JP2002105006A - Method for producing 1,1,1,3,3-heptafluoropropane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for industrially advantageously producing 1,1,1,3,3-pentafluoropropane. SOLUTION: This method for producing the 1,1,1,3,3-pentafluoropropane from 1-chloro-3,3,3-trifluoropropane and hydrogen fluoride in the presence of chlorine, comprising using a fluorination reaction device containing a reactor (A) and a reactor (B) charged with antimony pentachloride-carrying activated carbon, respectively, arranging the first reactor set to >=150 deg.C and the second reactor set to 20 to 150 deg.C in series from the upstream side, performing the reaction in the reactor (A) as the first reactor and in the reactor (B) as the second reactor in the first time division, performing the reaction in the reactor (B) as the first reactor and in the reactor (A) as the second reactor in the second time division, and then similarly carrying out the reaction, while alternating the reactor (A) with the reactor (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing 1,1,1,3,3-pentafluoropropane, which comprises fluorinating (chloro) fluoropropene with hydrogen fluoride.

[0002]

2. Description of the Related Art Many methods have been proposed for producing 1,1,1,3,3-pentafluoropropane.

[0003] For example, CF3-CClX-CF2Cl
(X represents a halogen atom) by contact hydrogen (JP-A-6-256235), 1,1,3,3,3
Method for hydrogenating -pentafluoro-1-propene with Pd-Al2O3 (Izvest. Aad. Nauk S .;
S. S. R. , Otdel. Khim. Nauk. 19
60, 1412-18; CA 55,349f),
A method for hydrogenating 1,2,2-trichloropentafluoropropane (US Pat. No. 2,942,036),
Liquid phase fluorination of 1,1,3,3-pentachloropropane with hydrogen fluoride in the presence of a catalyst (US Pat. No. 5,57
4,192), 1,1,1,3,3-
A method of fluorinating pentachloropropane with hydrogen fluoride in the presence of a catalyst (Japanese Patent Application Laid-Open No. 9-002983), similarly, using 1,1,1,3,3-pentachloropropane in the gas phase with hydrogen fluoride in the presence of a catalyst Fluorinated 1-chloro-
A method is known in which 3,3,3-trifluoropropene is obtained, and the compound obtained by removing the accompanying hydrogen chloride is vapor-phase fluorinated with hydrogen fluoride in the presence of a catalyst (JP-A-9-183740). ing.

Japanese Patent Application Laid-Open No. 2000-7591 discloses that 1-chloro-3,3,3-trifluoropropene or 1,3,3,3-tetrafluoropropene is prepared using an active carbon catalyst carrying antimony pentachloride. A method for producing 1,1,1,3,3-pentafluoropropane by vapor-phase fluorination with hydrogen fluoride is disclosed.

Further, US Pat. No. 5,895,825 discloses that 1-chloro-3,3,3-trifluoropropene is vapor-phase fluorinated with hydrogen fluoride using a chromium oxide catalyst.
Then, a method of vapor-phase fluorinating the obtained 1,3,3,3-tetrafluoropropene with hydrogen fluoride using an antimony pentachloride-supported activated carbon catalyst to obtain 1,1,1,3,3-pentafluoropropane. Is disclosed.

[0006]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 2000-7
No. 591 describes a method for producing 1,1,1,3,3-pentafluoropropane using an antimony pentachloride-supported activated carbon catalyst, in addition to the fact that the raw materials are easily obtained,
This is an industrially advantageous method characterized by extremely high product selectivity.

In general, it is known that it is preferable to coexist an oxidizing agent such as chlorine or oxygen in the reaction system in order to maintain the activity of the fluorination catalyst.
-The effect of adding chlorine was also observed in the production of pentafluoropropane.

However, when the reaction is carried out at a relatively high temperature, a decrease in the activity of the catalyst can be avoided by the addition of chlorine. However, propenes, which are unsaturated compounds, are added to the product in a small amount, However, it was found that it was relatively difficult to maintain the activity of the catalyst for a long time despite the addition of chlorine.

[0009]

SUMMARY OF THE INVENTION In view of the above problems, the present inventors have proposed a method for producing 1,1,1,3,3-pentafluoropropane using an activated carbon catalyst carrying antimony pentachloride. A study was conducted with the aim of developing a reaction method that makes it possible to use the catalyst for a long period of time while maintaining a high selectivity of the product.When the reaction was carried out in the presence of chlorine together with an organic raw material and hydrogen fluoride in the reaction system,
Antimony pentachloride loading can be achieved by applying a catalyst with reduced activity to a reaction at a relatively high temperature by using the catalyst at a low temperature for the purpose of high 1,1,1,3,3-pentafluoropropane selectivity. It has been found that the activity of the activated carbon catalyst can be regenerated, and the present invention has been completed.

That is, the present invention relates to 1-chloro-3,
3,3-trifluoropropene or 1,3,3,3-
A raw material containing at least tetrafluoropropene, hydrogen fluoride and chlorine is passed through a fluorination reactor to 1,1,1,
A method for producing 3,3-pentafluoropropane, comprising using a fluorination reactor comprising a reactor (A) and a reactor (B) each filled with antimony pentachloride-loaded activated carbon, and ℃ or more, preferably 1
First reactor set at 50-220 ° C, 20-150
° C, preferably 20-120 ° C, are arranged in series, with reactor (A) being the first reactor and reactor (B) being the second reactor in the first time interval. In the second time interval, the reaction is carried out using the reactor (B) as the first reactor and the reactor (A) as the second reactor, and then reacting the reactor (A) and the reactor (B) in the same manner as described above. 1,1,1,3,3 consisting of carrying out a reaction by repeating the exchange of
-A method for producing pentafluoropropane.

In the method of the present invention, the second reactor for performing the low-temperature reaction is at 20 to 150 ° C., preferably 20 to 120 ° C.
Despite the presence of chlorine in the reaction system, it is unavoidable to reduce the activity of the catalyst because it is set to about ℃,
At a temperature of 150 ° C. or higher, preferably 150 to 220 ° C. in the first reactor for performing a high-temperature reaction, the activity of the catalyst does not decrease. It can be said that this is a method for extending the life of the catalyst based on a very specific reaction system which is also effective. In both the first reactor and the second reactor, no compound is generated due to the reaction of chlorine with the organic compound.

1-chloro-3,3,3 used in the present invention
-Trifluoropropene or 1,3,3,3-tetrafluoropropene may be produced by any method. For example, 1,1,1,3,3-pentachloropropane and hydrogen fluoride are reacted under non-catalytic liquid phase pressurization, or gas-phase fluorination using fluorinated chromia, fluorinated alumina, chromium fluoride, etc. as a catalyst It is obtained by reacting under conditions. In addition, 1,3,3,3-tetrafluoropropene can also be obtained by reacting under a gas-phase fluorination condition using chromium oxide, chromium fluoride or the like as a catalyst. 1-chloro-3,3,3 obtained by these methods
In the state obtained from the reactor, 3-trifluoropropene and the like are not limited to 1-chloro-3,3,3-trifluoropropene, which is the main product, and 1,1,1,3,3-pentafluoropropane and the like. In some cases, unreacted hydrogen fluoride, by-product hydrogen chloride, and the like may be contained together with the low fluorinated product, but a part of them may be removed and used, or they may be used as they are.

In the fluorination reactor of the present invention, at least two fluorination reactors, that is, a first reactor and a second reactor are arranged in series from the upstream in order. These fluorination reactors respectively correspond to the reactor (A) and the reactor (B) in the first time section or to the reactor (B) and the reactor (A) in the second time section, After the third time period, the reaction can be maintained for a long period of time by repeating the change of the order.

The temperature of the first reactor is set at 150 ° C. or higher. Preferably 150 to 250 ° C, more preferably 150 to 2
The temperature is 20 ° C, more preferably about 170 to 200 ° C. Even at a temperature lower than 150 ° C., 1,1,1,3,3-pentafluoropropane is produced to a sufficiently satisfactory degree, but the activity of the catalyst is reduced, and the catalyst used as the second reactor is reactivated. It is not preferable because it cannot be converted. At a temperature higher than 250 ° C., a decrease in the activity of the catalyst may be observed, and decomposition products and the like may be formed, and
It is preferable to avoid 1,3,3-pentafluoropropane because it reduces the selectivity.

The temperature of the second reactor is set at about 20 to 150 ° C. It is preferably about 20 to 120 ° C, and 50 to 10 ° C.
0 ° C. is more preferred. If the temperature is lower than 20 ° C, the raw material or the intermediate product may be liquefied, which is not preferable. If the temperature is higher than 150 ° C, the content of the unsaturated compound increases, which is not preferable.

[0016] Reactor (A) and reactor (B) are substantially the same reactor. That is, the mechanical structure, the type and amount of the internal catalyst, and the like are substantially the same. The reaction type may be any of a fixed bed, a fluidized bed and the like.

The reactor may be made of a material having heat resistance and corrosion resistance to hydrogen fluoride, hydrogen chloride, chlorine and the like, and is preferably iron, stainless steel, Hastelloy, Monel, platinum or the like. It can also be made of materials lined with these metals.

In the method of the present invention, the reaction gas generated in the first reactor is mostly 1,1,1,1 as an organic component.
3,3-pentafluoropropane (trans form or cis form) and a small amount of unreacted 1-chloro-3,3,3-
Contains trifluoropropene and a small amount of 1,3,3,3-
It may also include tetrafluoropropene. In addition, it contains unreacted hydrogen fluoride and chlorine. The composition of this reaction gas can be easily known by preliminary experiments. However, in carrying out the method of the present invention, since the first and second reactors are connected, it is not always necessary to accurately know the organic components contained in the reaction gas.

The fluorination catalyst according to the present invention is a catalyst in which antimony pentachloride is supported on activated carbon. In the present specification, “antimony pentachloride” of “antimony pentachloride-supported activated carbon” means an antimony compound represented by SbCl _x F _5-x (x is an integer of 0 to 5). That is, when antimony pentachloride is active as a catalyst, SbCl _x F _{5 -x}
(X is an integer of 2 to 4), which is considered to be a chlorinated fluorinated antimony state. Therefore, when used in the preparation of the catalyst, it is not necessary to use antimony pentachloride, and antimony pentachloride, antimony trichloride, antimony pentafluoride and the like can be used. These can also be used by supporting them on activated carbon and converting them to pentavalent antimony with an oxidizing agent such as chlorine. Further, a compound containing bromine instead of chlorine can also be used.

The preparation method is not particularly limited as long as antimony pentachloride adheres to the activated carbon. In the case of antimony pentachloride, which is a liquid at around normal temperature, a basic substance, a treatment with an acid or hot water or a pretreatment for dehydration treatment as described later is directly dropped on activated carbon, sprayed,
It can be directly attached by a method such as immersion. When the compound is a liquid or solid compound at room temperature, it is impregnated by immersing activated carbon in a solution of the compound in a solvent, or attached to the activated carbon by a method such as spraying. Next, the activated carbon to which the antimony compound thus obtained is attached is heated or / and dried under reduced pressure, and then the activated carbon to which antimony is attached is brought into contact with hydrogen fluoride, chlorine or the like under heating to prepare a catalyst. Is done. In the case where antimony pentachloride is supported, it is desirable to treat the catalyst with one or more equivalents of chlorine at 100 ° C. or more for activation of the catalyst.

When the antimony compound is dissolved and used for preparing the catalyst, the solvent can dissolve the antimony compound,
At that time, any solvent that does not decompose the antimony compound may be used. Specifically, chlorinated solvents such as methylene chloride, chloroform, tetrachloroethylene and tetrachloroethane, 1,1-dichloro-1-fluoroethane 3,3-dichloro-1,1,2,2,3-pentafluoropropane, Fluorinated solvents such as 1,3-bis (trifluoromethyl) benzene and trifluoromethylbenzene, and 3-chloro-1,1,1,3-tetrafluoropropane and 3,3-dichloro-1,1,1 -Fluorinated propane such as trifluoropropane. When these solvents are used or when no solvent is used, it is preferable to remove a substance having reactivity with a halide such as water from the solvent and the treatment system, and carry the substance substantially in the absence of water.

The supported amount of the antimony compound used in the preparation of the catalyst used in the present invention is 0.1 to 100 parts by weight of activated carbon.
To 500 parts by weight, preferably 1 to 250 parts by weight. It is also preferable to adjust the catalytic activity by using another metal in combination with the antimony compound. In that case, an antimony compound (especially antimony pentachloride) is used as a main component, and another niobium compound (especially niobium pentachloride) or a tantalum compound (especially tantalum pentachloride) is combined with a halide of tin, titanium, niobium, tantalum, or molybdenum. Is preferred. The atomic ratio of the subcomponent metal / antimony compound may be 50/50 to 0/100 because the subcomponent metal may not be contained, and 30/70.
~ 0/100 is preferred.

Activated carbon used as a catalyst or a carrier in the first and second steps of the present invention is a plant based on wood, charcoal, coconut shell charcoal, palm kernel charcoal, ash, etc., peat, lignite, lignite, There are coal based on bituminous coal and anthracite, petroleum residue, petroleum based on oil carbon, and synthetic resin based on polyvinylidene chloride. It is possible to select and use these commercially available activated carbons, for example, activated carbon produced from bituminous coal (BPL granular activated carbon manufactured by Toyo Calgon), coconut shell charcoal (granular Shirasagi GX, G2 manufactured by Takeda Pharmaceutical Co., Ltd.)
X, SX, CX, XRC, PCB manufactured by Toyo Calgon, and the like, but are not limited thereto. The shape and size are also usually used in the form of granules, but they can be used within the ordinary knowledge range as long as they are suitable for a spherical, fibrous, powdery, or honeycomb reactor.

The activated carbon used in the present invention is preferably an activated carbon having a large specific surface area. The specific surface area and the pore volume of the activated carbon are within the range of the specifications of commercial products, but are preferably larger than 400 m 2 / g and larger than 0.1 cm 3 / g, respectively. In addition, each 800-3000m
2 / g, 0.2 to 1.0 cm3 / g. Furthermore, when using activated carbon as a carrier, ammonium hydroxide, sodium hydroxide, or immersed in a basic aqueous solution such as potassium hydroxide at about room temperature for about 10 hours or more,
It is desirable to perform a pretreatment with an acid such as nitric acid, hydrochloric acid, hydrofluoric acid, etc., which is conventionally performed when using activated carbon as a catalyst carrier, to activate the carrier surface and remove ash in advance.

When the catalyst according to the present invention is pretreated by any of the methods, water is removed by heating or reducing the pressure in advance so that the catalyst does not deteriorate due to hydrolysis or the like during the supporting treatment of the antimony compound. It is desirable to perform as much as possible.

Before use, the catalyst prepared by any of the methods is brought into contact with a fluorinating agent such as hydrogen fluoride and / or chlorine in advance to change the composition of the catalyst during the reaction, shorten the life,
It is effective to prevent abnormal reactions and the like.

In the method of the present invention, 1-chloro-
It is necessary to supply chlorine into the reaction system together with 3,3,3-trifluoropropene and hydrogen fluoride. Since chlorine is not required in the second reactor, it can be removed before introduction into the second reactor, but usually need not be removed. The amount of chlorine introduced may be an amount that exceeds at least the amount that can maintain the activity of the catalyst in the first reactor. Accordingly, chlorine depends on the temperature of the first reactor and other reaction conditions, but is about 0.001 to 10 mol based on 100 mol of 1-chloro-3,3,3-trifluoropropene as a raw material. It is desirable.

The life of an antimony pentachloride-supported activated carbon catalyst is generally determined by the action of a reducing agent.
It is said that when the organic material having high polymerizability is reduced from trivalent to trivalent, and the organic material having high polymerizability is fluorinated, the catalytic action is lost because the high boiling organic compound covers the surface of the catalyst. These problems can be prevented by coexisting an oxidizing agent such as chlorine in the reaction system.

The raw material 1-chloro- in the method of the present invention is used.
The molar ratio of hydrogen fluoride to 3,3,3-trifluoropropene is 2 moles or more, and 50 moles or less,
It is preferably at most 20 times mol. Usually, it may be about 3 to 10 moles. Excess of hydrogen fluoride increases the load on the reactor and after-treatment equipment, and may hinder economic efficiency.However, the problem can be avoided by recovering and reusing it, and there is a problem in terms of reaction products. There is no. It is also possible to add hydrogen fluoride in the middle between the first reactor and the second reactor.

The reaction pressure of the method of the present invention may be normal pressure (around 1 atm). However, since the reaction is assumed to be an equilibrium reaction, a pressurized system is advantageous for biasing the reaction toward the product. For this reason, it is generally more preferable that the pressure be higher than normal pressure. In addition, since the physical adsorption effect of the reaction substrate on the catalyst surface is increased by pressurization and an increase in the reaction rate can be expected, a high pressure is preferable from this viewpoint. Since this effect is expected to be particularly prominent in an activated carbon catalyst having a large surface area, activated carbon having a large surface area is preferably used. On the other hand, since a pressure that is too high is difficult to use due to the pressure resistance of the reactor, economy, etc., the reaction pressure is 0 to 0.
Preferably, the pressure is about 5.0 MPa (gauge pressure). In particular, it is desirable that raw material organic substances, intermediate substances, and hydrogen fluoride present in the system do not liquefy in the reaction system and conform to the mechanical conditions of the catalyst. Therefore, the pressure is more preferably 0 to 2.0 MPa (gauge pressure), and in practice, it is preferably performed at about 0 to 1.0 MPa.

The contact time of the reaction according to the method of the present invention is:
It is usually 0.1 to 300 seconds, and preferably 1 to 60 seconds from the viewpoint of productivity.

The 1,1,1, produced by the method of the present invention
For 3,3-pentafluoropropane, a general purification method performed on a fluorinated product of a halogenated hydrocarbon with hydrogen fluoride can be applied. For example, the reactor effluent gas consisting of organic matter containing the target product, unreacted hydrogen fluoride, and generated hydrogen chloride that flows out of the reactor is separated and extracted using the difference in solubility, such as water washing and basic solution washing. After removing the acidic gas by separation or distillation, the organic substance is further purified and distilled to obtain the target 1,1,
1,3,3-pentafluoropropane can be obtained.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In Examples and Tables, “%” of the organic composition is “area%” of the gas chromatogram.

[0034]

EXAMPLES [Preparation Example 1] Granular coconut shell charcoal having a surface area of 1200 m ² / g and a pore size of 18 Å (granular Shirasagi G2X manufactured by Takeda Pharmaceutical Co., Ltd.) was placed in a 1-liter glass flask.
One liter of the solution (4 to 6 mesh) was heated to 130 to 150 ° C., and then water was removed by a vacuum pump. When the distillation of water was stopped, nitrogen was introduced into the flask to adjust the pressure to normal pressure.

[Preparation Example 2] Granular coconut shell charcoal having a surface area of 1200 m ² / g and a pore size of 18 Å (granular Shirasagi G2X manufactured by Takeda Pharmaceutical Co., Ltd.) was placed in a 1-liter glass flask.
One liter of the solution (4 to 6 mesh) was heated to 130 to 150 ° C., and then water was removed by a vacuum pump. When the distillation of water was no longer observed, nitrogen was introduced into the flask to normal pressure, and 500 g of antimony pentachloride was introduced into the activated carbon layer while stirring with a dropping funnel for 1 hour. Activated carbon impregnated with antimony pentachloride should be
Aged at 50 ° C.

[Example 1] A diagram in which reactors a and b having the same shape are connected in series by pipes, and pipes are provided so that raw materials can be supplied from the reactor a or the reactor b by switching channels. The fluorination reaction apparatus shown in 1 was used. Preparations for stabilizing the catalyst before supplying the organic material were performed independently for each reactor.

For the reactor a and the reactor b, 250 ml of the catalyst prepared in Preparation Example 2 was charged into a cylindrical reaction tube (SUS316L, diameter 4.0 cm, length 30 cm) equipped with an electric furnace, and about 25 ml The temperature of the reaction tube was raised to 100 ° C. while flowing nitrogen gas at a flow rate of / min., And then the nitrogen gas was stopped and the temperature was maintained at 100 ° C. for 6 hours while supplying hydrogen fluoride at a rate of about 0.2 g / min. Next, the temperature of the reactor a was raised to 180 ° C., and the temperature of the reactor b was lowered to 80 ° C. to complete the reaction preparation.

Thereafter, the reactor a and the reactor b are respectively a first reactor and a second reactor, which are connected in series, and a supply rate of 0.32 g / min of hydrogen fluoride and 1.3 mg / min of chlorine is used. At the inlet of the first reactor, and immediately thereafter
Chloro-3,3,3-trifluoropropene was vaporized beforehand and started to be fed into the first reactor at a rate of 0.26 g / min.

Immediately after the start of the reaction, the product gas (reaction gas) at the outlet of the first reactor was sampled and analyzed by gas chromatography after removing the acidic gas containing hydrogen chloride.
1,1,1,3,3-pentafluoropropane 97.5
%, 1-chloro-3,3,3-trifluoropropene (trans / cis isomer molar ratio is 9/1) 2.1%,
The composition was 0.1% of 1,3,3,3-tetrafluoropropene.

[1-1] The reaction was continued as it was, and the reaction was stable 2 hours after the start of the reaction. Thereafter, the product gas flowing out of the second reactor was blown into water for 4 hours, and then the acidity of hydrogen chloride or hydrogen fluoride was increased. After removing the gas, organic substances were collected with a dry ice-acetone trap. The weight of the collected organic matter was 60.8 g, which was analyzed by gas chromatography to find that the 1,1,1,3,3-
98.1% pentafluoropropane, 1-chloro-3,
3,3-trifluoropropene (trans / cis isomer molar ratio: 9/1) 0.3% and 1,3,3,3-tetrafluoropropene 0.1%.

[1-2] After the reaction was further continued and 100 hours later, the outlet gas of the second reactor (reactor b) was sampled and analyzed by gas chromatography after removing the acidic gas containing hydrogen chloride. , 1,1,3,3-pentafluoropropane 96.8%, 1-chloro-3,3,3
-Trifluoropropene 2.7%.

[1-3] Then, the raw material is supplied from the reactor b by changing the connection order of the reactor a and the reactor b so as to use the flow path shown by the broken line in FIG. 1 by operating the valve. The second and first reactors were set at 180 ° C. and 80 ° C., respectively. Two hours after the resumption of the reaction, the outlet gas of the second reactor (reactor a) was sampled, and analyzed by gas chromatography after removing the acidic gas containing hydrogen chloride, and the result was 1,1,1,3,3-pentafluoropropane. 98.4% and 1-chloro-3,3,3-trifluoropropene 0.2%.

[1-4] Next, the connection order of the reactor a and the reactor b is changed again, and the first connection order is set so that the raw materials are supplied from the first reactor (reactor a). The vessel temperatures were 180 ° C. and 80 ° C., respectively. Reaction restart 2
After a lapse of time, the outlet gas of the second reactor (reactor b) was sampled, and analyzed by gas chromatography after removing the acidic gas containing hydrogen chloride. As a result, 1,1,1,3,3-pentafluoropropane 98.2 was obtained. %, 1-chloro-3,3,
3-trifluoropropene was 0.2%.

Table 1 shows each reaction condition and product composition.

[0045]

[Table 1]

Example 2 The same reactor as in Example 1 was used, and preparation for stabilizing the catalyst was performed independently for each reactor before supplying the organic material.

The reactor is a cylindrical reaction tube (S) equipped with an electric furnace.
US316L, diameter 4.0 cm, length 30 cm) was filled with 250 ml of the catalyst prepared in Preparation Example 2 as a catalyst, and the temperature of the reaction tube was raised to 100 ° C. while flowing nitrogen gas at a flow rate of about 25 ml / min. After that, the nitrogen gas was stopped, and the temperature was maintained at 100 ° C. for 6 hours while supplying hydrogen fluoride at a rate of about 0.2 g / min. Next, in the reactor a, the temperature was raised to 200 ° C., and in the reactor b, the temperature of the reaction tube was lowered to 50 ° C. to complete the reaction preparation.

Thereafter, the reactor a and the reactor b were connected in series as a first reactor and a second reactor, respectively, and the first reactor was supplied at a supply rate of 0.32 g / min of hydrogen fluoride and 2.6 mg / min of chlorine. Supplied from the reactor inlet, and immediately thereafter, 1-chloro-3,
3,3-trifluoropropene is vaporized in advance to 0.2
Feeding was started at a rate of 6 g / min to the inlet of the first reactor.

[2-1] Since the reaction was stable 2 hours after the start of the reaction, the product gas flowing out of the second reactor was blown into water for 4 hours to remove the acid gas such as hydrogen chloride and hydrogen fluoride. Organic matter was collected with a dry ice-acetone trap. The weight of collected organic matter is 6
When analyzed by gas chromatography, 98.8% of 1,1,1,3,3-pentafluoropropane and 1-chloro-3,3,3-trifluoropropene (trans form / The molar ratio of the cis form is 9/1) 0.
2%.

[2-2] 100 hours after the reaction was further continued, the outlet gas of the second reactor (reactor b) was sampled and analyzed by gas chromatography after removing the acidic gas containing hydrogen chloride. , 1,1,3,3-pentafluoropropane 96.3%, 1-chloro-3,3,3
-Trifluoropropene 3.0%.

[2-3] Then, the raw material is supplied from the reactor b by changing the connection order of the reactor a and the reactor b by operating the valve so that the flow path shown by the broken line in FIG. 1 is used. The first and second reactors were set at 200 ° C. and 50 ° C., respectively. Two hours after the resumption of the reaction, the outlet gas of the second reactor (reactor a) was sampled and analyzed by gas chromatography after removing the acidic gas containing hydrogen chloride, and the result was 1,1,1,3,3-pentafluoropropane. 98.9%, 1-chloro-3,3,3-trifluoropropene 0.1% and 1,3,3,3-tetrafluoropropene 0.1%.

[2-4] Next, the connection order of the reactor a and the reactor b is changed again, and the first connection order is set so that the raw materials are supplied from the first reactor (reactor a). The vessel temperatures were 200 ° C. and 50 ° C., respectively. Reaction restart 2
After a lapse of time, the outlet gas of the second reactor (reactor b) was sampled and analyzed by gas chromatography after removal of an acid gas containing hydrogen chloride. As a result, 1,1,1,3,3-pentafluoropropane 98.7 was obtained. %, 1-chloro-3,3,
0.1% of 3-trifluoropropene, 1,3,3,3-
Tetrafluoropropene was 0.1%.

Table 1 shows each reaction condition and product composition.

[0054]

According to the method of the present invention, the catalyst used in the second reactor can be reactivated under the reaction conditions in the first reactor, so that the temperature setting and the supply flow path of the raw material are changed during the reaction. There is an effect that the operation can substantially extend the life of the catalyst.

[Brief description of the drawings]

FIG. 1 is a drawing showing an example of a reaction apparatus used in the method of the present invention. DESCRIPTION OF SYMBOLS 1 ... Reactor a 2 ... Reactor b 3 ... Valve

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Fuyuhiko Saku 2805 Imafukunakadai, Kawagoe-shi, Saitama Central Glass Glass Co., Ltd. 4G069 AA03 BA08A BA08B BB08A BB08B BC26A BC26B BD12A BD12B CB25 CB69 DA06 EA02Y EC05Y EC13Y ED05 EE07 4H006 AA02 AC30 BA13 BA37 BA55 BC10 BD60 BE01 CD53 4039

Claims (2)

[Claims] 1. A raw material containing at least 1-chloro-3,3,3-trifluoropropene or 1,3,3,3-tetrafluoropropene, hydrogen fluoride and chlorine is passed through a fluorination reactor to obtain 1,1. A method for producing 1,1,3,3-pentafluoropropane, wherein a fluorination reaction apparatus comprising a reactor (A) and a reactor (B) each filled with activated carbon carrying antimony pentachloride is used. , The first reactor set at 150 ° C. or higher from the upstream, 20 to 150
The second reactor set at 0 ° C. is arranged in series, the reactor (A) being the first reactor, the reactor (B) being the second reactor and the second time interval in the first time interval. In the above, 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 for producing 1,1,1,3,3-pentafluoropropane. 2. The first reactor is set at 150 to 220 ° C.,
The method for producing 1,1,1,3,3-pentafluoropropane according to claim 1, wherein the second reactor is set at 20 to 120C.