JPH08104656A - Reaction process using phosphate catalyst - Google Patents

Abstract

PURPOSE: To provide a process for the defluorinating hydrogenation of an F- containing halogenated hydrocarbon in high efficiency over a long period while keeping long catalytic life and suitable e.g. for the production of unsaturated fluorinated hydrocarbons by contacting an F-containing halogenated hydrocarbon with a phosphoric acid salt catalyst. CONSTITUTION: (A) An F-containing halogenated hydrocarbon such as a 2-6C F-containing halogenated hydrocarbon is subjected to defluorinating hydrogenation by contacting the component A with (B) a phosphate catalyst containing a group 1-13 element of the long-period periodic table such as an alkaline earth metal as the metal constituting the phosphoric acid salt (e.g. magnesium phosphate). The component B preferably further contains a group 3-12 element of the long-period periodic table. The component B is prepared e.g. by a supporting method and the supporting raw material salt is chloride, nitrate, etc., for noble metal and chloride, nitrate, acetate, sulfate, carbonate, etc., for the other metals. The supporting amount is 0.01-20wt.%, especially 0.02-10wt.%.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a dehydrofluorination reaction, a fluorination reaction and a decomposition reaction of a halogenated hydrocarbon containing a fluorine atom, and is applied to the production of an industrially useful unsaturated fluorohydrocarbon. It is expected to be applied to the synthesis of functional saturated fluorine-containing compounds, the removal and purification of trace impurities, and the decomposition reaction of unnecessary CFCs.

[0002]

2. Description of the Related Art In the method for producing an unsaturated fluorine-containing monomer, it is important to select raw materials and reaction conditions using heat or light. Various methods using a catalyst have been investigated, but Ni is used as a method for producing chlorotrifluoroethylene (JP-A-3-2).
64542), Co, Pt, Pb, Ag, Cr ₂
O ₃ and activated carbon are exemplified. As a method of using a phosphate, US Pat. No. 3,789,016 discloses Ni or Cr.
A catalyst in which the phosphate of 1 is supported on alumina is described.
In this patent, a specific unsaturated monomer is synthesized from a halogenated hydrocarbon containing a specific fluorine atom, and dehydrofluorination does not occur, but desorption of hydrogen chloride occurs. JP 62-
No. 61936 discloses that a specific unsaturated monomer is synthesized from a halogenated hydrocarbon containing a specific fluorine atom, and it may be used as activated carbon treated with calcium phosphate as a catalyst. Hydrogen reaction does not occur and desorption of hydrogen chloride occurs.

As a method of using phosphoric acid, which is not a phosphate, in JP-B-47-35667, a chromium and aluminum catalyst containing phosphoric acid as a constituent is used in the presence of substantially hydrogen fluoride for a specific raw material. Although fluorinated, hydrogen chloride is eliminated without dehydrofluorination to synthesize a fluorinated monomer.

Although there is an alternative CFC as a saturated functional fluorine-containing compound, there are many studies on fluorinated oxychrome catalysts. In Japanese Patent Publication No. 25892/1990, a phosphoric acid-supported calcium fluoride catalyst is used in a fluorination reaction with hydrogen fluoride. In recent years, many studies have been reported on the decomposition reaction of CFCs with a catalyst due to environmental problems. (Catalyst vol.34 p
age464,470 1992)

As a method of using a phosphate, Freon 12 (CF ₂ Cl) is disclosed in the Chemical Society of Japan, page 645 (1991).
Aluminum phosphate and boron phosphate have been proposed as catalysts for the catalytic decomposition of ₂ ). Both are in the presence of a large excess of oxygen,
The oxygen utilization rate (conversion rate) is extremely low at about 2.5%. Aluminum phosphate has a low activity and a marked decrease in activity. Boron phosphate does not change the initial activity after about 5 hours of reaction, but requires a catalyst life test with hydrogen fluoride for a longer time.

[0006]

A reaction for desorbing hydrogen fluoride from a halogenated hydrocarbon containing a fluorine atom as a raw material,
Reaction for fluorinating halogenated hydrocarbon, reaction for removing trace amount of unsaturated halogenated hydrocarbon in halogenated hydrocarbon and / or chlorine-containing or bromine-containing halogenated hydrocarbon with hydrogen fluoride And, a catalyst having high activity and long life in decomposition reaction has been desired.

In view of the above-mentioned problems, the present invention proposes a catalyst that promotes a reaction in the presence of hydrofluoric acid, which is supplied or generated, is less likely to be fluorinated, prevents a significant decrease in catalytic activity, and achieves a long life. To aim.

[0008]

Hydrogen fluoride is usually used as a fluorinating agent in freon synthesis. In addition, hydrogen fluoride is produced as a by-product in the fluorocarbon decomposition reaction. Although metal oxides are often used as catalysts, the free energy of formation of metal fluorides is negatively larger than the free energy of formation of metal oxides, so when hydrogen fluoride coexists, the metal oxides gradually become fluoride. Change. As a result of intensive studies to solve the above problems, the present invention has found a production method characterized in that a phosphate catalyst is used under the condition of reacting a halogenated hydrocarbon substantially in the presence of hydrogen fluoride.

The present invention will be described in detail below. In the present invention, the halogenated hydrocarbon refers to a hydrocarbon in which hydrogen is replaced by a halogen, of which a halogenated aliphatic alkane or alkene is preferable, and a preferable carbon number is 1 to 18, but more preferably 1 It is -12, More preferably, it is 2-6. Halogen refers to chlorine, bromine, or fluorine, and is preferably a halogenated hydrocarbon which is substituted with one or more of these halogens and particularly contains fluorine. As such a compound, for example, when the number of carbon atoms is 2, an all halogen-substituted compound C ₂
F ₃ Cl ₃ , C ₂ F ₄ Cl ₂ , C ₂ F ₅ Cl, hydrogen is 1
Existing compounds C ₂ HF ₂ Cl ₃ , C ₂ HF ₃ Cl
₂ , C ₂ HF ₄ Cl, C ₂ HF ₅ , and compounds having two hydrogen atoms C ₂ H ₂ F ₂ Cl ₂ , C ₂ H ₂ F ₃ Cl, C ₂ H ₂
F ₃ Br, C ₂ H ₂ F ₄ , compounds having 3 hydrogen atoms, C ₂ H ₃ FCl ₂ , C ₂ H ₃ F ₂ Cl, C ₂ H ₃ F ₃ ,
Compounds having 4 hydrogens C ₂ H ₄ FCl, C ₂ H ₄ F
₂ , C ₂ H ₅ F having 5 hydrogen atoms, and C ₂ Cl ₄ , C ₂ HCl ₃ , C ₂ H ₂ Cl _{2 and the} like as unsaturated compounds. These may be a single compound or a mixture. A compound having 3 or more carbon atoms can be easily analogized.

The phosphate catalyst in the present invention will be described. Phosphate refers to orthophosphate and also includes monohydrogen phosphate and dihydrogen phosphate. Condensed phosphates are also included, such as pyrophosphate (by dehydration condensation of acidic orthophosphate), tripolyphosphate, tetrapolyphosphate, chain polymer phosphate (high polyphosphate), trimetaphosphate, tetrametaphosphate, etc. Cyclic phosphate of The synthesis method differs depending on the metal salt,
A generally known method may be used. Sodium phosphate (Na
₃ PO ₄ ) is obtained by adding a concentrated aqueous solution of sodium hydroxide to a concentrated aqueous solution of sodium dihydrogen phosphate, heating and concentrating, and then cooling to obtain crystals. Magnesium phosphate (Mg ₃ (PO ₄ ) ₂ ) is Mg
Obtained by heat treatment of HPO ₄ . Calcium phosphate (C
a ₃ (PO ₄ ) ₂ ) is obtained by appropriately applying ammonia water to a mixed solution of CaCl ₂ and phosphoric acid, filtering, drying, and firing. The drying temperature is substantially 70 ° C to 150 ° C, preferably 80 ° C to 130 ° C. If the temperature is too low, the purpose of drying is not achieved, and on the contrary, if it is rapidly exposed to high temperature, the catalyst performance is adversely affected. After the moisture is sufficiently removed by baking, the temperature is 300 ° C or higher and 900 ° C or lower, preferably 400 ° C or higher and 800 ° C or lower,
It is more preferably 450 ° C. or higher and 700 ° C. or lower. If the temperature is too low, fluorination is likely to occur during the reaction. On the contrary, if the temperature is too high, the surface area and pore volume are remarkably reduced and the catalytic activity is sacrificed. 10 in the presence of water in the autoclave
It can also be prepared by hydrothermal synthesis at a temperature of 0 ° C or higher. It may be prepared by a melting and firing method.

The metal constituting the phosphate is preferably an element selected from elements of groups 1 to 13 (new IUPAC nomenclature) of the long-periodic periodic table, alkali metals such as Li, Na and K, and M.
Alkaline earth metals such as g, Ca, Sr, Ba, rare earths, Ti, Zr, V, Cr, Mn, Fe, Co, Ni,
Cu, Ag, Zn, Cd, Al, Ga and B can be exemplified. More preferably, the metal constituting the phosphate is a group of 1 to 4 and 8 to 12 of the long periodic table (new IU
PAC nomenclature) is at least one metal element selected from the elements. Of these, the preferred metals are alkaline earth metals. Most preferred is magnesium phosphate.

The phosphate catalyst may further contain at least one element selected from the group consisting of the above-mentioned phosphates and elements of Groups 3 to 12 (new IUPAC nomenclature) of the long-periodic periodic table. For example, Sc, Y, La, Ti, Zr, Hf,
V, Nb, Cr, Mn, Re, Fe, Ru, Co, R
h, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd
Can be illustrated.

The supporting method is generally used as a preparation method, but other methods such as a precipitation method may be used. When loaded, the raw material salt is preferably a chloride or nitrate of a noble metal, and a chloride, nitrate, acetate, sulfate, carbonate or the like is used as a metal other than the precious metal. The supported amount depends on the type of reaction and the type of metal, but is 0.0
It is 1% by weight or more and 20% by weight or less. More preferably 0.
The amount is 02% by weight or more and 10% by weight or less. A small supporting amount is not effective, and a large supporting amount lowers the performance.

The catalyst thus prepared can be used in a reaction system in which hydrogen fluoride is substantially present, in an elimination reaction or halogen (including halogen) of a halogenated hydrocarbon containing a fluorine atom (especially with fluorine). Especially with fluorine)
It is used in the production of industrially useful unsaturated fluorohydrocarbons that exhibit excellent performance in exchange reactions and in the synthesis of functional fluorine compounds. It is also useful for the decomposition reaction of unnecessary fluorocarbons.

As a method for obtaining an industrially useful unsaturated fluorinated hydrocarbon, a halogenated hydrocarbon containing a fluorine atom as a raw material and having 2 to 6 carbon atoms is preferable. Taking C2 as an example, all halogen-substituted compounds C ₂
F ₃ Cl ₃ , C ₂ F ₄ Cl ₂ , C ₂ F ₅ Cl, hydrogen is 1
Existing compounds C ₂ HF ₂ Cl ₃ , C ₂ HF ₃ Cl
₂ , C ₂ HF ₄ Cl, C ₂ HF ₅ , and compounds having two hydrogen atoms C ₂ H ₂ F ₂ Cl ₂ , C ₂ H ₂ F ₃ Cl, C ₂ H
₂ F ₃ Br, C ₂ H ₂ F ₄ , compounds having 3 hydrogen atoms, C ₂ H ₃ FCl ₂ , C ₂ H ₃ F ₂ Cl, C ₂ H ₃ F ₃ ,
Compounds having 4 hydrogen atoms C ₂ H ₄ FCl, C ₂ H ₄ F
_{2 and the} like are brought into contact with the above phosphate catalyst under high temperature conditions.

If desired, a reaction promoting gas can be supplied. As the reaction promoting gas, oxygen, nitrous oxide, water, chlorine, hydrogen or the like can be used. A combination of them is also possible. It may be diluted with a diluent gas such as nitrogen, helium or argon. Particularly preferred is hydrogen gas. Hydrogen / raw material ratio to be supplied is 100 times to 0.1
It is twice. It is preferably 50 times to 0.5 times. It is more preferably 20 times to 1 time. High ratios are problematic for economic reasons, too low ratios have no accelerating effect.

The reaction temperature is 150 ° C. or higher and 700 ° C. or lower, although it varies depending on the desorption performance containing the halogen as the raw material. It is preferably 200 ° C. or higher and 650 ° C. At low temperatures, the reaction rate decreases, and at high temperatures the reaction tends to occur and the catalyst life becomes short. Fluorohydrocarbons generated by dehydrofluorination are unsaturated fluorohydrocarbons having 2 to 6 carbon atoms.
Is. Taking 2 carbon atoms as an example, C ₂ HF ₃ Cl ₂ , C
₂ HF ₄ Cl, C ₂ HF ₅ , C ₂ H ₂ F ₂ Cl ₂ , C ₂
H ₂ F ₃ Cl, C ₂ H ₂ F ₃ Br, C ₂ H ₂ F ₄ , C ₂
H ₃ FCl ₂ , C ₂ H ₃ F ₂ Cl, C ₂ H ₃ F ₃ , C ₂
When H ₄ FCl, C ₂ H ₄ F _2, etc. are brought into contact with the above-mentioned phosphate catalyst under reaction conditions, C ₂ F ₂ Cl ₂ , C ₂ F ₃ C
1, C ₂ F ₄ , C ₂ HFCl ₂ , C ₂ HF ₂ Cl, C ₂
HF ₂ Br, C ₂ HF ₃ , C ₂ H ₂ FCl, C ₂ H ₂ F
₂ , C ₂ H ₃ F, etc. are generated.

A more specific description will be given below. In the case of 1,1,1-trifluoroethane (HFC143a) as a raw material, magnesium phosphate (Mg ₃
(PO ₄ ) ₂ ) can be used. More preferably, a catalyst in which at least one of Ti, V and Ni is supported on magnesium phosphate has improved activity. Further, the components for improving the selectivity to the desired vinylidene fluoride (CF ₂ ═CH ₂ ) are C, in addition to V and Ni, which are also the activity improving components.
A catalyst in which at least one of o, Mn, Ag, Au, and Fe is supported on magnesium phosphate exerts a good effect. As a catalyst-adding component having a high selectivity for the target compound at a relatively low temperature, a catalyst in which noble metals such as Pt, Ru, Pd, Au and Ni, and at least one of these components are supported on magnesium phosphate is effective. .

The reaction temperature is 300 ° C. or higher and 650 ° C. or lower,
More preferably, it is 400 ° C. or higher and 600 ° C. or lower. Hydrogen can be used as a reaction promoting gas. The ratio of raw material to hydrogen is raw material: hydrogen = 1: 0.5 to 1:20, and more preferably raw material: hydrogen = 1: 1 to 1:10. If the fixed bed is used, the space time is 100 / hr-10000.
/ Hr and more preferably 300 / hr to 3000 /
It is hr. The material of the reactor is a material that can withstand the released hydrofluoric acid, and Inconel, nickel, Hastelloy C or the like can be used.

As an application to the synthesis of a functional fluorine-containing compound such as a halogen exchange reaction, when the number of carbon atoms is 2 as an example, all halogen-substituted compounds C ₂ F ₃ Cl ₃ and C ₂ F are used.
₄ Cl ₂ , C ₂ F ₅ Cl, compound C having one hydrogen
₂ HF ₂ Cl ₃ , C ₂ HF ₃ Cl ₂ , C ₂ HF ₄ Cl,
C ₂ HF ₅ , a compound having two hydrogen atoms C ₂ H ₂ F ₂ C
l ₂ , C ₂ H ₂ F ₃ Cl, C ₂ H ₂ F ₃ Br, C ₂ H ₂
F ₄ , a compound having 3 hydrogen atoms C ₂ H ₃ FCl ₂ , C
₂ H ₃ F ₂ Cl, C ₂ H ₃ F ₃ , compounds having 4 hydrogen atoms C ₂ H ₄ FCl, C ₂ H ₄ F ₂ , unsaturated compounds C ₂ Cl ₄ , C ₂ HCl ₃ , C ₂ H ₂ Cl ₂ or the like can be contacted in the presence of a phosphate catalyst to promote the fluorination reaction. The reaction temperature is 200 ° C or higher and 500 ° C or lower, preferably 230 ° C or higher and 450 ° C or lower. The hydrofluoric acid to be supplied has a molar ratio of 1 to 30 with respect to the raw material, and preferably 2 to 15. If the proportion of hydrofluoric acid is too low, the accumulation of carbonaceous substances on the catalyst will increase and the catalyst life will be shortened. On the other hand, if the proportion of hydrofluoric acid is increased, production costs will be high and it is not realistic.

In the phosphate catalyst used, the metal constituting the phosphate is at least one metal element selected from the elements of Groups 1 to 13 (new IUPAC nomenclature) of the long-periodic periodic table, more preferably phosphoric acid. The metals that make up the salt are the long period type periodic table, groups 1 to 4 and 8 to 12 (new IUPAC
Nomenclature) At least one metal element selected from elements. The above-mentioned salts are preferably alkaline earth metal phosphates, and more preferably magnesium phosphate (Mg ₃ (PO _3
4 ) ₂ ). A catalyst can be used in which the phosphate and the metal include an element selected from the group consisting of elements of Groups 3 to 12 (New IUPAC nomenclature) of the long-periodic periodic table. The supporting method is generally used as the preparation method. It is also possible to supply oxygen or the like as the reaction promoting gas. Others can be produced based on generally known information.

The obtained product is a saturated fluorohydrocarbon whose main component is a saturated fluorohydrocarbon having 1 to 6 carbon atoms, and the saturated fluorohydrocarbon may be changed depending on the corresponding raw materials and reaction conditions described above. Hydrogenated fluorocarbons or fluorocarbons can be synthesized. Particularly, they are difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluoroethane, heptafluoropropane and hexafluorobutane.

As a method for purifying a halogenated hydrocarbon containing a trace amount of an unsaturated hydrocarbon and / or a chlorine-containing compound, the halogenated hydrocarbon is fluorinated with hydrogen fluoride in the presence of a phosphate catalyst to remove trace components. can do.
In the phosphate catalyst used, the metal constituting the phosphate is at least one metal element selected from the elements of groups 1 to 13 (new IUPAC nomenclature) of the long-periodic periodic table, more preferably the phosphate is constituted. The metal to be used is at least one metal element selected from elements of Groups 1 to 4 and Groups 8 to 12 (New IUPAC Nomenclature) of the long-periodic periodic table. Of the above salts, alkaline earth metal phosphates are preferable, and magnesium phosphate (Mg ₃ (PO ₄ ) ₂ ) is more preferable. These phosphates and metals are from 3 to 12 of the long periodic table.
A catalyst containing an element selected from the group consisting of Group (new IUPAC nomenclature) elements can be used. The supporting method is generally used as the preparation method.

The obtained product is a saturated fluorinated hydrocarbon whose main component is a saturated fluorinated hydrocarbon having 1 to 6 carbon atoms, and the saturated fluorinated hydrocarbon may be changed depending on the corresponding raw materials and reaction conditions described above. Hydrogenated fluorocarbons or fluorocarbons can be synthesized. Particularly, they are difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluoroethane, heptafluoropropane and hexafluorobutane. If the trace components contained in these main components are contained by the reaction, the types and amounts differ depending on the reaction conditions.

Tetrafluoroethane (HFC134a)
Is produced by reacting 2-chloro-1,1,1-trichloroethane with hydrogen fluoride in a gas phase, but the trace impurities change depending on the catalyst and production conditions. As these trace impurities, unsaturated hydrocarbons are CClF = CF ₂ , CHCl = CClF, CHCl =
CF ₂ , CHF = CF ₂ , CHF = CHF and the like are chlorine-containing compounds such as CCl ₂ F ₂ , CH ₂ ClF and CCl.
F ₂ CClF ₂ , CCl ₂ FCF ₃ , CClF ₂ CF
₃ , CHClFCF ₃ , CH ₂ ClCF _{3 and the} like can be exemplified. Although the reaction conditions vary depending on the type and proportion of the mixture composition, it is possible to fluorinate and remove trace impurities such as unsaturated hydrocarbons and chlorine-containing compounds in the presence of hydrogen fluoride. The reaction temperature is preferably 150 ° C or higher and 500 ° C or lower, more preferably 180 ° C or higher and 400 ° C or lower. 15
If the temperature is 0 ° C. or lower, the reaction proceeds slowly, and if it is 500 ° C. or higher, a reaction other than the purpose proceeds, which causes an increase in by-products. The space velocity of the raw material gas with respect to the catalyst may be in the range of 10 to 5000 / hr. Particularly preferably 100 to 10
00 / hr is preferable. When the space velocity is 10 / hr or less, the productivity is low, and when it is 5000 / hr or more, the removal rate decreases. The molar ratio of hydrofluoric acid to the raw material is preferably from 1 to 60, more preferably from 1 to 30 in view of economy.

It can also be used for the decomposition reaction of CFCs such as CFCs. As CFCs, CFCl ₃ , CF ₂
For example, Cl ₂ , CF ₃ Cl ₃ , CF ₄ Cl ₂ , CF ₅ Cl can be decomposed into carbon dioxide gas, hydrogen chloride, hydrogen fluoride or the like by supplying oxygen or air as a reaction promoting gas. Water vapor may be present so as not to generate chlorine or fluorine gas. Reaction temperature is from 300 ℃ to 600 ℃
It is a low temperature reaction compared to the combustion method.

The phosphate catalyst used in the present invention capable of carrying out the decomposition reaction in the presence of the phosphoric acid catalyst is such that the metal constituting the phosphate is selected from the elements of Groups 1 to 13 (New IUPAC nomenclature) of the long periodic table. And at least one kind of metal element, more preferably the metal constituting the phosphate, is a group of 1 to 4 and 8 to 12 of the long periodic table (new IUPAC).
Nomenclature) At least one metal element selected from elements. The above-mentioned salts are preferably alkaline earth metal phosphates, and more preferably magnesium phosphate (Mg ₃ (PO _3
4 ) ₂ ). A catalyst can be used in which the phosphate and the metal include an element selected from the group consisting of elements of Groups 3 to 12 (New IUPAC nomenclature) of the long-periodic periodic table. The supporting method is generally used as the preparation method.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples.

Example 1 (Preparation of Magnesium Phosphate) Magnesium monohydrogen phosphate (MgHPO ₄ .3H ₂ O) was calcined in an inert atmosphere at 550 ° C. for 3 hours to regulate the particle size. This catalyst is referred to as Catalyst A.

Example 2 (Supporting metal) A 2M silver nitrate (AgNO ₃ ) aqueous solution was impregnated into the magnesium phosphate prepared in Example 1 and evaporated to dryness. The mixture was calcined in an air stream at 550 ° C. for 3 hours, further reduced in a hydrogen stream at 300 ° C. for 3 hours, and then sized. 3% by weight of A based on magnesium phosphate
g was supported. This catalyst is referred to as catalyst B.

Example 3 (Preparation of calcium phosphate) _{2 in} a mixed solution of 0.3M CaCl ₂ and 0.3M phosphoric acid.
A 5% ammonia water was added dropwise to obtain a precipitate. After filtration and washing,
Particles were sized by firing at 550 ° C. for 3 hours in an inert atmosphere. This catalyst is designated as catalyst C.

Example 4 A 2M silver nitrate (AgNO ₃ ) aqueous solution was impregnated into the calcium phosphate prepared in Example 3 and evaporated to dryness. 5 in the air stream
The mixture was calcined at 50 ° C. for 3 hours, further reduced in a hydrogen stream at 300 ° C. for 3 hours, and then sized. 3% by weight of Ag was supported on the calcium phosphate. This catalyst is designated as catalyst D.

Comparative Example 1 (Preparation of chromia carrying Ag) A chromia prepared by mixing chromium nitrate and aqueous ammonia was prepared by carrying silver nitrate in the same manner as in Example 2. 5% by weight of Ag was supported on the chromia after the calcination reduction. This catalyst is referred to as catalyst E.

Examples 5 and 6 and Comparative Example 2 (reaction example) The reaction was carried out using a fixed pressure bed flow reactor. Inner diameter 10m
1.50 g of the catalyst was filled in a stainless steel reaction tube of m. The raw material gas composition is CF ₃ CH ₃ : H ₂ : He = 1: 3: 1.
6 and the total flow rate was 30 ml / min. The obtained results are shown in Table 1.

[0035]

[Table 1]

The conversion rate was determined from the difference between F143a (CF ₃ CH ₃ ) in and out of the reactor. Selectivity is F1132a (C
It was calculated from the amount of F ₂ = CH ₂ ) produced and the conversion rate.

Examples 7 to 14 (Reaction Example) According to Example 2, catalysts were prepared by using each metal salt instead of silver nitrate. The amount of metal supported was adjusted to 3% by weight based on magnesium phosphate. Using the obtained catalyst, a reaction was performed at a predetermined reaction temperature and in the same manner as in Example 5. The obtained results are shown in Table 2.

[0038]

[Table 2]

Examples 15 to 28 (reaction example) The reaction was carried out at 550 ° C in the same manner as in Example 7, and the results obtained are shown in Table 3.

[0040]

[Table 3]

Example 27 (Pyrophosphate) An aqueous solution of sodium pyrophosphate was added dropwise to an aqueous solution of nickel nitrate to obtain a precipitate. After washing, drying and firing, nickel pyrophosphate (Ni ₂ P ₂ O ₇ ) was obtained. Reaction was carried out at 550 ° C. in the same manner as in Example 15. F143a conversion rate is 34.9
%, The selectivity of F1132a was 53.9%.

Examples 28, 29 and 30 Under the conditions of Example 2, the reaction temperature was 500 ° C. and the catalyst A was Mg.
The time course of the reaction was examined using a ₃ (PO ₄ ) ₂ catalyst.

[0043]

[Table 4]

After the reaction time of 24 hours, no change was observed in the XRD pattern of the catalyst taken out of the reactor.
The specific surface area of the catalyst was 23 m ² / g before the reaction and 22 m ² / g after the reaction, which was almost unchanged.

Example 31 Tetrafluoroethane (CFH ₂ CF ₃ ) containing 205 ppm of unsaturated hydrocarbon CHCl = CF ₂ was used at 250 ° C. using an Inconel reactor in an atmospheric fixed bed flow system, and hydrofluoric acid was used as a raw material. Ratio (mol) is 8, space velocity is 1000
When contacted with the catalyst of Example 19 under the condition of / hr, unsaturated hydrocarbon CHCl = CF ₂ was not detected in the analysis by gas chromatography for 5 hours, and CF ₃ CH ₂ C was not detected.
1 was produced. No change was observed even after the reaction time of 50 hours.

Example 32 Using the reactor of Example 31, the catalyst of Example 19 was reacted at 210 ° C. with a hydrofluoric acid / methylene chloride ratio of 6 mol.
The main product was 32.0% difluoromethane.

Example 33 Chlorodifluoromethane / oxygen / steam / nitrogen = 1/2
The catalyst A was evaluated at a molar ratio of / 3/14 in a small heating annular furnace at 480 ° C. When calculated from the disappearance of chlorodifluoromethane, the conversion rate of dichlorodifluoromethane is 9
It was 5.3%. Oxygen utilization rate (conversion rate) is 23.8%
Met.

[0048]

INDUSTRIAL APPLICABILITY According to the present invention, by using a phosphate catalyst for a halogenated hydrocarbon in the presence of hydrofluoric acid to be supplied or produced, a decomposition reaction, elimination including halogen, a fluorination reaction, etc. can be efficiently performed. It can be done for a period of time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // C07B 61/00 300

Claims (27)

[Claims] 1. A method for dehydrofluorinating a halogenated hydrocarbon containing a fluorine atom by bringing the halogenated hydrocarbon containing a fluorine atom into contact with a phosphate catalyst. 2. The method according to claim 1, wherein the metal constituting the phosphate is at least one metal element selected from elements of Groups 1 to 13 (New IUPAC nomenclature) of the long-periodic periodic table. 3. The metal constituting the phosphate is at least one metal element selected from elements of groups 1 to 4 and 8 to 12 (new IUPAC nomenclature) of the long-periodic periodic table. The method described. 4. The method according to claim 1, wherein at least one kind of metal constituting the phosphate is an alkaline earth metal. 5. The phosphate further comprises at least one element selected from elements of Groups 3 to 12 (New IUPAC Nomenclature) of the long-periodic periodic table.
~ The method according to any one of 4 to 4. 6. The dehydrofluorination according to claim 1, wherein the fluorohydrocarbon synthesized by dehydrofluorination from a halogenated hydrocarbon containing a fluorine atom is an unsaturated fluorohydrocarbon. Method. 7. The method according to claim 6, wherein the main component of the halogenated hydrocarbon containing a fluorine atom is a halogenated hydrocarbon containing a fluorine atom having 2 to 6 carbon atoms. 8. The method according to claim 6, which is carried out while supplying a reaction promoting gas. 9. The reaction promoting gas is hydrogen.
The method described in either. 10. A method for synthesizing a saturated fluorohydrocarbon by contacting a halogenated hydrocarbon with a phosphate catalyst in the presence of hydrogen fluoride. 11. The method according to claim 10, wherein the phosphate catalyst is the catalyst according to any one of claims 2 to 5. 12. The method according to claim 10, wherein the main component of the saturated fluorohydrocarbon is a saturated fluorohydrocarbon having 1 to 6 carbon atoms. 13. The method according to claim 10, wherein the saturated fluorohydrocarbon is hydrogenated fluorocarbon or fluorocarbon. 14. The hydrogenated fluorocarbon or fluorocarbon is difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluoroethane, heptafluoropropane or hexafluorobutane. The method described. 15. The method according to claim 10, which is carried out while supplying a reaction promoting gas. 16. The reaction promoting gas is oxygen.
15. The method according to any one of 15 to 15. 17. A halogenated hydrocarbon containing a fluorine atom, which contains a trace amount of an unsaturated halogenated hydrocarbon and / or a halogenated hydrocarbon containing chlorine or bromine, is contacted with a phosphate catalyst in the presence of hydrogen fluoride. A method for purifying saturated fluorinated hydrocarbons. 18. The method according to claim 17, wherein the phosphate catalyst is the catalyst according to any one of claims 2 to 5. 19. The method according to claim 17, wherein the main component of the saturated fluorohydrocarbon is a saturated fluorohydrocarbon having 1 to 6 carbon atoms. 20. The method according to claim 17, wherein the saturated fluorohydrocarbon is hydrogenated fluorocarbon or fluorocarbon. 21. The hydrogenated fluorocarbon or fluorocarbon is difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluoroethane, heptafluoropropane, or hexafluorobutane. The method described. 22. The method according to claim 17, wherein the trace amount of the unsaturated halogenated hydrocarbon and / or the chlorine-containing or bromine-containing halogenated hydrocarbon is a saturated fluorohydrocarbon having 1 to 6 carbon atoms. the method of. 23. A method of contacting a halogenated hydrocarbon containing a fluorine atom with a phosphate catalyst in the presence of hydrogen fluoride substantially in the reaction system to decompose the halogenated hydrocarbon. 24. The method according to claim 23, wherein the phosphate catalyst is the catalyst according to any one of claims 2 to 5. 25. The method according to claim 23, which is carried out while supplying a reaction promoting gas. 26. The reaction promoting gas is oxygen.
25. The method according to any of 25. 27. The method according to claim 23, wherein water is allowed to coexist.