JP2011162382A - Method for producing chlorine - Google Patents

Abstract

The present invention provides a method for efficiently producing chlorine by oxidizing hydrogen chloride in hydrochloric acid water with oxygen.
In a water phase containing hydrochloric acid in the presence of a supported ruthenium oxide catalyst in which ruthenium oxide is supported on a support containing rutile crystalline titanium oxide, the reaction temperature is 140 to 260 ° C. and the oxygen partial pressure is Hydrogen chloride is vapor-phase contact oxidized with oxygen in the gas phase of 1 to 10 MPa. At this time, the aqueous phase is preferably obtained by supplying a gas containing hydrogen chloride and a hardly water-soluble gas to water and separating the hardly water-soluble gas. Furthermore, the hydrochloric acid concentration in the aqueous phase is preferably 15 to 40% by weight, and the supported ruthenium oxide catalyst is preferably contained in an amount of 0.1 to 50% by weight with respect to the aqueous phase.
[Selection figure] None

Description

  The present invention relates to a method for producing chlorine using a ruthenium catalyst, and more particularly to a method for producing chlorine in which hydrogen chloride in hydrochloric acid water is oxidized by oxygen in the presence of a ruthenium catalyst.

As a method for producing chlorine by oxidizing hydrogen chloride with oxygen, a method using a copper catalyst called a Deacon catalyst has been known for a long time. In addition, a method using a chromium catalyst (for example, see Patent Documents 1 to 4), a method using a ruthenium catalyst (for example, see Patent Documents 5 to 10), and the like have been proposed.
The raw material hydrogen chloride gas used in the above production method includes pyrolysis reaction or combustion reaction of chlorine compounds, carbonylation reaction of organic compounds with phosgene, chloroformylation reaction or chlorination reaction, chlorination reaction of organic compounds with chlorine, chloro Chlorine generated in various by-product hydrogen chloride gas generated by the reaction of alkane and hydrogen fluoride or the production of chlorofluoroalkane by the reaction of alkane, chlorine and hydrogen fluoride, and combustion exhaust gas generated from an incinerator Hydrogen gas or the like is generally used. However, this hydrogen chloride gas may contain a large amount of impurity gas other than hydrogen chloride gas. Therefore, when gas phase oxidation is performed with oxygen as it is, the reaction is hindered by impurities in the reaction gas, and the reaction efficiency may be lowered. is there.

Patent Document 6 discloses a chlorine production method in which hydrogen chloride is oxidized with oxygen in an aqueous phase using a ruthenium catalyst.
Specifically, as the ruthenium catalyst, ruthenium chloride, ruthenium chloride and titanium chloride, supported metal ruthenium, ruthenium oxide, supported ruthenium oxide, the reaction temperature is 90 to 150 ° C., the reaction pressure is about atmospheric pressure to about 10 atmospheres, A method for producing chlorine in which hydrogen chloride is oxidized with oxygen in an aqueous phase is disclosed.

JP-A-61-136902 JP 61-275104 A JP 62-113701 A JP-A-62-270405 JP-A-9-67103 JP 10-338502 A (Claim 7, paragraph [0088]) JP 2000-229239 A JP 2000-281314 A JP 2002-79093 A JP 2002-292279 A

  Most of the impurity gas contained in the hydrogen chloride gas is a hardly water-soluble gas. Therefore, as described in Patent Document 6, when hydrogen chloride is oxidized with oxygen in the aqueous phase, the impurity gas in the hydrogen chloride gas can be excluded from the liquid phase, and improvement in reaction efficiency can be expected. It has been desired to further improve the reaction efficiency from hydrogen chloride to chlorine.

  Accordingly, an object of the present invention is to provide a method for efficiently producing chlorine by oxidizing hydrogen chloride in hydrochloric acid water with oxygen.

  In order to solve the above-mentioned problems, the present inventor has conducted extensive research on the oxidation reaction conditions of hydrogen chloride in hydrochloric acid water. As a result, a gas containing hydrogen chloride is supplied to water, and the hydrogen chloride is once absorbed into water to form hydrochloric acid water. In the presence of a catalyst in which ruthenium oxide is supported on a titanium oxide carrier, It has been found that chlorine can be efficiently produced by oxidation with the use of the above, and the present invention has been completed.

(1) In a gas phase having an oxygen partial pressure of 1 to 10 MPa in an aqueous phase containing hydrochloric acid in the presence of a supported ruthenium oxide catalyst in which ruthenium oxide is supported on a support containing rutile crystalline titanium oxide. A method for producing chlorine in which hydrogen chloride is vapor-phase contact oxidized with oxygen.
(2) The method for producing chlorine according to (1), wherein the reaction temperature is 140 to 260 ° C.
(3) The method for producing chlorine according to (1) or (2), wherein the gas phase portion in the reactor is replaced with oxygen, and the reaction pressure is set to 1 to 10 MPa.
(4) The aqueous phase is obtained by supplying a gas containing hydrogen chloride and a hardly water-soluble gas to water, and separating the hardly water-soluble gas from the chlorine of any one of (1) to (3). Production method.
(5) The hydrochloric acid concentration in the aqueous phase is 15 to 40% by weight, and the supported ruthenium oxide catalyst is contained in an amount of 0.1 to 50% by weight with respect to the aqueous phase. ) The method for producing chlorine according to any of the above.

  According to the chlorine production method of the present invention, hydrogen chloride in hydrochloric acid water can be efficiently converted into chlorine.

It is a schematic explanatory drawing which shows typically one Embodiment of the manufacturing method of the chlorine of this invention.

  Hereinafter, an embodiment of a method for producing chlorine according to the present invention will be described in detail with reference to the drawings with reference to FIG. FIG. 1 is a schematic explanatory diagram according to the present embodiment. As shown in the figure, in the present embodiment, an absorption tower 10 that obtains hydrochloric acid water by absorbing a gas containing hydrogen chloride into water, and a reaction that oxidizes hydrogen chloride in the obtained hydrochloric acid water with oxygen to obtain chlorine. It consists of a container 20.

  The absorption tower 10 may use any method such as a packed tower method or a multi-stage tray method in which shelves are provided with a scattering cylinder.

  Examples of the gas containing hydrogen chloride include a gas generated by a reaction between hydrogen and chlorine, a gas generated by heating hydrochloric acid, a pyrolysis reaction or combustion reaction of a chlorine compound, and a carbonylation of an organic compound with phosgene. Reaction, chlorination reaction of organic compounds with chlorine, various by-product gases generated by the production of chlorofluoroalkane, and combustion exhaust gas generated from an incinerator can be used. These by-product gas and combustion exhaust gas usually contain a large amount of poorly water-soluble gas.

Here, examples of the thermal decomposition reaction of the chlorine compound include a reaction in which vinyl chloride is generated from 1,2-dichloroethane, a reaction in which tetrafluoroethylene is generated from chlorodifluoromethane, and the like.
Examples of the carbonylation reaction of an organic compound with phosgene include a reaction in which an isocyanate is produced from an amine and a reaction in which a carbonate is produced from a hydroxy compound.
Examples of the chlorination reaction of an organic compound with chlorine include a reaction in which allyl chloride is produced from propylene, a reaction in which ethyl chloride is produced from ethane, and a reaction in which chlorobenzene is produced from benzene.
Examples of the production of chlorofluoroalkane include the production of dichlorodifluoromethane and trichloromonofluoromethane by the reaction of carbon tetrachloride and hydrogen fluoride, and dichlorodifluoromethane and trichloromonofluoro by the reaction of methane, chlorine and hydrogen fluoride. Examples include methane production.

These gases are absorbed in the absorption tower 10 and water (preferably pure water) is absorbed in water (preferably pure water), which is mainly hydrogen chloride in the hydrogen chloride-containing gas, to form hydrochloric acid water. At that time, the hardly water-soluble gas is separated from the hydrochloric acid water.
Slightly water-soluble gases include light-boiling hydrocarbons such as methane, ethane, ethylene, acetylene, propane, and propylene, light-boiling chlorohydrocarbons such as chloromethane and chloroethane, carbonyl sulfide, carbon monoxide, carbon dioxide, nitrogen, and hydrogen. Etc.

  The concentration of hydrogen chloride in the obtained hydrochloric acid water is usually 15 to 40% by weight, preferably 20 to 40% by weight, and more preferably 25 to 40% by weight. When the concentration of hydrogen chloride is lower than 15% by weight, the amount of hydrochloric acid present as ions in the aqueous hydrochloric acid increases, and the reaction does not proceed efficiently. When the concentration is higher than 40% by weight, it is difficult to handle the hydrochloric acid. Absent.

  The hydrochloric acid water obtained in the absorption tower 10 is sent to the reactor 20. At this time, when a continuous tank-type slurry aqueous phase reaction method is used as the reaction method of the reactor 20, the supply rate of hydrochloric acid to the reactor 20 is 0.4 to 1000 mol as the amount of hydrochloric acid supplied per liter of catalyst. It is preferably about HCl / hour.

  Examples of the reaction system of the reactor 20 include a fixed bed flow system, a continuous and / or batch batch tank type slurry aqueous phase reaction system, and the like. In the case of a fixed bed flow system, any of upflow, downflow, and trickle flow may be used as the flow of hydrochloric acid water and oxygen.

  When the reactor 20 oxidizes hydrogen chloride in hydrochloric acid with oxygen to obtain chlorine, a supported ruthenium oxide catalyst in which ruthenium oxide is supported on a carrier is used as a catalyst.

  As the carrier in the supported ruthenium oxide catalyst, a carrier containing rutile crystalline titanium oxide is used, but if necessary, a metal oxide such as α-alumina, silica, zirconia, niobium oxide, etc. may be contained. . In addition to the rutile crystalline titanium oxide, the carrier may contain anatase crystalline titanium oxide, amorphous titanium oxide, and the like.

  The carrier preferably contains titanium oxide in a proportion of 30 to 100% by weight with respect to the total amount of the carrier.

  In particular, in the titanium oxide, the ratio of the rutile crystalline titanium oxide to the rutile crystalline titanium oxide and the anatase crystalline titanium oxide (hereinafter sometimes referred to as “rutile crystalline titanium oxide ratio”) is 20%. Above, preferably 80% or more, more preferably 90% or more. The higher the rutile crystal titanium oxide ratio, the better the catalytic activity of the supported ruthenium oxide catalyst.

  The rutile crystal form titanium oxide ratio is a value measured by an X-ray diffraction method (hereinafter referred to as “XRD method”) and calculated from the following formula (I).

  The supported ruthenium oxide catalyst in the method for producing chlorine of the present invention comprises ruthenium oxide supported on the support. The ruthenium oxide is 0.1 to 20% by weight, preferably 0.5 to 5% by weight, based on the total amount of the supported ruthenium oxide catalyst. If the ruthenium oxide is less than 0.1% by weight relative to the total amount of the supported ruthenium oxide catalyst, the catalyst activity may not be sufficient. If it is more than 20% by weight, the catalyst activity corresponding to the cost cannot be obtained.

  As the supported ruthenium oxide catalyst in the method for producing chlorine of the present invention, a catalyst in which ruthenium oxide and silica are supported on the above-mentioned support, and a catalyst in which ruthenium oxide is supported on a titania support described later can be suitably employed.

Examples of the supported ruthenium oxide catalyst include those obtained by the production methods shown in the following (i) to (iv).
(I) A product obtained by supporting a silicon compound on the carrier, then supporting a ruthenium compound, and then firing in an oxidizing gas atmosphere.
(Ii) A titanium compound and a silicon compound are heat-treated in an oxidizing gas atmosphere to obtain a titania support on which silica is supported, and after the ruthenium compound is supported on the support, firing is performed in an oxidizing gas atmosphere. What you get.
(Iii) A product obtained by supporting a ruthenium compound on the carrier, then supporting a silicon compound, and then firing in an oxidizing gas atmosphere.
(Iv) A product obtained by supporting a silicon compound and a ruthenium compound on the carrier and firing in an oxidizing gas atmosphere.
Of the supported ruthenium oxide catalysts (i) to (iv) obtained by the above production method, the supported ruthenium oxide catalyst obtained by the production methods (i) and (ii) is particularly preferable.

Examples of the silicon compound in the production methods (i) to (iv) include silicon alkoxide compounds such as Si (OR) ₄ (hereinafter, R represents an alkyl group having 1 to 4 carbon atoms), silicon chloride ( Examples include silicon halides such as SiCl ₄ ) and silicon bromide (SiBr ₄ ), and silicon halide alkoxide compounds such as SiCl (OR) ₃ , SiCl ₂ (OR) ₂ , and SiCl ₃ (OR). Tetraethyl (Si (OC ₂ H ₅ ) ₄ ) is preferable, and the hydrate may be used as necessary, or two or more of them may be used.

  The oxidizing gas in the production methods (i) to (iv) is a gas containing an oxidizing substance, and examples thereof include an oxygen-containing gas whose oxygen concentration is usually about 1 to 30% by volume. As this oxygen-containing gas, air or pure oxygen is usually used, and air is particularly preferable. This oxygen-containing gas may contain an inert gas or water vapor as necessary.

  The firing temperature in the production methods (i) to (iv) is usually 100 to 1000 ° C, preferably 250 to 450 ° C.

  In addition, as a method of supporting the silicon compound or ruthenium compound on the carrier or titania carrier in the production methods (i) to (iv), a method of impregnating the carrier with a solution obtained by dissolving each compound in an appropriate solvent And a method of immersing the carrier in the solution to adsorb each compound.

  In the supported ruthenium oxide catalyst in which ruthenium oxide and silica are supported on the support in the methods (i) to (iv) or ruthenium oxide is supported on a titania support, the amount of silica used is 1 mol of the support. In general, the amount is 0.001 to 0.3 mol, and preferably 0.004 to 0.03 mol.

  Examples of the supported ruthenium oxide catalyst in which ruthenium oxide and / or silica are supported on the carrier or titania carrier in the production methods (i) to (iv) described above include, for example, JP 2008-155199 A and JP 2002-2002. Those described in Japanese Patent No. 292279 are suitable.

  The supported ruthenium oxide catalyst in the chlorine production method of the present invention is usually contained in an amount of 0.1 to 50% by weight, preferably 1 to 25% by weight, based on the aqueous phase. When the amount of the supported ruthenium oxide catalyst is lower than 0.1% by weight, the proportion of the supported ruthenium oxide catalyst that promotes the gas phase catalytic oxidation reaction of hydrogen chloride with respect to hydrogen chloride in the aqueous phase is low, and the catalytic action There is a large amount of hydrogen chloride that cannot be achieved, and chlorine cannot be produced efficiently. If it is higher than 50% by weight, the proportion of the supported ruthenium oxide catalyst that promotes the gas phase catalytic oxidation reaction of hydrogen chloride with respect to hydrogen chloride in the aqueous phase is high, and the catalytic action is demonstrated because the amount of hydrogen chloride is small There is a large amount of supported ruthenium oxide catalyst that cannot be produced, and not only chlorine cannot be produced efficiently, but also disadvantageous in terms of cost.

  The supported ruthenium oxide catalyst can be in any shape such as particles, granules, spheres, and cylinders, but when adopting a fixed bed type reactor, a molded body such as spheres and cylinders is preferable. In the case of using the type slurry aqueous phase reaction method, it is preferable to use particles having a particle size of 150 μm or less.

  The reactor 20 usually comprises a liquid phase part of hydrochloric acid water and a gas phase part mainly composed of oxygen in the presence of the supported ruthenium oxide catalyst. Under the present circumstances, the oxygen partial pressure of a gaseous-phase part is 1-10 Mpa normally, Preferably it is 3-8 Mpa. If the oxygen partial pressure is too low, the concentration of oxygen dissolved in the liquid phase decreases, and the reaction may not proceed efficiently. On the other hand, if the oxygen partial pressure is too high, the oxygen concentration in the reaction gas becomes too high, so unreacted oxygen becomes the main part of the gas phase, and the chlorine separation efficiency is low, which may be disadvantageous in cost. .

  As the oxygen source in the method for producing chlorine according to the present invention, air or pure oxygen may be used. From the viewpoint of further improving the reaction efficiency of hydrogen chloride in the gas phase catalytic oxidation with oxygen, and since the reactor material may be expensive to withstand the reaction pressure when it is high, from the viewpoint of cost. In order to increase the oxygen partial pressure and suppress the increase in the total pressure, it is preferable to use pure oxygen. Further, the reaction pressure in the reaction vessel 20 is 1 to 10 MPa, preferably 3 to 8 MPa in order to suppress an increase in the total pressure. At this time, it is preferable that all the gas phase portions in the reaction vessel 20 are oxygen.

  The reaction temperature in the method for producing chlorine according to the present invention is usually 100 to 300 ° C, preferably 140 to 260 ° C. If the reaction temperature is too low, the reaction may not proceed efficiently, and if it is too high, the reactor material may be expensive to withstand the high pressure in the reactor, which is disadvantageous in cost. Sometimes.

  In the reactor 20, unreacted hydrochloric acid water and unreacted oxygen can be recycled for both the fixed bed flow system and the tank type slurry aqueous phase reaction system. Furthermore, unreacted hydrogen chloride and unreacted oxygen discharged from the reactor 20 can be reacted in a gas phase reactor and converted to chlorine. Moreover, when using a continuous tank type slurry aqueous phase reaction system, the catalyst discharged | emitted when extracting the reaction liquid of a liquid phase part can also be reproduced | regenerated suitably, and can also be recycled.

  According to the above production method, chlorine is efficiently produced by oxidizing hydrogen chloride in hydrochloric acid water with oxygen.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example. In the following examples, the parts and% representing the content or amount used are based on weight unless otherwise specified. In the following examples, the gas supply rate (ml / min) is a converted value of 0 ° C. and 0.1 MPa unless otherwise specified.

<Example 1>
(Production of supported ruthenium oxide catalyst)
50 parts of titanium oxide (“STR-60R” manufactured by Sakai Chemical Co., Ltd., 100% rutile type) and 50 parts of α-alumina (“AES-12” manufactured by Sumitomo Chemical Co., Ltd.) were mixed, and then 12.8 parts of titanium oxide sol [“CSB” manufactured by Sakai Chemical Industry Co., Ltd. containing 39% titanium oxide] was diluted with pure water and kneaded with 100 parts of the mixture. The obtained kneaded product was extruded into a cylindrical shape having a diameter of 1.5 mmΦ, dried, and then crushed to a length of about 2 to 4 mm. The obtained molded body was fired in air at 650 to 680 ° C. for 3 hours to obtain a carrier made of a mixture of titanium oxide and α-alumina. This carrier was impregnated with a commercially available aqueous solution of ruthenium chloride hydrate, dried, and then calcined in air at 250 ° C. for 2 hours to be supported on the carrier having a ruthenium oxide content of 4% by weight. The obtained supported ruthenium oxide catalyst was obtained as Catalyst A.

(Absorption of hydrogen chloride)
A gas containing hydrogen chloride as the main component (hydrogen chloride about 80 vol%, nitrogen about 20 vol%) is created, and this is absorbed in pure water by a gas absorption bottle, and it is a poorly water-soluble component mainly containing nitrogen from the gas phase. Was removed to obtain 36% by weight of aqueous hydrochloric acid.

(Chlorine production)
The obtained hydrochloric acid water was diluted to 29.2% by weight with pure water, charged with 50 g in a tantalum autoclave (internal volume 190 ml), and charged with 10 g of powder obtained by pulverizing and classifying catalyst A to a particle size of 75 to 150 μm. And sealed with a flange with a turbine blade. The operation of blowing oxygen at 0.5 MPaG from the top of the autoclave and depressurizing was repeated 5 times, the gas phase part of the autoclave was replaced with oxygen, and oxygen was blown into the autoclave to a pressure of 3 MPaG to seal the autoclave. The stirring speed of the turbine blade was set to 600 rpm, and the body temperature of the autoclave was adjusted with an electric heater so that the internal temperature became 150 ° C., and the temperature was maintained for 1 hour. The reaction pressure at that time was 4 MPaG. Thereafter, heating of the electric furnace was stopped and the autoclave was cooled to 70 ° C. or lower. After cooling, chlorine in the gas phase portion and liquid phase portion was absorbed with 30% KI water, and the amount of generated chlorine was determined from the amount of generated iodine. The conversion rate of HCl was determined from the amount of generated chlorine according to the following formula.
Conversion rate (%) = [Amount of chlorine produced (mol) × 2 ÷ Total amount of hydrogen chloride charged (mol)] × 100
Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Example 2>
The reaction was performed under the same conditions as in Example 1 except that the concentration of hydrochloric acid water was 19.9% by weight. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Example 3>
The reaction was carried out under the same conditions as in Example 1 except that the concentration of hydrochloric acid water was 16.7% by weight. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Example 4>
The reaction was performed under the same conditions as in Example 1 except that the concentration of hydrochloric acid water was 16.7% by weight and the internal temperature of the autoclave was 200 ° C. The pressure during the reaction was 5 MPaG. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Example 5>
The reaction was carried out under the same conditions as in Example 1 except that the concentration of hydrochloric acid water was 16.7% by weight and the internal temperature of the autoclave was 250 ° C. The pressure during the reaction was 7.2 MPaG. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Example 6>
The reaction was performed under the same conditions as in Example 3 except that the amount of catalyst A charged was 1 g. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Example 7>
(Production of supported ruthenium oxide catalyst)
100 parts of titania powder [“F-1R” manufactured by Showa Titanium Co., Ltd., rutile-type titania ratio 93%] and 2 parts of organic binder [“YB-152A” manufactured by Yuken Industry Co., Ltd.] Next, 29 parts of pure water and 12.5 parts of titania sol [“CSB” manufactured by Sakai Chemical Co., Ltd., titania content 40%] were added and kneaded to obtain a mixture.

This mixture was extruded into a noodle shape having a diameter of 3.0 mmφ and cut to a length of 3 to 5 mm with a piano wire in the vicinity of the exit of the extruder. The obtained carrier was dried, heated from room temperature to 600 ° C. in air over 1.7 hours, and then calcined by holding at the same temperature for 3 hours. 900 g of the obtained fired product is impregnated with a solution prepared by dissolving 31.9 g of tetraethyl orthosilicate [“Si (OC ₂ H ₅ ) ₄ ” manufactured by Wako Pure Chemical Industries, Ltd.) in 153 g of ethanol. A white solid was obtained.

  Nitrogen containing 2.3 vol% of water was passed through this white solid at 8 L / min, and dried at 20 to 30 ° C. for 3 hours while rotating with a mixer. The obtained solid was heated from room temperature to 300 ° C. in an air atmosphere over 0.8 hours and then calcined by holding at the same temperature for 2 hours. The white content of the silica was 1.0% by weight. Thus, a titania carrier on which a solid, that is, silica was supported, was obtained.

To 90 g of the titania carrier obtained above, 2.16 g of ruthenium chloride hydrate [“RuCl ₃ · nH ₂ O” manufactured by NE Chemcat Co., Ltd., Ru content 40.0%] was added to 20.5 g of pure water. It was impregnated with an aqueous solution prepared by dissolution and dried while rotating with a mixer at 35 ° C. for 6 hours under an air flow of 2 L / min. The obtained solid was heated from room temperature to 250 ° C. over 1.3 hours under air flow, and then calcined by maintaining at the same temperature for 2 hours. As a result, a blue-gray solid having a ruthenium oxide content of 1.25% by weight, that is, a supported ruthenium oxide catalyst in which ruthenium oxide and silica were supported on a titania support, was obtained as catalyst B.

(Chlorine production)
The reaction was conducted under the same conditions as in Example 6 except that the catalyst A was changed to the catalyst B. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Comparative Example 1>
The reaction was performed under the same conditions as in Example 6 except that the catalyst A was changed to 1 g of a commercially available ruthenium oxide powder [“RuO ₂ ” manufactured by NE Chemcat Co., Ltd.]. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Comparative example 2>
The reaction was performed under the same conditions as in Example 6 except that the catalyst A was changed to 0.74 g of commercially available ruthenium chloride [“RuCl ₃ · nH ₂ O” manufactured by NE Chemcat Co., Ltd., Ru content 40.0%]. went. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Comparative Example 3>
Commercially available 6.6% RuO ₂ / anatase type TiO ₂ [“1 to 2 mm sphere” manufactured by NE Chemcat Co., Ltd.] was pulverized and classified to 75 to 150 μm, and this powder was used as catalyst C. The reaction was carried out under the same conditions as in Example 3 except that the catalyst A was changed to the catalyst C. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

<Comparative example 4>
The reaction was conducted under the same conditions as in Example 6 except that the catalyst A was changed to the catalyst C. Table 1 shows the amount of chlorine produced and the conversion rate per gram of ruthenium.

As shown in Table 1, Comparative Examples 1 to 4 did not use a supported ruthenium oxide catalyst in which ruthenium oxide was supported on a support containing rutile crystalline titanium oxide, so the conversion rate or the amount of generated chlorine was low. .
In contrast, in Examples 1 to 7, hydrogen chloride was vapor-phase catalytically oxidized using a supported ruthenium oxide catalyst in which ruthenium oxide was supported on a support containing rutile crystal form titanium oxide. It can be seen that both the rate and the amount of chlorine produced are high, and as the hydrochloric acid concentration is increased, the amount of chlorine produced increases. In particular, at 29.2% exceeding 25%, the amount of chlorine produced increases dramatically. On the other hand, as shown in Example 7, it can be seen that the supported ruthenium oxide catalyst using a rutile crystalline titanium oxide support on which silica is supported as a catalyst has a high activity per Ru.

  As mentioned above, although preferred embodiment concerning this invention was shown, it cannot be overemphasized that this invention is applicable to what was changed and improved in the range which is not limited to embodiment mentioned above and does not deviate from the summary of this invention. .

10 Absorption tower 20 Reactor

Claims (5)

  In the presence of a supported ruthenium oxide catalyst in which ruthenium oxide is supported on a support containing rutile crystal form of titanium oxide, in a water phase containing hydrochloric acid, it is salified by oxygen in the gas phase having an oxygen partial pressure of 1 to 10 MPa. A method for producing chlorine in which hydrogen undergoes gas phase catalytic oxidation.   The method for producing chlorine according to claim 1, wherein the reaction temperature is 140 to 260 ° C.   The method for producing chlorine according to claim 1 or 2, wherein the gas phase in the reactor is replaced with oxygen, and the reaction pressure is set to 1 to 10 MPa.   The said aqueous phase is the manufacturing method of chlorine in any one of Claims 1-3 obtained by supplying the gas containing hydrogen chloride and a hardly water-soluble gas to water, and isolate | separating a slightly water-soluble gas.   The hydrochloric acid concentration in the said water phase is 15 to 40 weight%, The said supported ruthenium oxide catalyst is contained in 0.1 to 50 weight% with respect to the said water phase. Of chlorine production.

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