JP2015120668A - Method for manufacturing fluoromethanes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing one or more kind fluoromethanes selected from dichlorofluoromethane, chlorodifluoromethane, chlorofluoromethane and difluoromethane without using hydrogen fluoride as a reaction raw material at low cost and high safety.SOLUTION: There is provided a method for manufacturing fluoromethanes by contacting a raw material composition containing at least one kind of trichloromethane and/or dichloromethane, and fluorocarbons represented by the formula: CFClH, where w is an integer of 1 or more, x is an integer of 1 to 2w+2 and y and z are integers of 0 to 2w+1, with a metallic catalyst to fluorinate the trichloromethane and/or the dichloromethane and convert the trichloromethane to dichlorofluoromethane or chlorodifluoromethane, the dichloromethane to chlorofluoromethane or difluoromethane respectively.

Description

  The present invention relates to a method for producing fluoromethanes, and more particularly to a method for producing at least one selected from dichlorofluoromethane, chlorodifluoromethane, chlorofluoromethane, and difluoromethane.

Fluoromethanes, particularly dichlorofluoromethane (R-21), chlorodifluoromethane (R-22), chlorofluoromethane (R-31) and difluoromethane (R-32) can be used as refrigerants, and resins It is an industrially important compound that can be used as an intermediate for synthesis, such as tetrafluoroethylene (TFE) used as a monomer for the above and dichloropentafluoropropane (R-225) used as a solvent.
In addition, in this specification, about halogenated hydrocarbon, the abbreviation (refrigerant number etc.) of the compound is described in the parenthesis after the compound name. Moreover, the abbreviation is used instead of the compound name as necessary.

  As a method for producing R-21 and R-22, a method of reacting trichloromethane (chloroform) (R-20) with hydrogen fluoride in the presence of a catalyst is known. As a production method, a method in which dichloromethane (R-30) is reacted with hydrogen fluoride in the presence of a catalyst is known (for example, see Patent Document 1).

  In the method for producing R-21, R-22, R-31 and R-32 described in Patent Document 1, since hydrogen fluoride is used as a reaction raw material, the reactor and piping are expensive and highly resistant to corrosion. It was necessary to compose with materials. Also, in preparation for the risk of accidents due to hydrogen fluoride, the current situation is that a great deal of effort is required for safety management at the time of leakage.

JP-A-7-233102

  The present invention has been made from the above viewpoint, and one or more fluoromethanes selected from R-21, R-22, R-31 and R-32, which are industrially important compounds, are fluorinated. An object is to provide an inexpensive and highly safe production method that can be obtained without using hydrogen as a reaction raw material.

In the present invention, a raw material composition containing R-20 and / or R-30 and at least one fluorocarbon represented by the following formula (1) is brought into contact with a metal catalyst, and the R-20 and / or Alternatively, the method for producing fluoromethanes comprising fluorinating R-30, converting R-20 to R-21 or R-22, and converting R-30 to R-31 or R-32, respectively. I will provide a.
_{C w F x Cl y H z} ............ (1)
(In formula (1), w is an integer of 1 or more, x is an integer of 1 to 2w + 2 and y and z are both integers of 0 to 2w + 1.)

  According to the present invention, at least one fluoromethane selected from R-21, R-22, R-31 and R-32 can be produced without using hydrogen fluoride as a reaction raw material. Therefore, the fluoromethanes can be produced safely and inexpensively.

It is a figure which shows an example of the reaction apparatus used for the manufacturing method of this invention.

  Embodiments of the present invention will be described below.

<Method for producing fluoromethanes>
A manufacturing method according to an embodiment of the present invention includes at least one of R-20 and R-30, the _formula: C _w F x in _Cl y _{H z} (wherein, w is an integer of 1 or more, x is 1 or 2w + 2 A raw material composition containing at least one fluorocarbon represented by the following integers, wherein y and z are integers of 0 or more and 2w + 1 or less (hereinafter referred to as fluorocarbons (A)). , Fluorination of R-20 and / or R-30 in the raw material composition by contacting with a metal catalyst, R-20 to R-21 or R-22, and R-30 to R-31 or R It is a method for producing at least one selected from R-21, R-22, R-31 and R-32 by converting each to -32.

  The reaction of R-20 and fluorocarbons (A) in the production method of the present invention can be represented by the following reaction formula (2). The reaction between R-30 and fluorocarbons (A) can be represented by the following reaction formula (3).

In the reaction formulas (2) and (3), w, x, y and z are all as described above. P is an integer of (x-1) or less, q is an integer of (y + 1) or more and (2w + 2) or less, and r is an integer of 0 or more (2w + 1) or less. That is, p, q, and r are integers that satisfy the following expressions, respectively.
p ≦ x−1
y + 1 ≦ q ≦ 2w + 2
0 ≦ r ≦ 2w + 1

  When a raw material composition containing at least one of R-20 and R-30 and a fluorocarbon (A) is brought into contact with a metal catalyst, a chlorine atom bonded to the carbon atom of R-20 and / or R-30 and a fluorocarbon ( A halogen exchange reaction with the fluorine atom bonded to the carbon atom of A) occurs. From R-20, R-21 in which one of the chlorine atoms of R-20 is substituted with a fluorine atom and R-22 in which two of the chlorine atoms are substituted with fluorine atoms are generated. . Also, R-30 produces R-31 in which one of the chlorine atoms of R-30 is substituted with a fluorine atom, and R-32 in which two of the chlorine atoms are substituted with fluorine atoms. .

The production method of the present invention may be a continuous production method or a batch production method. In a continuous production method, to a reaction site (for example, a reactor containing a metal catalyst) of R-20 and / or R-30, which are reaction components constituting the raw material composition, and the fluorocarbons (A). These are all continuously supplied. In the batch production, the above-mentioned reaction components (R-20 and / or R-30 and fluorocarbons (A)) may be supplied either earlier or simultaneously. . That is, when one of the components R-20 and / or R-30 and the fluorocarbons (A) is supplied, even if the other component is not supplied into the reactor, the previously supplied component reacts. The component to be supplied later is supplied while staying in the reactor, and R-20 and / or R-30 and the fluorocarbons (A) may be brought into contact with the metal catalyst in the reactor for a predetermined time.
The production method of the present invention is preferably a continuous method in terms of production efficiency. Hereinafter, unless otherwise specified, an embodiment in which the method of the present invention is applied to continuous production will be described, but the present invention is not limited thereto.

<Raw material composition>
The raw material composition in the present invention contains R-20 and / or R-30 and fluorocarbons (A).

(R-20 and / or R-30)
In this invention, what is necessary is just to contain at least one of R-20 and R-30 as a raw material composition. When the raw material composition contains both R-20 and R-30, the content ratio (molar ratio) is not particularly limited.

(Fluorocarbons (A))
The structure of the fluorocarbons (A) may be linear, branched or cyclic, and is not particularly limited, but the reaction of fluorinating R-20 and / or R-30. From the viewpoint of ease, a compound having a linear carbon skeleton is preferred. The carbon number w of the fluorocarbons (A) is not particularly limited as long as it is 1 or more, but a compound having 1, 2 or 3 carbon atoms is preferable from the viewpoint of easy reaction and suppression of by-products. The presence or absence of an unsaturated hydrocarbon group is not particularly limited.
Moreover, as a fluorocarbon (A), the by-product and reaction intermediate produced | generated by the said Reaction formula (2) or (3) can also be used. Fluorocarbons (A) may be used alone or in combination of two or more.

As fluorocarbons (A), vinylidene fluoride (VdF), 1,2-dichloro-1,1-difluoroethane (R-132b), 1,1,2-trichloro-2,2-difluoroethane (R-122) 1-chloro-2,2,2-trifluoroethane (R-133a), 1,1,1,2-tetrachloro-2,2-difluoroethane (R-112a), dichlorofluoromethane (R-21) , Chlorodifluoromethane (R-22), trifluoromethane (R-23), dichlorodifluoromethane (R-12), chlorofluoromethane (R-31), difluoromethane (R-32), trichlorofluoromethane (R- 11), tetrafluoroethylene, chlorotrifluoroethylene, 1,1-dichloro-2,2-difluoroethylene (R-1 12a), 1,1,1-trifluoroethane (R-143a), hexafluoropropene (R-1216) and the like.
Among these, from the viewpoint of reaction efficiency, use of VdF, R-132b, R-122, R-133a, R-1112a, or the like is preferable.

In the raw material composition, the molar ratio between the content of the fluorocarbons (A) and the total content of R-20 and R-30 (hereinafter, fluorocarbons (A) / (R-20 and R-30) ( The molar ratio is preferably in the range of 2/1 to 1/10 from the viewpoint of suppressing side reactions.
In the present embodiment employing the continuous production method, the fluorocarbons / (R-20 and R-30) (molar ratio) are represented by the ratio of the molar flow rate per unit time.

  In this invention, a raw material composition can contain another component other than said 20 and / or R-30 which are reaction components, and said fluorocarbon (A). The total content of R-20, R-30 and fluorocarbons (A) in the raw material composition is preferably 10 mol% or more and 100 mol% or less from the viewpoint of suppressing side reactions and improving the durability of the metal catalyst. 30 mol% or more and 70 mol% or less is more preferable, and 30 mol% or more and 50 mol% or less is particularly preferable.

Other components that can be contained in the raw material composition are not particularly limited, but include inert gases such as nitrogen, argon, and helium from the viewpoint of suppressing side reactions and improving the durability of the metal catalyst. It is preferable. By containing these gases, the reaction components R-20, R-30 and fluorocarbons (A) can be diluted. Hereinafter, these gases are referred to as dilution gases.
90 mol% or less is preferable with respect to the whole quantity of a raw material composition, the content rate of the dilution gas in a raw material composition has more preferable 30-70 mol%, and 50-70 mol% is especially preferable.

<Metal catalyst>
The metal catalyst is a reaction of R-20 and / or R-30 with a fluorocarbon (A) (halogen exchange between a chlorine atom of R-20 and / or R-30 and a fluorine atom of the fluorocarbon (A). It has a catalytic action against (reaction). As a metal catalyst, a metal simple substance, a metal oxide, a metal halide etc. are mentioned, for example. Among these, since R-20 can be efficiently converted to R-21 and / or R-22 and R-30 can be efficiently converted to R-31 and / or R-32, metal oxide or metal halide Is preferred. A metal catalyst may be used individually by 1 type, and may use 2 or more types together.

Examples of the metal constituting the simple metal, metal oxide, and metal halide include transition metal elements, Group 12 metal elements, and Group 13 metal elements. Among these, Group 6 metal elements, Group 8 metal elements, Group 10 metal elements, Group 12 metal elements, and Group 13 metal elements are preferable, and chromium, iron, zinc, and aluminum are more preferable.
The single metal catalyst may be one of the above metals or an alloy of two or more metals.
The metal oxide catalyst may be one kind of the above-described metal oxide or a composite oxide of two or more kinds of metals.
The metal halide may be a single halide of the above-described metal or a composite halide of two or more metals.

  Specific examples of the metal catalyst include cobalt, nickel, palladium, chromium oxide (chromia), aluminum oxide (alumina), zinc oxide, iron fluoride, aluminum fluoride, aluminum chloride, chromium fluoride, and chromium chloride. Can be mentioned. Among these, alumina and chromia are preferable in that R-20 and / or R-30 can be efficiently converted.

  Such a metal catalyst may be supported on a carrier. Examples of the carrier include an alumina carrier, a zirconia carrier, a silica carrier, a silica alumina carrier, a carbon carrier represented by activated carbon, a barium sulfate carrier, and a calcium carbonate carrier. Examples of the activated carbon include activated carbon prepared from raw materials such as wood, charcoal, fruit glass, coconut shell, peat, lignite and coal.

  The metal catalyst is preferably activated in advance from the viewpoint of improving reactivity. Examples of the activation treatment method include a method in which a metal catalyst is brought into contact with an activation treatment agent with heating or without heating. Examples of the activation treatment agent include hydrogen fluoride, hydrogen chloride, and a fluorine-containing carbon compound. Among these, a fluorine-containing carbon compound is preferable. Examples of the fluorine-containing carbon compound include trichlorofluoromethane (R-11), R-21, R-22, TFE, and the like.

  In addition to the activation treatment before the reaction, a reactivation treatment can be performed on the metal catalyst. That is, when the activity of the metal catalyst decreases in the conversion reaction, and the conversion rate of the raw material components and the selectivity of the target product R-21, R-22, R-31 or R-32 decrease, It is preferable to activate again. By the reactivation process, the metal catalyst can be reused by regenerating the activity of the metal catalyst. Examples of the reactivation treatment method include a method in which the metal catalyst is brought into contact with the activation treatment agent under heating or non-heating as in the activation treatment before use. As a treatment agent (reactivation treatment agent) for reactivation treatment, oxygen, hydrogen fluoride, hydrogen chloride, a chlorine-containing compound, a fluorine-containing compound, or the like can be used. Examples of the chlorine-containing compound include carbon tetrachloride (R-10), chloroform (R-20), dichloromethane (R-30), vinyl chloride and the like. Furthermore, as a fluorine-containing compound, R-11, R-21, R-22, TFE, etc. can be mentioned. Here, an inert gas such as nitrogen, argon or helium can be used to dilute the reactivation treatment agent in terms of suppressing side reactions and improving the durability of the metal catalyst.

<Reactor and reaction conditions>
The reactor for reacting R-20 and / or R-30 with the fluorocarbons (A) is not particularly limited in shape and structure as long as it can withstand the temperature and pressure described below. A vertical reactor can be used. As the material of the reactor, glass, iron, nickel, an alloy mainly composed of iron and nickel, or the like is used. The reactor may include heating means such as an electric heater inside.

  A metal catalyst is accommodated in such a reactor, and a reaction part is formed. The metal catalyst may be accommodated in either a fixed bed type or a fluidized bed type. In addition, in the case of a fixed bed type, it may be either a horizontal fixed bed type or a vertical fixed bed type, but in a mixed gas composed of multiple components, the concentration distribution of each component is generated depending on the location due to the difference in specific gravity. It is preferable to use a vertical fixed floor type.

  The metal catalyst in the reactor may be activated before being accommodated in the reactor, but since the operation is simple and the work efficiency is good, the activation treatment is performed in a state accommodated in the reactor. It is preferable. Therefore, before supplying the raw material composition, it is preferable to perform the activation treatment by introducing an activation treatment agent into the reactor containing the metal catalyst. The activation treatment agent may be introduced into the reactor at room temperature. However, from the viewpoint of improving the reactivity, it is preferable to introduce the activation treatment agent after adjusting the temperature by heating or the like.

  In order to increase the efficiency of the treatment, it is preferable to carry out the activation treatment while the inside of the reactor is heated. In that case, the temperature in the reactor is preferably 200 to 400 ° C.

  R-20 and / or R-30 and fluorocarbons (A) constituting the raw material composition may each be introduced into the reactor at room temperature, but in order to improve the reactivity in the reactor, It is preferable to supply after heating (preheating) before introducing into the reactor. When preheating is performed, R-20 and / or R-30 is preferably supplied to the reactor after having a temperature of 80 to 150 ° C. Further, the fluorocarbons (A) are also preferably supplied to the reactor after the temperature is set to 80 to 150 ° C. These preheating may be performed in a lump after mixing R-20 and / or R-30 and the fluorocarbons (A), or separately preheating and further mixing, and then the mixture is brought to a predetermined temperature. You may adjust to a desired temperature in two steps, such as heating.

<Reaction conditions>
In an embodiment of the present invention, the conversion reaction to R-21 or R-22 by fluorination of R-20 and the conversion reaction to R-31 or R-32 by fluorination of R-30 are carried out in the gas phase or Although it can be carried out in any liquid phase, it is preferably carried out in the gas phase. In the case of a gas phase reaction, the produced R-21, R-22, R-31 or R-32 can be easily desorbed from the catalyst surface, and the concentration of the product on the catalyst surface can be lowered. There is an advantage. Therefore, it is preferable that R-20 and R-30, which are liquids at room temperature, are introduced into the reactor after being heated to the preferred temperature and vaporized. Further, among the fluorocarbons (A), those which are liquid at room temperature such as R-132b, R-122, R-133a, R-1112a, etc. are reacted with those heated to the above-mentioned preferable temperatures to form a gas. It is preferable to introduce into the vessel.
Hereinafter, the case where the reaction of R-20 and / or R-30 with the fluorocarbons (A) is carried out in the gas phase will be described.

  As described above, the raw material composition includes a diluent gas together with R-20 and / or R-30 and fluorocarbons (A), which are reaction components, from the viewpoint of suppressing side reactions and improving the durability of the metal catalyst. However, in the case of a gas phase reaction, mixing of such a dilution gas is also preferable from the viewpoint of easy supply of the raw material composition to the reactor and adjustment of the flow rate.

  From the point of improving the reactivity, the raw material composition containing the diluent gas and the reaction component is preferably introduced into the reactor after having a temperature of 80 to 150 ° C. as described above. The reaction component and the dilution gas may be mixed after preheating to the above temperature, and the mixed raw material composition at the above temperature may be supplied to the reactor, or the raw material composition may be mixed first to obtain the raw material composition. The composition may be heated to the above temperature and fed to the reactor.

  Further, the reaction components R-20 and / or R-30 and fluorocarbons (A), and the diluent gas used as necessary may be supplied to the reactor separately, You may supply after mixing. When R-20 and / or R-30, fluorocarbons (A), and diluent gas are mixed and then supplied, reaction components R-20 and / or R-30 and fluorocarbons (A) are grouped together. For example, it may be divided into a component that is a gas at normal temperature and a component that is a liquid at normal temperature, and each component may be mixed in each group and supplied separately to the reactor. Moreover, you may supply, after mixing all the components, without carrying out such a grouping.

  In this manner, the reaction components R-20 and / or R-30 and the fluorocarbons (A) supplied to the reactor come into contact with the metal catalyst in the reactor. At this time, the temperature in the reactor is preferably 50 to 400 ° C, more preferably 150 to 350 ° C, from the viewpoint of improving the reactivity. The pressure condition is preferably 0 to 2 MPa gauge pressure as the pressure in the reactor. The contact time between the reaction component and the metal catalyst in the reactor is preferably 0.1 to 500 seconds, more preferably 1 to 50 seconds.

(Reactor)
In the present invention, an example of a reaction apparatus used for production of fluoromethanes is shown in FIG. A reaction apparatus 1 shown in FIG. 1 includes a reactor 2 including heating means such as an electric heater. In addition, in the reactor 2, installation of a heating means is not essential.

  A metal catalyst 3 is accommodated in the reactor 2. The reactor 2 is connected to a preheating mixer 4 having heating means such as an electric heater. The preheating mixer 4 is connected to the reactor 2 by a raw material supply line 5. A raw material composition comprising R-20 and / or R-30, fluorocarbons (A) and a diluent gas is mixed in the preheating mixer 4 and then supplied to the reactor 2 in a gaseous state. The preheating mixer 4 includes a first supply line 6 that supplies a component that is liquid at room temperature (hereinafter referred to as a liquid source component) among the raw material components, and a component that is gas at room temperature (hereinafter referred to as a liquid source component). A second supply line 7 for supplying a gas source component), an activation treatment agent supply line 8 for supplying an activation treatment agent, and a dilution gas supply line 9 for supplying a dilution gas are connected to each other.

  The first supply line 6 is provided with a preheater (preheater) 6 a equipped with an electric heater or the like, and the supplied liquid raw material component is preheated to a predetermined temperature and then supplied to the preheat mixer 4. . Here, the predetermined temperature is preferably a temperature equal to or higher than the boiling point of the liquid raw material component. That is, it is preferable that the liquid raw material component is supplied to the preheating mixer 4 after being preheated and in a gaseous state. In addition, a preheater (preheater) (not shown) having an electric heater or the like is installed in at least one of the second supply line 7, the activation treatment agent supply line 8, and the dilution gas supply line 9. The gas raw material component, the activation treatment agent, or the dilution gas supplied in (1) may be preheated. In addition, installation of the preheater (preheater) 6a in the 1st supply line 6 is not essential.

  An outlet line 11 in which a cooling means 10 such as a heat exchanger is installed is connected to the outlet of the reactor 2. In the outlet line 11, a steam and acidic liquid recovery tank 12, an alkali cleaning device 13 and a dehydration tower 14 are further installed in this order. The gas derived from the outlet of the reactor 2 (hereinafter referred to as outlet gas) is dehydrated by the dehydration tower 14 and then analyzed for components by an analyzer such as a gas chromatograph (GC). It has come to be quantified.

<Outlet gas component>
In the production method of the present invention, when the raw material composition contains R-20, R-21 and R-22 are obtained as the outlet gas components of the reactor by fluorination of R-20. Moreover, when a raw material composition contains R-30, R-31 and R-32 are obtained as an exit gas component of a reactor by fluorination of R-30.
In addition to the target components R-21 and R-22, the outlet gas obtained by fluorination of R-20 includes unreacted R-20, unreacted fluorocarbons (A), and fluorocarbons (A). And the like in which a fluorine atom bonded to a carbon atom is substituted with a chlorine atom. In addition to the target components R-31 and R-32, the outlet gas obtained by fluorination of R-30 includes unreacted R-30, unreacted fluorocarbons (A), and fluorocarbons ( The compound etc. in which the fluorine atom couple | bonded with the carbon atom of A) was substituted by the chlorine atom are contained.

  These reaction products obtained as outlet gas components can be used for various purposes as they are, but are selected from the target components R-21, R-22, R-31 and R-32 by purification. It is preferable to increase the purity of at least one selected from the above. Examples of the purification method include distillation, adsorption, washing with an acidic aqueous solution, a basic aqueous solution, or a neutral aqueous solution. These purifications can be performed under normal pressure, under pressure or under reduced pressure. In particular, purification by distillation is preferred.

  According to the production method of the present invention, it is possible to produce at least one fluoromethane selected from R-21, R-22, R-31 and R-32 without using hydrogen fluoride as a reaction raw material. Can do. Therefore, the production method of the present invention, for example, manages the cost and safety risk required for production equipment, as compared with the method of obtaining the fluoromethanes by reacting R-20 or R-30 with hydrogen fluoride in the presence of a catalyst. Can reduce labor.

  Fluoromethane, which is at least one selected from R-21, R-22, R-31 and R-32 obtained by the production method of the present invention, is used as a refrigerant or an intermediate for synthesis such as TFE or R-225. Can be used as a body.

Examples of the present invention will be described below, but the present invention is not limited to the examples.
In addition, what was described below was used as a reaction apparatus in catalyst activation examples 1-4 and Examples 1-22. Moreover, in Examples 5-22, raw material liquid mixture (1)-(4) is prepared with the method shown to the preparation examples 1-4 described below, and those raw material liquid mixture (1)-(4) is used. did. Furthermore, the gas chromatogram provided with the column (Agilent Technology Co., Ltd. product name: DB-1301) of length 60m * internal diameter 250micrometer x thickness 1micrometer was used for the composition analysis of a raw material liquid mixture and exit gas.

(Reactor)
As the reaction apparatus in Examples 1 to 22, the reaction apparatus 1 shown in FIG. 1 was used.
As the reactor 2, a vertical fixed bed reactor made of stainless steel (SUS316) having an inner diameter of 14 mm and a height of 400 mm was used. An insertion tube made of SUS316 having a diameter of 3.1 mm was introduced into the center of the reactor 2, a K-type thermocouple was inserted therein, and the temperature in the reactor 2 (hereinafter also referred to as internal temperature) was measured. . The central part of the reactor 2 was filled with the metal catalyst 3 at a height of 150 mm, and the inside of the reactor 2 was heated by an electric heater. The preheating mixer 4 connected to the first supply line 6 and the second supply line 7 is connected to the upper part of the reactor 2, and the preheater 6a and the preheating mixer 4 installed in the first supply line 6 are respectively Heated to 100 ° C. with an electric heater.

R-22, which is a catalyst activator, VdF used as the raw material component 2 in Examples 1 to 4, and nitrogen, the gas flow rate is adjusted by a mass flow controller, the activation treatment agent supply line 8, the second supply line 7 and the dilution gas supply line 9 respectively supplied to the preheating mixer 4.
Moreover, R-20 used as raw material component 1 in Examples 1 to 4, and a mixed solution of R-132b and R-20 used as raw material compositions in Examples 6 to 16 (R-132b / R-20 mixed) Hereinafter, the mixed solution is similarly indicated.), The R-122 / R-20 mixed solution used in Examples 17 and 18, and the R-1112a / R-20 mixed solution used in Examples 19 and 20. The R-112a / R-20 mixed solution used in Examples 21 and 22 was adjusted to a liquid flow rate using a plunger pump, heated to 100 ° C. by the preheater 6a and vaporized, and then the preheated mixer 4 was supplied.

  The outlet gas, which is a reaction product, was continuously taken out from the lower part of the reactor 2, and after performing steam and acidic liquid recovery and alkali washing in order, dehydration treatment was performed, and then analysis and quantification were performed using GC. In addition, the temperature, reaction temperature, and pressure of the preheater 6a and the preheat mixer 4 are measured values, respectively.

(Catalyst preparation example 1: chromia catalyst preparation)
Dissolving 2200g of _{Cr (NO 3) 3 · 9H} 2 O and 300g of _{Mg (NO 3) 2 · 6H} 2 O 5.0 liters of water was added an aqueous solution 4000g of 28% ammonium hydroxide. This was added to 8 liters of heated water while stirring to obtain a hydroxide precipitate. Subsequently, the precipitate was separated by filtration, washed with pure water, and dried, followed by firing at 420 ° C. for 5 hours to obtain an oxide powder. The obtained oxide powder was formed into a cylindrical shape having a diameter of 5 mm and a height of 5 mm by a tableting machine to prepare a chromia catalyst.

(Catalyst activation example 1) <Activation of alumina catalyst>
The reactor of the reactor was filled with 20 g of alumina catalyst (Al ₂ O ₃ , (Al ₂ O ₃ , manufactured by Catalyst Kasei Co., Ltd., product name: ACBM-1, shape: particle size 2 mm spherical), and nitrogen gas at 100 sccm. The mixture was dried for 10 hours at 300 ° C. After that, the flow rate of R-22 (molar flow rate per unit time, the same applies hereinafter) was 1.37 mmol / min, and the flow rate of nitrogen was 2.74 mmol / min. After that, the reaction was continuously supplied to the reactor, and the activation was terminated at a reaction temperature of 300 ° C. for 9 hours.

(Catalyst activation example 2) <Activation of chromia catalyst>
The reactor was charged with 29 g of the chromia catalyst prepared in Catalyst Preparation Example 1, and dried at 300 ° C. for 10 hours while flowing nitrogen gas at 100 sccm. Then, after mixing with the flow volume of R-22 as 1.37 mmol / min and the flow volume of nitrogen as 2.74 mmol / min, it supplied continuously to the reactor. An activation reaction was performed at a reaction temperature of 300 ° C. for 8 hours, and after confirming that the outlet gas composition was stabilized, the activation was terminated.

(Catalyst activation example 3) <Activation of chromia / alumina catalyst>
Fill reactor with 25 g of chromia-alumina catalyst (Al ₂ O ₃ 65.4%, Cr ₂ O ₃ 14.2%, MgO 2.2%, manufactured by JGC Catalysts & Chemicals, product name: N401AG, shape: pellet type) Then, it was dried at 300 ° C. for 10 hours while flowing nitrogen gas at 100 sccm. Then, after mixing with the flow volume of R-22 as 1.37 mmol / min and the flow volume of nitrogen as 2.74 mmol / min, it supplied continuously to the reactor. An activation reaction was performed at a reaction temperature of 300 ° C. for 8 hours, and after confirming that the outlet gas composition was stabilized, the activation was terminated.

(Catalyst activation example 4) <Activation of copper chromium catalyst>
The reactor was charged with 27 g of copper chromium catalyst (CuO 36.7%, Cr ₂ O ₃ 44.8%, Mn ₂ O ₃ 3.5%, manufactured by JGC Catalysts & Chemicals, product name: N201, shape: pellet type). The sample was dried at 300 ° C. for 10 hours while flowing nitrogen gas at 100 sccm. Then, after mixing with the flow volume of R-22 as 1.37 mmol / min and the flow volume of nitrogen as 2.74 mmol / min, it supplied continuously to the reactor. An activation reaction was performed at a reaction temperature of 300 ° C. for 16 hours, and after confirming that the outlet gas composition was stabilized, the activation was terminated.

(Preparation Example 1) <Preparation of R-132b / R-20 raw material mixture>
Into a 2 L polyethylene bottle, 702.8 g of R-20 and 397.2 g of R-132b were added and shaken up and down to stir well to obtain a raw material mixture (1). When the composition of the raw material mixture (1) was analyzed by GC, it was found that R-20 was 66.0 mol% and R-132b was 34.0 mol%.

(Preparation Example 2) <Preparation of R-122 / R-20 raw material mixture>
In a 500 mL cylinder made of SUS316 with upper and lower needle valves connected, 386.1 g of R-20 and 273.9 g of R-122 were added and stirred well to obtain a raw material mixture (2). As a result of GC analysis of the composition of the raw material mixture (2), R-20 was 67.7 mol%, and R-122 was 32.3 mol%.

(Preparation Example 3) <Preparation of R-1112a / R-20 raw material mixture>
In a cylinder similar to that in Preparation Example 2, 376.6 g of R-20 and 213.0 g of R-1112a were added and stirred well to obtain a raw material mixture (3). As a result of GC analysis of the composition of the raw material mixture (3), R-20 was 69.4 mol%, and R-1112a was 30.6 mol%.

(Preparation Example 4) <Preparation of R-112a / R-20 raw material mixture>
In a cylinder similar to that in Preparation Example 2, 259.6 g of R-20 and 221.6 g of R-112a were added and stirred well to obtain a raw material mixture (4). As a result of GC analysis of the composition of the raw material mixture (4), R-20 was 67.9 mol% and R-112a was 32.1 mol%.

Example 1
The temperature in the reactor filled with the activated alumina catalyst activated by the method of catalyst activation example 1 (hereinafter referred to as reaction temperature) is 250 ° C., the flow rate of R-20 is 1.50 mmol / min, VdF. Was mixed with a preheating mixer at a flow rate of 0.75 mmol / min and a nitrogen flow rate of 2.25 mmol / min, and then the mixed gas was introduced into the reactor. The reaction was terminated for 6 hours while continuously supplying R-20, VdF and nitrogen, and the reaction was terminated after confirming that the outlet gas composition was stable. The results of GC analysis of the composition of the outlet gas at 6 hours are shown in Table 1 together with the component composition at the inlet of the reactor calculated from the raw material input ratio.
In Table 1, R-20 is shown as raw material component 1, and VdF is shown as raw material component 2.

Examples 2-4
In the same manner as in Example 1, except that the activated metal catalyst shown in Table 1 was used and the reaction conditions shown in the same table (reaction temperature, flow rate of raw material 1 and raw material 2, flow rate of nitrogen, reaction time) were used, R -20 was reacted with VdF. The GC analysis results of the outlet gas composition obtained as a result of the reaction are shown in Table 1 together with the composition of the inlet component calculated from the raw material input ratio.

Example 5
The temperature of the reactor filled with the activated alumina catalyst activated by the method of catalyst activation example 1 is set to 200 ° C., the flow rate of the raw material mixture (1) prepared in preparation example 1 is 2.49 mmol / min, After mixing at a flow rate of 2.49 mmol / min, the mixed gas was introduced into the reactor. The mixture was reacted for 15 hours while continuously supplying the raw material mixture (1) and nitrogen, and the reaction was terminated after confirming that the outlet gas composition was stable. The results of GC analysis of the outlet gas composition at 15 hours are shown in Table 2 together with the composition of the inlet components.

Examples 6-10
The raw material mixture (1) prepared in Preparation Example 1 was reacted in the same manner as in Example 5 except that the activated metal catalyst shown in Table 2 was used and the reaction conditions shown in the same table were used. Table 2 shows the GC analysis result of the outlet gas composition obtained as a result of the reaction, and the composition of the inlet component calculated from the raw material input ratio.

Examples 11-16
The raw material mixture (1) prepared in Preparation Example 1 was reacted in the same manner as in Example 5 except that the activated metal catalyst shown in Table 3 was used and the reaction conditions shown in the same table were used. Table 3 shows the GC analysis results of the outlet gas composition obtained as a result of the reaction, together with the composition of the inlet components.

Example 17
The temperature of the reactor filled with the activated chromia catalyst activated by the method of catalyst activation example 2 is set to 200 ° C., and the flow rate of the R-122 / R-20 raw material mixture (2) prepared in preparation example 2 is set to 2 After mixing at .49 mmol / min and a nitrogen flow rate of 2.49 mmol / min, the mixed gas was introduced into the reactor. The reaction was terminated for 13.5 hours while continuously supplying the raw material mixture (2) and nitrogen, and the reaction was terminated after confirming that the outlet gas composition was stable. The results of GC analysis of the composition of the outlet gas at 13.5 hours are shown in Table 4 together with the component composition at the inlet.

Examples 18-22
The same activated chromia catalyst as in Example 17 was used, and the raw material mixtures (2) to (4) shown in Table 4 were reacted under the reaction conditions shown in the same table. Table 4 shows the GC analysis results of the outlet gas composition obtained as a result of the reaction, together with the composition of the inlet components.

Example 23
The reactor shown below was used for reaction of a raw material component. That is, in the reaction apparatus 1 shown in FIG. 1, a vertical fixed bed reactor made of SUS316 having an inner diameter of 47.5 mm and a height of 800 mm is used as the reactor 2, and the difference between the reactor 2 made of SUS316 having a diameter of 4.0 mm is used. A built-in tube was introduced, a K-type thermocouple was inserted therein, and the internal temperature was measured. In the central part of the reactor 2, a metal catalyst was filled to a height of 500 mm. Other than that was comprised similarly to the reactor used for Examples 1-22.
With this reactor 1, the catalyst was activated as shown below.

(Catalyst activation example 5) <Activation of chromia catalyst>
The reactor of the reactor was filled with 1180 g of the chromia catalyst prepared in Catalyst Preparation Example 1, and dried at 300 ° C. for 15 hours while flowing nitrogen gas at 800 sccm. Then, after mixing with the flow rate of R-22 being 8.93 mmol / min and the flow rate of nitrogen being 8.93 mmol / min, the mixture was continuously supplied to the reactor. An activation reaction was performed at a reaction temperature of 300 ° C. for 8 hours, and after confirming that the outlet gas composition was stabilized, the activation was terminated.

  The temperature of the reactor filled with the activated chromia catalyst thus activated was 325 ° C., the flow rate of R-30 was 27.9 mmol / min, the flow rate of R-32 was 27.9 mmol / min, and the preheating mixer 4 After mixing, the mixed gas was introduced into the reactor. The reaction was continued for 15 hours while continuously supplying R-30 and R-32, and the reaction was terminated after confirming that the outlet gas composition was stable. The results of GC analysis of the outlet gas composition at 15 hours are shown in Table 5 together with the composition of the inlet components.

  As can be seen from Tables 1 to 5, according to the present example, at least one of R-20 and R-30 and fluorocarbons (A) are used as raw materials, and hydrogen fluoride is not used as a raw material, but a refrigerant or synthesis. At least one selected from R-21, R-22, R-31 and R-32, which are fluoromethanes useful as an intermediate for use, can be obtained.

  The process for producing fluoromethanes of the present invention is a novel process that is inexpensive and highly safe, and includes R-21, R-22, R-31 and R-32 which are useful as refrigerants and intermediates for synthesis. It can use suitably for manufacture.

  DESCRIPTION OF SYMBOLS 1 ... Reaction apparatus, 2 ... Reactor, 3 ... Metal catalyst, 4 ... Preheating mixer, 5 ... Raw material supply line, 6 ... 1st supply line, 7 ... 2nd supply line, 8 ... Activation processing agent supply Line 9, dilution gas supply line, 10, cooling means, 11, outlet line, 12, steam and acidic liquid recovery tank, 13, alkali cleaning device, 14, dehydration tower.

Claims (6)

A raw material composition containing trichloromethane and / or dichloromethane and at least one fluorocarbon represented by the following formula (1) is contacted with a metal catalyst to fluorinate the trichloromethane and / or the dichloromethane, A process for producing fluoromethanes, characterized in that trichloromethane is converted to dichlorofluoromethane or chlorodifluoromethane, and the dichloromethane is converted to chlorofluoromethane or difluoromethane, respectively.
_{C w F x Cl y H z} ............ (1)
(In formula (1), w is an integer of 1 or more, x is an integer of 1 to 2w + 2 and y and z are both integers of 0 to 2w + 1.)   The method for producing fluoromethanes according to claim 1, wherein the metal catalyst is at least one selected from the group consisting of a metal simple substance, a metal oxide, and a metal halide.   The method for producing a fluoromethane according to claim 2, wherein the metal catalyst is at least one selected from the group consisting of aluminum oxide (alumina) and chromium oxide (chromia).   The method for producing a fluoromethane according to any one of claims 1 to 3, wherein the raw material composition and the metal catalyst are contacted in a gas phase.   The fluorocarbons represented by the formula (1) are 1,1-difluoroethylene, 1,2-dichloro-1,1-difluoroethane, 1,1,2-trichloro-2,2-difluoroethane, 1-chloro-2. , 2,2-trifluoroethane, trifluoromethane, 1,1-dichloro-2,2-difluoroethylene is one or more selected from the group consisting of 1,2-fluoro A method for producing methanes.   The method for producing a fluoromethane according to any one of claims 1 to 5, wherein a temperature at which the raw material composition is brought into contact with the metal catalyst is 50 to 400 ° C.

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