JP3465865B2 - Method for producing 1,3,3,3-tetrafluoropropene - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 1,3,3,3-useful as an intermediate raw material for medical and agricultural chemicals, functional materials or a refrigerant.
The present invention relates to a method for producing tetrafluoropropene. 2. Description of the Related Art As a method for producing 1,3,3,3-tetrafluoropropene, conventionally, 1,3,3,3-tetrafluoro-1-propane iodide is removed by alcoholic potassium hydroxide. Method for hydrogen iodide (RN Haseze)
ldine et al. Chem. Soc. 1953, 11
99-4206; CA 48 5787f) or a method of dehydrofluorinating 1,1,1,3,3-pentafluoropropane with potassium hydroxide in dibutyl ether (IL Kunyanants et al., Izvest.
Akad. Nauk S.D. S. S. R. , Otdel.
Khim. Nauk. 1960, 1412-18; CA
55, 349f) and the like are known. [0003] The above-mentioned method of dehydrohalogenating with potassium hydroxide is a method excellent in the reaction rate and the selectivity, but the potassium hydroxide has a stoichiometric amount or more. It is necessary and the raw materials 1,3
3,3-Tetrafluoro-1-propane iodide or 1,1,1,3,3-pentafluoropropane must be prepared in advance, and there are many difficulties for industrial application. SUMMARY OF THE INVENTION [0004] The inventors of the present invention have used a material which is available on an industrial scale or which can be produced relatively easily from raw materials available on an industrial scale. A study was conducted on a method for producing 3,3,3-tetrafluoropropene. 1-Chloro-3,3,3-trifluoropropene was used as a raw material, and this was fluorinated with hydrogen fluoride to obtain 1,3,3-tetrafluoropropene. , 3,3-tetrafluoropropene is obtained, and it is also found that it is particularly preferable to use activated carbon or activated carbon carrying a metal compound such as a chromium compound as a catalyst in the gas phase fluorination. The invention has been reached. That is, the present invention is characterized in that 1-chloro-3,3,3-trifluoropropene is reacted with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst. A process for producing 3-tetrafluoropropene, wherein the fluorination catalyst is activated carbon or activated carbon carrying a metal compound such as a chromium compound. Production of 1,3,3,3-tetrafluoropropene Is the law. 1-chloro-3,3,3 used in the present invention
-Trifluoropropene is 3-bromo-3-chloro-
Method for dehydrochlorinating 1,1,1-trifluoropropane with alcoholic potassium hydroxide (RN Has
zeldine, J .; Chem. Soc. , 1951,
2495), a method of adding hydrogen chloride to 3,3,3-trifluoropropyne (J. Chem. Soc., 19).
52, 3490), a method of dehydroiodating 3-chloro-1,1,1-trifluoro-3-iodopropane with alcoholic potassium hydroxide (J. Chem. So
c. , 1953, 1199. ) Or 1,3,3,3-
It can be obtained by a method of fluorinating tetrachlorolopropene with an antimony catalyst (US Pat. No. 2,787,646). Japanese Patent Application No. 8-5 filed by the present applicant.
No. 971 discloses a method for vapor-phase fluorination of 1,1,1,3,3-pentachloropropane with hydrogen fluoride. [0007] The activated carbon according to the present invention is a plant based on wood, sawdust, charcoal, coconut husk charcoal, palm kernel charcoal, ash, etc., or a raw material from peat, lignite, lignite, bitumen, anthracite, etc. And petroleum based on petroleum residue, sulfuric acid sludge, oil carbon, etc. Since various types of such activated carbons are commercially available, they may be selected and used. For example, activated carbon produced from bituminous coal (for example, Calgon granular activated carbon CAL (Toyo Calgon Co., Ltd.)
And coconut shell charcoal (for example, manufactured by Takeda Pharmaceutical Co., Ltd.) and the like, but are not limited to these types and manufacturers. These activated carbons are usually used in the form of granules, but their shapes and sizes are not particularly limited.
The size of the reactor can be determined based on ordinary knowledge. [0008] The activated carbon according to the present invention may be an oxide of one or more metals selected from aluminum, chromium, manganese, nickel, cobalt and titanium;
Activated carbon carrying fluoride, chloride, fluoride chloride, oxyfluoride, oxychloride, oxyfluoride chloride or the like may be used. The method for preparing these metal-supported activated carbon catalysts is not limited, but chromium, titanium, manganese may be added to activated carbon as it is or to activated carbon previously modified with halogen such as hydrogen fluoride, hydrogen chloride, or chlorinated fluorinated hydrocarbon. One or two selected from nickel, nickel and cobalt
It is prepared by impregnating or spraying a solution of a soluble compound of one or more metals. The amount of the metal carried is 0.1 to 80% by weight, preferably 1 to 40% by weight. Examples of the soluble compound of the metal supported on the activated carbon include nitrates, chlorides and oxides of the metal dissolved in a solvent such as water, ethanol and acetone. Specifically, chromium nitrate, chromium trichloride, chromium trioxide, potassium dichromate, titanium trichloride, manganese nitrate, manganese chloride, manganese dioxide, nickel nitrate, nickel chloride, cobalt nitrate, cobalt chloride, etc. may be used. it can. [0011] The catalyst supporting the metal by any method is treated with a fluorinating agent such as hydrogen fluoride, fluorinated (and chlorinated) hydrocarbon at a temperature higher than a predetermined reaction temperature before use, and It is effective to prevent a change in the composition of the catalyst inside. Supplying oxygen, chlorine, fluorinated or chlorinated hydrocarbons, etc. into the reactor during the reaction is effective for extending the life of the catalyst, improving the reaction rate, and improving the reaction yield. The reaction temperature is 200-600 ° C., preferably 300-500 ° C. If the reaction temperature is lower than 200 ° C., the reaction is slow and not practical. When the reaction temperature exceeds 600 ° C., the catalyst life is shortened, and the reaction proceeds quickly, but decomposition products and the like are generated, and the selectivity of 1,3,3,3-tetrafluoropropene decreases, which is not preferable. . In the method of the present invention, the molar ratio of 1-chloro-3,3,3-trifluoropropene / hydrogen fluoride supplied to the reaction zone can be changed depending on the reaction temperature.
It is 1 to 1/60, preferably 1/1 to 1/30. If the amount of hydrogen fluoride exceeds 60 mole times that of 1-chloro-3,3,3-trifluoropropene, the amount of organic matter to be treated in the same reactor decreases, and the amount of unreacted hydrogen fluoride discharged from the reaction system and the product decreases. The separation of the mixture is hindered. On the other hand, if the amount of hydrogen fluoride is less than 1 mol times, the reaction rate is decreased and the selectivity is undesirably decreased. In the method of the present invention, it is preferable to use an excess amount of hydrogen fluoride, so that unreacted hydrogen fluoride is separated from unreacted organic substances and products and recycled to the reaction system. Separation of hydrogen fluoride and organic matter can be performed by a known means. The reaction pressure is not particularly limited, but is preferably ¹ to 10 kg / cm ² from the viewpoint of the apparatus. It is desirable to select conditions so that the raw material organic substances, intermediate substances and hydrogen fluoride present in the system are not liquefied in the reaction system.
The contact time is usually 0.1 to 300 seconds, preferably 5 to 6 seconds.
0 seconds. The reactor may be made of a material having heat resistance and corrosion resistance to hydrogen fluoride, hydrogen chloride and the like, and is preferably made of stainless steel, Hastelloy, Monel, platinum or the like.
It can also be made of materials lined with these metals. The product containing 1,3,3,3-tetrafluoropropene which is treated by the method of the present invention and flows out of the reactor is purified by a known method to obtain a product. Although the purification method is not limited, for example, a product from which hydrogen fluoride to be recovered is separated in advance is first washed with water or / and an alkaline solution to remove acidic substances such as hydrogen chloride and hydrogen fluoride, and then dried. Thereafter, distillation can be performed to remove organic impurities. [Preparation Example 1] 100 g of crushed coconut shell charcoal made by Toyo Calgon (P
CB (4 × 10 mesh) was immersed in 150 g of pure water, and separately mixed with a solution prepared by dissolving 40 g of a special-grade reagent CrCl ₃ .6H ₂ O in 100 g of pure water, stirred, and allowed to stand overnight. Next, the activated carbon was removed by filtration, and was placed in an electric furnace for 200 hours.
C. and baked for 2 hours. The obtained chromium-supporting activated carbon was converted into a cylindrical SU having a diameter of 5 cm and a length of 30 cm equipped with an electric furnace.
S316L into a reaction tube,
The temperature was raised to 00 ° C., and at the time when the outflow of water was no longer observed, the concentration of nitrogen gas was gradually increased by accompanying hydrogen fluoride. When a hot spot due to the adsorption of hydrogen fluoride on the filled chromium-supported activated carbon reached the outlet end of the reaction tube, the reactor temperature was raised to 400 ° C., and this state was maintained for 2 hours to prepare a catalyst. [Preparation Example 2] 100 g of crushed coconut shell made of Toyo Calgon (PCB 4 × 10 mesh) and 150 g of pure water
, And separately mixed and stirred with 200 g of a 20% aqueous solution of TiCl _3, and left overnight. Next, the activated carbon was removed by filtration and calcined at 200 ° C. for 2 hours in an electric furnace. The obtained titanium-supported activated carbon was charged into a cylindrical SUS316L reaction tube having a diameter of 5 cm and a length of 30 cm equipped with an electric furnace,
The temperature was raised to 200 ° C. while flowing nitrogen gas, and when the outflow of water was no longer observed, the concentration of nitrogen gas was gradually increased by accompanying hydrogen fluoride. When a hot spot due to the adsorption of hydrogen fluoride on the filled titanium-supported activated carbon reached the outlet end of the reaction tube, the reactor temperature was raised to 400 ° C., and the state was maintained for 2 hours to prepare a catalyst. [Preparation Example 3] 336 g of special grade reagent CrCl
The ₃ · 6H ₂ O was 1L dissolved in pure water. To this solution was added granular γ-alumina 250 having a diameter of 5 mm and a surface area of 340 m ^2.
ml was immersed and left overnight. Next, γ-alumina was removed by filtration, kept at 100 ° C. in a hot air circulating dryer, and further dried overnight. The obtained chromium-carrying alumina was cylindrical S with a diameter of 5 cm and a length of 30 cm equipped with an electric furnace.
The reactor was filled in a US316L reaction tube, heated to 300 ° C. while flowing nitrogen gas, and when the outflow of water was no longer observed, hydrogen gas was accompanied by hydrogen fluoride to gradually increase the concentration. When the hot spot due to the fluorination of the charged chromium-supported alumina reached the outlet end of the reaction tube, the reactor temperature was raised to 450 ° C., and the state was maintained for 1 hour to prepare a catalyst. Example 1 Preparation Example 1 as a gas phase fluorination catalyst in a gas phase reactor (SUS316L, 1 inch in diameter and 30 cm in length) comprising a cylindrical reaction tube equipped with an electric furnace.
150 ml of the catalyst prepared in the above was charged. About 100ml /
While flowing nitrogen gas at a flow rate of 200 min.
° C and hydrogen fluoride was entrained with nitrogen gas at a rate of about 0.10 g / min. The temperature of the reaction tube was raised to 500 ° C. and kept for 1 hour. Next, the temperature of the reaction tube was lowered to 400 ° C., and hydrogen fluoride was supplied at a supply rate of 0.15 g / min.
-Chloro-3,3,3-trifluoropropene was previously vaporized and started to be supplied to the reactor at a rate of 0.06 g / min. Since the reaction was stable 1 hour after the start of the reaction, the product gas flowing out of the reactor was blown into water for 2 hours from that time to remove acidic gas, and then 6.0 g of dry ice-acetone trap was used. Organics were collected. The results of analysis of the collected organic matter by gas chromatography are shown in Table 1. [Table 1] Example 2 Using the catalyst prepared in Preparation Example 2, after the same preparation steps as in Example 1, the same reaction operation, recovery operation and analysis as in Example 1 were performed under the conditions shown in Table 1. Was.
Table 1 shows the results. Example 3 Using activated carbon alone, the same reaction operation, recovery operation, and analysis as in Example 1 were performed under the conditions shown in Table 1. Table 1 shows the results. REFERENCE EXAMPLE After the same preparation steps as in Example 1 except that the chromium-supported alumina catalyst of Preparation Example 3 was used as the catalyst, the same reaction operation as in Example 1 was performed under the conditions shown in Table 1.
Recovery operation and analysis were performed. Table 1 shows the results. According to the process for producing 1,3,3,3-tetrafluoropropene of the present invention, 1-chloro-3,3,3-trifluoropropene is used as a raw material, , 3,3
-It is useful as an industrial production method because tetrafluoropropene can be produced.

────────────────────────────────────────────────── (5) References JP-A-9-183740 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 17/20 C07C 21/18 CA (STN )

Claims (1)

(57) [Claims] [Claim 1] Activated carbon or chromium or titanium in a gas phase
Of aluminum, manganese, nickel and cobalt
Oxides of one or more metals selected from the group consisting of
Nitride, chloride, fluoride chloride, oxyfluoride, oki
Reacting 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride in the presence of an activated carbon catalyst supporting dichloride and oxyfluoride chloride ;
A method for producing 1,3-tetrafluoropropene.