JP2001270706A - Method for recovering sulfur from gas containing hydrogen sulfide, and sulfur recovering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recovering sulfur from a gas containing hydrogen sulfide in a high sulfur recovery without installing a reheating equipment such as inline burner and heat-exchanger and provide a sulfur-recovery apparatus. SOLUTION: The gas containing hydrogen sulfide is subjected to incomplete combustion in a reactive combustion furnace 2 under an oxygen deficient condition, sulfur element is formed by the thermal Claus reaction of the sulfur dioxide formed by combustion with the hydrogen sulfide remained after the combustion, the reaction gas is cooled in the 1st sulfur condenser 4 to recover the sulfur element, the cooled gas is brought into contact with the oxidation catalyst in the 1st reactor 6 and reheated by the oxidation reaction heat of the hydrogen sulfide and elemental sulfur, the heated gas is brought into contact with the Claus catalyst in the 1st reactor 6 to form elemental sulfur by the catalytic Claus reaction of sulfur dioxide with hydrogen sulfide and the reaction gas is cooled with the 2nd sulfur condenser 7 to recover the elemental sulfur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for recovering elemental sulfur from a gas containing hydrogen sulfide.

[0002]

2. Description of the Related Art The Claus-type sulfur recovery method uses a hydrogen sulfide-containing gas such as an acid gas as a raw material, and partially oxidizes the hydrogen sulfide contained in the raw material gas to convert the sulfur atoms of the hydrogen sulfide into elemental sulfur. This is the process of collecting. Such Claus-type sulfur recovery methods are used in refineries and natural gas processing plants.

The recovery of elemental sulfur from a hydrogen sulfide-containing gas by the Claus-type sulfur recovery method is performed, for example, using a sulfur recovery apparatus shown in FIG. 2 as follows. While supplying air from the air blower 1, the hydrogen sulfide-containing gas, which is a raw material gas, is incompletely burned in the reaction combustion furnace 2. That is, about one third of the hydrogen sulfide is burned by oxygen in the air, and sulfur dioxide is generated as in the following equation (1).

[0004]

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[0005] Combustion gas is 1000 to 14 due to combustion heat.
It reaches 00 ° C. At such a high temperature, sulfur dioxide generated by combustion reacts with hydrogen sulfide remaining without burning in the absence of a catalyst to produce elemental sulfur as shown in the following formula (2). This reaction is a so-called thermal Claus reaction.

[0006]

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The reaction gas discharged from the reaction furnace 2 is
Cooled by generating steam in the waste heat boiler 3 and the first sulfur condenser 4, elemental sulfur contained in the gas is condensed in the first sulfur condenser 4 and recovered. Elemental sulfur generated in the reaction combustion furnace 2 is 60 to 70% of the amount of sulfur that can be recovered from hydrogen sulfide in the raw material gas.
Therefore, a considerable amount of sulfur compounds (mainly, hydrogen sulfide and sulfur dioxide) still remain in the cooling gas discharged from the first sulfur condenser 4. Therefore, in order to further recover sulfur from the cooling gas, the following steps are performed. The cooling gas discharged from the first sulfur condenser 4 is reheated by the first reheater 5, and the heated gas is brought into contact with the Claus catalyst in the first reactor 21. At this time, sulfur dioxide and hydrogen sulfide remaining in the heating gas react with each other to generate elemental sulfur as shown in the following formula (3). This reaction is a so-called catalytic Claus reaction.

[0008]

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The reaction gas discharged from the first reactor 21 is cooled in the second sulfur condenser 7, and elemental sulfur contained in the reaction gas is condensed in the second sulfur condenser 7 and recovered. . To further increase sulfur recovery,
The step of the catalytic Claus reaction and the step of cooling are repeatedly performed as follows. The cooling gas discharged from the second sulfur condenser 7 is reheated in the second reheater 8, and the heated gas is then brought into contact with the Claus catalyst in the second reactor 22. The reaction gas discharged from the second reactor 22 is
Elemental sulfur that is cooled in the third sulfur condenser 10 and contained in the reaction gas is condensed and recovered in the third sulfur condenser 10. Further, the cooling gas discharged from the third sulfur condenser 10 is reheated by the third reheater 11, and then the heated gas is brought into contact with the Claus catalyst in the third reactor 23. The reaction gas discharged from the third reactor 23 is cooled in the fourth sulfur condenser 13, and elemental sulfur contained in the reaction gas is condensed in the fourth sulfur condenser 13 and collected.

[0010]

The first reheater 5 and the second reheater 5
Examples of a method of reheating the cooling gas in the reheater 8 and the third reheater 11 include an indirect heating method. The indirect heating method uses a high-temperature heat medium, for example, high-pressure steam, and uses the first reheater 5, the second reheater 8, and the third reheater 8.
This is a method in which a cooling gas is heated by a heat exchanger provided in the reheater 11. Some small sulfur recovery systems employ electric heating. This indirect heating method has the advantage of easy operation management, but has the disadvantages of large pressure loss due to the heat exchanger, energy consumption due to the use of high pressure steam and electric power, and high cost. was there.

Other reheating methods for the cooling gas include an acid gas combustion in-line burner method, a fuel gas combustion in-line burner method, a heating method using a reaction gas, and a hot gas bypass method. In the acid gas combustion inline burner system, a part of the raw acid gas (hydrogen sulfide-containing gas) is branched and burned by the inline burner, and the resulting high-temperature combustion gas is mixed with the cooling gas to heat the cooling gas. It is a method to do. Although this acid gas combustion in-line burner method has the advantage that pressure loss is small, attention must be paid to the operation management of acid gas combustion, and the sulfur recovery rate is reduced because acid gas as a raw material is bypassed. There were drawbacks such as. The fuel gas combustion in-line burner system is a system in which fuel gas supplied from the outside is burned by an in-line burner, and the obtained high-temperature combustion gas is mixed with a cooling gas to heat the cooling gas. This fuel gas combustion in-line burner method has the advantage of low pressure loss, but requires attention to the operation management of fuel gas combustion, requires fuel gas, is expensive, and increases the amount of process gas. There were drawbacks such as.

In the heating method using a reaction gas, a reaction gas discharged from a first reactor 21, a second reactor 22, and a third reactor 23 is used as a high-temperature heat source, and the reaction gas is first reheated. In this method, the cooling gas is heated by passing through a heat exchanger provided in the heater 5, the second reheater 8, and the third reheater 11. This heating method using a reaction gas has the advantage that it is not necessary to consume energy such as fuel for heating, but a large heat exchanger is required because the pressure loss due to the heat exchanger is large and the heat transfer rate is small. There were drawbacks such as.

In the hot gas bypass system, the reaction combustion furnace 2
From the first reactor 21 and the second reactor 22 by heating the cooling gas by branching and mixing the combustion gas discharged from the exhaust gas or the outlet gas discharged from the waste heat boiler 3 with the cooling gas. In this method, a part of the discharged reactant gas is branched and mixed with the coolant gas by bypassing the second sulfur condenser 7 and the third sulfur condenser 10, respectively. Although this hot gas bypass method has the advantage of not requiring equipment for reheating, the gas containing a large amount of elemental sulfur, hydrogen sulfide and sulfur dioxide is bypassed, so the sulfur recovery rate is reduced. However, there is a drawback that is reduced. In addition, when using the combustion gas discharged from the reaction combustion furnace 2, it is difficult to select a flow control valve for branching because the temperature of the combustion gas is 1000 ° C. or higher. On the other hand, when the combustion gas discharged from the waste heat boiler 3 is used, since the temperature of the combustion gas is low, the amount of gas required for heating the cooling gas increases, and the sulfur recovery rate further decreases. There was a disadvantage.

Therefore, an object of the present invention is to provide a reheating device such as an in-line burner or a heat exchanger without installing reheating devices.
An object of the present invention is to provide a method and an apparatus for recovering sulfur from a hydrogen sulfide-containing gas, which can achieve a high sulfur recovery rate.

[0015]

That is, the method for recovering sulfur from a hydrogen sulfide-containing gas according to the present invention comprises incomplete combustion of a hydrogen sulfide-containing gas under oxygen-deficient conditions, and elemental sulfur by a thermal Claus reaction. A thermal Claus reaction step of producing a reaction gas containing sulfur, a sulfur recovery step of cooling a reaction gas containing elemental sulfur to recover elemental sulfur, and cooling of heating a cooling gas after the sulfur recovery step A gas heating step and contacting the heated gas with the Claus catalyst to cause a reactive Clause reaction between sulfur dioxide and hydrogen sulfide remaining in the gas in the presence of the Claus catalyst to produce a reactive gas containing elemental sulfur A catalytic Claus reaction step, wherein the cooling gas heating step comprises mixing air with the cooling gas after recovering elemental sulfur. Both hydrogen sulphide and / or elemental sulfur remaining in the cooling gas is an oxidation reaction in the presence of an oxidation catalyst, characterized in that it is a step of heating the cooled gas by the reaction heat. In the method for recovering sulfur from a hydrogen sulfide-containing gas of the present invention, a sulfur recovery step of recovering elemental sulfur by cooling a reaction gas containing elemental sulfur, and mixing air with the cooling gas after the recovery. In addition, a cooling gas heating step of oxidizing hydrogen sulfide and / or elemental sulfur remaining in the cooling gas in the presence of the oxidation catalyst and heating the cooling gas by the reaction heat, and bringing the heated gas into contact with the Claus catalyst In this way, each step of the catalytic Claus reaction step of producing a reactive gas containing elemental sulfur by subjecting the sulfur dioxide and hydrogen sulfide remaining in the gas to a catalytic Claus reaction in the presence of a Claus catalyst is repeated at least once. Is preferred.

Further, the sulfur recovery apparatus of the present invention is a thermal Claus reactor for incompletely burning a hydrogen sulfide-containing gas under oxygen-deficient conditions and for generating a reaction gas containing elemental sulfur by a thermal Claus reaction. And a sulfur condensing device for cooling the reaction gas containing elemental sulfur to recover elemental sulfur, and mixing air with the cooling gas from the sulfur condensing device to remove hydrogen sulfide and / or element remaining in the cooling gas. An oxidation catalyst layer for oxidizing and reacting elemental sulfur, and a Claus catalyst layer for producing a reaction gas containing elemental sulfur by reacting sulfur dioxide and hydrogen sulfide in the reaction gas at a subsequent stage of the oxidation catalyst layer. And a contact Claus reactor. Further, in the sulfur recovery apparatus of the present invention, a sulfur condensing apparatus for recovering elemental sulfur by cooling a reaction gas containing elemental sulfur, and mixing air with the cooling gas from the sulfur condensing apparatus, An oxidation catalyst layer for oxidizing hydrogen sulfide and / or elemental sulfur remaining in the reaction gas, and reacting sulfur dioxide and hydrogen sulfide in the reaction gas with the oxidation gas at a stage subsequent to the oxidation catalyst layer to form a reaction gas containing elemental sulfur. It is preferable to have at least one combination with a catalytic Claus reactor having a Claus catalyst layer to be formed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a diagram showing an example of the sulfur recovery device of the present invention.
This sulfur recovery device incompletely burns a hydrogen sulfide-containing gas in the presence of oxygen in the air supplied from the air blower 1 and an air blower 1 for supplying air into the sulfur recovery device, A reaction combustion furnace 2 (thermal Claus reaction apparatus) for causing a thermal Claus reaction between sulfur and hydrogen sulfide; a waste heat boiler 3 for cooling a reaction gas discharged from the reaction combustion furnace 2; First sulfur condenser 4 (sulfur condenser) for further cooling the reaction gas discharged from heat boiler 3 and recovering elemental sulfur
Then, the cooling gas discharged from the first sulfur condenser 4 is heated by the reaction heat generated by the oxidation reaction of hydrogen sulfide and / or elemental sulfur, and the sulfur dioxide and hydrogen sulfide remaining in the heated gas are brought into contact with each other. First reactor 6 for performing a Claus reaction
(A contact Claus reactor), a second sulfur condenser 7 (sulfur condenser) for cooling the reaction gas discharged from the first reactor 6 and recovering elemental sulfur, and a second sulfur condenser. The second reaction for heating the cooling gas discharged from 7 with the reaction heat generated by the oxidation reaction of hydrogen sulfide and / or elemental sulfur and causing the sulfur dioxide and hydrogen sulfide remaining in the heated gas to undergo a catalytic Clause reaction A reactor 9 (contact Claus reactor), a third sulfur condenser 10 (sulfur condenser) for cooling the reaction gas discharged from the second reactor 9 and recovering elemental sulfur, The cooling gas discharged from the condenser 10 is heated by reaction heat generated by the oxidation reaction of hydrogen sulfide and / or elemental sulfur, and the sulfur dioxide and hydrogen sulfide remaining in the heated gas are subjected to a contact Clause reaction to form a contact Clause reaction. 3 reactors 12 Contact Claus reactor), a fourth sulfur condenser 13 for the reaction gas discharged from the third reactor 12 to recover cooling to elemental sulfur (sulfur condenser)
And is schematically configured.

The first reactor 6, the second reactor 9 and the third reactor 12 are cooled from the air supplied from the air blower 1 and cooled in the presence of oxygen in the air heated by the air heater 14. An oxidation catalyst layer for oxidizing hydrogen sulfide and / or elemental sulfur in the gas, and a Claus catalyst layer for producing elemental sulfur by reacting sulfur dioxide and hydrogen sulfide remaining in a heated gas from the oxidation catalyst layer And is provided.

As the oxidation catalyst, a low-temperature active W is used.
_{-TiO 2, Mo-TiO 2,} V / W-TiO 2, iron-based catalyst can be used. Among them, it is preferable to select an iron-based catalyst capable of mainly causing the oxidation reaction of the formula (5) described later. As the Claus catalyst, alumina or titania used in a conventional method can be used. In the illustrated example, the oxidation catalyst and the Claus catalyst are housed in the same reactor. However, in the sulfur recovery device of the present invention, a reactor housing the oxidation catalyst and a reactor housing the Claus catalyst are separately provided. You may. However, since the amount of the oxidation catalyst is smaller than the amount of the Claus catalyst, it is possible to fill the oxidation catalyst on the Claus catalyst layer. Therefore, it is not necessary to newly provide a reactor for accommodating the oxidation catalyst.

Next, a method for recovering sulfur from a hydrogen sulfide-containing gas according to the present invention will be described. While supplying air from the air blower 1, about one third of the hydrogen sulfide of the hydrogen sulfide-containing gas is burned in the reaction combustion furnace 2 by oxygen in the air,
The sulfur dioxide generated by the combustion and the hydrogen sulfide remaining without the combustion undergo a thermal Claus reaction at high temperature in the absence of a catalyst to produce elemental sulfur. The reaction gas discharged from the reaction combustion furnace 2 is cooled by generating steam in the waste heat boiler 3 and the first sulfur condenser 4, and elemental sulfur contained in the reaction gas is converted into the first sulfur condenser 4. Condensed and recovered.

The cooling gas discharged from the first sulfur condenser 4 is supplied from the air blower 1 and supplied to the air heater 14.
After being mixed with the air heated in the above, the mixture is brought into contact with the oxidation catalyst layer in the first reactor 6. Due to the contact at this time, hydrogen sulfide and elemental sulfur in the cooling gas are converted into the following formula (4)
It is oxidized according to the reaction of (6).

[0022]

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Since these oxidation reactions are exothermic,
The temperature of the gas is raised to the temperature required for the catalytic Claus reaction and reheating of the gas is achieved. Next, the heated gas is brought into contact with the Claus catalyst layer in the first reactor 6. At this time, the sulfur dioxide remaining in the heating gas and the hydrogen sulfide undergo a catalytic Claus reaction to generate elemental sulfur. The reaction gas discharged from the first reactor 6 is cooled in the second sulfur condenser 7, and elemental sulfur contained in the reaction gas is condensed in the second sulfur condenser 7 and recovered.

In order to further increase the sulfur recovery, the step of the catalytic Claus reaction and the step of cooling are repeated as follows. The cooling gas discharged from the second sulfur condenser 7 is supplied from the air blower 1 and comes into contact with the oxidation catalyst layer in the second reactor 9 in the presence of oxygen in the air heated by the air heater 14. The reheated gas is then brought into contact with the Claus catalyst layer in the second reactor 9. The reaction gas discharged from the second reactor 9 is cooled in the third sulfur condenser 10, and elemental sulfur contained in the reaction gas is condensed in the third sulfur condenser 10 and collected. Further, the cooling gas discharged from the third sulfur condenser 10 is supplied from the air blower 1,
And it is reheated by contacting the oxidation catalyst layer in the third reactor 12 in the presence of oxygen in the air heated by the air heater 14, and then this heated gas is removed by the Claus catalyst in the third reactor 12. The layers are brought into contact. The reaction gas discharged from the third reactor 12 is cooled in the fourth sulfur condenser 13, and elemental sulfur contained in the reaction gas is condensed in the fourth sulfur condenser 13 and recovered. The cooling gas discharged from the third sulfur condenser 10 is used as a tail gas.
It is exhausted outside the sulfur recovery device.

The reaction temperature in the reaction furnace 2 is usually
1000-1400 ° C. Although air is supplied to the reaction combustion furnace 2 in the illustrated example, oxygen gas may be supplied instead of air. The air mixed with the cooling gas is preferably heated to 200 ° C. or higher by the air heater 14. By setting the air to 200 ° C. or higher, it is possible to prevent the condensation of sulfur in the oxidation catalyst layer. When supplying oxygen gas to the reaction combustion furnace 2, oxygen gas may be mixed with cooling gas instead of air.

The temperature of the cooling gas brought into contact with the oxidation catalyst layer is preferably from 160 to 230 ° C. If the sulfur recovery device operates at low load or if the temperature of the cooling gas needs to be increased due to a decrease in the activity of the oxidation catalyst, a part of the combustion gas at the outlet of the waste heat boiler 3 is removed as necessary. By branching to a bypass 15 connected in the middle of each flow path between the sulfur condenser and the reactor and mixing with a cooling gas,
The cooling gas may be heated by the heat of the combustion gas. In addition, since it is not necessary to heat to the temperature required for the catalytic Claus reaction to proceed as in the conventional hot gas bypass method, a large amount of combustion gas is not required unlike the hot gas bypass method, and the sulfur recovery rate is reduced. It does not lower.

The GHSV (space velocity) of the gas in the oxidation catalyst layer is from 2000 to 20000 l / hr, preferably from 5000 to 10000 l / hr. The reaction pressure in the oxidation catalyst layer is determined by the operating pressure of the sulfur recovery device, and is usually 5 to 50 kPaG. The temperature of the heated gas brought into contact with the contact Claus catalyst layer is usually 1
90-230 ° C. The temperature of the heating gas can be adjusted by the amount of air mixed with the cooling gas brought into contact with the oxidation catalyst layer.

In the illustrated example, the reheating of the cooling gas is performed as follows.
Although all the reactors are provided with an oxidation catalyst layer, it is not always necessary to reheat all the cooling gas in the oxidation catalyst layer. For example, reheating of the cooling gas discharged from the first sulfur condenser 4 and the second sulfur condenser 7 is performed in the first reactor 6.
The reheating of the cooling gas discharged from the third sulfur condenser 10 may be performed by an indirect heating method using high-pressure steam.

In such a sulfur recovery method and a sulfur recovery apparatus, the cooling gas is supplied to the first reactor 6 in the presence of oxygen.
The cooling gas is brought into contact with the oxidation catalyst in the second reactor 9 and the third reactor 12 and reheated by the reaction heat generated when oxidizing hydrogen sulfide and / or elemental sulfur remaining in the cooling gas. Therefore, a high sulfur recovery rate can be achieved without installing reheating equipment such as an inline burner and a heat exchanger. Further, since there is no need to install a reheating device, the sulfur recovery device can be made compact and the cost of the device itself can be reduced. Further, since no heat exchanger is provided, pressure loss can be reduced. Further, there is no need to consume energy such as fuel for reheating, so that operation costs can be reduced.

[0030]

Embodiments are described below. As a source gas (hydrogen sulfide-containing gas), the following acid gas (device capacity: 123)
Tons of sulfur / day). Pressure: 73KPaG, Temperature: 66 ° C. _{Composition: H 2 S 80.09mol% CH 4} 0.07mol% H 2 O 10.23mol% H 2 0.14mol% NH 3 9.30mol% CO 2 0.17mol% Also, The following was used as combustion air. pressure:
73KPaG, temperature 80 ° C. (provided that the air oxidation reaction was heated to 230 ° C. in air heater 14.) _{Composition: N 2 71.8mol% O 2 19.3mol} % H 2 O 8.9mol%

Example 1 The effect of the present invention was verified by a process simulator in accordance with a flow scheme of a sulfur recovery apparatus as shown in FIG. Table 1 shows the operating conditions of the sulfur recovery device and the sulfur recovery rate.

Comparative Example 1 As shown in FIG. 2, the process was verified by a process simulator in accordance with a flow scheme of a sulfur recovery apparatus employing an indirect heating method using high-pressure steam. Table 1 shows the operating conditions of the sulfur recovery device and the sulfur recovery rate.

[0033]

[Table 1]

As is clear from the results in Table 1, the sulfur recovery method using the sulfur recovery apparatus of the embodiment uses the sulfur recovery apparatus of the comparative example without installing a reheating device such as a heat exchanger. It can be seen that a high sulfur recovery rate equivalent to the conventional sulfur recovery method was achieved.

[0035]

As described above, according to the method for recovering sulfur from a hydrogen sulfide-containing gas of the present invention, in the Claus type sulfur recovery method, air is mixed with the cooling gas after recovering elemental sulfur. Since the hydrogen sulfide and / or elemental sulfur remaining in the cooling gas undergoes an oxidation reaction in the presence of an oxidation catalyst, and the heat of the reaction heats the cooling gas, reheating devices such as in-line burners and heat exchangers are required. High sulfur recovery can be achieved without installation.

Further, the sulfur recovery apparatus of the present invention is a thermal Claus reaction apparatus which incompletely burns a hydrogen sulfide-containing gas under oxygen-deficient conditions and generates a reaction gas containing elemental sulfur by a thermal Claus reaction. And a sulfur condensing device for cooling the reaction gas containing elemental sulfur to recover elemental sulfur, and mixing air with the cooling gas from the sulfur condensing device to remove hydrogen sulfide and / or element remaining in the cooling gas. An oxidation catalyst layer for oxidizing and reacting elemental sulfur, and a Claus catalyst layer for producing a reaction gas containing elemental sulfur by reacting sulfur dioxide and hydrogen sulfide in the reaction gas at a subsequent stage of the oxidation catalyst layer. Since it has a contact Claus reaction apparatus, a high sulfur recovery rate can be achieved without installing reheating equipment such as an inline burner and a heat exchanger.

Further, since it is not necessary to install a reheating device, the sulfur recovery device can be made compact, and the cost of the device itself can be reduced. Further, since no heat exchanger is provided, pressure loss can be reduced. Further, there is no need to consume energy such as fuel for reheating, so that operation costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a sulfur recovery device of the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a conventional sulfur recovery device.

[Explanation of symbols]

 2 Reaction combustion furnace (thermal Claus reactor) 4 First sulfur condenser (sulfur condenser) 6 First reactor (contact Claus reactor) 7 Second sulfur condenser (sulfur condenser) 9 Second reactor ( Catalytic Claus Reactor) 10 Third Sulfur Condenser (Sulfur Condenser) 12 Third Reactor (Contact Claus Reactor) 13 Fourth Sulfur Condenser (Sulfur Condenser)

Continued on front page F term (reference) 4D048 AA03 AB01 AC06 BA03Y BA07Y BA23Y BA26Y BA27Y BA36Y BA41Y CA07 CC32 CC46 CC50 CC54 CD08 DA06

Claims (4)

[Claims] 1. A thermal Claus reaction step in which a hydrogen sulfide-containing gas is incompletely burned under oxygen-deficient conditions and a thermal Claus reaction produces a reaction gas containing elemental sulfur; A sulfur recovery step of cooling the reaction gas to recover elemental sulfur, a cooling gas heating step of heating the cooling gas after the sulfur recovery step, and contacting the heated gas with a Claus catalyst to form a gas. A catalytic Clause reaction step of subjecting the remaining sulfur dioxide and hydrogen sulfide to a catalytic Clause reaction in the presence of a Clause catalyst to generate a reactive gas containing elemental sulfur. The heating step mixes air with the cooling gas after recovering the elemental sulfur and removes hydrogen sulfide and / or elemental sulfur remaining in the cooling gas from the oxidation catalyst. By oxidation reaction standing under sulfur recovery method of the hydrogen sulfide-containing gas, characterized in that the step of heating the cooled gas by the reaction heat. 2. A sulfur recovery step of recovering elemental sulfur by cooling a reaction gas containing elemental sulfur, mixing air with the recovered cooling gas and removing hydrogen sulfide and / or element remaining in the cooling gas. Gas-oxidation reaction in the presence of an oxidation catalyst in the presence of an oxidation catalyst and heating the cooling gas by the heat of the reaction, and sulfur dioxide and hydrogen sulfide remaining in the gas by bringing the heated gas into contact with the Claus catalyst 2. The sulfidation process according to claim 1, wherein each step of the contact Claus reaction step of producing a reaction gas containing elemental sulfur by causing a contact Claus reaction in the presence of a Claus catalyst is repeated at least once. A method for recovering sulfur from a hydrogen-containing gas. 3. A thermal Claus reactor which incompletely burns a hydrogen sulfide-containing gas under oxygen-deficient conditions and generates a reactive gas containing elemental sulfur by a thermal Claus reaction, and wherein the elemental sulfur is contained. A sulfur condensing device that cools the reaction gas to recover elemental sulfur, and an oxidation catalyst that mixes air with the cooling gas from the sulfur condensing device and oxidizes hydrogen sulfide and / or elemental sulfur remaining in the cooling gas. A catalytic reactor having a catalytic reaction layer comprising, at the subsequent stage of the oxidation catalyst layer, a sulfur dioxide in the reaction gas and hydrogen sulfide in the reaction gas to produce a reaction gas containing elemental sulfur. A sulfur recovery device characterized by the above-mentioned. 4. A sulfur condensing device for cooling a reaction gas containing elemental sulfur to recover elemental sulfur, mixing air with a cooling gas from the sulfur condensing device, and removing hydrogen sulfide remaining in the cooling gas and An oxidation catalyst layer for oxidizing elemental sulfur and / or a Claus catalyst layer for reacting sulfur dioxide and hydrogen sulfide in a reaction gas to form a reaction gas containing elemental sulfur at a subsequent stage of the oxidation catalyst layer. 4. The sulfur recovery apparatus according to claim 3, wherein at least one set is provided in combination with a catalytic Claus reactor equipped with: