Regeneration method of iron oxide-based catalyst for preparing sulfur by oxidizing hydrogen sulfide and application of iron oxide-based catalyst

Abstract

The invention relates to the technical field of sulfur recovery, in particular to a regeneration method of an iron oxide-based catalyst for preparing sulfur by oxidizing hydrogen sulfide and application of the iron oxide-based catalyst. The method comprises the following steps: introducing an oxygen raw material and a hydrogen sulfide raw material, and contacting with a to-be-regenerated catalyst in a reactor for regeneration; the volume content of oxygen in the gas-phase product flow after contact regeneration is at least 5%. Efficient regeneration of the catalyst can be achieved, the activity of the catalyst is recovered to 99% or above, the service life is prolonged, and the regeneration process is simple, environmentally friendly and free of secondary pollution. The catalyst activity can be effectively recovered, the catalyst replacement frequency of the device can be effectively reduced, the service life of the catalyst can be effectively prolonged, the device can realize normal production without replacing the catalyst, and remarkable economic benefits and social benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of sulfur recovery, and relates to a regeneration method for an iron oxide-based catalyst for preparing sulfur by oxidizing hydrogen sulfide and application thereof. Background Art

[0002] In the sulfur recovery process, direct oxidation process has attracted wide attention due to its simple operation and high sulfur recovery rate. It uses a special catalyst to directly catalytically oxidize H2S in the process gas into elemental sulfur. This process can treat both lean acid gas and conventional Claus tail gas.

[0003] The Super Claus process and the EuroClaus process are currently the most successful and widely used direct oxidation processes. The Super Claus sulfur recovery process is an extension of the traditional Claus process. On the basis of the conventional Claus process, a selective catalytic oxidation reaction section is added, and an advanced H2S selective oxidation catalyst is used to selectively oxidize the residual H2S in the process gas from the last Claus section into elemental sulfur. Based on this concept, the Claus part of the Super Claus process no longer controls H2S:SO2=2:1, but controls the H2S concentration at the outlet of the last Claus reactor. The reaction equation is: H2S+1 / 2O2→S+H2O. Since the reaction is a thermodynamically complete reaction, a higher sulfur recovery rate can be obtained, which can reach more than 99.0%.

[0004] US2620313A discloses a regeneration method for a fluidized iron oxide catalyst, which is mainly used for the regeneration of iron-based catalysts for the synthesis of liquid hydrocarbons from CO and H2. The regeneration is to burn the carbon deposits in the iron-based catalyst to achieve regeneration. Only the carbon is burned. Over-oxidation of the iron-based catalyst is not desired, otherwise it will affect the catalytic activity.

[0005] JPS5439391A discloses a high-temperature gas refining catalyst regeneration method, which uses air diluted with water vapor to oxidize iron sulfide to produce iron oxide to achieve the purpose of regeneration. The main reaction is the reaction of ferrous sulfide and water to produce iron oxide. Summary of the invention

[0006] The purpose of the present invention is to overcome the problem of low regeneration efficiency of iron oxide-based catalysts for oxidizing H2S to prepare sulfur in the prior art, and to provide a regeneration method and application of iron oxide-based catalysts for oxidizing hydrogen sulfide to prepare sulfur. The regeneration method can ensure the service life of the catalyst, improve the sulfur recovery rate of the device, and reduce the frequency of catalyst replacement in the device.

[0007] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a method for regenerating an iron oxide-based catalyst for preparing sulfur by oxidizing hydrogen sulfide, the method comprising: introducing an oxygen raw material and a hydrogen sulfide raw material to contact and regenerate the catalyst to be regenerated in a reactor; after the contact regeneration, the volume content of oxygen in the gas phase product flow is at least 5%.

[0008] The second aspect of the present invention provides an application of the regeneration method described in the first aspect of the present invention in the selective oxidation of hydrogen sulfide to produce sulfur in the Super Claus process and / or the Euro Claus process.

[0009] Through the above technical solution, the present invention has the following beneficial effects:

[0010] The present invention can realize efficient regeneration of the catalyst, restore the catalyst activity to more than 99%, extend the service life, and the regeneration process is simple, environmentally friendly, and no secondary pollution is generated. The catalyst activity can be effectively restored, the frequency of device replacement can be effectively reduced, the service life of the catalyst can be effectively extended, and the device can achieve normal production without replacing the catalyst, which has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The invention discloses a preferred regeneration device and flow chart for oxidizing H2S to prepare a sulfur catalyst in the process of selectively oxidizing hydrogen sulfide to prepare sulfur in the Super Claus process and the Euro Claus process.

[0012] Description of Reference Numerals

[0013] 1. Reactor; 4. Primary heater;

[0014] 2. Waste heat boiler; 5. Primary reactor;

[0015] 3. Primary sulfur condenser; 6. Secondary sulfur condenser;

[0016] 7. Secondary heater; 13. Fourth-stage heater;

[0017] 8. Secondary reactor; 14. Selective oxidation reactor;

[0018] 9. Three-stage sulfur condenser; 15. Five-stage sulfur condenser;

[0019] 10. Three-stage heater; 16. Incinerator;

[0020] 11. Three-stage reactor; 17. Alkali washing tower;

[0021] 12. Four-stage sulfur condenser; 18. Chimney. DETAILED DESCRIPTION

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0023] The present invention provides a regeneration method for an iron oxide-based catalyst for preparing sulfur by oxidizing hydrogen sulfide. The method comprises: introducing oxygen raw material and hydrogen sulfide raw material to contact and regenerate the catalyst to be regenerated in a reactor; after the contact regeneration, the volume content of oxygen in the gas phase product flow is at least 5%.

[0024] The regeneration of the catalyst of the present invention is mainly applicable to the situation where the catalyst for preparing sulfur by oxidizing H2S is sulfided due to insufficient oxygen, and loses its catalytic activity, resulting in excessively high concentrations of SO2 and H2S in the tail gas. By adopting the above method of the present invention, the regeneration efficiency of the catalyst can be significantly improved.

[0025] In the present invention, the contact regeneration is under oxygen-rich conditions, and the oxygen-rich conditions refer to that the volume content of oxygen in the gas phase product flow after contact regeneration is in a higher range. According to a preferred embodiment of the present invention, the volume content of oxygen in the gas phase product flow after contact regeneration is 5-21%; for example, it can be 5%, 8%, 10%, 13%, 15%, 18%, 21%.

[0026] According to a preferred embodiment of the present invention, the volume content of oxygen in the gas phase product stream after the contact regeneration is 8-15%. By adopting the above preferred solution, the regeneration efficiency of the sulfur catalyst prepared by oxidizing H2S can be further improved.

[0027] In the present invention, the contact regeneration is carried out in a relatively low concentration of hydrogen sulfide. A high concentration of hydrogen sulfide will cause the bed temperature of the selective oxidation reactor to be too high, affecting the regeneration effect. According to a preferred embodiment of the present invention, the concentration of hydrogen sulfide in the contact regeneration system is 0.2-1%, preferably 0.3-0.6%, by volume. By adopting the above preferred scheme, the regeneration efficiency of the sulfur catalyst prepared by oxidizing H2S can be further improved.

[0028] According to a preferred embodiment of the present invention, the hydrogen sulfide raw material does not contain ammonia and sulfur dioxide.

[0029] According to a preferred embodiment of the present invention, the volume content of oxygen in the oxygen raw material is not less than 10%.

[0030] When the main active component of the iron oxide-based catalyst for oxidizing H2S to prepare sulfur is Fe2O3, there is insufficient oxygen in the reactor, which causes Fe2O3 to react with H2S to generate FeS, and FeS promotes the reaction of sulfur with water to generate H2S and SO2, resulting in excessively high concentrations of SO2 and H2S in the tail gas and increased SO2 emissions in the flue gas. The regeneration method of the present invention can solve the above problems and achieve efficient regeneration of the catalyst. The relevant reactions are:

[0031] FeS is the active agent of the Claus reverse reaction: 3S+2H2O→2H2S+SO2 (1)

[0032] The regeneration process of the present invention uses acidic gas and air to regenerate the selective oxidation catalyst, FeS reacts with O2 to generate Fe2(SO4)3 and Fe2O3, and in the presence of H2S, H2S reacts with Fe2(SO4)3 to generate FeSO4, and FeSO4 continues to react with H2S to generate FeS, which is oxidized by oxygen to Fe2O3.

[0033] 3FeS + 6.75O2 →Fe2(SO4)3+0.5Fe2O3 (2)

[0034] Fe2(SO4)3+H2S→2FeSO4+H2SO4+S (3)

[0035] 2FeSO4+8H2S→8FeS+8S+8H2O (4)

[0036] After reaction (4), reaction (2) continues to occur, and the cycle repeats until FeS is converted into Fe2O3 and activation is completed.

[0037] According to a preferred embodiment of the present invention, the contact regeneration conditions include: the reactor inlet temperature is 170-240°C, preferably 180-230°C.

[0038] According to a preferred embodiment of the present invention, the contact regeneration conditions include: the catalyst bed temperature is not greater than 280°C, preferably 200-240°C.

[0039] According to a preferred embodiment of the present invention, the contact regeneration conditions include: the reaction time is 8-72h, preferably 24-60h.

[0040] By adopting the aforementioned preferred contact conditions, the regeneration efficiency of the catalyst for preparing sulfur by oxidizing H2S can be further improved.

[0041] According to a preferred embodiment of the present invention, before the oxygen feedstock and the hydrogen sulfide feedstock are introduced, the reactor inlet temperature is controlled to be 170-200°C.

[0042] According to a preferred embodiment of the present invention, before the oxygen raw material and the hydrogen sulfide raw material are introduced, the reactor inlet temperature is controlled to be 180-190° C. By adopting the above preferred scheme, the regeneration efficiency of the sulfur catalyst for oxidizing H2S can be further improved.

[0043] According to a preferred embodiment of the present invention, after the oxygen feedstock and the hydrogen sulfide feedstock are introduced, the reaction inlet temperature is increased at 10-20° C. / h to 170-240° C., preferably 180-230° C. By adopting the above preferred scheme, the regeneration efficiency of the catalyst for preparing sulfur by oxidizing H2S can be further improved.

[0044] According to a preferred embodiment of the present invention, the gas phase product stream after contact regeneration comprises oxygen, hydrogen sulfide and optionally an inert gas, and preferably the inert gas is selected from at least one of nitrogen, argon and helium.

[0045] According to a preferred embodiment of the present invention, the regenerated tail gas is directly fed into an incinerator for treatment and / or fed into a reactor as an oxygen raw material, preferably directly fed into an incinerator for treatment.

[0046] The second aspect of the present invention provides an application of the regeneration method in the selective oxidation of hydrogen sulfide to produce sulfur in the Super Claus process and the Euro Claus process.

[0047] According to a preferred embodiment of the present invention, the regeneration temperature of the catalyst for preparing sulfur by oxidizing H2S is 5-20°C higher than the operating temperature.

[0048] According to a preferred embodiment of the present invention, the operating temperature of the catalyst for preparing sulfur by oxidizing H2S is 180-230°C, preferably 200-220°C.

[0049] The present invention provides a regeneration method for a catalyst for preparing sulfur by oxidizing H2S in a process for preparing sulfur by hydrogen sulfide selective oxidation in a Super Claus process and / or a EuroClaus process. The method comprises the following steps: in the process for preparing sulfur by oxidizing H2S in a selective oxidation reactor, when regenerating the catalyst for preparing sulfur by oxidizing H2S in the selective oxidation reactor, a condensate stream originally introduced into the selective oxidation reactor is sent for incineration treatment, an oxygen raw material and a hydrogen sulfide raw material are introduced into the selective oxidation reactor, and the oxygen raw material and the hydrogen sulfide raw material are contacted and regenerated with the catalyst to be regenerated in the selective oxidation reactor; and the oxygen volume content in the gas phase product stream after the contact regeneration is at least 5%.

[0050] like Figure 1As shown, a regeneration device for oxidizing H2S to prepare a sulfur catalyst in the process of sulfur production by hydrogen sulfide selective oxidation in the Super Claus process and / or the EuroClaus process, the device comprises: a parallel selective oxidation reactor 14 in the Super Claus process and / or the EuroClaus process is provided with a cross-line 1 for sending the condensate flow originally introduced into the selective oxidation reactor to incineration treatment; the selective oxidation reactor 14 is provided with a hydrogen sulfide raw material (regeneration acid gas) and an oxygen raw material (regeneration air) feed pipeline, and a four-stage heater 13 and a valve are arranged on the pipeline.

[0051] The regeneration process includes:

[0052] (1) gradually lowering the inlet temperature of the selective oxidation reactor 14 to 170-200° C., preferably 180-190° C.;

[0053] (2) After the Claus reaction raw materials (acid gas and air) undergo four-stage Claus reactions, the tail gas at the outlet of the four-stage sulfur condenser 12 is introduced into the incinerator 16 for treatment through the cross-line 1, and then passed into the alkali washing tower for washing, and then the waste gas is discharged from the chimney 18;

[0054] (3) hydrogen sulfide raw material and oxygen raw material are introduced into the front of the four-stage heater 13 for regeneration, and the H2S concentration in the control system is 0.2%-1%, preferably 0.3-0.6%, so that the selective oxidation reactor operates in an oxygen-rich state (the oxygen volume content in the gas phase product stream after regeneration is at least 5%, preferably 5-21%, and more preferably 8-15%) for regeneration;

[0055] (4) gradually increasing the reaction temperature by 10-20°C / h to regenerate the catalyst until the inlet temperature reaches 170-240°C, preferably 180-230°C. The regeneration process takes 8-72 hours, preferably 24-60 hours;

[0056] (5) After regeneration is completed, gradually reduce the reactor catalyst bed temperature to 180-230°C, preferably 200-220°C;

[0057] (6) closing the crossover line 1 of the tail gas from the outlet of the fourth-stage sulfur condenser entering the incinerator, and introducing the tail gas from the outlet of the fourth-stage sulfur condenser into the selective oxidation reactor;

[0058] (7) Turn off the hydrogen sulfide feed and oxygen feed before the fourth-stage heater;

[0059] (8) Put into normal production, maintain the oxygen content in the outlet gas of the selective oxidation reactor at 0.5%-2% (V), and operate under peroxo conditions.

[0060] The following will be done by adopting Figure 1The present invention is described in detail by way of the embodiments of the scheme. In the following embodiments, the H2S conversion rate and the selectivity parameters of the generated sulfur are measured by a sulfur microreactor evaluation device; the raw materials are all commercially available products.

[0061] Example 1

[0062] A 20,000 ton / year sulfur recovery unit uses a selective oxidation process to recover sulfur. One year after the start of operation, the selective oxidation reactor was calibrated and it was found that the H2S conversion rate and the selectivity of sulfur generation in the selective oxidation reactor were greatly reduced. It was judged that the catalyst was seriously deactivated. After checking the historical records, no temperature runaway phenomenon was found in the bed. It was initially judged that the catalyst was in an oxygen-deficient state, so the catalyst needed to be regenerated. The regeneration steps are as follows:

[0063] (1) gradually reducing the inlet temperature of the selective oxidation reactor to 180°C;

[0064] (2) introducing the tail gas from the outlet of the fourth-stage sulfur condenser into an incinerator for treatment via crossover line 1;

[0065] (3) Regeneration acid gas (hydrogen sulfide raw material without ammonia and sulfur dioxide, the same below) and air are introduced before the fourth-stage heater for regeneration, and the H2S concentration is controlled at 0.4%. The rest is all air, so that the selective oxidation reactor is operated in an oxygen-rich state for regeneration, and the oxygen volume content in the regenerated gas phase product is 8%;

[0066] (4) The catalyst was regenerated by gradually increasing the reaction temperature at 15°C / h until the inlet temperature reached 230°C and the catalyst bed temperature reached 240°C for 24 hours;

[0067] (5) After regeneration is completed, the reactor catalyst bed temperature is gradually reduced to 220°C;

[0068] (6) closing the crossover line 1 of the tail gas from the outlet of the fourth-stage sulfur condenser entering the incinerator, and introducing the tail gas from the outlet of the fourth-stage sulfur condenser into the selective oxidation reactor;

[0069] (7) Regenerate acid gas and air before shutting down the fourth-stage heater;

[0070] (8) Put into normal production, maintain the oxygen content in the outlet gas of the selective oxidation reactor at 0.5% (V), and operate under peroxo conditions.

[0071] After activation, normal operating conditions were restored, with H2S conversion above 95% and sulfur selectivity >90%, which were equivalent to the activity of fresh catalysts, indicating that the regeneration effect was good.

[0072] Example 2

[0073] A 10,000 ton / year sulfur recovery unit uses a selective oxidation process to recover sulfur. Three years after it was put into operation, the selective oxidation reactor was calibrated and it was found that the H2S conversion rate and the selectivity of sulfur generation in the selective oxidation reactor were greatly reduced. It was judged that the catalyst was seriously deactivated. After checking the historical records, no temperature runaway phenomenon was found in the bed. It was initially judged that the catalyst was in an oxygen-deficient state, so the catalyst needed to be regenerated. The regeneration steps are as follows:

[0074] (1) gradually reducing the inlet temperature of the selective oxidation reactor to 190°C;

[0075] (2) introducing the tail gas from the outlet of the fourth-stage sulfur condenser into an incinerator for treatment via crossover line 1;

[0076] (3) Regeneration acid gas and oxygen-containing raw material (mixed gas of oxygen and helium) are introduced before the fourth-stage heater for regeneration, and the H2S concentration is controlled at 0.6%, so that the selective oxidation reactor operates in an oxygen-rich state for regeneration, and the oxygen volume content in the regenerated gas phase product is 15%;

[0077] (4) The catalyst was regenerated by gradually increasing the reaction temperature at 10°C / h until the inlet temperature reached 220°C and the catalyst bed temperature reached 235°C for 60 hours;

[0078] (5) After regeneration is completed, the reactor catalyst bed temperature is gradually reduced to 195°C;

[0079] (6) closing the crossover line 1 of the tail gas from the outlet of the fourth-stage sulfur condenser entering the incinerator, and introducing the tail gas from the outlet of the fourth-stage sulfur condenser into the selective oxidation reactor;

[0080] (7) Regeneration of acid gas and oxygen-containing feedstock before shutting down the fourth-stage heater;

[0081] (8) Put into normal production, maintain the oxygen content in the outlet gas of the selective oxidation reactor at 0.8% (V), and operate under peroxo conditions.

[0082] After activation, normal operating conditions were restored, with H2S conversion above 95% and sulfur selectivity >90%, which were equivalent to the activity of fresh catalysts, indicating that the regeneration effect was good.

[0083] Example 3

[0084] A 5,000 ton / year sulfur recovery unit uses a selective oxidation process to recover sulfur. Two years after it was put into operation, the selective oxidation reactor was calibrated and it was found that the H2S conversion rate and the selectivity of sulfur generation in the selective oxidation reactor were greatly reduced. It was judged that the catalyst was seriously deactivated. After checking the historical records, no temperature runaway phenomenon was found in the bed. It was initially judged that the catalyst was in an oxygen-deficient state, so the catalyst needed to be regenerated. The regeneration steps are as follows:

[0085] (1) gradually reducing the inlet temperature of the selective oxidation reactor to 185°C;

[0086] (2) introducing the tail gas from the outlet of the fourth-stage sulfur condenser into an incinerator for treatment via crossover line 1;

[0087] (3) Regeneration acid gas and oxygen-containing raw material (mixed gas of oxygen and argon) are introduced before the fourth-stage heater for regeneration, and the H2S concentration is controlled at 0.3%. The rest is all air, so that the selective oxidation reactor operates in an oxygen-rich state for regeneration; the oxygen volume content in the regenerated gas phase product is 10%;

[0088] (4) The catalyst was regenerated by gradually increasing the reaction temperature at 20°C / h until the inlet temperature reached 210°C and the catalyst bed temperature reached 220°C for 32 hours;

[0089] (5) After regeneration is completed, the reactor catalyst bed temperature is gradually reduced to 210°C;

[0090] (6) closing the crossover line 1 of the tail gas from the outlet of the fourth-stage sulfur condenser entering the incinerator, and introducing the tail gas from the outlet of the fourth-stage sulfur condenser into the selective oxidation reactor;

[0091] (7) Regeneration of acid gas and oxygen-containing feedstock before shutting down the fourth-stage heater;

[0092] (8) Put into normal production, maintain the oxygen content in the outlet gas of the selective oxidation reactor at 1.0% (V), and operate under peroxo conditions.

[0093] After activation, normal operating conditions were restored, with H2S conversion above 95% and sulfur selectivity >90%, which were equivalent to the activity of fresh catalysts, indicating that the regeneration effect was good.

[0094] Example 4

[0095] A 10,000 ton / year sulfur recovery unit uses a selective oxidation process to recover sulfur. Five years after it was put into operation, the selective oxidation reactor was calibrated and it was found that the H2S conversion rate and the selectivity of sulfur generation in the selective oxidation reactor were greatly reduced. It was judged that the catalyst was seriously deactivated. After checking the historical records, no temperature runaway phenomenon was found in the bed. It was initially judged that the catalyst was in an oxygen-deficient state, so the catalyst needed to be regenerated. The regeneration steps are as follows:

[0096] (1) gradually reducing the inlet temperature of the selective oxidation reactor to 200°C;

[0097] (2) introducing the tail gas from the outlet of the fourth-stage sulfur condenser into an incinerator for treatment via crossover line 1;

[0098] (3) Regeneration acid gas and air are introduced before the fourth-stage heater for regeneration, and the H2S concentration is controlled at 0.2%, so that the selective oxidation reactor operates in an oxygen-rich state for regeneration; the oxygen volume content in the regenerated gas phase product is 8%;

[0099] (4) The catalyst was regenerated by gradually increasing the reaction temperature at 10°C / h until the inlet temperature reached 230°C and the catalyst bed temperature reached 240°C for 24 hours;

[0100] (5) After regeneration is completed, gradually reduce the reactor catalyst bed temperature to 200°C;

[0101] (6) closing the crossover line 1 of the tail gas from the outlet of the fourth-stage sulfur condenser entering the incinerator, and introducing the tail gas from the outlet of the fourth-stage sulfur condenser into the selective oxidation reactor;

[0102] (7) Regenerate acid gas and air before shutting down the fourth-stage heater;

[0103] (8) Put into normal production, maintain the oxygen content in the outlet gas of the selective oxidation reactor at 1.5% (V), and operate under peroxo conditions.

[0104] After activation, normal operating conditions were restored, with H2S conversion above 95% and selectivity for generated sulfur > 89%, indicating a good regeneration effect.

[0105] Example 5

[0106] Same as Example 1, except that:

[0107] Step (3) is to introduce regeneration acid gas (hydrogen sulfide raw material without ammonia and sulfur dioxide, the same below) and air before the four-stage heater for regeneration, control the H2S concentration to be 0.4%, and the rest is all air, so that the selective oxidation reactor is operated in an oxygen-rich state for regeneration, and the oxygen volume content in the regenerated gas phase product is 5%;

[0108] After activation, normal operating conditions are restored, with H2S conversion above 90% and selectivity for generated sulfur > 88%.

[0109] Example 6

[0110] Same as Example 1, except that:

[0111] Step (3) is to introduce regeneration acid gas and air before the four-stage heater for regeneration, control the H2S concentration to be 0.9%, and the rest is all air, so that the selective oxidation reactor is operated in an oxygen-rich state for regeneration, and the oxygen volume content in the regenerated gas phase product is 8% for regeneration;

[0112] After activation, normal operating conditions are restored, with H2S conversion above 90% and selectivity for generated sulfur > 85%.

[0113] Example 7

[0114] Same as Example 1, except that:

[0115] (4) The catalyst was regenerated by gradually increasing the reaction temperature at 15°C / h until the inlet temperature reached 185°C and the catalyst bed temperature reached 195°C for 24 hours;

[0116] After activation, normal operating conditions are restored, with H2S conversion above 90% and selectivity for generated sulfur > 85%.

[0117] Comparative Example 1

[0118] A 10,000 ton / year sulfur recovery unit used a selective oxidation process to recover sulfur. The SO2 emission concentration of the flue gas from the sulfur recovery unit continued to be high. The H2S concentration at the inlet and outlet of the selective oxidation reactor was sampled and analyzed. It was calculated that the H2S conversion rate of the catalyst in the selective oxidation reactor was between 25% and 40%, and the selectivity of generated sulfur was between 30% and 50%. The catalyst was severely deactivated, so the unit was shut down for catalyst replacement. The catalyst was only used for two and a half years, resulting in high operating costs for the unit.

[0119] Comparative Example 2

[0120] The same as Example 1, except that no hydrogen sulfide raw material (regeneration acid gas) is passed for regeneration. After regeneration, the H2S conversion rate is above 80%, and the selectivity of generated sulfur is >72%.

[0121] Comparative Example 3

[0122] The same as Example 1, except that the oxygen content in the contact regeneration gas phase product stream is 2%, the H2S conversion rate after regeneration is above 82%, and the selectivity of generated sulfur is >85%.

[0123] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for regenerating an iron oxide-based catalyst for oxidizing hydrogen sulfide to prepare sulfur, characterized in that: The method comprises: introducing oxygen raw material and hydrogen sulfide raw material to contact and regenerate the catalyst to be regenerated in the reactor; The oxygen volume content in the gas phase product stream after the contact regeneration is at least 5%.

2. The regeneration method according to claim 1, wherein: The volume content of oxygen in the gas phase product stream after the contact regeneration is 5-21%, preferably 8-15%.

3. The regeneration method according to claim 1 or 2, wherein: The concentration of hydrogen sulfide in the contact regeneration system is 0.2-1% by volume, preferably 0.3-0.6%.

4. The regeneration method according to any one of claims 1 to 3, wherein: The hydrogen sulfide raw material does not contain ammonia and sulfur dioxide.

5. The regeneration method according to any one of claims 1 to 4, wherein: The contact regeneration conditions include: The reactor inlet temperature is 170-240°C, preferably 180-230°C; and / or The catalyst bed temperature is not more than 280°C, preferably 200-240°C; and / or The reaction time is 8-72h, preferably 24-60h.

6. The regeneration method according to any one of claims 1 to 5, wherein: Before introducing oxygen raw material and hydrogen sulfide raw material, the reactor inlet temperature is controlled to be 170-200°C, preferably 180-190°C.

7. The regeneration method according to any one of claims 1 to 6, wherein: After the oxygen feedstock and the hydrogen sulfide feedstock are introduced, the reaction inlet temperature is increased at a rate of 10-20°C / h to 170-240°C, preferably 180-230°C.

8. The regeneration method according to any one of claims 1 to 7, wherein: The gas-phase product stream after contact regeneration comprises oxygen, hydrogen sulfide and optionally an inert gas, and preferably the inert gas is selected from at least one of nitrogen, argon and helium.

9. Use of the regeneration method according to any one of claims 1 to 8 in the selective oxidation of hydrogen sulfide to produce sulfur in the Super Claus process and / or the Euro Claus process.

10. The use according to claim 9, wherein: The regeneration temperature of the catalyst for preparing sulfur by oxidizing H2S is 5-40°C higher than the operating temperature, preferably 5-20°C; Preferably, the operating temperature of the catalyst for oxidizing H2S to prepare sulfur is 180-230°C, preferably 200-220°C.

Images