Complex iron sulfur recovery device and method

Abstract

The invention discloses a complex iron sulfur recovery device and method, the complex iron sulfur recovery device comprises an acid gas separator, a tail gas desulfurization tower, a regeneration oxidation tower and a filter, the acid gas separator is connected with the tail gas desulfurization tower through a pipeline, and a rich liquid pump, a barren liquid pump and a solution heat exchanger are arranged between the tail gas desulfurization tower and the regeneration oxidation tower; and the regeneration oxidation tower is connected with the filter through a pipeline. According to the complex iron desulfurization technology, H2S can be converted into the element S in one step, the removal rate of H2S can reach 99% or above, and the sulfur recovery rate reaches up to 99.99%. In the complex iron desulfurization process, side reactions are few, the generation amount of side salts is low, and the catalyst is nontoxic and harmless to the environment and human bodies and has good environmental protection benefits. And when the sulfur yield is less than 20t / d, the equipment investment and the operation cost of the process have obvious advantages. And the equipment is small in size, easy to skid-mount and suitable for requirements of small projects.

Description

Technical Field

[0001] The invention relates to the technical field of sulfur recovery, and in particular to a complex iron sulfur recovery device and method. Background Art

[0002] The existing sulfur recovery technologies are mainly liquid phase oxidation process (complex iron desulfurization) and Claus process. However, the Claus process currently has the following problems:

[0003] 1. System blockage

[0004] Liquid sulfur seal blockage: Liquid sulfur seal is an important part of Claus sulfur recovery unit, used to prevent liquid sulfur generated by reaction from entering the liquid sulfur storage tank. However, in actual operation, liquid sulfur seal is prone to blockage, affecting the pressure of sulfur recovery system, resulting in incomplete combustion of combustion furnace, and even causing excessive discharge and system shutdown.

[0005] Other blockage problems: In addition to liquid sulfur seals, equipment such as sulfur condensers and mist collectors may also be blocked due to improper operation or design defects, resulting in increased pressure drop and affecting the normal operation of the device.

[0006] 2. Reaction efficiency and conversion rate

[0007] Reaction efficiency: Affected by chemical reaction conditions and thermal conditions, the reaction efficiency of Claus sulfur recovery unit may not reach the optimal state. This will result in some hydrogen sulfide not being completely converted into sulfur, resulting in resource waste and environmental pollution.

[0008] Conversion rate: The two-stage catalytic conversion rate of the traditional Claus sulfur recovery process is only 90-95%, and the three-stage conversion rate is only 95-98%. This means that a part of hydrogen sulfide is still not effectively recovered, affecting the recovery rate and purity of sulfur.

[0009] 3. Energy consumption and cost

[0010] Energy consumption: Some Claus sulfur recovery units were not designed with energy conservation in mind, resulting in high energy consumption during operation. For example, using high-pressure steam as the heat source for process gas heaters not only increases energy costs, but can also cause energy waste.

[0011] Cost issues: Frequent equipment corrosion, leakage and blockages require frequent shutdowns for inspection and maintenance, increasing operating costs. At the same time, low reaction efficiency and conversion rates also increase raw material consumption and production costs. Summary of the invention

[0012] The object of the present invention is to provide a complex iron sulfur recovery device and method to solve the above technical problems in sulfur recovery in the prior art.

[0013] To achieve the above object, the present invention provides the following technical solutions:

[0014] The present invention provides a complex iron sulfur recovery device, which comprises an acid gas separator, a tail gas desulfurization tower, a regeneration oxidation tower and a filter. The acid gas separator is connected to the tail gas desulfurization tower through a pipeline. A rich liquid pump, a lean liquid pump and a solution heat exchanger are arranged between the tail gas desulfurization tower and the regeneration oxidation tower. The regeneration oxidation tower is connected to the filter through a pipeline.

[0015] Furthermore, the tail gas desulfurization tower is a conical container, the bottom of the tail gas desulfurization tower is connected to the upper end of the regeneration oxidation tower through a rich liquid pump and a pipeline, the upper end of the tail gas desulfurization tower is connected to the lower end of the regeneration oxidation tower through a lean liquid pump and a pipeline, and a solution heat exchanger is provided on the pipeline where the lean liquid pump is located.

[0016] Furthermore, a sulfur slurry pump is provided on the discharge pipe at the bottom of the regeneration oxidation tower, and the sulfur slurry pump pumps the material into the filter. The top of the regeneration oxidation tower is also connected to the air heat exchanger, and the top of the regeneration oxidation tower is also provided with a reagent feed port.

[0017] Furthermore, the reagents are complexing agents, sulfur precipitants, KOH, and iron ion reagents, and the complexing agents, sulfur precipitants, KOH, and iron ion reagents are respectively connected to the complexing agent tank, the sulfur precipitant tank, the KOH tank, and the iron ion tank by pipelines, and the pipelines are respectively provided with complexing agent dosing pumps, sulfur precipitant dosing pumps, KOH dosing pumps, and iron ion dosing pumps; a blower is provided at the air inlet end of the air heat exchanger.

[0018] Furthermore, the filter is a vacuum belt filter, which is respectively connected to a filtrate recovery tank, a mother liquid tank, and a washing liquid tank. The filtrate recovery tank is connected to a regeneration oxidation tower, and a filtrate pump is provided between the filtrate recovery tank and the regeneration oxidation tower.

[0019] Furthermore, the discharge port of the mother liquid tank is connected to the filtrate recovery tank, the bottom pipeline of the washing liquid tank is connected to the buffer tank, the bottom of the buffer tank is connected to the filtrate recovery tank, and the mother liquid tank and the washing liquid tank are also connected to the vacuum pump gas-liquid separator through a vacuum pump.

[0020] The present invention also provides a method for a complex iron sulfur recovery device, comprising the following steps:

[0021] (1) The acid gas enters the acid gas separator, which is equipped with a blade-type mist collector to remove condensate or solution in the gas, and then is evenly distributed into the desulfurization tower through the aeration device of the tail gas desulfurization tower;

[0022] (2) The tail gas desulfurization tower contains an iron ion catalyst solution. The H2S-containing gas reacts with the Fe in the solution. 3+After the reaction, it is converted into elemental sulfur. The gas after H2S removal is discharged from the top of the tail gas desulfurization tower, and the solution after absorbing H2S is discharged from the bottom of the tail gas desulfurization tower and transported to the regeneration oxidation tower through the rich liquid pump.

[0023] (3) The blower pressurizes the air and enters the air heat exchanger for cooling. The cooled air enters the aeration device of the regeneration oxidation tower and is evenly distributed to the regeneration oxidation tower to react with the solution after absorbing H2S, removing Fe 2+ Oxidized to Fe 3+ , generating complex iron solution and sulfur slurry, the complex iron solution is transported to the tail gas desulfurization tower through the lean liquid pump and the solution heat exchanger, the sulfur slurry is discharged from the bottom of the regeneration oxidation tower and transported to the filter through the sulfur slurry pump;

[0024] (4) After the sulfur slurry enters the filter, it is vacuum filtered. The filtrate is recovered to the filtrate recovery tank through the mother liquid tank, washing liquid tank and buffer tank, and then pumped to the regeneration oxidation tower by the filtrate pump. The filter cake continues to be dehydrated under the action of vacuum force. The filtered sulfur cake is bagged and shipped out.

[0025] Furthermore, the iron ion catalyst solution is composed of EDTA iron amine, nitrilotriacetic acid sodium salt, and water, the complexing agent is composed of nitrilotriacetic acid sodium salt, sodium hydroxide, and water, and the sulfur precipitation agent is composed of nonylphenol C 9.5 Ethoxylates, Nonylphenol C 1.5 It is composed of ethoxylate, isopropyl alcohol and water.

[0026] Furthermore, when the mass percentage of sulfur in the sulfur slurry is 6-10%, the sulfur slurry is transported into the filter through a sulfur slurry pump.

[0027] The principle involved in the present invention:

[0028] The liquid phase oxidation process improves the Claus reaction and provides a constant temperature, low-cost method for removing hydrogen sulfide:

[0029] H2S + 1 / 2 O2 → H2O + S° (1)

[0030] This reaction occurs in a water-based solution and is completed by adding water-soluble metal ions. Because in air or acid gas, water-soluble metal ions are easily oxidized by oxygen and have a stable electrode to oxidize sulfur ions into elemental sulfur. In other words, since the reaction is carried out in a water-based solution, the water-based solution containing metal ions can easily convert divalent sulfur (HS - ) releases electrons to form elemental sulfur, and transfers electrons to oxygen during the regeneration process. Although there are many metal ions that can complete the above reaction, iron ions are selected for the liquid phase oxidation process because of their low cost and non-toxicity.

[0031] The basic chemical reaction of the liquid phase oxidation desulfurization process can be divided into two parts: absorption and regeneration, as shown below:

[0032] Absorption part:

[0033] Ratio solution to absorb H2S gas:

[0034]

[0035] ionization:

[0036]

[0037] High-valent iron ions (Fe3+) oxidize divalent sulfur:

[0038] HS - + 2Fe 3+ →2Fe 2+ + H + + S0 (4)

[0039] The total equation for the absorption part (Equations 2, 3, and 4 are superimposed)

[0040] H2S (gas hydrogen sulfide) + 2Fe 3+ → 2H + + S°+ 2Fe 2+ (5)

[0041] Regeneration part:

[0042] Ratio of solution to absorb oxygen:

[0043]

[0044] Ferrous ion regeneration reaction (Fe2+)

[0045] 1 / 2 O2 (liquid) + H2O + 2Fe2 + → 2OH - + 2Fe 3+ (7)

[0046] The total equation of the regeneration part (Equation 6, 7 superimposed)

[0047] 1 / 2 O2 (gas) + H2O + 2Fe 2+ → 2OH - + 2Fe 3+ (8)

[0048] In the overall reaction, the role of iron ions is to release the electrons generated in the absorption reaction to the regeneration reaction. Since the production of each elemental sulfur requires the consumption of two iron atoms, at least two iron atoms are provided during the reaction. Therefore, iron ions are used as reactants. However, iron ions are not consumed in the overall reaction, and iron ions serve as catalysts for the reaction of hydrogen sulfide and oxygen. Due to this dual function, iron ion complexes are generally defined as catalytic reactants.

[0049] In water-based solutions, ferrous ions (Fe 2+ ) and high iron ions (Fe 3+ ) cannot exist stably, and usually tend to form iron hydroxide or iron sulfide precipitation through the following reactions:

[0050] Fe 3+ + 3OH - → Fe(OH)3(solid) (9)

[0051] Fe 2+ + S2 - → FeS (solid) (10)

[0052] To prevent the above precipitation, the system uses a chelating agent to keep the iron ions stable in the proportioning solution over a wide pH range. A chelating agent is an organic compound that wraps a metal ion in a claw-like structure, allowing the metal ion to form a chemical bond with two or more non-metallic ions. The system's metal ion and chelating agent mixture consists of a catalytic reactant, an iron oxidizer, and a chelating agent.

[0053] In the liquid phase oxidation process, the pH value of the circulating solution is a very important variable operating factor, because the total amount of H2S gas that can be absorbed by the solution depends entirely on the pH value of the solution (Equations 2, 3). The pH value is a way to measure the acidity and alkalinity of the aqueous solution. A pH value of 7 represents a neutral solution, that is, it is neither acidic nor alkaline; a pH value of 1 to 7 represents an acidic solution; and a pH value of 7 to 14 represents an alkaline solution. The double-headed arrows in Equations 2 and 3 indicate that the reaction is in a stable equilibrium state. If H is increased, + ion concentration, the reaction will proceed to the left, and the total amount of H2S that can be absorbed by the proportioning solution will decrease. - The concentration of ions, H + will be neutralized to form water (OH - +H+→H2O), so the reaction will proceed to the right, and the total amount of H2S that can be absorbed by the proportioning solution will increase.

[0054] Equation 1 shows that the reaction has no H + Ions and OH -The net product of ions is generated, so the pH value of the solution will not change. However, the side reaction will release H+ ions, which will reduce the pH value of the solution and ultimately reduce the total amount of H2S absorbed by the solution.

[0055] 2HS - + O2 →S2O3 + H2O (11)

[0056] When this reaction is combined with the ionization reaction (Equation 3), it can be seen that as thiosulfate (S2O3 2- ) produces, H + ions to form a net product.

[0057] The following reactions are for the presence of CO2 in the source gas:

[0058] The treatment of acid gas is accompanied by carbon dioxide (CO2) gas, especially as the partial pressure increases, a side reaction of lowering the pH value will occur. Carbon dioxide is highly soluble in water and will form bicarbonate (HCO3 - ) and carbonates (CO3 2- ), the reaction is as follows:

[0059]

[0060] In order to stabilize the pH value of the proportioning solution, it is necessary to add alkaline substances such as potassium hydroxide into the system, which reacts with carbon dioxide as follows:

[0061]

[0062] Generally, weak alkaline solutions with a pH value of 8.0 to 8.5 are suitable for most reactions, but in some cases, a higher pH value can improve the reaction efficiency. A higher pH value will promote the formation of thiosulfate ions, reduce the absorption of oxygen, and ultimately hinder the condensation of elemental sulfur; too low a pH value will hinder the absorption of H2S gas. It should be emphasized that the pH value of the system needs to be tracked and monitored.

[0063] Since sulfur exists in the water-based solution in the form of particles, solid-liquid separation must be performed by a method similar to precipitation. Generally speaking, sulfur is formed in the absorption tower and wetted in the water-based solution. Since the density of sulfur is about twice that of water, the precipitation rate is relatively fast. The following two special cases are exceptions:

[0064] 1. In the initial trial operation stage, when the catalyst proportioning solution is just added to the system, it is very easy to form fine sulfur particles, which are not easy to separate. When the sulfur concentration in the proportioning solution reaches 4-6 g / L (0.4-0.6 wt%), the sulfur particles are about 15 microns, which is within the operable range. These sulfur particles will serve as "mother particles" and promote the formation of large particles of 100-150 microns.

[0065] 2. Sulfur particles may be adsorbed on microbubbles, or be wrapped by hydrocarbons, or float on the top of the solution instead of settling to the bottom of the solution. Usually, if there is no place in the system that is blocked by the accumulation of floating sulfur, the floating sulfur will eventually be wetted and settled by the solution. Surfactants will be continuously added to the system to facilitate the wetting and precipitation of sulfur particles.

[0066] As shown in Equation 1, water is produced as sulfur is produced. This water must still be injected back into the system to compensate for the water lost during the venting of the absorber oxidation tower (or absorber and oxidation tower / tank). Even if the input gas stream is saturated with water before entering the process, it is still necessary to inject the generated water. The heat generated by the production of 1 kg of sulfur is enough to evaporate more than 3 kg of water, but only 0.56 kg of water is produced for each kg of sulfur in the reaction. If the acid gas and input gas streams are not saturated with water, the water content requirement of the proportioning solution will be higher because in the absorber oxidation tower (or absorber and oxidation tower / tank), the gas streams are saturated with water after mixing.

[0067] Based on the above technical solution, the embodiments of the present invention can at least produce the following technical effects:

[0068] (1) The complex iron sulfur recovery device provided by the present invention has high efficiency desulfurization capability and high removal rate: the complex iron desulfurization technology can convert H2S into elemental S in one step, the H2S removal rate can reach more than 99%, and the sulfur recovery rate is as high as 99.99%. Wide applicability: the technology is suitable for occasions with low H2S concentration or high H2S concentration but small gas flow.

[0069] (2) The complex iron sulfur recovery device and method provided by the present invention has significant environmental benefits and low pollution: after the purified tail gas is incinerated, the sulfur dioxide content in the flue gas can be reduced to 20 mg / Nm 3 , far below environmental standards, which helps reduce air pollution. No by-product pollution: There are few side reactions and low amount of by-salts produced during the complex iron desulfurization process, and the catalyst is non-toxic and harmless to the environment and human body, with good environmental benefits.

[0070] (3) The complex iron sulfur recovery device and method provided by the present invention has low equipment investment and operating costs: when the sulfur output is less than 20t / d, the equipment investment and operating costs of the process have obvious advantages. The equipment is small in size and easy to be skid-mounted, which is suitable for the needs of small projects. Catalyst regeneration: The complex iron catalyst can be regenerated and recycled, and only a small amount of catalyst lost in the desulfurization process needs to be supplemented, which reduces the operating cost.

[0071] (4) The complex iron sulfur recovery device and method provided by the present invention have great operational flexibility: the system has strong anti-fluctuation ability and can maintain a stable desulfurization effect even when the H2S content in the raw gas fluctuates greatly.

[0072] The conditions are loose: the complex iron desulfurization technology is not affected by the CO2 content in the gas source and can maintain a certain desulfurization effect within a wide temperature range (such as when the desulfurization liquid temperature is maintained at around 50°C).

[0073] (4) The complex iron sulfur recovery device and method provided by the present invention integrates desulfurization and sulfur recovery: the complex iron desulfurization technology not only has a high desulfurization efficiency, but also can effectively recover sulfur and realize resource recycling.

[0074] In summary, the complex iron desulfurization technology has shown broad application prospects and important practical significance in the field of desulfurization with its characteristics of high efficiency, environmental protection, economy, simplicity and excellent comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0076] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0077] Figure 2 is a schematic structural diagram of an embodiment of the present invention;

[0078] Figure 3 yes Figure 1 A partial enlarged view of

[0079] Figure 4 yes Figure 1 A partial enlarged view of

[0080] Figure 5 yes Figure 1 A partial enlarged view of

[0081] Figure 6 yes Figure 2 A partial enlarged view of

[0082] Figure 7 yes Figure 2 A partial enlarged view of . DETAILED DESCRIPTION

[0083] The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0084] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application; the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0085] The present invention provides a complex iron sulfur recovery method, comprising the following steps:

[0086] (1) The acid gas enters the acid gas separator, which is equipped with a blade-type mist collector to remove condensate or solution in the gas, and then is evenly distributed into the desulfurization tower through the aeration device of the tail gas desulfurization tower;

[0087] (2) The tail gas desulfurization tower contains an iron ion catalyst solution. The H2S-containing gas reacts with the Fe in the solution. 3+ After the reaction, it is converted into elemental sulfur. The gas after H2S removal is discharged from the top of the tail gas desulfurization tower, and the solution after absorbing H2S is discharged from the bottom of the tail gas desulfurization tower and transported to the regeneration oxidation tower through the rich liquid pump.

[0088] (3) The blower pressurizes the air and enters the air heat exchanger for cooling. The cooled air enters the aeration device of the regeneration oxidation tower and is evenly distributed to the regeneration oxidation tower to react with the solution after absorbing H2S, removing Fe2+ Oxidized to Fe 3+ , generating complex iron solution and sulfur slurry, the complex iron solution is transported to the tail gas desulfurization tower through the lean liquid pump and the solution heat exchanger, the sulfur slurry is discharged from the bottom of the regeneration oxidation tower and transported to the filter through the sulfur slurry pump;

[0089] (4) After the sulfur slurry enters the filter, it is vacuum filtered. The filtrate is recovered to the filtrate recovery tank through the mother liquid tank, washing liquid tank and buffer tank, and then pumped to the regeneration oxidation tower by the filtrate pump. The filter cake continues to be dehydrated under the action of vacuum force. The filtered sulfur cake is bagged and shipped out.

[0090] In this embodiment, the iron ion catalyst solution is composed of EDTA iron amine, nitrilotriacetic acid sodium salt, and water, the complexing agent is composed of nitrilotriacetic acid sodium salt, sodium hydroxide, and water, and the sulfur precipitation agent is composed of nonylphenol C 9.5 Ethoxylates, Nonylphenol C 1.5 It is composed of ethoxylate, isopropyl alcohol and water.

[0091] In this embodiment, when the mass percentage of sulfur in the sulfur slurry is 6-10%, the sulfur slurry is transported into the filter through a sulfur slurry pump; the part of the sulfur slurry in (3) that is circulated and transported to the regeneration oxidation tower is provided with a reflux pipe, and there is a siphon interruption in the reflux pipe, which can prevent backflow when the filter is working and the sulfur slurry pump is turned off.

[0092] The structures, functions and connection forms disclosed in this article can be implemented in other ways. For example, the embodiments described above are only exemplary, for example, multiple components can be combined or integrated into another component; in addition, each functional component in each embodiment of this article can be integrated into one functional component, or each functional component can exist physically separately, or two or more functional components can be integrated into one functional component.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all fall within the protection scope of the present invention.

Claims

1. A complex iron sulfur recovery device, characterized in that: It includes an acid gas separator, a tail gas desulfurization tower, a regeneration oxidation tower and a filter. The acid gas separator is connected to the tail gas desulfurization tower through a pipeline. A rich liquid pump, a lean liquid pump and a solution heat exchanger are arranged between the tail gas desulfurization tower and the regeneration oxidation tower. The regeneration oxidation tower is connected to the filter through a pipeline.

2. The complex iron sulfur recovery device according to claim 1, characterized in that: The tail gas desulfurization tower is a conical container. The bottom of the tail gas desulfurization tower is connected to the upper end of the regeneration oxidation tower through a rich liquid pump and a pipeline. The upper end of the tail gas desulfurization tower is connected to the lower end of the regeneration oxidation tower through a lean liquid pump and a pipeline. A solution heat exchanger is provided on the pipeline where the lean liquid pump is located.

3. The complex iron sulfur recovery device according to claim 1, characterized in that: A sulfur slurry pump is provided on the discharge pipe at the bottom of the regeneration oxidation tower, and the sulfur slurry pump pumps the material into the filter. The top of the regeneration oxidation tower is also connected to the air heat exchanger, and the top of the regeneration oxidation tower is also provided with a reagent feed port.

4. The complex iron sulfur recovery device according to claim 3, characterized in that: The reagents are complexing agent, sulfur precipitant, KOH, and iron ion reagents, which are respectively connected to the complexing agent tank, sulfur precipitant tank, KOH tank, and iron ion tank through pipelines, and the pipelines are respectively provided with a complexing agent dosing pump, a sulfur precipitant dosing pump, a KOH dosing pump, and an iron ion dosing pump; a blower is provided at the air inlet end of the air heat exchanger.

5. The complex iron sulfur recovery device according to claim 1, characterized in that: The filter is a vacuum belt filter, which is respectively connected to a filtrate recovery tank, a mother liquid tank, and a washing liquid tank. The filtrate recovery tank is connected to a regeneration oxidation tower, and a filtrate pump is provided between the filtrate recovery tank and the regeneration oxidation tower.

6. The complex iron sulfur recovery device according to claim 5, characterized in that: The discharge port of the mother liquid tank is connected to the filtrate recovery tank, the bottom pipeline of the washing liquid tank is connected to the buffer tank, the bottom of the buffer tank is connected to the filtrate recovery tank, and the mother liquid tank and the washing liquid tank are also connected to the vacuum pump gas-liquid separator through a vacuum pump.

7. The method of the complex iron sulfur recovery device according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) The acid gas enters the acid gas separator, which is equipped with a blade-type mist collector to remove condensate or solution in the gas, and then is evenly distributed into the desulfurization tower through the aeration device of the tail gas desulfurization tower; (2) The tail gas desulfurization tower contains an iron ion catalyst solution. The H2S-containing gas reacts with the Fe 3+ After the reaction, it is converted into elemental sulfur. The gas after H2S removal is discharged from the top of the tail gas desulfurization tower, and the solution after absorbing H2S is discharged from the bottom of the tail gas desulfurization tower and transported to the regeneration oxidation tower through the rich liquid pump. (3) The blower pressurizes the air and then enters the air heat exchanger for cooling. The cooled air enters the aeration device of the regeneration oxidation tower and is evenly distributed in the regeneration oxidation tower to react with the solution after absorbing H2S, removing Fe 2+ Oxidized to Fe 3+ , generating complex iron solution and sulfur slurry, the complex iron solution is transported to the tail gas desulfurization tower through the lean liquid pump and the solution heat exchanger, the sulfur slurry is discharged from the bottom of the regeneration oxidation tower and transported to the filter through the sulfur slurry pump; (4) After the sulfur slurry enters the filter, it is vacuum filtered. The filtrate is recovered to the filtrate recovery tank through the mother liquid tank, washing liquid tank and buffer tank, and then pumped to the regeneration oxidation tower through the filtrate pump. The filter cake continues to be dehydrated under the action of vacuum force. The filtered sulfur cake is bagged and shipped out.

8. The method of the complex iron sulfur recovery device according to claim 7, characterized in that: The iron ion catalyst solution is composed of EDTA iron amine, nitrilotriacetic acid sodium salt, and water; the complexing agent is composed of nitrilotriacetic acid sodium salt, sodium hydroxide, and water; the sulfur precipitation agent is composed of nonylphenol C 9.5 Ethoxylates, Nonylphenol C 1.5 It is composed of ethoxylate, isopropyl alcohol and water.

9. The method of the complex iron sulfur recovery device according to claim 7, characterized in that: When the mass percentage of sulfur in the sulfur slurry is 6-10%, the sulfur slurry is transported into the filter through a sulfur slurry pump; the sulfur slurry in (3) is circulated and transported to the regeneration oxidation tower, and a reflux pipe is provided.

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