JP2005289800A - Method of producing chlorine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing chlorine having a high oxidation reactivity of carbon monoxide, phosgene, hydrogen, or an organic compound and a high inversion rate of hydrogen chloride to chlorine, in producing chlorine by contacting a mixed gas containing carbon monoxide, phosgene, hydrogen or an organic compound, and hydrogen chloride with a gas containing oxygen, where at least one compound selected from the carbon monoxide, the phosgene, the hydrogen or the organic compound contained in the gas is oxidized and the hydrogen chloride is oxidized into chlorine as well. <P>SOLUTION: In the presence of ruthenium carried on titanium oxide and/or a ruthenium compound, a mixed gas containing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen, and an organic compound and hydrogen chloride is contacted with a gas containing oxygen, and at least one of the compounds is oxidized and the hydrogen chloride is oxidized into chlorine as well. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for producing chlorine in which at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound is oxidized, and at the same time, hydrogen chloride is oxidized to chlorine. More specifically, the present invention is directed to bringing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and a mixed gas containing hydrogen chloride into contact with a gas containing oxygen, and said at least one compound Is a method for producing chlorine in which hydrogen chloride is oxidized to chlorine at the same time as oxidation of carbon monoxide, oxidization of carbon monoxide, phosgene, hydrogen or organic compounds is high, and conversion rate of hydrogen chloride to chlorine is high. The present invention relates to a method for producing chlorine having the above characteristics.

A method of oxidatively decomposing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and a compound gas containing hydrogen chloride using a gas containing oxygen is known. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-171103), carbon monoxide is impregnated in the presence of a catalyst obtained by impregnating a ruthenium compound with zirconium oxide calcined between 300 ° C. and 800 ° C. Oxidative decomposition of at least one compound selected from phosgene and an organic compound and at least one compound selected from carbon monoxide, phosgene and an organic compound in a mixed gas containing hydrogen chloride using a gas containing oxygen A method is disclosed.

JP 2003-171103 A JP 2000-229239 A JP 2000-281314 A JP 2002-79093 A JP 2004-181408 A

However, the conventional method has a problem that the reaction rate of oxidative decomposition of carbon monoxide, phosgene or an organic compound is low. In such a situation, the problem to be solved by the present invention is to bring a mixed gas containing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and hydrogen chloride into contact with a gas containing oxygen. A method for producing chlorine wherein the at least one compound is oxidized simultaneously with the oxidation of hydrogen chloride to chlorine, wherein the reaction rate of oxidation of the at least one compound is high and the conversion rate of hydrogen chloride to chlorine is high. The object is to provide production of chlorine having excellent characteristics.

That is, the present invention provides a mixed gas containing hydrogen chloride and at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound in the presence of ruthenium and / or ruthenium compounds supported on titanium oxide. The invention relates to a method for producing chlorine, which is brought into contact with a gas containing oxygen to oxidize at least one compound and simultaneously oxidize hydrogen chloride to chlorine.

According to the present invention, at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen, and an organic compound and a mixed gas containing hydrogen chloride are brought into contact with a gas containing oxygen, and thereby the monoxide is oxidized at a high reaction rate. Carbon, phosgene, hydrogen or organic compounds can be oxidized to produce chlorine from hydrogen chloride with high conversion.

In the present invention, it is necessary to use ruthenium and / or a ruthenium compound supported on titanium oxide as a catalyst. Thereby, the reaction rate of oxidation of carbon monoxide, phosgene, hydrogen or an organic compound is high, and the conversion rate of hydrogen chloride to chlorine can be increased.

The ruthenium and / or ruthenium compound used in the present invention includes ruthenium metal, ruthenium oxide, ruthenium chloride, ruthenium chloride hydrate, nitrosyl ruthenium nitrate, ruthenium carbonyl complex, and any combination thereof. The mixture which consists of is mentioned.

The mixed gas containing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and organic compounds and hydrogen chloride used in the present invention includes a reaction between hydrogen and chlorine, a thermal decomposition reaction and a combustion reaction of a chlorine compound. Any compound containing hydrogen chloride generated in the phosgenation reaction or chlorination reaction of organic compounds, production of chlorofluoroalkane, heating of hydrochloric acid, combustion in an incinerator, etc. can be used.

Examples of the thermal decomposition reaction of the chlorine compound include production of vinyl chloride from 1,2-dichloroethane, production of tetrafluoroethylene from chlorodifluoromethane, and the like.

Examples of the phosgenation reaction of an organic compound include production of isocyanate by reaction of amine and phosgene, and production of carbonate ester by reaction of alcohol and / or aromatic alcohol with phosgene.

The chlorination reaction of organic compounds includes the production of allyl chloride by the reaction of propylene and chlorine, the production of ethyl chloride by the reaction of ethane and chlorine, the production of trichlorethylene and tetrachloroethylene by the reaction of 1,2-dichloroethane and chlorine, Examples include production of chlorobenzene by reaction of benzene and chlorine.

The production of chlorofluoroalkane includes the production of dichlorodifluoromethane and trichloromonofluoromethane by the reaction of carbon tetrachloride and hydrogen fluoride, and the production of dichlorodifluoromethane and trichloromonofluoromethane by the reaction of methane, chlorine and hydrogen fluoride. Manufacturing etc. are mentioned.

Examples of the organic compound in the mixed gas used in the present invention include aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, and aromatic alcohols.

Aliphatic hydrocarbons include ethane, ethylene, acetylene, propane, propylene, methyl chloride, dichloromethane, trichloromethane, carbon tetrachloride, ethyl chloride, vinyl chloride, 1,2-dichloroethane, dichloroethane, trichloroethane, tetrachloroethane, penta Examples include chloroethane and hexachloroethane.

Examples of the aromatic hydrocarbon include dichlorobenzene such as benzene, monochlorobenzene and orthodichlorobenzene, trichlorobenzene, tetrachlorobenzene, pentachlorobenzene and hexachlorobenzene.

Examples of the alcohol include methanol, ethanol, and propanol.
Examples of the aromatic alcohol include phenol and cresol.

As the gas containing oxygen used in the present invention, oxygen or air is used. Oxygen can be obtained by ordinary industrial methods such as pressure swing of air or cryogenic separation.

In the present invention, the catalyst is preferably ruthenium oxide supported on titanium oxide, and ruthenium oxide supported on rutile crystalline titanium oxide has a high oxidation reaction rate of carbon monoxide, phosgene, hydrogen or an organic compound, and chloride. More preferable because of the high conversion rate of hydrogen to chlorine. Catalysts containing ruthenium oxide supported on titanium oxide include, for example, Patent Document 2 (Japanese Patent Laid-Open No. 2000-229239), Patent Document 3 (Japanese Patent Laid-Open No. 2000-281314), and Patent Document 4 (Japanese Patent Laid-Open No. 2002-79093). No.].

The titanium oxide used in the present invention includes composite oxides of titanium oxide and other metal oxides, and mixtures of titanium oxide and other metal oxides such as alumina, zirconium oxide, and silica. Further, the catalyst can be used after diluted with a substance that is inert to the reaction with alumina, zirconium oxide, silica or the like.

The catalyst may be used in the form of a spherical particle, a cylindrical pellet, an extruded shape, a ring shape, a honeycomb shape, or an appropriately sized granule that has been pulverized and classified after molding. At this time, the diameter of the catalyst is preferably 5 mm or less. When the diameter of the catalyst is large, the reaction rate of oxidative decomposition of carbon monoxide, phosgene, hydrogen or an organic compound may be low, or the conversion rate of hydrogen chloride to chlorine may be low. The lower limit of the diameter of the catalyst is not particularly limited, but if it becomes excessively small, pressure loss in the catalyst layer increases, and therefore, a catalyst having a diameter of 0.5 mm or more is usually used. The diameter of the catalyst here means the diameter of a sphere in the case of spherical particles, the diameter of a circular cross section in the case of a cylindrical pellet, and the maximum diameter of the cross section in other shapes.

The amount of the catalyst used is usually 10 in terms of the ratio (GHSV) to the supply rate of the mixed gas containing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and hydrogen chloride in the standard state. ˜50000 h ⁻¹ .

In the present invention, the concentration of carbon monoxide in the mixed gas is usually 5% by volume or less, preferably 1% by volume or less, more preferably 0.5% by volume or less. If the concentration of carbon monoxide is too high, the activity of the catalyst may decrease.

In the present invention, the concentration of phosgene in the mixed gas is usually 5% by volume or less, preferably 1% by volume or less, more preferably 0.5% by volume or less.

In the present invention, the hydrogen concentration in the mixed gas is usually 5% by volume or less, preferably 1% by volume or less, more preferably 0.5% by volume or less.

In the present invention, the concentration of the organic compound in the mixed gas is usually 5% by volume or less, preferably 1% by volume or less, more preferably 0.1% by volume or less. If the concentration of the organic compound is too high, the activity of the catalyst may decrease.

In the present invention, the concentration of hydrogen chloride in the mixed gas is usually 50% by volume or more, preferably 80% by volume or more, more preferably 90% by volume or more.

In the present invention, the molar ratio of oxygen to the total amount of at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and hydrogen chloride is preferably 0.2 or more. The above is more preferable. If the amount of oxygen is too small, the reaction rate of oxidation of carbon monoxide, phosgene, hydrogen or organic compounds may be low.

In this invention, although reaction temperature is 200-500 degreeC normally, it is preferable to set it as 250-450 degreeC, and 300-400 degreeC is still more preferable. When the reaction temperature is too low, the reaction rate of oxidation of carbon monoxide, phosgene, hydrogen or an organic compound may be low, or the conversion rate of hydrogen chloride to chlorine may be low. On the other hand, if the reaction temperature is too high, the catalyst components may volatilize.

The reaction pressure is usually 0.1 to 5 MPa, preferably 0.1 to 1 MPa.

The gas linear velocity based on the empty column is usually 0.1 to 20 m / s. The superficial gas linear velocity of the present invention means the ratio of the total supply rate of all the gases supplied to the reactor in the standard state to the cross-sectional area of the reactor.

Examples of the reaction method include a fixed bed gas phase flow reaction method and a fluidized bed gas phase flow reaction method.

In the case of the fixed bed gas phase flow reaction method, the temperature control can be performed by a heat exchange method. The heat exchange system of the present invention means a system having a jacket portion outside the reaction tube filled with a catalyst and removing reaction heat generated by the reaction with a heat medium in the jacket. In the heat exchange system, the temperature of the catalyst packed bed in the reaction tube is controlled by the heat medium in the jacket. Industrially, it is possible to use a multi-tube heat exchanger type fixed-bed multi-tubular reactor having reaction tubes arranged in parallel and having a jacket portion on the outside.

In the present invention, chlorine can be obtained by the following steps.
(1) Reaction step: contacting at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and a mixed gas containing hydrogen chloride with a gas containing oxygen, and oxidizing the at least one compound And simultaneously oxidizing hydrogen chloride to chlorine
(2) Absorption step: The gas obtained in the reaction step is cooled, brought into contact with water and / or hydrochloric acid, or brought into contact with water and / or hydrochloric acid and then cooled, and then cooled with hydrogen chloride. A step of collecting a solution containing water as a main component to obtain a gas containing chlorine and unreacted oxygen as main components
(3) Drying step: A step of obtaining a dried gas by removing moisture in the gas obtained in the absorption step.
(4) Purification step: A step of obtaining chlorine by separating the dried gas obtained in the drying step into a liquid or gas mainly containing chlorine and a gas mainly containing unreacted oxygen.
(5) Circulation step: A step of supplying a part or all of the gas mainly composed of unreacted oxygen obtained in the purification step to the reaction step.
(6) Detoxification step: After removing chlorine contained in the gas from the gas mainly composed of unreacted oxygen obtained in the purification step or the gas not supplied to the reaction step in the circulation step, Discharging process

In this invention, after making this mixed gas contact activated carbon, it can use for a reaction process.

In the present invention, the solution containing hydrogen chloride and water as main components obtained in the absorption step is used as it is or after removing chlorine contained in the solution by heating and / or bubbling with an inert gas such as nitrogen. It can be used as a raw material for pH adjustment of electrolytic cells, neutralization of boiler feed water, production of 4,4′-diphenylmethanediamine by condensation rearrangement reaction of aniline and formalin, and hydrochloric acid electrolysis. In addition, hydrogen chloride is recovered from the top of the distillation column by being subjected to distillation for hydrogen chloride recovery and used in the reaction as a part of the mixed gas, and part or all of the liquid at the bottom of the distillation column is distilled for dehydration. Then, water can be recovered from the top of the distillation column, and a part or all of the liquid at the bottom of the distillation column can be supplied to the distillation column for recovering hydrogen chloride.

In the present invention, the sulfuric acid mist can be removed by bubbling a part or all of the gas mainly composed of unreacted oxygen obtained in the purification step to the absorbing solution by the air diffuser.

In the present invention, the chlorine obtained in the purification step can be used for production of 1,2-dichloroethane by reaction with ethylene, phosgene by reaction with carbon monoxide, and allyl chloride by reaction with propylene. Phosgene can be used in the production of isocyanates by reaction with amines, and in the production of carbonate esters by reaction with alcohols and / or aromatic alcohols. Examples of the isocyanate include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and hexamethylene-1,6-diisocyanate. Examples of the carbonate ester include diphenyl carbonate and dimethyl carbonate.

Hereinafter, the present invention will be described with reference to examples.

Example 1
In the same manner as catalyst b (1.5 mmφ extruded titanium oxide-α-alumina-supported ruthenium oxide catalyst) described in Example 16 of Patent Document 4 (Japanese Patent Laid-Open No. 2002-79093), the amount of ruthenium oxide supported was A catalyst A having 2.0% by mass and a catalyst B having a ruthenium oxide loading of 4.0% by mass were prepared.

Using the obtained catalyst, the reaction of oxidizing hydrogen chloride with oxygen was performed as follows to stabilize the activity of the catalyst, and then an organic substance addition experiment was performed. That is, 3.71 g (2.7 cm ³ ) of catalyst B was filled in an upright quartz reaction tube (inner diameter: 14 mm), and 8.11 g (6.1 cm ³ ) of catalyst A and diameter were further above catalyst B. A mixture with 6.0 g of 2 mm α-alumina spheres (SSA995, manufactured by Nikkato Co., Ltd.) was charged.

From the upper part of the reaction tube, hydrogen chloride gas was continuously supplied at a flow rate of 80 ml / min, and oxygen gas was supplied at a flow rate of 40 ml / min (both absolute pressure 0.1 MPa, converted to 0 ° C.). The reaction temperature was 340-359 ° C., the reaction pressure was 0.1 MPa, and the GHSV with respect to the catalyst volume was 549 h ⁻¹ .

After 1.5 hours from the start of supply of hydrogen chloride gas and oxygen gas, the gas is collected by circulating the gas at the outlet of the reaction tube through a 30% by mass potassium iodide aqueous solution, and the amount of generated chlorine is determined by iodine titration. The amount of unreacted hydrogen chloride was measured by a neutralization titration method. . The conversion rate of hydrogen chloride is shown in Table 1.

After 23 hours from the start of supply of hydrogen chloride gas and oxygen gas, the supply of phenol gas diluted to 0.45% by volume with nitrogen was started at a flow rate of 20 ml / min. The concentration of phenol with respect to hydrogen chloride gas in the raw material is calculated to be 0.1% by volume.

27 hours and 93 hours after the supply of hydrogen chloride gas and oxygen gas, the gas at the outlet of the reaction tube was passed through a 30% by mass potassium iodide aqueous solution to collect the gas, and the amount of chlorine produced by iodine titration The amount of unreacted hydrogen chloride was analyzed by gas chromatography by a neutralization titration method, and the amount of carbon dioxide at the outlet was measured. The conversion rate of each hydrogen chloride and the yield of carbon dioxide with respect to phenol are shown in Table 1.

Table 1
━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Reaction time phenolic hydrogen chloride carbon dioxide
Addition time (h) Conversion (%) To phenol
Yield (%)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1.5-84.0-
27 4 84.5 87
93 70 84.9 87
━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Example 2
Catalysts C and D were prepared in the same manner except that the catalyst diameters of the catalysts A and B used in Example 1 were 3.0 mmφ. The amount of ruthenium oxide supported on catalyst C was 2.0% by mass, and the amount of ruthenium oxide supported on catalyst D was 4.0% by mass. Similarly, Catalyst E having a catalyst diameter of 3 mmφ and a ruthenium oxide loading of 1.0% by mass was prepared.

Catalyst F was prepared by the following method. That is, 30.0 g of powdery zirconium oxide support (Nippon Denko DN Co., Ltd.) and 0.6 g of Metroz (Shin-Etsu Chemical, 65SH-4000) were mixed well. Further, an aqueous solution obtained by mixing 6.0 g of pure water and 6.0 g of an aqueous zirconyl nitrate solution (containing 25% by mass of Zirconol ZN Zirconia, a first rare element chemical industry) was added and then kneaded well.

Next, the product obtained by kneading was extruded into a 3 mmφ noodle shape by an extruder and then dried in the air at 60 ° C. for 4 hours using a hot air circulating dryer to obtain a solid. Next, the extruded dried product thus obtained was heated at a rate of 6 ° C./min from room temperature to 600 ° C. in air using a muffle furnace, and baked at the same temperature for 3 hours. The carrier was cut to a length of about 5 mm to obtain a zirconium oxide extruded carrier. Next, commercially available ruthenium chloride hydrate (Ru content 40.7 wt%) was dissolved in pure water and stirred well to obtain a ruthenium chloride solution. The obtained aqueous solution was dropped onto the zirconium oxide extruded carrier, and ruthenium chloride was impregnated and supported so that ruthenium oxide obtained by the subsequent treatment was 2.0% by mass. The supported one was left overnight at room temperature. Subsequently, it dried at 60 degreeC in the air for 2 hours, and the zirconium oxide carrying | support ruthenium chloride was obtained. The obtained zirconium oxide-supported ruthenium chloride was heated to 400 ° C. in air at a rate of 6 ° C./min using a muffle furnace, and calcined at the same temperature for 3 hours. The zirconium oxide-supported ruthenium oxide catalyst thus obtained is referred to as catalyst F.

Using the obtained catalyst, the reaction of oxidizing hydrogen chloride with oxygen was performed as follows to stabilize the activity of the catalyst, and then an organic substance addition experiment was performed.

That is, 3.12 g (2.4 cm ³ ) of catalyst D was filled in an upright quartz reaction tube (inner diameter 14 mm), and 3.66 g (2.8 cm ³ ) of catalyst C and diameter were further above catalyst D. A mixture of 8.0 mm of 2 mm α-alumina spheres (Nikkato Co., Ltd., SSA995) was charged, and 1.87 g (1.4 cm ³ ) of catalyst E and 2 mm diameter α-alumina spheres ( A mixture of 1.0 g of SSA995 manufactured by Nikkato Co., Ltd. was charged, and 2.01 g (1.3 cm ³ ) of catalyst F was further filled thereover.

From the upper part of the reaction tube, hydrogen chloride gas was continuously supplied at a flow rate of 80 ml / min, and oxygen gas was supplied at a flow rate of 40 ml / min (both absolute pressure 0.1 MPa, converted to 0 ° C.). The reaction temperature was 337-363 ° C., the reaction pressure was 0.1 MPa, and the GHSV relative to the catalyst volume was 602 h ⁻¹ .

Two hours after the start of supply of hydrogen chloride gas and oxygen gas, gas was collected by circulating the gas at the outlet of the reaction tube through a 30% by mass potassium iodide aqueous solution, and the amount of chlorine produced was neutralized by the iodometric titration method. The amount of unreacted hydrogen chloride was measured by a titration method. The conversion rate of hydrogen chloride is shown in Table 2.

23 hours after the start of supply of hydrogen chloride gas and oxygen gas, carbon tetrachloride gas diluted to 19% by volume with nitrogen was started to be supplied at a flow rate of 3.5 ml / min. The concentration of carbon tetrachloride with respect to hydrogen chloride gas in the raw material is calculated as 0.8% by volume.

After 25 and 52 hours from the start of the supply of hydrogen chloride gas and oxygen gas, gas was collected by circulating the gas at the outlet of the reaction tube through a 30% by mass potassium iodide aqueous solution, and the amount of chlorine produced by the iodine titration method The amount of unreacted hydrogen chloride was analyzed by gas chromatography by a neutralization titration method, and the amount of carbon dioxide at the outlet was measured. Table 2 shows the conversion rate of each hydrogen chloride and the yield of carbon dioxide with respect to carbon tetrachloride.

Table 2
━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Reaction time Carbon tetrachloride Hydrogen chloride Carbon dioxide
Addition time (h) Conversion (%) To carbon tetrachloride
Yield (%)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2-84.4-
25 2 87.6 100
52 29 87.8 99
━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Example 3
A 3.0 mmφ extruded titanium oxide-α-alumina-supported ruthenium oxide catalyst was prepared by the same method as in Catalyst Production Example 1 of Patent Document 5 (Japanese Patent Application Laid-Open No. 2004-181408). The amount of ruthenium oxide supported was 2.0% by mass. Using the obtained catalyst, the reaction of oxidizing hydrogen chloride with oxygen was performed as follows to stabilize the activity of the catalyst, and then a carbon monoxide addition experiment was performed.

Three nickel reaction tubes (inner diameter 25 mm) filled with 650 g of the catalyst were connected in series, and each was installed in a heating medium jacket made of molten salt. Before and after the catalyst layer, α-alumina spheres (manufactured by Nikkato Co., Ltd., SSA-995) were filled and used for preheating and cooling of the reaction gas. As the molten salt, a mixture of sodium nitrite and potassium nitrate in a weight ratio of 1: 1 was used. From this reaction tube inlet, hydrogen chloride gas is 1.66 m ³ / h, oxygen gas is 0.83 m ³ / h, carbon monoxide gas is 0.0623 m ³ / h (0.75% by volume with respect to hydrogen chloride gas). (Both absolute pressure 0.1 MPa, 0 ° C. conversion). The temperature of the heating medium jacket with molten salt is 280 to 306 ° C. in the first stage, 310 to 315 ° C. in the second stage, 330 ° C. in the third stage, the reactor inlet pressure is 0.42 MPaG, and the GHSV for the catalyst is 1140 h ^−1. It was. Under these conditions, a continuous experiment for 1250 hours was conducted. Periodically collect the reactor outlet gas, measure the amount of chlorine produced by iodometric titration, the amount of unreacted hydrogen chloride by neutralization titration, and the amount of produced carbon dioxide and the amount of unreacted carbon monoxide by gas chromatography did. Table 3 shows the conversion rate of hydrogen chloride and the yield of carbon dioxide with respect to carbon monoxide.

Table 3
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Reaction time Carbon monoxide Hydrogen chloride Carbon dioxide
Addition time (h) Conversion (%) To carbon monoxide
Yield (%)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━
118 118 58.5 100
504 504 58.5 100
1191 1191 54.7 100
━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Claims (7)

In the presence of ruthenium and / or a ruthenium compound supported on titanium oxide, a mixed gas containing at least one compound selected from the group consisting of carbon monoxide, phosgene, hydrogen and an organic compound and hydrogen chloride, and a gas containing oxygen A method for producing chlorine comprising contacting and oxidizing the at least one compound and simultaneously oxidizing hydrogen chloride to chlorine. The method of claim 1, wherein the ruthenium compound is ruthenium oxide. The method according to claim 1, wherein the titanium oxide is rutile crystalline titanium oxide. The method according to claim 1, wherein the concentration of carbon monoxide in the mixed gas is 1% by volume or less. The method according to claim 1, wherein the concentration of the organic compound in the mixed gas is 0.1% by volume or less. The method according to claim 1, wherein the concentration of hydrogen chloride in the mixed gas is 80% by volume or more. The process according to claim 1, wherein the reaction temperature is 250 to 450 ° C.