrogen fluoride in the “hydrogen fluoride separation step”;
In the “dehydration step”, an operation of dehydrating the residue D after separating hydrogen chloride in the “hydrogen chloride separation step”;
In the “purification step”, the residue E after dehydration in the “dehydration step” is rectified to obtain trans-1,3,3,3-tetrafluoropropene as a fraction and cis-1, Operation to obtain 3,3,3-tetrafluoropropene,
In the “conversion step”, an operation of converting cis-1,3,3,3-tetrafluoropropene in the residue F of the “purification step” into 1,1,1,3,3-pentafluoropropane is performed.

  Further, in the parallel production method of the present invention, unreacted 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride in the “reaction step” are recovered in the “distillation step”, and the “reaction step” The product is returned to the reaction system and reused as a raw material compound. The provision of the “distillation step” for generally recovering hydrogen fluoride reduces the burden of the subsequent steps “hydrogen fluoride separation step” and “hydrogen chloride separation step”. The subsequent provision of the “dehydration drying step” reduces the load of the “purification step” for purifying trans-1,3,3,3-tetrafluoropropene by rectification. Also, hydrogen fluoride separated and recovered from the reaction product in the “hydrogen fluoride separation step” can be returned to the “reaction step”, and cis-1,3,3,3 in the residue F of the “purification step” 3-tetrafluoropropene is converted to 1,1,1,3,3-pentafluoropropane.

  In the parallel production method of the present invention, 1-chloro-3,3,3-trifluoropropene, which is a starting material, is reacted with hydrogen fluoride to efficiently produce trans-1,3,3,3- Tetrafluoropropene and 1,1,1,3,3-pentafluoropropane can be produced in parallel, and are useful for mass production of these alternative chlorofluorocarbons in industrial plants.

  In the parallel production method of the present invention, the efficiency is further improved by selecting a fluorination catalyst to be used.

  In the present specification, reaction product A means trans-1,3,3,3-tetrafluoropropene which is a target compound, 1-chloro-3,3,3-trifluoropropene which is an unreacted substance, and fluorine. This refers to a mixture after the “reaction step” including hydrogen chloride as a by-product and organic substances (including cis-1,3,3,3-tetrafluoropropene) in addition to hydrogen fluoride. The bottom liquid means a liquid rich in low volatility components obtained from the bottom of the distillation column after distillation. Unless otherwise specified, in this specification, 1-chloro-3,3,3-trifluoropropene refers to a cis isomer or a trans isomer or a mixture thereof, and 1,3,3,3-tetrafluoropropene and Refers to cis or trans isomers or mixtures thereof. Rectification refers to an operation of purifying a target compound by distillation. Specifically, the residue E, which is a mixture of trans-1,3,3,3-tetrafluoropropene and cis-1,3,3,3-tetrafluoropropene in the “purification step”, is purified by distillation. This refers to an operation for obtaining pure trans-1,3,3,3-tetrafluoropropene.

2. Processes Each process included in the method of parallel production of the present invention will be described.

2.1. Reaction step (first step)
The “reaction step” is a method in which 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride as raw materials are used in a gas phase in a reactor, using a fluorination catalyst, at a temperature of 200 ° C. or higher and 450 ° C. or lower. The reaction is carried out at a pressure of 0.05 MPa or more and 0.3 MPa or less, and the target product, trans-1,3,3,3-tetrafluoropropene, and the by-product cis-1,3,3,3- Reaction product A containing tetrafluoropropene, 1,1,1,3,3-pentafluoropropane and hydrogen chloride and unreacted 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride It is the process of obtaining.

  In this step, 1-chloro-3,3,3-trifluoropropene which is a starting material is fluorinated with hydrogen fluoride using a fluorination catalyst, and trans-1,3,3,3-tetrafluoropropene is converted. obtain.

  In this step, in order to increase the selectivity and yield of trans-1,3,3,3-tetrafluoropropene and advance the reaction quickly, 1-chloro-3,3,3-trifluoro, which is a raw material, is used. It is preferable to supply an excess amount of hydrogen fluoride relative to propene into the reaction system, specifically into the reactor. Further, excessive supply of hydrogen fluoride leads to protection of the fluorination catalyst, and has an effect of prolonging the lifetime having catalytic activity. In addition, 1-chloro-3,3,3-trifluoropropene, which is a raw material compound in this step, has a cis isomer and a trans isomer, but only a cis isomer or a trans isomer, or a mixture of a cis isomer and a trans isomer. Even if it exists, the reaction in this step proceeds.

  In this step, readily available 1-chloro-3,3,3-trifluoropropene is used as a starting material and reacted with hydrogen fluoride in the presence of a fluorination catalyst, and the reaction temperature and pressure suitable for the reaction are set. adjust. To make the reaction proceed rapidly while maintaining the catalytic activity of the fluorination catalyst, supply excess hydrogen fluoride into the reactor relative to 1-chloro-3,3,3-trifluoropropene. It is preferable to do.

[Fluorination catalyst]
The fluorination catalyst used in this step is chromium, titanium, aluminum, manganese, nickel, cobalt, iron, copper, zinc, silver, molybdenum, zirconium, niobium, tantalum, iridium, tin, hafnium, vanadium, magnesium, lithium Nitrate, chloride, oxide, sulfate, fluoride, fluorinated chloride, oxyfluoride, oxychloride or oxyfluorinated chloride of at least one metal selected from the group consisting of sodium, potassium, calcium and antimony Things can be exemplified.

  The metal oxide is preferably one in which part or all of the oxygen atoms are replaced with fluorine atoms using hydrogen fluoride or a fluorine-containing organic compound. For example, alumina, chromia, zirconia, titania or magnesia is fluorinated. It can be selected from fluorinated oxides in which some or all of the oxygen atoms are substituted with fluorine atoms. In particular, it is preferable to use a fluorinated oxide of alumina, and specific examples include fluorinated alumina prepared by fluorinating activated alumina with hydrogen fluoride or the like. Hereinafter, in the present invention, the metal fluorinated oxide may be simply referred to as “metal oxide”.

  A commercial item can be used for the said metal oxide, and it can prepare it by a well-known method. A metal oxide can be prepared by adjusting the pH of an aqueous solution of a metal salt using ammonia or the like to precipitate a hydroxide, and drying or baking the precipitate. The obtained metal oxide may be used after being pulverized or molded. For example, alumina is usually obtained by shaping or dewatering a precipitate produced by adding ammonia or the like to an aqueous solution of an aluminum salt. Further, as the fluorination catalyst used in this step, γ-alumina commercially available for catalyst support or for drying can be preferably used. Moreover, titania, zirconia, etc. can be prepared by the same method, and a commercial item can be used. These metal oxides may be a composite oxide prepared by a coprecipitation method or the like, and can be suitably used as a fluorination catalyst in this step.

  Moreover, a metal supported catalyst can also be used as a fluorination catalyst. For the metal-supported catalyst, the type, amount, and method of the supported metal can be selected based on ordinary knowledge of those skilled in the art of catalyst.

[Metal-supported catalyst]
As the metal-supported catalyst, nitrate, chloride, oxide of at least one metal selected from the group consisting of chromium, titanium, aluminum, manganese, nickel, cobalt, zirconium, iron, copper, silver, molybdenum, and antimony, A metal-supported catalyst in which sulfate, fluoride, fluorinated chloride, oxyfluoride, oxychloride or oxyfluorinated chloride is supported on a support such as fluorinated alumina or activated carbon can be employed.

  As a method for preparing the metal-supported catalyst, a method in which a carrier is impregnated with a solution in which one or more kinds of metal compounds are dissolved in a solvent, or is dispersed and adhered can be used.

  Examples of the metal compound soluble in the solvent include nitrates, chlorides, oxides or sulfates of the above metals. Specifically, chromium nitrate, chromium trichloride, chromium trioxide, potassium dichromate, iron chloride, iron sulfate, iron nitrate, titanium trichloride, titanium tetrachloride, manganese nitrate, manganese chloride, manganese dioxide, nickel nitrate, Examples thereof include nickel chloride, cobalt nitrate, cobalt chloride, copper nitrate, copper sulfate, copper chloride, silver nitrate, copper chromite, copper dichromate, silver dichromate, and sodium dichromate.

  The solvent is not particularly limited as long as it dissolves the metal compound and does not alter the metal compound. For example, water, alcohols such as methanol, ethanol or isopropanol, ketones such as methyl ethyl ketone or acetone, ethyl acetate or Examples thereof include carboxylic acid esters such as butyl acetate, halogen compounds such as methylene chloride, chloroform and trichloroethylene, and aromatics such as benzene and toluene. If it is difficult to dissolve in water, the dissolution may be accelerated by adding an acid such as hydrochloric acid, sulfuric acid nitrate or aqua regia, or an alkali such as sodium hydroxide, potassium hydroxide or ammonia water. it can.

  In order to increase the reaction rate, selectivity of trans-1,3,3,3-tetrafluoropropene and yield in this step, as a catalyst, chromium, iron or copper nitrate, chloride, oxide as fluorinated alumina Alternatively, a metal-supported catalyst supporting sulfate or the like can be used.

  Further, in order to increase the reaction rate, the selectivity of trans-1,3,3,3-tetrafluoropropene and the yield in this step, nitrate, chloride, oxide or sulfuric acid selected from chromium, iron or copper A metal-supported catalyst in which a salt is supported on activated carbon can be used, and a metal compound selected from chromium oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride or oxyfluorinated chloride is activated carbon. A metal-supported catalyst supported on the catalyst can be used.

  The activated carbon supporting the fluorination catalyst, which is a catalyst, includes vegetation based on wood, sawdust, charcoal, coconut shell charcoal, palm kernel charcoal, or raw ash, peat, lignite, lignite, bituminous coal, anthracite, etc. As a raw material, coal-based, petroleum residue, sulfuric acid sludge or oil carbon as a raw material, or synthetic resin as a raw material. Such activated carbon is commercially available and can be selected from commercially available products and used in this reaction step. For example, activated carbon (trade name, Calgon granular activated carbon CAL, manufactured by Calgon Carbon Japan Co., Ltd., etc.), coconut shell charcoal (manufactured by Nippon Enviro Chemicals Co., Ltd.) and the like manufactured from bituminous coal can be exemplified. However, the activated carbon used in the parallel production method of the present invention is not limited to these types and manufacturers. Moreover, although activated carbon is normally used in a granular form, the shape, particle size, and the like are not particularly limited. The activated carbon may be used as it is, or activated carbon previously modified with a halogen such as hydrogen fluoride, hydrogen chloride, chlorinated fluorinated hydrocarbon, or the like.

  The amount of the metal supported on the carrier is 0.1% by mass or more and 80% by mass or less, preferably 1% by mass or more and 50% by mass or less based on the carrier. When the amount is less than 0.1% by mass, the catalytic effect is thin, and it is difficult to support more than 80% by mass and there is no necessity.

  In addition, even if it is a fluorination catalyst prepared by any method, fluorine such as hydrogen fluoride, fluorinated hydrocarbon or fluorinated chlorinated hydrocarbon is previously used at a temperature equal to or higher than a predetermined reaction temperature before use in the reaction. It is effective to heat together with the agent to prevent changes in the composition of the catalyst during the reaction.

[Amount of addition of fluorination catalyst]
The amount of the fluorination catalyst added is preferably equal to or less than the amount of the raw material compound supplied to the reactor. It is not necessary to use more than 1x.

[Protection of fluorination catalyst]
In order to prevent coking in which carbonaceous solid adheres to the surface of the catalyst during the reaction, a gas such as oxygen, air or chlorine may be added as a companion gas in the reaction vessel as long as the reaction is not hindered. An inert gas having poor reactivity, such as nitrogen, argon, or helium, is preferable. The supply amount of the gas is less than 1 times the total volume of organic substances and hydrogen chloride as reactants. If the supply amount of the inert gas to the reactor is 1 or more times, it is difficult to recover trans-1,3,3,3-tetrafluoropropene in the subsequent “purification step” (sixth step). .

[Activation of fluorination catalyst]
For the activation (activation or regeneration) of the fluorination catalyst used, a usual method used for regeneration of the fluorination catalyst can be employed. For example, the catalyst having reduced activity at a temperature equal to or higher than the reaction temperature employed in this step can be activated by appropriately contacting it with dry air, chlorine, hydrogen fluoride or the like while controlling heat generation.

[Reaction temperature]
The reaction temperature in this step is 200 ° C. or higher and 450 ° C. or lower, preferably 350 ° C. or higher and 400 ° C. or lower. When the reaction temperature is lower than 200 ° C., the reaction rate is slow and the reaction is difficult to proceed, which is not practical. When the reaction temperature exceeds 450 ° C., the reaction proceeds quickly, but decomposition products, high molecular weight organic substances, etc. are generated, and the selectivity for trans-1,3,3,3-tetrafluoropropene is lowered, which is not preferable. . The higher the reaction temperature, the faster the reaction proceeds because the equilibrium state in the reactor is closer to the target product. However, the sustainability of catalyst activity (catalyst life) of the fluorination catalyst is shortened, catalyst deterioration is fast, the material of the reactor is limited, and the heating operation is difficult especially in plants, so practically higher than 450 ° C. It is preferred to avoid temperatures, preferably above 400 ° C.

[Reaction pressure]
The reaction pressure is preferably reduced or equal to normal pressure (atmospheric pressure, about 0.1 MPa, the same shall apply hereinafter), but is not limited as long as it does not inhibit the reaction even if the pressure is higher than atmospheric pressure. The existing hydrogen fluoride and organic matter do not have to be liquefied in the reaction system of this step, and the pressure is 0.05 MPa or more and 0.3 MPa or less.

[Reaction time]
The contact time (reaction time) in the gas phase reaction is usually from 0.1 seconds to 300 seconds, preferably from 3 seconds to 60 seconds. If the contact time is shorter than 0.1 seconds, the reaction may not proceed, and preferably 3 seconds or more. If it is longer than 300 seconds, it takes too much process work time (tact time) in the actual production in the plant, which is not efficient. Preferably, it is 60 seconds or less.

[Molar ratio of hydrogen fluoride to 1-chloro-3,3,3-trifluoropropene]
In this step, the molar ratio of hydrogen fluoride to 1-chloro-3,3,3-trifluoropropene basically has to be higher than the theoretical value of hydrogen fluoride, but trans-1,3,3, To obtain a high selectivity and yield of 3-tetrafluoropropene, expressed in molar ratio, the range of hydrogen fluoride: 1-chloro-3,3,3-trifluoropropene = 8: 1 to 25: 1 It is preferable that If hydrogen fluoride is excessively supplied so that this ratio exceeds 25: 1, unreacted hydrogen fluoride contained in the reaction product A of this step and the target product 1,3,3,3- This hinders separation of organic substances such as tetrafluoropropene by distillation. On the other hand, if hydrogen fluoride is supplied excessively so that this ratio is smaller than 8: 1, the reaction rate is lowered and the selectivity for trans-1,3,3,3-tetrafluoropropene is preferably lowered. Absent.

[Reactor material]
The material of the reactor should be heat resistant and have corrosion resistance against hydrogen fluoride and hydrogen chloride, and it is preferable to use stainless steel, nickel alloy, platinum or the like. For example, Hastelloy (trade name) with molybdenum, nickel or chromium added as the main component, Monel (trade name) with nickel as the main component and copper added, or iron, chromium, niobium or molybdenum with nickel as the main component Inconel (trade name) to which is added can be exemplified. Moreover, you may use the reactor which coat | covered the reactor wall with these metals (lining).

2.2 Distillation process (second process)
In the “distillation step”, the reaction product A obtained in the “reaction step” (first step) is distilled using a distillation column or the like, and unreacted 1-chloro-3,3,3-trifluoro is obtained. This is a step of returning the bottoms having propene and hydrogen fluoride to the gas phase reactor in the “reaction step” (first step) of the previous step.

  The fraction B in this step is hydrogen fluoride that could not be recovered from the reaction product A in this step, trans-1,3,3,3-tetrafluoropropene as the target product, and chloride as a by-product. And other organics. The fraction B is sent to the “hydrogen fluoride separation step” (third step) of the next step. The fraction B has a different composition depending on the reaction conditions of the previous step “reaction step” (first step), but is generally 1-chloro-to 1 mol of 1,3,3,3-tetrafluoropropene. 3,3,3-trifluoropropene is 0.5 mol or more and 1 mol or less, 1,1,1,3,3-pentafluoropropane is 0.1 mol or more and 0.2 mol or less, and hydrogen chloride is 1 The amount of hydrogen fluoride is 1.5 mol or less and hydrogen fluoride is 0.5 mol or more and 10 mol or less.

[Distillation conditions]
The distillation conditions in this step are preferably 0.1 MPa or more and 1.0 MPa or less as the operation pressure. When the operation pressure is normal pressure, the temperature conditions are the tower bottom temperature of 5 ° C. or more and 25 ° C. or less, the tower top temperature − 20 degreeC or more and 5 degrees C or less are preferable. When distillation is performed under pressurized conditions, the cooling heat transfer area of the separation tower can be reduced. In that case, it is preferable to provide a compressor at the inlet of the separation tower and a pressure regulating valve at the outlet.

[Filler]
The packing material for the separation tower includes hydrogen fluoride, stainless steel that is corrosion resistant to hydrogen chloride, nickel, the nickel alloy such as the trade name Hastelloy or the trade name Monel, tetrafluoroethylene resin, chlorotrifluoroethylene resin, and vinylidene fluoride. Regular packing made of fluororesin such as resin or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (hereinafter sometimes abbreviated as PFA), or irregular packing such as lessing ring, pole ring or sulzer packing Can be used.

[Number of separation towers]
The number of stages of the separation column varies depending on the operating pressure, but it may be 15 or more at normal pressure.

2.3 Hydrogen fluoride separation process (third process)
In the “hydrogen fluoride separation step”, hydrogen fluoride is recovered from the fraction B after the bottoms are recovered in the “distillation step” (second step) and supplied to the gas phase reactor in the reaction step. It is a process.

  The fraction B contains hydrogen fluoride, hydrogen chloride, trans-1,3,3,3-tetrafluoropropene and other organic substances distilled from the separation column in the “distillation step” (second step).

  In this step, for example, hydrogen fluoride is absorbed into sulfuric acid by a contact operation between fraction B and sulfuric acid. That is, a liquid phase part mainly composed of hydrogen fluoride and sulfuric acid, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene and 1,1,1,3, Hydrogen fluoride can be separated and recovered by dividing it into an organic substance such as 3-pentafluoropropane and a gas phase portion mainly composed of hydrogen chloride, and mainly separating hydrogen fluoride from the liquid phase portion. The gas phase portion is supplied as the residue C to the subsequent “hydrogen chloride separation step” (fourth step).

  The mass ratio of sulfuric acid to hydrogen fluoride when recovering hydrogen fluoride is sulfuric acid: hydrogen fluoride = 2: 1 to 20: 1. Preferably, it is sulfuric acid: hydrogen fluoride = 2: 1 to 15: 1, and more preferably, sulfuric acid: hydrogen fluoride = 2: 1 to 10: 1. In a system in which hydrogen chloride is mixed in the system, if the ratio of sulfuric acid is less than 2, the dissolution of hydrogen fluoride is not sufficient, and hydrogen fluoride is accompanied in the gas phase, making it difficult to remove hydrogen chloride. .

  The liquid phase portion mainly composed of hydrogen fluoride and sulfuric acid obtained in this step evaporates the hydrogen fluoride by heating, and then condenses it to separate and recover the hydrogen fluoride. The recovered hydrogen fluoride can be supplied again to the “reaction step” (first step).

[Contact conditions]
In this step, any apparatus configuration and operation method may be adopted as long as hydrogen fluoride can be absorbed into sulfuric acid, but it is preferable that fraction B is brought into contact with sulfuric acid in a gaseous state. Therefore, the liquid temperature of sulfuric acid is preferably 10 ° C. or higher and 50 ° C. or lower, more preferably 10 ° C. or higher and 30 ° C. or lower at normal pressure. Sulfuric acid and hydrogen fluoride form fluorosulfuric acid (fluorosulfonic acid) by reaction, but it is difficult to operate when the temperature of sulfuric acid is 10 ° C. or lower, and 1,3,3,3 in the reaction product at 50 ° C. or higher. -Tetrafluoropropene and the like are not preferable because they are polymerized. A method in which sulfuric acid is put into a tank and a fraction B is blown in a gas state, a method in which a fraction B is blown into a sulfuric acid washing tower filled with a packing, and a gas in the fraction B and sulfuric acid are brought into countercurrent contact is adopted. As long as absorption of hydrogen fluoride into sulfuric acid is possible, not only these methods but also other methods may be used.

2.4 Hydrogen chloride separation process (4th process)
In this step, hydrogen chloride is brought into contact with the residue C after recovering hydrogen fluoride from the fraction B in the “hydrogen fluoride separation step” (third step) in the previous step, and then contacted with water or an aqueous sodium hydroxide solution. This is a step of separating and removing.

  Specifically, the residue C is washed with water by a method in which the residual C is blown into the water tank so as to be in a fine bubble state, a method in which the residue C is blown into the water washing tower filled with the packing and brought into countercurrent contact, and the hydrogen chloride is absorbed in water. Liquid phase, ie hydrochloric acid, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene and 1,1,1,3,3-pentafluoropropane Hydrogen chloride is separated and removed from organic substances such as

  In this step, any apparatus configuration and operation method may be adopted as long as hydrogen chloride can be separated and removed from the residue C. Moreover, the organic substance separated from hydrogen chloride can be recovered in a gas or liquid state. In a mixture with a low composition of low-boiling trans-1,3,3,3-tetrafluoropropene (boiling point -19 ° C.), it is absorbed in contact with water in a gaseous state, and hydrogen chloride is absorbed from the mixture of organic matter and hydrogen chloride. It is preferable to separate and recover.

  Hydrochloric acid recovered by absorbing hydrogen chloride in water in this step can be purified by using known means such as adsorbing impurities such as hydrogen fluoride and organic substances on an adsorbent such as zeolite.

  In this step, instead of washing with water, hydrogen chloride may be separated and recovered by bringing the residue C after the “hydrogen fluoride separation step” (third step) of the previous step into contact with an aqueous sodium hydroxide solution.

[Separation conditions]
The mass ratio of water to hydrogen chloride used for removing hydrogen chloride by washing with water should be water: hydrogen chloride = 3: 1 to 20: 1 at room temperature (about 20 ° C., the same shall apply hereinafter) and normal pressure. Is preferred. More preferably, water: hydrogen chloride = 5: 1 to 10: 1. The solubility of hydrogen chloride in water is preferably 25% by mass in normal conditions and 37% by mass in saturated conditions at normal temperature and normal pressure. If the water is less than 3, excess hydrogen chloride is liable to vaporize and easily volatilize. Absent.

2.5 Dehydration process (5th process)
The “dehydration step” is a step of dehydrating the residue D after separating and removing hydrogen chloride in the “hydrogen chloride separation step” (fourth step) of the previous step.

  Residue D accompanies water, gaseous mist, and the like accompanying water washing or contact with an aqueous sodium hydroxide solution in the “hydrogen chloride separation step” (fourth step) in the previous step. In this step, a method of dehydrating the entrained water of the residue D by using a heat exchanger to freeze and solidify on the cooling surface of the heat exchanger, or a method of desorbing by adsorbing to an adsorbent such as zeolite Is used.

[Method using heat exchanger]
The method of dehydrating using a heat exchanger not only freezes and separates the entrained water in the residue D, but also condenses 1,3,3,3-tetrafluoropropene at the same time. Compared to dehydration using zeolite, the dehydration equipment can be reduced in size and simplified, making the dehydration operation efficient and easy.

  If a dehydration method in which the entrained water is frozen and solidified using a heat exchanger is separated and dehydrated, a residue D containing a large amount of water exceeding the saturated water amount after the “hydrogen chloride separation step” (fourth step) in the previous step. That is, a mixed gas in which organic substances such as 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,3,3-pentafluoropropane are mixed. Is introduced into a heat exchanger set to a temperature equal to or lower than the condensation temperature of these organic substances, and condensed on a cooling surface, which is a cooled heat transfer surface, to substantially remove entrained water.

  The melted frozen water is discharged from the lower part of the heat exchanger as a dehydrating device in the state of water or steam. The molten water containing this organic substance can be used in the “hydrogen chloride separation step” (fourth step) in the previous step.

[Heat exchanger]
In this step, the heat exchanger used for freezing the entrained water in the residue D (mixed gas) is preferably a partition-type heat exchanger, and is cooled through the partition walls of the partition-type heat exchanger. Heat exchange is performed between the medium and the residue D. The partition wall is provided with a heat transfer surface in contact with the cooling medium and a cooling surface for freezing and solidifying the mixed water of the mixed gas. Examples of such a partition wall type heat exchanger include a double tube type, a cylindrical multiple tube type, a cylindrical coil type, or a cylindrical heat exchanger with a jacket. A heat exchanger in which the heat transfer area is expanded by attaching an external jacket to a cylindrical multi-tube type or a cylindrical coil type can also be used.

  The material of the heat exchanger is preferably a metal having high thermal conductivity, such as iron, steel, copper, lead, zinc, brass, stainless steel, titanium, aluminum, magnesium, or nickel such as trade name Monel, trade name Inconel or Hastelloy. When an alloy is used and a corrosive substance is included, a heat exchanger in which a resin lining, ceramics, glass lining, or the like is applied to the heat transfer surface on the side where the mixed gas is cooled and condensed can be used.

  The heat transfer area of the heat exchanger depends on the temperature of the cooling medium used, but at a minimum, the area sufficient to condense the gaseous residue D and exchange the amount of heat necessary to freeze the accompanying water. It is preferable that there is. In addition, since the heat transfer coefficient decreases when entrained water freezes and solidifies on the cooling surface of the heat exchanger, it is preferable to take at least 1.5 times the heat transfer area necessary for calculation.

  Moreover, what attached the fin to the heat-transfer surface of a heat exchanger can also be used. In particular, it is also effective from the viewpoint of heat transfer efficiency to attach fins to the cooling surface side with which the residue D is in contact to expand the heat transfer area.

  Examples of the method for introducing the residue D into the heat exchanger include a flow-through method in which the residue D is passed through a heat exchanger having a sufficient heat transfer area. The direction of introduction of the residue D, which is a mixed gas, is preferably such that the gas is introduced from the top when the heat exchanger is a vertical type, in which case freezing and solidification of the entrained water starts from the top of the cooling surface of the heat exchanger. Since it occurs and closes, it is desirable to provide a plurality of inlets at the bottom and move the introduction of the residue D to the bottom. Also, the heat exchanger can be used as a horizontal type, and in this case as well, it is desirable to introduce the residue D from the top, and a plurality of inlets can be provided in parallel.

  Although the cooling medium used for heat exchange is not particularly limited, an aqueous medium, inorganic brine, or organic brine can be selected and used depending on the cooling temperature.

  As an intermediate purification step in an industrial production method, when gas is condensed by a heat exchanger, it is conceivable that the liquefied gas is evaporated again and supplied to a distillation column. For example, the latent heat of vaporization of liquefied trans-1,3,3,3-tetrafluoropropene can be used. If evaporation of the liquefied gas is performed on the cooling medium flow side of the heat exchange dehydrator, the heating and heat removal load by the external heat source can be reduced, which is also effective from the viewpoint of energy saving. Preferably employed.

[Dehydration conditions by heat exchanger]
The set temperature of the cooling surface in the heat exchanger, that is, the cooling temperature is not particularly limited, but gaseous trans-1,3,3,3-tetrafluoropropene (boiling point: −19 ° C.) is condensed under the operating pressure. Lower the temperature below the The cooling temperature is −50 ° C. or more and −20 ° C. or less at normal pressure, and −40 ° C. or more and −25 ° C. or less is preferable. The entrained water is removed by freezing and solidification, and the condensed and liquefied mixed gas is collected in a receiving tank provided at the lower part of the heat exchanger. The temperature of the receiving tank is preferably not higher than the temperature at which trans-1,3,3,3-tetrafluoropropene is condensed. In addition, a U-shaped or coil-type cooling pipe is installed inside the receiving tank, and liquefied 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene and 1,1,3 It is also possible to remove the entrained water in the residue D containing 1,3,3-pentafluoropropane by freezing and solidifying.

  Dehydration using the heat exchanger in this step may be performed under a pressurized condition, and the pressure of the mixed gas in the heat exchanger is usually preferably 0.1 MPa or more and 1 MPa or less. The cooling temperature under the pressurizing condition can be appropriately selected according to the processing pressure.

  In the flow method in the heat exchanger, the linear velocity of the residue D to be dehydrated in the heat exchanger is about 30 m / hr or more and 1200 m / hr or less, preferably 60 m / hr or more and 600 m / hr or less. If the linear velocity is less than 30 m / hr, the dehydration time becomes longer, which is not preferable. When it is higher than 1200 m / hr, the freezing and coagulation of the entrained water in the residue D and the condensation of the organic matter become insufficient, which is not preferable.

  Further, in the flow method in the heat exchanger, the amount of frozen water adhering to the cooling surface of the heat exchanger, which is a dehydrator, increases as the flow time of the mixed gas containing water becomes longer. For this reason, it is necessary to melt and remove frozen water after a certain period of time. As a method for melting and removing frozen water, a method can be used in which a dried inert gas having a temperature of 5 ° C. or higher and 200 ° C. or lower is circulated from the top of the heat exchanger as a dehydrator. The temperature of the inert gas may be high, but is preferably 20 ° C. or higher and 100 ° C. or lower from the viewpoint of thermal stress load and energy saving of the material of the dehydrator using the heat exchanger. As a heating method for melting the frozen water, it is possible to circulate the heating medium so as to face the portion where the cooling medium circulates. At this time, the cooling medium and the heating medium are not limited to be the same substance or different substances. The type of inert gas is not particularly limited, but it is desirable to use dry air or dry nitrogen from the viewpoint of economy.

[Method using adsorbent]
A method of dehydrating using an adsorbent, for example, a method of dehydrating in contact with a specific zeolite is performed regardless of whether 1,3,3,3-tetrafluoropropene in the residue D is in a gaseous state or a liquid state. It is possible and excellent. However, when this dehydration method is carried out using a dehydration tower packed with zeolite, the residue D after the “hydrogen chloride separation step” (fourth step) in the previous step contains water vapor and has a water content of 1000 ppm or more. In order to correspond to the amount commensurate with industrial production, the mixed gas containing entrained water that passes through the dehydration tower per unit time because the volume is approximately 230 times that of the liquid. It is necessary to increase the mass flow rate. However, when the mass flow rate is increased, the capacity of the dehydration tower needs to be increased accordingly, a large amount of zeolite as a dehydrating agent must be used, and regeneration of the zeolite is also necessary.

[Before and after the dehydration process]
Further, it is preferable to provide a water separation step using a mist separator or the like between the previous step “hydrogen chloride separation step” (fourth step) and this step. As described above, in the “hydrogen chloride separation step” (fourth step) in the previous step, the residue C after the “hydrogen fluoride separation step” (third step) in the previous step is replaced with the “chlorination” in the previous step. In the "hydrogen separation step" (fourth step), the residue D after the "hydrogen chloride separation step" (fourth step) of the previous step is entrained by washing with water or contacting with an aqueous sodium hydroxide solution to separate and remove hydrogen chloride. Contains water, if accompanied by gas mist with accompanying water. Usually, the content of entrained water in the residue D after washing with water is 3000 ppm or more and 10% or less. However, if a water separation step using a mist separator or the like is provided between the previous step “hydrogen chloride separation step” (fourth step) and this step, the water content can be reduced to about 1300 ppm. After dehydrating with a mist separator, if the moisture in the reaction product is frozen and solidified using a heat exchanger in this step, the water content of the residue E is reduced to less than 100 ppm. Can be made.

  Further, in the liquid obtained by condensing the residue D, when further moisture reduction is desired, the residue D is dehydrated such as calcium chloride, calcium oxide, magnesium sulfate, or diphosphorus pentoxide at a later stage of this step. It can be dried by contacting with an adsorbent or an adsorbent such as silica gel or zeolite.

2.6 Purification step (sixth step)
The “purification step” is a step of rectifying the residue E after dehydration in the previous step “dehydration step” (fifth step) to obtain a fraction containing trans-1,3,3,3-tetrafluoropropene. It is. In this case, a residue F containing cis-1,3,3,3-tetrafluoropropene is obtained.

[Rectification]
Rectification can be carried out either batchwise or continuously, and can be carried out at normal pressure or under pressure, but pressure conditions that can increase the condensation temperature in rectification should be selected. Is preferred.

  Rectification can be carried out batchwise using a single multi-stage distillation column, but it is more efficient to carry out rectification continuously using a double distillation column comprising a first distillation column and a second distillation column. .

  In the first distillation column, low-boiling point 3,3,3-trifluoropropyne, 2,3,3,3-tetrafluoropropene, which is a by-product contained in a trace amount in the residue E, is removed from the top of the distillation column. It is recovered as a distillate and returned again to the reaction system of the “reaction step” (first step), that is, supplied to the gas phase reactor for reuse and 1,1,1,3,3-penta Fluoropropane is obtained. In the second distillation column, the bottoms of the first distillation column can be distilled, and the target trans-1,3,3,3-tetrafluoropropene can be recovered as a distillate from the top of the distillation column. . On the other hand, cis-1,3,3,3-tetrafluoropropene and 1-chloro-3,3,3-trifluoropropene are recovered as a bottom boiling liquid, and the first “reaction step” (No. 1 step) and can be reused. The recovered mixture of cis-1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene and 1,1,1,3,3-pentafluoropropane If a distillation column is used, it can be separated and purified by operations such as extractive distillation.

[Distillation tower]
The distillation column used in this step may be any wall as long as the wall surface is inert to the distillate, the wall surface may be made of glass or stainless steel, tetrafluoroethylene resin, chlorotrifluoroethylene resin on a substrate such as steel Also, a distillation column having a vinylidene fluoride resin, PFA resin or glass lined inside may be used. The distillation column may be a plate type or a packed column packed with packing such as Raschig ring, Lessing ring, Dickson ring, pole ring, interlock saddle or sulzer packing.

  The rectification can be performed under normal pressure, but it is preferable to perform the rectification under a pressurized condition because the pressure loss in the distillation column can be reduced and the load on the condenser can be reduced. The number of distillation columns required for the rectification operation is not limited, but is preferably 5 to 100, more preferably 10 to 50. If the number of stages is less than 5, the purity of trans-1,3,3,3-tetrafluoropropene is not sufficiently increased, and if the number of stages is 100 or more, the economic burden of the distillation column itself increases. In addition, the time required for the rectification operation is increased, which is not preferable.

  The boiling point of 1-chloro-3,3,3-trifluoropropene is 21 ° C. for the trans isomer and 39 ° C. for the cis isomer. The boiling point of 1,3,3,3-tetrafluoropropene is −19 ° C. for the trans isomer and 9 ° C. for the cis isomer. The boiling point of 1,1,1,3,3-pentafluoropropane is 15 ° C. From these mixtures, trans-1,3,3,3-tetrafluoropropene is separated and purified by rectification due to the difference in boiling points. Is possible.

2.7. Conversion process (7th process)
In the conversion step, cis-1,3,3,3-tetrafluoropropene in residue F after the previous step “purification step” (sixth step) is converted into 1,1,1,3,3-pentafluoropropane. And 1,1,1,3,3-pentafluoropropane.

  When 1-chloro-3,3,3-trifluoropropene or cis-1,3,3,3-tetrafluoropropene is contained in the residue F, these compounds are converted into 1,1,1,3,3. -Methods for converting to pentafluoropropane are disclosed in Patent Documents 1 to 3, and these known methods can be used.

  For example, to convert cis-1,3,3,3-tetrafluoropropene to 1,1,1,3,3-pentafluoropropane, antimony pentachloride, antimony trichloride, antimony pentabromide, triodor At least one metal compound selected from antimony fluoride, tin tetrachloride, titanium tetrachloride, molybdenum pentachloride, tantalum pentachloride, niobium pentachloride, and the like can be used. It is preferable to use a metal-supported catalyst that is a solid catalyst supported on a support such as activated carbon, fluorinated alumina, or fluorinated zirconia. Cis-1,3,3,3-tetrafluoropropene is preferably reacted with excess hydrogen fluoride in the gas phase or with hydrogen fluoride in the liquid phase, and in particular, antimony pentachloride is activated carbon. It is preferable to continuously react with hydrogen fluoride using a supported metal supported catalyst.

3. Features and Functions of the Parallel Production Method of the Present Invention In the “reaction step” in the parallel production method of the present invention, 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride are reacted to form trans-1,3 The reaction that produces 3,3-tetrafluoropropene has a chemical equilibrium, and in order to tilt the equilibrium toward the reaction product, the ratio of hydrogen fluoride to 1-chloro-3,3,3-trifluoropropene in the reaction Need to be increased. Add excess hydrogen fluoride to 1-chloro-3,3,3-trifluoropropene, select a specific fluorination catalyst, and adjust the reaction conditions (pressure and temperature) for the fluorination catalyst As a result, the reaction proceeds well as an effect of maintaining the catalytic activity of the fluorination catalyst.

  In the average production method of the present invention, a distillation operation is performed in the “distillation step”, the reaction product A after the “reaction step” is distilled, and unreacted 1-chloro-3,3,3-trifluoro is obtained. It is characterized in that most of propene and hydrogen fluoride are recovered by distillation as a bottoms which is a liquid rich in low volatility components obtained from the bottom of the distillation column.

  In the “reaction step”, if an excessive amount of hydrogen fluoride is supplied into the reaction system of the “reaction step”, a large amount of unreacted hydrogen fluoride remains in the reaction product A, and hydrogen fluoride remains. When the rectification to obtain trans-1,3,3,3-tetrafluoropropene by distilling the reaction product A in this state, the load of rectification increases. However, in the parallel production method of the present invention, most of the hydrogen fluoride was separated and recovered in the “distillation step” that follows the “reaction step”. In addition, the fraction B after the “distillation step” is sent to the “hydrogen fluoride separation step” in the next step, and the remaining hydrogen fluoride is separated and recovered to form a residue C. The “hydrogen chloride separation step” in the next step The hydrogen chloride produced as a by-product is separated and removed to form a residue D, and the residue after dehydration in the next “dehydration step” is rectified in the “purification step”. In the “hydrogen chloride separation step”, when the reaction product (residue C) is washed with water or brought into contact with an aqueous sodium hydroxide solution to separate and remove hydrogen chloride, entrained water is mixed into the reaction product. Since the entrained water is dehydrated in the “dehydration step”, rectification of trans-1,3,3,3-tetrafluoropropene in the “purification step” is facilitated.

  As described above, most of the hydrogen fluoride is separated and removed in the “distillation step”, so that it is easy to separate and recover hydrogen fluoride in the subsequent “hydrogen fluoride separation step”. ”,“ Dehydration process ”and“ purification process ”, the load of the process due to the remaining hydrogen fluoride is reduced, and in the“ purification process ”, trans-1,3,3,3-tetrafluoropropene is converted to hydrogen fluoride or chloride. It becomes easy to easily obtain high-purity trans-1,3,3,3-tetrafluoropropene without mixing with hydrogen. In addition, performing distillation by providing a “distillation step” can reduce the amount of sulfuric acid used in the separation of hydrogen fluoride in which the fraction B is brought into contact with sulfuric acid in the subsequent “hydrogen fluoride separation step”. .

  The parallel production method of the present invention is the above-mentioned “conversion step”, wherein cis-1,3,3,3-tetrafluoropropene in the residue F after the “purification step” is converted to trans-1,3,3,3-tetrafluoro. By converting to propene, 1,1,1,3,3-pentafluoropropane is obtained, and trans-1,3,3,3-tetrafluoropropene, 1,1,1,3,3-pentafluoropropane and Can be produced in parallel.

  Due to the above effects, actual production of cis-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane in an industrial plant is performed using the method of parallel production of the present invention. In this case, labor saving of the process, stabilization and safety of the operation after the “distillation process”, and protection of the apparatus against hydrofluoric acid can be achieved. Further, in the separation and purification by rectification of the reaction product in the subsequent “purification step”, high-purity trans-1,3,3,3-tetrafluoropropene can be obtained more easily. From the reaction product A, most of unreacted 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride were separated and recovered as a bottoms, and the recovered 1-chloro-3,3,3- Returning trifluoropropene and hydrogen fluoride back to the initial “reaction step” is a recyclable and environmentally friendly process that is efficient in industrial production.

  The parallel production method of the present invention comprises 1-chloro-3,3, after the residue E is rectified in the first “purification step” to obtain trans-1,3,3,3-tetrafluoropropene. Supplying a residue F containing 3-trifluoropropene, cis-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane to the first “reaction step”; Furthermore, you may add. By this step, further re-feeding of unreacted substances and effective utilization of by-products can be achieved.

4). Description of the Flowchart of the Method of the Present Invention An example of the method for producing 1,1,1,3,3-pentafluoropropane and trans-1,3,3,3-tetrafluoropropene according to the present invention is shown in FIG. This will be described with reference to a flow diagram. FIG. 1 is an example of the method of the present invention. The method of the present invention is not limited to the following method.

  In the “reaction step” (first step), 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride as raw materials a are reacted in the gas phase reactor 1 in the presence of a fluorination catalyst. The reaction for obtaining trans-1,3,3,3-tetrafluoropropene is carried out.

  The reaction product A after the reaction is supplied to the separation column 2 of the “distillation step” (second step) to perform distillation, and trans-1,3,3,3-tetrafluoropropene, hydrogen chloride and hydrogen fluoride. And the like and other organic matter fraction B, and unreacted 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride b of separation tower 2 containing hydrogen fluoride, Is supplied to the gas phase reactor 1 and reused as a raw material compound. Distillation B, which is a distillate rich in highly volatile components, is obtained from the top of the separation column 2 by distillation, and a bottom b, rich in low volatile components, is obtained from the bottom.

  For example, the bottoms b stored in the lower heating tank of the separation tower 2 is an organic substance mainly composed of 1-chloro-3,3,3-trifluoropropene and 1,1,1,3,3-pentafluoropropane. And recovering the hydrogen fluoride and returning it to the gas phase reactor 1 in the reaction step causes the raw material compound 1-chloro-3,3,3-trifluoropropene to react with hydrogen fluoride, trans-1, It is effective for obtaining 3,3,3-tetrafluoropropene, and can improve the efficiency of the parallel production method of the present invention.

  In addition, by collecting hydrogen fluoride in the separation tower 2 and returning it to the gas phase reactor 1 in the reaction step, excess hydrogen fluoride is produced relative to the starting material 1-chloro-3,3,3-trifluoropropene. It is easily supplied, and a high selectivity of trans-1,3,3,3-tetrafluoropropene after the reaction is obtained, and the hydrogen fluoride in the product A is mostly recovered in the separation tower 2, Recovery of hydrogen fluoride c and d using sulfuric acid in the hydrogen fluoride absorption tower 3 and diffusion tower 4 in the hydrogen fluoride separation process, separation of hydrogen chloride e in the hydrogen chloride absorption tower 5 in the hydrogen chloride separation process, dehydration The load of separation and purification of trans-1,3,3,3-tetrafluoropropene g in the rectifying column 8 in the purification process is significantly reduced by dehydration by the mist separator 6 and the heat exchanger 7 in the process.

  Next, in the “hydrogen fluoride separation step” (third step), the fraction B is sent to the hydrogen fluoride absorption tower 3 and is brought into contact with sulfuric acid, whereby hydrogen fluoride is absorbed by the sulfuric acid. The mixture c containing sulfuric acid and hydrogen fluoride is sent to the stripping tower 4, hydrogen fluoride d is taken out, and the taken out hydrogen fluoride d is supplied to the gas phase reactor 1 and reused as a raw material compound. .

  Residue C after the recovery of hydrogen fluoride d is introduced into hydrogen chloride absorption tower 5 in the “hydrogen chloride separation process” (fourth process), and in hydrogen chloride absorption tower 5, water or sodium hydroxide is introduced. It is washed with water by means such as contact mixing with an aqueous solution, for example, bubbling, and hydrogen chloride e is separated and removed.

  In the “dehydration step” (fifth step), the residue D from which hydrogen chloride e has been separated and removed is introduced into the mist separator 6 and dehydrated to remove moisture h1 if necessary. Thereafter, the residue D is introduced into the heat exchanger 7, the entrained water in the residue D is cooled and frozen and solidified, and the organic matter in the residue D is cooled and condensed from the gas to become a liquefied product. Water h2 is removed.

  Residue E from which the entrained water has been removed after the “dehydration step” (fifth step) is sent to the rectification column 8 in the “purification step” (sixth step), and trans-1,3,3,3- Tetrafluoropropene g is purified.

  In the “conversion step” (seventh step), 1-chloro-3,3,3-trifluoropropene and cis-1, when trans-1,3,3,3-tetrafluoropropene g is purified. 3,3,3-tetrafluoropropene is contained and cis-1,3,3,3-tetrafluoropropene in the residue F is converted to 1,1,1,3,3-pentafluoropropane.

  EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The composition ratio of the reaction product in this example is such that a reaction product containing a distillate from a distillation column is directly injected into gas chromatography (hereinafter abbreviated as GC), and a hydrogen flame is applied to the detector. Measurement was performed using an ion detector (hereinafter abbreviated as FID). The composition ratio of each component is shown as a molar ratio determined from the area of the GC chart.

[Preparation of fluorination catalyst]
First, a fluorination catalyst used for the formation reaction of trans-1,3,3,3-tetrafluoropropene was prepared by the following procedure.

[Catalyst Preparation Example 1]
Hydrogen fluoride was brought into contact with activated alumina to form fluorinated alumina, and chromium was supported on the fluorinated alumina to obtain a fluorination catalyst. The detailed procedure is as follows.

Activated alumina having a particle size of 2 mm to 4 mm (manufactured by Sumitomo Chemical Co., Ltd., trade name, NKHD-24, specific surface area, 340 m ² / g) was weighed and washed 1200 g. Next, 460 g of hydrogen fluoride was dissolved in 4140 g of water to prepare 10% by mass hydrofluoric acid. While stirring 10% by mass of hydrofluoric acid, the washed activated alumina was gradually added, and then allowed to stand for 3 hours. The activated alumina was again washed with water and filtered, and then heated to 200 ° C. in an electric furnace and dried for 2 hours. Dry activated alumina, 1600 ml (1600 cm ³ ) was charged to the gas phase reactor. While flowing nitrogen into a gas phase reactor composed of a cylindrical reaction tube made of stainless steel (SUS316L) having a mantle connected to the heat medium circulation device having a diameter of 5 cm and a length of 90 cm, the heat medium circulation device was operated, A 200 ° C. heat medium was circulated to heat the cylindrical reaction tube. Next, hydrogen fluoride was introduced along with nitrogen at a mass ratio of HF / N ₂ = 1/10 to 1/5. As hydrogen fluoride is introduced, the temperature of the activated alumina increases. At that time, the flow rate of hydrogen fluoride and nitrogen and the ratio of hydrogen fluoride and nitrogen were adjusted so that the temperature of the activated alumina did not exceed 350 ° C. When the heat generation was completed, the set temperature of the heat medium was changed to 450 ° C., and hydrogen fluoride and nitrogen were further introduced for 2 hours to prepare fluorinated alumina. Next, 2016 g of a commercially available special grade reagent, CrCl ₃ · 6H ₂ O, was dissolved in pure water to obtain a 1 L (1000 cm ³ ) aqueous solution. In the aqueous solution, 1500 ml (1500) of the prepared fluorinated alumina was immersed and allowed to stand overnight. Next, the fluorinated alumina was removed by filtration, and further dried in a hot air circulating dryer heated to 100 ° C. for a whole day and night to obtain a chromium-supported fluorinated alumina. After filling the obtained chromium-supported fluorinated alumina in a cylindrical SUS316L reaction tube having a diameter of 5 cm and a length of 90 cm, the temperature of the reaction tube was raised to 300 ° C. while flowing nitrogen gas, and water was retained from the reaction tube. When no longer seen, nitrogen fluoride was accompanied by hydrogen fluoride and introduced into the reaction tube to gradually increase the concentration of hydrogen fluoride. When the hot spot, which is a part that is hotter than the surroundings, has reached the outlet end of the reaction tube due to adsorption of the fluorinated alumina loaded with chromium, the temperature of the reaction tube is increased to 450 ° C., then 1 hour at 450 ° C. The fluorination catalyst was obtained by keeping the time.

[Catalyst Preparation Example 2]
4 × 10 coconut shell crushed charcoal mesh under (Calgon Carbon Japan Co., Ltd., product name, PCB) 100g was immersed in pure water 150g, separately, by dissolving CrCl ₃ · 6HO the (special grade reagent) 40g of pure water 100g After mixing with the solution and stirring, it was left to stand overnight. Next, the liquid after standing was filtered to remove activated carbon, heated to 200 ° C. in an electric furnace, and baked for 2 hours. The obtained activated carbon loaded with chromium chloride is filled into a cylindrical reaction tube made of SUS316L having a diameter of 5 cm and a length of 30 cm, and the reaction tube is heated to 200 ° C. while flowing nitrogen gas. When it was no longer possible, the concentration of hydrogen fluoride was gradually increased by bringing hydrogen fluoride into the nitrogen gas. When the hot spot, which is a part having a higher temperature than the surrounding due to adsorption of hydrogen fluoride on the filled chromium-supported activated carbon, reaches the outlet end of the reaction tube, the temperature is raised to 450 ° C., and then at 450 ° C. for 1 hour. And a fluorination catalyst was obtained.

[Production of 1,3,3,3-tetrafluoropropene (reaction process)]
Next, using the fluorination catalyst obtained in Catalyst Preparation Example 1 and Catalyst Preparation Example 2, 1-chloro-3,3,3-trifluoropropene (CTFP) was reacted with hydrogen fluoride (HF) to produce trans- The reaction for obtaining 1,3,3,3-tetrafluoropropene (trans-TFP) was carried out in the gas phase reactor 1. At that time, the supply amount of 1-chloro-3,3,3-trifluoropropene (CTFP) is kept constant, the supply amount of hydrogen fluoride (HF) is 0.25 g / min or 0.49 g / min, the temperature Was 360 ° C. or 380 ° C., and the pressure in the reactor was 0.1 MPa or 0.2 MPa. The detailed procedure is shown below.

Fluorine prepared in Preparation Example 1 or Preparation Example 2 was added to a stainless steel (SUS316L) tubular gas phase reactor 1 made of a cylindrical reaction tube having a diameter of 1 inch (about 2.54 cm) and a length of 30 cm. 50 ml (50 cm ³ ) of the fluorination catalyst was charged.

Next, while flowing nitrogen at a flow rate of 30 ml / min (30 cm ³ / min), the reaction tube of the gas phase reactor 1 is heated to 200 ° C., and then hydrogen fluoride is flowed at a flow rate of 0.10 g / min. In the reaction tube, the reaction tube was heated to 450 ° C. and kept for 1 hour while being accompanied by nitrogen.

  Next, the temperature of the reaction tube is lowered to 360 ° C. or 380 ° C., and hydrogen fluoride (HF) is supplied at a rate of 0.25 g / min or 0.49 g / min, and 1-chloro-3,3 previously vaporized is supplied. , 3-trifluoropropene (CTFP) was fed to the gas phase reactor 1 at a rate of 0.16 g / min.

  The reaction is stabilized after 1 hour from the start of the reaction, and then the product gas as the reaction product A distilled from the gas phase reactor 1 is blown into water for 2 hours, and the acidic gas is separated and removed. 6.0 to 8.0 g of organic matter was collected with an acetone trap, and GC analysis of the collected organic matter was performed.

  In addition, the molar amount of supply when the supply rate of 1-chloro-3,3,3-trifluoropropene (CTFP) is 0.16 g / min and the supply rate of hydrogen fluoride (HF) is 0.25 g / min. The ratio is CTFP: HF = 1: 8, where the supply rate of 1-chloro-3,3,3-trifluoropropene (CTFP) is 0.16 g / min and the supply rate of hydrogen fluoride (HF) The molar ratio of the supply amount in the case of 0.49 g / min is CTFP: HF = 1: 20.

Table 1 shows the ratio (selectivity) of the reaction product A to the reaction conditions measured by GC using an FID detector. The unit is mol%, and is obtained from the area for each organic substance in the GC chart by the FID detector using an area percentage method in which the total area of the gas chromatography peak is 100%.

  In the reaction system using the catalyst of Catalyst Preparation Example 1, trans-1,3,3,3-tetrafluoropropene (trans-TFP) when the supply rate of hydrogen fluoride (HF) is 0.25 g / min. ) In the case where the HF feed rate is 0.49 g / min compared to 32.1 mol% and 34.5 mol%, trans-1,3,3,3-tetrafluoropropene (trans-TFP) ) Are high, 44.4 mol% and 46.6 mol%, respectively. Moreover, under the same reaction conditions, the selectivity of trans-1,3,3,3-tetrafluoropropene (trans-TFP) is higher at 380 ° C. than at the reaction temperature of 360 ° C. Specifically, as shown in Table 1, when the catalyst of Catalyst Preparation Example 1 was used, trans-1,3,3 under the conditions of HF supply rate of 0.25 g / min and reaction temperature of 360 ° C. , 3-tetrafluoropropene (trans-TFP) has a selectivity of 32.1 mol%, but is 34.5% at a reaction temperature of 380 ° C. In addition, the selectivity of trans-1,3,3,3-tetrafluoropropene (trans-TFP) at a feed rate of HF of 0.49 g / min and a reaction of 360 ° C. is 44.4 mol%. It is 46.6 mol% at 380 ° C.

  In the reaction system using the catalyst of Catalyst Preparation Example 2, trans-1,3,3,3-tetrafluoropropene (trans-TFP) under the conditions of HF supply rate of 0.25 g / min and reaction temperature of 360 ° C. The selectivity of is 30.3 mol%, but it is 33.1 mol% at a reaction temperature of 380 ° C.

  Further, the catalyst of Catalyst Preparation Example 1 was used, the temperature of the reaction tube was set to 150 ° C., and hydrogen fluoride (HF) was supplied at a rate of 0.25 g / min or 0.49 g / min, and vaporized in advance 1− Chloro-3,3,3-trifluoropropene (CTFP) was supplied to the gas phase reactor 1 at a rate of 0.16 g / min. After 1 hour from the start of the reaction, the reaction is stabilized. After that, the gas distilled from the gas phase reactor 1 is blown into water for 2 hours to remove the acidic gas, and then 8.5 g of organic matter is removed with a dry ice-acetone trap. Was collected, and gas chromatography analysis of the collected organic matter was performed. Most of the obtained organic substance is unreacted 1-chloro-3,3,3-trifluoropropene (CTFP), and the target product, trans-1,3,3,3-tetrafluoropropene (trans- The yield of TFP) was less than 1% and was not satisfactory. This is a result of the reaction temperature being too low.

[Production and recycling of 1,3,3,3-tetrafluoropropene (reaction process + separation process)]
[Process Example 1]
1200 ml (1200 cm3) of the fluorination catalyst obtained in Preparation Example 1 was packed in a gas phase reactor 1 made of stainless steel (SUS316L) composed of a cylindrical reaction tube having an inner diameter of 52.7 cm and a length of 58 cm.

  Next, a separation tower 2 equipped with a cooling condenser at the upper part and a heating tank at the lower part was installed in the subsequent stage of the gas phase reactor 1. Separation tower 2 is a distillation tower, having a heating tank for heating the bottoms at the bottom, a cooling condenser for liquefying the distillate at the top, and an inner diameter of separation tower 2 of 54.9 mm, The length was 40 cm and filled with 6 mm Raschig rings.

  Next, 1-chloro-3,3,3-trifluoropropene (CTFP) is reacted with hydrogen fluoride (HF) to obtain trans-1,3,3,3-tetrafluoropropene (trans-TFP). The reaction was carried out in the gas phase reactor 1. 1-chloro-3,3,3-trifluoropropene (CTFP) vaporized in advance at a reaction temperature of 360 ° C., a reaction pressure of 0.2 MPa, and a supply amount of hydrogen fluoride (HF) of 6.0 g / min. Was supplied to the gas phase reactor 1 under the condition of 3.8 g / min. The molar ratio of the supply amount is CTFP: HF = 1: 10.

  The reaction product A, which is a gas, was introduced into the separation column 2 two hours after the start of the reaction for producing trans-1,3,3,3-tetrafluoropropene (trans-TFP) after the reaction had stabilized.

Table 2 shows the distillation conditions in the separation tower 2 and the composition measurement results of the distillate (fraction B).

  As shown in Table 2, distillation was performed under two types of distillation conditions in which the temperature setting of the heating tank and the temperature setting of the cooling condenser were changed. Specifically, as condition 1, the temperature of the heating tank is 24 ° C., the temperature of the cooling condenser is −5 ° C., the pressure in the separation tower 2 is 0.2 MPa, and as the condition 2, the temperature of the heating tank is 25 ° C. Distillation was performed using the separation tower 2 at a condenser temperature of 1 ° C. and a pressure in the separation tower 2 of 0.2 MPa. Quantification of hydrogen fluoride (HF) and hydrogen chloride (HCl) was performed by titration. The distillation rate in Table 2 means the organic matter, HF or HCl in the fraction B, which is a distillate in distillation, when the amount of the organic matter, HF or HCl in the reaction product A is 100, respectively. Is expressed in mol%. That is, the calculation was performed by dividing the molar amount (in the fraction B) at the outlet by the molar amount (in the reaction product A) at the inlet of the separation tower 2 of each compound.

  Distillation rate of organic substance in fraction B of condition 1 is 48.1 mol%, distillation rate of hydrogen fluoride (HF) is 6.9 mol%, distillation rate of hydrogen chloride is 91.8 mol% The concentration of trans-1,3,3,3-tetrafluoropropene (trans-TFP) in the organic substance is 26.0 mol% at the inlet of the separation tower 2 and 55.6 mol% at the outlet. Was 2.1. The distillation rate of organic matter in fraction 2 of condition 2 is 63.8 mol%, the distillation rate of hydrogen fluoride (HF) is 10.2 mol%, and the distillation rate of hydrogen chloride is 91.5 mol%. The concentration of trans-1,3,3,3-tetrafluoropropene (trans-TFP) in the organic substance is 26.6 mol% at the inlet of the separation tower 2 and 42.5 by the distillate at the outlet of the separation tower 2. The concentration ratio was 2.1.

  Moreover, when the organic substance composition in the reaction product A gas at the inlet of the separation tower 2 when distilled under condition 1 was measured by GC, trans-1,3,3,3-tetrafluoropropene (trans-TFP) ) Is 26.0 mol%, cis-1,3,3,3-tetrafluoropropene (cis-TFP1234zeZ) is 6.3 mol%, 1,1,1,3,3-pentafluoropropane (PFP) is 17.7 mol%, 1-chloro-3,3,3-trifluoropropene (CTFP) was 49.6 mol%. On the other hand, the organic composition in the outlet gas of the separation tower 2, that is, the fraction B of the separation tower 2, is 55.6 mol% of trans-1,3,3,3-tetrafluoropropene (trans-TFP). Cis-1,3,3,3-tetrafluoropropene (cis-TFP) is 9.3 mol%, 1,1,1,3,3-pentafluoropropane (PFP) is 9.6 mol%, 1- Chloro-3,3,3-trifluoropropene (CTFP) was 25.3 mol%.

  That is, if distillation is performed using the separation column 2 under the distillation conditions of Condition 1, trans-1,3,3,3-tetrafluoropropene (trans-TFP) is the main component as the fraction B after the separation column 2. As a result, about 50 mol% of the organic matter was distilled out with respect to the organic matter in the reaction product A after the reaction step, and about 90 mol% of hydrogen chloride with respect to the theoretical production amount.

[Process example 2]
Subsequently, 1200 ml of the fluorination catalyst obtained in Preparation Example 1 was charged into the gas phase reactor 1 made of stainless steel (SUS316L) composed of a cylindrical reaction tube having an inner diameter of 52.7 cm and a length of 58 cm.

  The above-mentioned condition 1 was adopted as the distillation condition using the separation tower 2 equipped with a cooling condenser at the top and a heating tank at the bottom, the inner diameter was 54.9 mm, the length was 40 cm, and 6 mm Raschig rings were packed. Raw material obtained by adding hydrogen fluoride (HF) and organic matter recovered as the bottoms b of the separation tower 2 and 1-chloro-3,3,3-trifluoropropene (CTFP) and hydrogen fluoride (HF). Is supplied to the gas phase reactor 1, and the reaction conditions are changed, and 1-chloro-3,3,3-trifluoropropene (CTFP) is reacted with hydrogen fluoride (HF) to produce trans-1,3,3. A reaction for obtaining 3,3-tetrafluoropropene (trans-TFP) was performed.

The reaction conditions and results are shown in Table 3. Specifically, in addition to the novel trans-1,3,3,3-tetrafluoropropene (trans-TFP) and hydrogen fluoride (HF), the recovered organic matter recovered as the bottoms b of the separation tower 2 is the gas. Feeded to phase reactor 1.

  As shown in Table 3, the reaction temperature is 360 ° C., the supply of 1-chloro-3,3,3-trifluoropropene (CTFP) is 1.2 g / min, and the supply of recovered organic matter is equal to 2.7 g / min. The hydrogen fluoride (HF) was fed at 3.5 g / min or 7.1 g / min, and the reaction pressure was 0.1 MPa or 0.2 MPa. As a result, 1,3,3,3-tetrafluoropropene (trans-TFP) was found to be 34.4 mol% and 29.2 mol when the supply amount of hydrogen fluoride (HF) was 3.5 g / min. % Of hydrogen fluoride (HF) supplied at 7.1 g / min is 47.3 mol%, and trans-1,3,3,3-tetrafluoropropene (trans-TFP) It was found that high selectivity can be obtained.

[Dehydrofluorination (hydrogen fluoride separation step), Dehydrochlorination (hydrogen chloride separation step) and Dehydration (dehydration step)]
In the separation step, the reaction product A is distilled by the separation tower 2 under the distillation condition 2 described above, and the fraction B distilled from the separation tower 2 is sulfuric acid in the hydrogen fluoride absorption tower 3 in the hydrogen fluoride separation step. And hydrogen fluoride (HF) was absorbed and removed by sulfuric acid.

  Residue C after separation of hydrogen fluoride was bubbled into water at a rate of 2.0 g / min in hydrogen chloride absorption tower 5 in the hydrogen chloride separation step to remove hydrogen chloride e.

  In the subsequent dehydration step, a SUS-316 mist separator 6 that was previously filled with a SUS-316 filler and cooled using a refrigerant at a temperature of 5 ° C. was prepared. Residue D after separation of hydrogen chloride e was introduced into the prepared mist separator 6. The mist separator 6 removed mist-like entrained water h1 accompanying the residue D, which is a mixed gas. A gas in which a plurality of organic substances, which are the residue D at the outlet of the mist separator 6, was collected and the water content was measured by the Karl Fischer method. As a result, the water concentration was 1300 ppm.

[Purification of trans-1,3,3,3-tetrafluoropropene (purification step)]
In the subsequent purification step, a double-tube cooling pipe made of SUS-316 having an inner diameter of 12 mm, an outer diameter of 6 mm, and a length of 300 mm as the heat exchanger 7 was prepared. A refrigerant of −40 ° C. is circulated through the inner pipe, and the gas which is the residue D after passing through the mist separator 6 is supplied at a rate of 2.0 g / min between the outer pipe and the inner pipe of the double pipe type cooling pipe. By supplying at a speed, the gas was cooled and condensed, and the liquefied organic matter (residue E) was collected from the lower part of the cooling pipe. The water concentration of the collected organic matter was measured by the Karl Fischer method and found to be 65 ppm. As a result of GC analysis, no new organic matter was found. In this way, 98.0% by mass of the organic matter introduced into the cooling pipe was recovered.

  The residue E, which is an organic substance dehydrated by the above method, is rectified in the rectification column 8 in the purification step, and as a distillate, trans-1,3,3,3-tetrafluoropropene g (trans-TFP ) Was isolated. The water concentration measured by the Karl Fischer method was 78 ppm, and the purity measured by gas chromatography was 99.9%.

[Conversion of cis-1,3,3,3-tetrafluoropropene to 1,1,1,3,3-pentafluoropropane (conversion step)]
1,1,1,3,3 of cis-1,3,3,3-tetrafluoropropene in residue F
-Conversion to pentafluoropropane was performed.

[Conversion Example 1]
In a 500 ml SUS304 autoclave equipped with a stirrer, a reflux condenser maintained at −30 ° C. and a pressure regulating valve, 6.0 g (0.02 mol) of antimony pentachloride and 100 g (5.0 mol) of hydrogen fluoride were used as catalysts. The mixture was stirred for 30 minutes to activate the catalyst. The generated hydrogen chloride is discharged from the pressure regulating valve provided at the rear of the reflux condenser, the pressure is returned to normal pressure, the pressure regulating valve is closed, the autoclave is cooled with dry ice-methanol, and cis-1, 3, 3, 114 g (1.0 mol) of 3-tetrafluoropropene was added, and the reaction temperature was raised to 50 ° C. while stirring. 3.5 hours after the start of the reaction, the reactor was cooled to room temperature, and the pressure was reduced to normal pressure. The gas distilled from the reactor was passed through an aqueous layer and a concentrated sulfuric acid layer, and then collected in a trap cooled with dry ice-methanol. The recovered organic substance weighed 123 g and the product composition analyzed by gas chromatography was 1,1,1,3,3-pentafluoropropane 98.5%, 1,3,3,3-tetrafluoropropene. 0.4% and 1-chloro-3,3,3-trifluoropropene 0.1%. The results are shown in Table 4.

[Conversion Examples 2, 3, 4, 5]
The reaction was conducted under the conditions shown in Table 4 by the same reaction procedure as in Conversion Example 1. The results are shown in Table 4.

DESCRIPTION OF SYMBOLS 1 Gas phase reactor 2 Separation tower 3 Hydrogen fluoride absorption tower 4 Stripping tower 5 Hydrogen chloride absorption tower 6 Mist separator 7 Heat exchanger 8 Rectifying tower A Reaction product A
B fraction (hydrogen fluoride, hydrogen chloride, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,3,3-pentafluoropropane Etc.)
C Residues (hydrogen chloride, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,3,3-pentafluoropropane, water, etc. Including)
D residue (including 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,3,3-pentafluoropropane, water, etc.)
E residue (including 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,3,3-pentafluoropropane, etc.)
F residue (residue after obtaining trans-1,3,3,3-tetrafluoropropene as a fraction by rectification)
a Raw materials (1-chloro-3,3,3-trifluoropropene and hydrogen fluoride)
b Canned liquid (unreacted organic matter such as 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride)
c Hydrogen fluoride and sulfuric acid d Hydrogen fluoride e Hydrochloric acid h1, h2 Entrained water g Trans-1,3,3,3-tetrafluoropropene

Claims (5)

1-chloro-3,3,3-trifluoropropene and hydrogen fluoride are reacted in the gas phase at a temperature of 200 ° C. or higher and 450 ° C. or lower and a pressure of 0.05 MPa or higher and 0.3 MPa or lower using a fluorination catalyst. Trans-1,3,3,3-tetrafluoropropene, cis-1,3,3,3-tetrafluoropropene, 1,1,1,3,3-pentafluoropropane and hydrogen chloride, A reaction step of obtaining a reaction product A containing 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride as reactants;
A distillation step of distilling reaction product A to return the bottoms containing 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride to the reaction step, and obtaining fraction B;
A hydrogen fluoride separation step in which hydrogen fluoride is separated and recovered from the fraction B after the distillation step and supplied to the reaction step;
A hydrogen chloride separation step of separating and removing hydrogen chloride by bringing water or an aqueous sodium hydroxide solution into contact with the residue C after recovering hydrogen fluoride in the hydrogen fluoride separation step;
The entrained water contained in the residue D after the separation of hydrogen chloride in the hydrogen chloride separation step is frozen on the cooling surface of the heat exchanger and at the same time the residue D is condensed to form a liquefied organic substance (residue E )
The residue E after dehydration in the dehydration step is rectified to contain a fraction containing trans-1,3,3,3-tetrafluoropropene and cis-1,3,3,3-tetrafluoropropene. A purification step to obtain residue F;
A conversion step of converting cis-1,3,3,3-tetrafluoropropene in residue F of the purification step into 1,1,1,3,3-pentafluoropropane;
including,
Parallel production method of trans-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane. Fluorination catalyst is chromium, titanium, aluminum, manganese, nickel, cobalt, iron, copper, zinc, silver, molybdenum, zirconium, niobium, tantalum, iridium, tin, hafnium, vanadium, magnesium, lithium, sodium, potassium, calcium And at least one metal selected from the group consisting of antimony and nitrates, chlorides, oxides, sulfates, fluorides, fluorides, oxyfluorides, oxychlorides or oxyfluoride chlorides. 1. The method of common production according to 1. The reaction in the reaction step is carried out by using fluorinated alumina supporting chromium chloride as a fluorination catalyst, and representing the supply amount of 1-chloro-3,3,3-trifluoropropene and hydrogen fluoride in molar ratio as 1- The parallel production method according to claim 1 or 2, wherein the chloro-3,3,3-trifluoropropene: hydrogen fluoride is 1: 8 to 1:25. The reaction in the reaction step is performed by using activated carbon carrying chromium oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride or oxyfluorinated chloride as a fluorination catalyst, and 1-chloro-3 , 3,3-trifluoropropene and hydrogen fluoride are represented by molar ratio, and 1-chloro-3,3,3-trifluoropropene: hydrogen fluoride = 1: 8 to 1:25. The parallel production method according to claim 1 or claim 2. The parallel production method according to any one of claims 1 to 4, wherein in the hydrogen fluoride separation step, hydrogen fluoride is absorbed and recovered by sulfuric acid.

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