JP3284879B2 - Method for producing chlorine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing chlorine. More specifically, the present invention relates to a method for producing chlorine by oxidizing hydrogen chloride, which is characterized by using a highly active catalyst and producing chlorine at a lower reaction temperature with a smaller amount of catalyst. The present invention is to provide a manufacturing method of the above.

[0002]

2. Description of the Related Art It is well known that chlorine is useful as a raw material for vinyl chloride, phosgene and the like, and is obtained by oxidation of hydrogen chloride. For example, Japanese Patent Laid-Open No. 62-270
No. 405 describes a method for oxidizing hydrogen chloride using a chromium oxide catalyst. However, the conventionally known method has a problem that the activity of the catalyst is insufficient.

[0003] Higher reaction temperatures are required when the activity of the catalyst is low, but the reaction of oxidizing hydrogen chloride with oxygen to produce chlorine is disadvantageously equilibrium at higher temperatures. Therefore, if the catalyst has high activity, the reaction temperature can be lowered, and the reaction becomes equilibrium advantageous.

Conventionally, when a supported ruthenium catalyst is used in a general oxygen oxidation reaction, there is a problem that ruthenium in a highly oxidized state volatilizes at a high temperature.

[0005]

Under such circumstances, an object of the present invention is to provide a method for producing chlorine by oxidizing hydrogen chloride, using a highly active catalyst and reducing the amount of chlorine. An object of the present invention is to provide a method for producing chlorine, which is characterized in that chlorine can be produced at a lower reaction temperature with a catalyst.

By conducting the reaction at a lower temperature, more favorable reaction conditions can be selected in equilibrium.

Further, by using the catalyst according to the present invention, the reaction can be carried out at a lower temperature, so that the volatilization of ruthenium, which has conventionally been a problem, can be further suppressed. Further, in the catalyst according to the present invention, since ruthenium is hardly volatilized, there is also an advantage that the active component, which has conventionally been a problem, does not disappear during the reaction.

[0008]

Means for Solving the Problems] The present invention is, per the producing chlorine by oxidizing hydrogen chloride with oxygen,
The present invention relates to a method for producing chlorine, wherein a supported metal ruthenium catalyst, a ruthenium oxide catalyst, or a ruthenium composite oxide catalyst is used.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The catalyst used in the present invention may be a supported metal ruthenium catalyst, a ruthenium oxide catalyst or
It is a ruthenium composite oxide catalyst .

Examples of the supported metal ruthenium catalyst include alumina, silica, silica alumina, zeolite, diatomaceous earth, oxides and composite oxides of elements such as titanium oxide, zirconium oxide and vanadium oxide, and carriers such as metal sulfate. Known methods (for example, catalyst course
Supported metal ruthenium catalysts prepared and supported by Catalyst Experiment Handbook, 1986, page 20, Kodansha), but commercially available catalysts may be used. As the carrier used for the supported catalyst, titanium oxide, alumina, zirconium oxide, zeolite, silica, titanium composite oxide, zirconium composite oxide, aluminum composite oxide is preferable,
Titanium oxide, zirconium oxide, and alumina are more preferably used.

The ratio of ruthenium to the carrier is usually from 0.1 to 20% by weight. Note that a third component other than ruthenium can be added, and as the third component, palladium, a copper compound, a chromium compound, a vanadium compound,
Alkali metal compounds, rare earth compounds, manganese compounds,
Alkaline earth compounds and the like. The addition amount of the third component is usually 0.1 to 10% by weight as a ratio to the carrier.
It is. The supported metal ruthenium catalyst may be used after being subjected to a reduction treatment, or may be used after being subjected to an oxidation treatment. As the ruthenium oxide catalyst, ruthenium oxide such as ruthenium dioxide or ruthenium hydroxide, or a known method (for example, Catalyst Handbook by Element, 1978, No. 544)
Page, Jinjinshokan), ruthenium hydroxide catalyst and the like, and commercially available ruthenium dioxide may be used. Further, a compound in which another element is bonded to ruthenium oxide such as a halogenated oxide may also be used.

As a preparation method, for example, RuCl ₃
A method of precipitating ruthenium hydroxide by adding an alkali to an aqueous solution of the above, washing and firing, to obtain ruthenium dioxide. Further, a catalyst in which ruthenium oxide is supported on a carrier is also a preferred example. As a carrier,
Examples thereof include oxides of elements such as titanium oxide, alumina, zirconium oxide, silica, titanium composite oxide, zirconium composite oxide, aluminum composite oxide, and silicon composite oxide, and composite oxides. The ratio of ruthenium oxide to the support is usually between 0.1 / 99.9 and 70/30. Examples of the compound to be supported include ruthenium oxide, ruthenium hydroxide, and ruthenium halide oxide. As carrier method, an aqueous solution of RuCl ₃ after impregnating the support, the alkali is added to precipitate ruthenium hydroxide on the carrier, and then calcined in air, a method of carrying ruthenium oxide, RuCl ₃ to the carrier After impregnating with an aqueous solution and drying, baking in air and oxidatively decomposing to carry ruthenium oxide. 100-500 ° C for firing
Below, about 30 minutes to 5 hours are normal.

The ruthenium composite oxide catalyst includes one or more oxides such as titanium oxide, zirconium oxide, alumina, silica, vanadium oxide, boron oxide, chromium oxide, niobium oxide, hafnium oxide, tantalum oxide, and tungsten oxide. Catalysts in which an oxide and ruthenium oxide are complexed.Examples of the compound in which ruthenium oxide is complexed are not limited to the above compounds, and various complex oxides such as copper chromite can also be mentioned as examples. .

As a method of compounding ruthenium, ruthenium such as ruthenium chloride or the like is obtained by hydrolyzing chlorides such as titanium, oxychlorides, nitrates, oxynitrates, alkali salts of oxyacids, sulfates, alkoxides and the like. A method in which a compound obtained by hydrolyzing a compound is added, followed by filtration, washing, and calcination in air may be used.

Examples of the ruthenium compound include the compounds described above as examples of the catalyst in which a ruthenium compound such as ruthenium chloride is supported on a carrier, and preferably, RuCl ₃ , R 2
uCl ₃ hydrate. Preferable examples of the oxide that forms ruthenium oxide include titanium oxide, zirconium oxide, alumina, silica, titanium composite oxide, zirconium composite oxide, aluminum composite oxide, and silicon composite oxide. Examples of the method of supporting the ruthenium composite oxide on a carrier include a method of impregnating the carrier with a chloride such as titanium, a nitrate or the like and a ruthenium compound such as ruthenium chloride, followed by firing in air. Examples of the carrier include titanium oxide, alumina, silica, zirconium oxide and composite oxides thereof.

The content of ruthenium oxide contained in the ruthenium composite oxide is usually from 0.1 to 80% by weight. In addition, a third component can be added, and examples of the third component include a palladium compound, a copper compound, a chromium compound, a vanadium compound, an alkali metal compound, a rare earth compound, a manganese compound, and an alkaline earth compound.
The amount of the third component is usually 0.1 to 10% by weight based on the weight of the ruthenium composite oxide.

Examples of the method for preparing the ruthenium composite oxide include a coprecipitation method, a method by mixing precipitation, and an impregnation method. Conditions for preparing the ruthenium composite oxide by firing are as follows: 200 ° C. to 1000 ° C., 1 hour to 5 hours.
Time is normal.

The method of supporting the ruthenium composite oxide on a carrier includes an impregnation method and a precipitation supporting method. In addition, the sintering of the supported material is similarly performed at 200 ° C. to 1000 ° C.
The temperature is usually about 1 hour to 5 hours under a temperature of ° C. Preferably 3
What baked at 00-500 degreeC is mentioned. Examples of the firing atmosphere include nitrogen and air.

Examples of the catalyst other than the above include ruthenium black prepared by a known method (for example, “Catalyst Preparation Chemistry” 1980, p. 233, Kodansha) and a supported catalyst containing ruthenium having a loading of more than 20% by weight. Is raised.

According to the present invention, chlorine is obtained by oxidizing hydrogen chloride with oxygen using a ruthenium catalyst. In obtaining chlorine, a flow system is mentioned as a reaction system, and a fixed bed gas phase flow system is usually preferably employed. When the reaction temperature is high, it is desired that the reaction be performed at a lower temperature because volatilization of the ruthenium oxide in a high oxidation state occurs.
00 to 380 ° C. Reaction pressure is usually from atmospheric pressure to 5
It is about 0 atm. As the oxygen source, air may be used as it is, or pure oxygen may be used. However, it is not preferable because other components are simultaneously released when the inert nitrogen gas is released outside the apparatus. Pure oxygen containing no active gas can be used. The theoretical molar amount of oxygen to hydrogen chloride is 1 /
Although it is 4 mol, it is usual to supply 0.1 to 10 times the theoretical amount. The amount of the catalyst used is the ratio G to the feed rate of the raw material hydrogen chloride under atmospheric pressure in the case of the fixed bed gas phase flow system.
When expressed in HSV, it is usually about 10 to 20000 h ^-1 .

[0021]

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

Example 1 A catalyst was prepared by the following method. That is, 8.6 g of water was placed in an ice-cooled flask, and 7.6 g of commercially available titanium tetrachloride was added dropwise with stirring to prepare an aqueous solution of titanium tetrachloride. Next, commercially available zirconium oxychloride octahydrate 1
A solution prepared by dissolving 3.1 g in 43.3 g of water was added dropwise to an already prepared aqueous solution of titanium tetrachloride with stirring to prepare a homogeneous solution. A solution consisting of 13.4 g of ammonium sulfate and 26.8 g of water and 1.1 g of 36% hydrochloric acid was added to the solution, and the mixture was stirred to prepare a uniform solution. Next, the homogeneous solution was heated to 70 ° C., and 25% by weight while stirring.
30.3 g of an aqueous ammonia solution was gradually added dropwise. As the solution was added, a white precipitate was formed. After the addition, the mixture was stirred at the same temperature for 1 hour. After completion of the stirring, the precipitate was filtered, washed with 300 ml of distilled water, and filtered again. After repeating this operation three times, the resultant was suspended in 150 ml of water. Next, commercially available ruthenium chloride hydrate (RuCl ₃ .nH ₂ O) 9.
A solution prepared by dissolving 74 g in 60 g of water and a solution prepared by dissolving 5.2 g of sodium hydroxide (content 96%) in 20 g of water were mixed, stirred, and immediately added dropwise to the already prepared suspension with stirring. 40 ml of water were added. After dropping, 6
A solution prepared by diluting 2.2 g of 1% by weight nitric acid with 30 g of water was added dropwise and stirred at room temperature for 1 hour. After completion of the stirring, the black precipitate was filtered, washed with 300 ml of distilled water, and filtered again. After repeating this operation three times, drying at 60 ° C. for 4 hours
6.3 g of a black solid were obtained. The solid was pulverized, heated in the air from room temperature to 350 ° C. for 3.5 hours, and calcined at the same temperature for 3 hours to obtain 13.5 g of a black catalyst. The same catalyst is used for another 5 times in the same manner as above.
5.4 g were obtained. The calculated value of the ruthenium oxide content was 3
It was 6% by weight. This powder is molded and 12 to 18.5
By forming a mesh, a ruthenium oxide titanium oxide zirconium oxide catalyst was obtained. 46.8 g of the thus obtained ruthenium oxide titanium oxide zirconium oxide catalyst was charged into a quartz reaction tube (22 mm inner diameter). 19.0 ml / min of hydrogen chloride gas and 9.3 ml of oxygen gas
/ Min (all at 0 ° C., 1 atm) and supplied under normal pressure. The quartz reaction tube was heated in an electric furnace, and the internal temperature (hot spot) was set to 265 ° C. Six hours after the start of the reaction, the gas at the outlet of the reaction tube was passed through a 30% aqueous solution of potassium iodide to perform sampling. Was measured. As a result, the conversion of hydrogen chloride was 95.9%.

Example 2 The same catalyst as used in Example 1 was mixed with 2.5 g of the same ruthenium oxide / titanium oxide / zirconium oxide catalyst and 5 g of a titanium oxide carrier having a size of 12 to 18.5 mesh to dilute the catalyst. Into a quartz reaction tube (inner diameter: 12 mm). Hydrogen chloride gas at 200 ml / min, oxygen gas at 200 ml / min (both at 0 ° C. and 1 atm)
It was supplied under normal pressure. The quartz reaction tube was heated in an electric furnace, and the internal temperature (hot spot) was set at 301 ° C. Reaction start 2.9
At the time after the elapse of time, sampling was performed by flowing the gas at the outlet of the reaction tube through a 30% aqueous solution of potassium iodide, and the amount of generated chlorine and the amount of unreacted hydrogen chloride were measured by an iodine titration method and a neutralization titration method, respectively. . The chlorine generation activity per unit catalyst weight determined by the following equation was 7.35.
× 10 ⁻⁴ mol / min · g-catalyst. Chlorine formation activity per unit catalyst weight (mol / min.g-catalyst)
= Amount of outlet chlorine generated per unit time (mol / min) /
Catalyst weight (g)

Example 3 A catalyst was prepared by the following method. That is, 27.0 g of water was placed in an ice-cooled flask, and 14.3 g of commercially available titanium tetrachloride was added dropwise with stirring to prepare an aqueous titanium tetrachloride solution. At room temperature, 1222 g of water was added to the solution, and a solution composed of 27.6 g of urea and 100 g of water was further injected.
After stirring, a homogeneous solution was prepared. Next, add the homogeneous solution to 1
The mixture was stirred for 2 hours while heating to 00 ° C. A white precipitate gradually formed. Next, at the same temperature, 3.2 g of urea and 26 g of water
Was added, and after sufficiently stirring, the precipitate was filtered. Next, it was washed with 300 ml of distilled water and filtered again.
After repeating this operation three times, the resultant was suspended in 150 ml of water. Next, a commercially available ruthenium chloride hydrate (RuCl ₃
NH ₂ O) A solution prepared by dissolving 7.12 g in 54 g of water and a solution in which 3.8 g of sodium hydroxide (content 96%) was dissolved in 20 g of water were mixed, stirred, and immediately mixed with the suspension already prepared. The mixture was added dropwise with stirring. 61% by weight after dropping
A solution prepared by diluting 1.57 g of nitric acid with 24 g of water was added dropwise.
Stirred at room temperature for 1 hour. After completion of the stirring, the black precipitate was filtered. Then, it was washed with 300 ml of distilled water and filtered again. After repeating this operation three times, it was dried at 60 ° C. for 4 hours to obtain 9.3 g of a black solid. The solid was pulverized, heated in the air from room temperature to 350 ° C. for 3.5 hours, and calcined at the same temperature for 3 hours to obtain 8.1 g of a black catalyst. The calculated value of the content of ruthenium oxide was 36% by weight. This powder was molded to have a mesh of 12 to 18.5 to obtain a ruthenium oxide titanium oxide catalyst. 1.9 g of the ruthenium titanium oxide catalyst was charged into a reaction tube in the same manner as in Example 2, and the reaction was carried out in accordance with the reaction method of Example 2 except that the internal temperature was set to 300 ° C. 1.9 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 9.05 × 10 ⁻⁴ mol / min · g-catalyst.

Example 4 A catalyst was prepared by the following method. That is, 20% by weight
54.7 g of an aqueous solution of titanium sulfate (Wako Pure Chemical Industries, Ltd.) was diluted with 110.3 g of water and mixed. The aqueous solution was placed in an ice-cooled flask, and 48.2 g of a 25% by weight aqueous ammonia solution was added dropwise with stirring. As a result, a white precipitate was gradually formed. After stirring at room temperature for 30 minutes, the precipitate was filtered.
Next, it was washed with 300 ml of distilled water and filtered again. After repeating this operation three times, the resultant was suspended in 150 ml of water. Next, a commercially available ruthenium chloride hydrate (RuCl _3.
nH ₂ O) A solution prepared by dissolving 9.86 g of water in 61 g of water and a solution of 5.2 g of sodium hydroxide (content: 96%) in 20 g of water were mixed, stirred, and immediately added to the already prepared suspension. The solution was added dropwise with stirring. After the dropwise addition, a solution prepared by diluting 2.15 g of 61% by weight nitric acid with 30 g of water was added dropwise, and the mixture was stirred at room temperature for 1 hour. After completion of the stirring, the black precipitate was filtered. Then, it was washed with 300 ml of distilled water and filtered again. After repeating this operation three times, the resultant was dried at 60 ° C. for 4 hours to obtain 12.0 g of a black solid. Crush this solid,
The temperature was raised from room temperature to 350 ° C. in the air for 3.5 hours, and calcined at the same temperature for 3 hours to obtain 9.9 g of a black catalyst. The calculated value of the ruthenium oxide content was 46% by weight. This powder was molded to have a mesh of 12 to 18.5 to obtain a ruthenium oxide titanium oxide catalyst. The reaction was carried out in the same manner as in Example 2, except that 2.5 g of the ruthenium titanium oxide catalyst was filled in a reaction tube and the internal temperature was changed to 299 ° C. 2.6 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 7.35 × 10 ⁻⁴ mol / min · g-catalyst.

Example 5 A catalyst was prepared by the following method. That is, 15.4 g of commercially available titanium tetrabutoxide was dissolved in 52 ml of ethanol. Next, commercially available ruthenium chloride hydrate (RuC
to that of l ₃ · nH ₂ O) 10.1g was dissolved in water 122 ml, sodium hydroxide (96% content) 14.8 g were mixed and dissolved in water 60 ml, after stirring, immediately titanium tetrabutoxide Under stirring in the ethanol solution,
Dropping was started. As the solution was added, a precipitate formed.
After the addition, the black precipitate was sufficiently stirred at room temperature. further,
A solution obtained by diluting 25.7 g of 61% by weight nitric acid with 62 g of water was added dropwise and stirred at room temperature for 1 hour. After completion of the stirring, the precipitate was filtered. Then, after washing with 300 ml of distilled water, filtration was performed again. After repeating this three times, it was dried at 60 ° C. for 4 hours to obtain 10.5 g of a black solid. The solid was pulverized, heated in the air from room temperature to 350 ° C. for 3.5 hours, and calcined at 350 ° C. for 3 hours to obtain 8.4 g of a black catalyst. The calculated value of the ruthenium oxide content was 5
7% by weight. This powder is molded and 12 to 18.5
By forming a mesh, a ruthenium oxide titanium oxide catalyst was obtained. This ruthenium oxide titanium oxide catalyst 2.5
g into a reaction tube in the same manner as in Example 2, and the internal temperature was set to 300 ° C.
The reaction was performed in accordance with the reaction method of Example 2 except that 1.9 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 7.7 × 10 ⁻⁴ mol / min · g-catalyst.

Example 6 A commercially available ruthenium oxide hydrate (RuO ₂ , Aldrich Chemical) was formed into a mesh of 12 to 18.5. A reaction tube was filled with 2.5 g of the ruthenium oxide in the same manner as in Example 2, and the reaction was performed in accordance with the reaction method of Example 2 except that the internal temperature was set to 300 ° C. At 1.5 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 5.35 × 10 ⁻⁴ mo.
1 / min · g-catalyst.

Example 7 A 3 mmφ spherical 2% by weight ruthenium titanium oxide catalyst (manufactured by NE Chemcat) was crushed, and 12 to 18.
Aligned to 5 mesh. Without diluting 2.5 g of this ruthenium titanium oxide catalyst with a titanium oxide carrier, the reaction tube was filled in the same manner as in Example 2, and hydrogen chloride gas was supplied at 190 ml / min.
And carried out in accordance with the reaction method of Example 2 except that the internal temperature was set to 300 ° C. 1.5 hours after the start of the reaction, the activity of forming chlorine per unit catalyst weight was 1.38 × 1.
It was 0 ^-4 mol / min.g-catalyst.

Example 8 The same 2% by weight ruthenium titanium oxide catalyst as used in Example 7 was adjusted to 12 to 18.5 mesh, and
g was not diluted with a titanium oxide carrier, and charged into a reaction tube in the same manner as in Example 2. Hydrogen chloride gas was passed at 196 ml / min, oxygen gas was passed at 170 ml / min, and the internal temperature was 380 ° C.
The reaction was performed in accordance with the reaction method of Example 2 except that Two hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 11.4 × 10 ⁻⁴ mol / min · g-catalyst.

Example 9 A 2% by weight ruthenium zirconium oxide catalyst (manufactured by NE Chemcat) of 1/8 inch pellets was crushed and
The size was adjusted to 2-18.5 mesh. Without diluting 2.5 g of the ruthenium zirconium oxide catalyst with a titanium oxide carrier, the reaction tube was filled in the same manner as in Example 2, hydrogen chloride gas was passed at 196 ml / min, oxygen gas was passed at 170 ml / min, and the internal temperature was lowered. The procedure was performed according to Example 2 except that the temperature was changed to 380 ° C. Three hours after the start of the reaction, the activity of forming chlorine per unit catalyst weight was 7.9 × 10 ^-4 mol / m.
ing-catalyst. The residual hydrogen chloride flow rate is 4.7
× 10 ^-3 mol / min.

Example 10 A 5% by weight ruthenium alumina powder catalyst (manufactured by NE Chemcat) was formed into a mesh of 12 to 18.5 mesh. Example 2 was repeated except that 5 g of this ruthenium alumina catalyst was not diluted with a titanium oxide carrier, but was charged into a reaction tube in the same manner as in Example 2, hydrogen chloride was passed at 193 ml / min, and the internal temperature was set to 380 ° C. Performed according to. Ten hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 6.7 × 10 ⁻⁴ mol / min · g-catalyst.

As described above, in Examples 1 to 5, ruthenium
Examples of the composite oxide catalyst, the example of Embodiment 6 in the ruthenium oxide catalyst, examples of Examples 7 to 10 in supported ruthenium catalyst
showed that.

Comparative Example 1 A catalyst was prepared by the following method. That is, 60.3 g of chromium nitrate nonahydrate was dissolved in 600 ml of water,
The temperature was raised to 5 ° C. and 25% by weight of aqueous ammonia 6 was stirred.
4.9 g was added dropwise over 1.5 hours, and stirring was continued at the same temperature for 30 minutes. To the generated precipitate, 3.3 l of water was added, and the mixture was allowed to stand overnight. After settling, the supernatant was removed by decantation. Next, 2.7 l of water was added, and the mixture was stirred well for 30 minutes. This operation was repeated 5 times to wash the precipitate, the supernatant was removed by decantation, 49 g of 20% by weight silica sol was added, and the mixture was stirred and evaporated to dryness at 60 ° C. by a rotary evaporator. Next, at 60 ° C., 8
After drying for an hour, and further drying at 120 ° C. for 6 hours, a green solid was obtained. The solid was dried in a nitrogen stream at 120 ° C. for 6 hours, and then cooled to room temperature to obtain a green solid. Next, this was baked at 600 ° C. for 3 hours in the air and formed into a mesh of 12 to 18.5 to obtain a Cr ₂ O ₃ —SiO ₂ catalyst. 2.5 g of the Cr ₂ O ₃ —SiO ₂ catalyst thus obtained was not diluted with a titanium oxide carrier, but charged into a reaction tube in the same manner as in Example 2, and 192 ml / min of hydrogen chloride gas. And carried out in accordance with Example 2 except that the internal temperature was 301 ° C. 3.7 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 0.19 × 10 ⁻⁴ mol / mi.
ng catalyst.

Comparative Example 2 2.5 g of the Cr ₂ O ₃ —SiO ₂ catalyst used in Comparative Example 1
Was not diluted with a titanium oxide carrier, and charged into a reaction tube in the same manner as in Example 2, and 192 ml / min. And carried out according to Example 2 except that the internal temperature was 380 ° C. At 5.8 hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 2.1 × 10 ⁻⁴ mol / mol.
min.g catalyst.

Comparative Example 3 5 g of the Cr ₂ O ₃ —SiO ₂ catalyst used in Comparative Example 1 was filled in a reaction tube in the same manner as in Example 2 without diluting with a titanium oxide carrier. min. And carried out according to Example 2 except that the internal temperature was 380 ° C. Five hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 2.7 × 10 ⁻⁴ mol / min.
G catalyst.

Comparative Example 4 A catalyst was prepared by the following method. That is, 1.02 g of commercially available ruthenium chloride hydrate (RuCl ₃ .nH ₂ O)
18.70 g of silica (AEROSIL-300) manufactured by Nippon Aerosil Co., Ltd. is suspended in an aqueous solution consisting of water and 80 g of water, and evaporated to dryness at 55 to 60 ° C. by a rotary evaporator, and then heated at 150 ° C. for 1 hour in a nitrogen stream. As a result, 18.1 g of a green-black ruthenium chloride catalyst was obtained. The loading ratio of RuCl ₃ was 5% by weight. The catalyst was formed into 12-18.5 mesh. 5 g of the thus obtained ruthenium chloride catalyst was not diluted with a titanium oxide carrier, but was charged into a reaction tube in the same manner as in Example 2, and 194 ml / min of hydrogen chloride gas. At 380 ℃
The procedure was performed in accordance with Example 2, except that Five hours after the start of the reaction, the activity of forming chlorine per unit weight of the catalyst was 5.9 × 10 ⁻⁴ mol / min · g-catalyst.

[0037]

As described above, according to the present invention, there is provided a method for producing chlorine by oxidizing hydrogen chloride, which comprises using a highly active catalyst, using a smaller amount of a catalyst and reducing the chlorine at a lower reaction temperature. A method for producing chlorine having the characteristic that it can be produced can be provided.

────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference European Patent 761594 (EP, B1) Hepel T. et al. , Effect of the crystallographic surface structure of the RuO2 single crystals on the chloronevoluti, J. et al. of the Electroanalytical Chemistry and Intellectual Electrochemistry, Vol. 188, no. 1/2, 281-285 (58) Fields investigated (Int. Cl. ⁷ , DB name) C01B 7/04 B01J 23/46 301

Claims (1)

(57) [Claims] 1. A method for producing chlorine by oxidizing hydrogen chloride with oxygen, comprising a supported metal ruthenium catalyst and a ruthenium oxide catalyst.
A method for producing chlorine, wherein a chlorine catalyst or a ruthenium composite oxide catalyst is used.