A sulfur production device, sulfur preparation system, and method based on flue gas SO2 staged iterative scale-up

Abstract

The present application relates to a kind of H2S production device based on flue gas SO2 cascade iteration amplification, sulfur preparation system and method.The H2S production device includes reactor main body, multistage feeding module and multistage catalytic module.The multistage feeding module is used to grade into SO2-CH4 raw gas, and specifically includes several feeding ports independently arranged from bottom to top along the reactor main body, and gas distribution assembly in the reactor main body and corresponding communication with each feeding port.Multistage catalytic module is used to cascade iteration amplification the production amount of H2S, and specifically includes mesh support plate between adjacent gas distribution assembly and catalyst layer filled on mesh support plate.Compared with prior art, the present application realizes the efficient reduction conversion of SO2 under the induction of H2S by the cascade segmented feeding of SO2 raw gas.

Description

Technical Field

[0001] This invention relates to the field of flue gas desulfurization technology, and in particular to an H2S production device, sulfur preparation system and method based on flue gas SO2 stepped iterative scale-up. Background Technology

[0002] Sulfur dioxide (SO2) in industrial flue gas is one of the main contributors to air pollution and acid rain. Reducing SO2 in flue gas into elemental sulfur (i.e., sulfur resource utilization) is an important way to achieve a win-win situation of environmental protection, emission reduction, and economic benefits.

[0003] For example, CN223439798U discloses an integrated device for the self-circulating catalytic reduction of hydrogen sulfide, which employs a Venturi jet device and a catalytic reduction section. Through a self-circulating process, sulfur dioxide is efficiently reduced to hydrogen sulfide under the action of a catalyst. In actual production, the feed gas containing sulfur dioxide and methane is directly injected at high speed into the reaction device through the primary feed gas inlet and the secondary feed gas inlet.

[0004] However, the aforementioned direct SO2 reduction catalytic technologies generally suffer from bottlenecks such as high reduction energy barriers, large external energy requirements for reaction initiation, and slow initial reaction rates. The lack of an effective internal catalytic induction mechanism leads to low single-pass utilization of the reducing agent (such as methane) and significant challenges in industrial application.

[0005] Therefore, how to lower the starting energy barrier of SO2 reduction reaction and achieve self-organized and efficient scale-up of the reaction process is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome at least one of the defects of the prior art, such as high reduction energy barrier, large external energy required for reaction start-up, and slow reaction rate in the early stage, and to provide an H2S production device, sulfur preparation system and method based on flue gas SO2 step-by-step iterative scale-up.

[0007] The objective of this invention can be achieved through the following technical solutions: The first aspect of the present invention provides an H2S production device based on flue gas SO2 stepped iterative scale-up, comprising a reactor body, wherein the H2S production device further comprises a multi-stage feeding module and a multi-stage catalytic module; The multi-stage feeding module is used to introduce SO2-CH4 raw material gas in stages. Specifically, it includes several feed ports that are independently set from bottom to top along the reactor body, and a gas distribution component that is located inside the reactor body and connected to each feed port. The multi-stage catalytic module is used to amplify the amount of H2S generated in a stepwise iteration. Specifically, it includes a mesh support plate disposed between adjacent gas distribution components and a catalyst layer filled on the mesh support plate.

[0008] Furthermore, the top of the reactor body is provided with an outlet for discharging high concentrations of H2S products.

[0009] Furthermore, the bottom of the reactor body is provided with a solid waste discharge port for discharging solid waste.

[0010] Furthermore, the feed inlet is provided with at least three inlets, namely, a primary feed inlet, a secondary feed inlet, and a tertiary feed inlet from bottom to top.

[0011] Furthermore, the catalyst layer includes at least a primary catalyst layer and a secondary catalyst layer.

[0012] Furthermore, the primary catalyst layer is located between the primary feed inlet and the secondary feed inlet, and the gas flow outlet of the primary feed inlet points towards the primary catalyst layer.

[0013] Furthermore, the secondary catalyst layer is located between the secondary feed inlet and the tertiary feed inlet, and the gas flow outlet of the secondary feed inlet points towards the secondary catalyst layer.

[0014] Furthermore, the gas distribution component specifically includes: The main pipeline connects to the feed inlet; A ring pipe, connected to the main pipeline; Several branch pipes are arranged in a radiating pattern outward from the ring pipe.

[0015] Furthermore, the main pipe, the ring pipe, and the branch pipes are all equipped with air outlets with a diameter of 5-8 mm.

[0016] Furthermore, the air outlet is arranged at an angle downwards, preferably at a downward angle of 30°.

[0017] Furthermore, the horizontal spacing of the air outlets is 35-45 mm.

[0018] Furthermore, the center of the mesh support plate is provided with a detachable perforated plate for easy loading of catalyst.

[0019] Furthermore, the mesh support plate has a mesh diameter of 5-8 mm and an opening rate of 35-40%.

[0020] Furthermore, the reactor body is provided with handholes for unloading at corresponding positions at the bottom of the catalyst layer.

[0021] Furthermore, the diameter of the hand hole is 150-200 mm.

[0022] Furthermore, the reactor body has temperature detection ports between adjacent catalyst layers.

[0023] Furthermore, a heating and insulation layer is provided on the outer wall of the reactor body.

[0024] A second aspect of the present invention provides a sulfur preparation system, comprising an H2S production device based on a stepped-scale aeration of flue gas SO2, and further comprising: The cooling heat exchange unit is connected to the discharge port of the reactor body and is used to cool H2S; The Claus process reaction unit is connected to the outlet of the cooling heat exchange unit and is used to convert H2S into sulfur.

[0025] A third aspect of the present invention provides a method for preparing sulfur, which is based on a sulfur preparation system; the preparation method includes the following steps: S1, Initial reaction stage: SO2-CH4 feed gas is introduced through the primary feed inlet, and the initial reaction is carried out in the primary catalyst layer to generate product gas containing H2S. S2, Step-by-Step Feeding Scale-Up Stage: SO2-CH4 feed gas is introduced through the secondary feed inlet. The newly introduced feed gas undergoes a reduction reaction in the secondary catalyst layer in conjunction with H2S generated in the primary catalyst layer to further produce H2S product gas. Further, SO2-CH4 feed gas is introduced in stages, so that the newly introduced feed gas and the newly generated H2S in the previous stage can undergo an induced reduction reaction in the corresponding catalyst layer, and the production of H2S product gas can be further scaled up iteratively. S4, Sulfur Recovery Stage: The final generated H2S gas flows out from the emission port, is cooled by the cooling and heat exchange unit, and is then transported to the downstream Claus process reaction unit to produce sulfur, thereby realizing the step-by-step iterative scale-up of flue gas SO2 to produce sulfur.

[0026] Furthermore, in steps S1 and S2, the molar ratio of CH4 to SO2 in the SO2-CH4 feed gas is controlled at 0.7 to 0.8.

[0027] Furthermore, in step S1, the SO2-CH4 feed gas accounts for 10-15% of the total feed amount.

[0028] Furthermore, in step S1, the temperature of the initiation reaction is 700-800℃.

[0029] Furthermore, in step S2, the SO2-CH4 feed gas accounts for 16-20% of the total feed amount.

[0030] Furthermore, in step S2, the temperature of the reduction reaction is 650-700℃.

[0031] Compared with the prior art, the present invention has the following technical advantages: (1) This invention innovatively utilizes the scientific principle of H2S self-amplification to promote sulfur production by using H2S as an inducer and promoter for subsequent reactions, thereby promoting the efficient reduction and conversion of SO2 and significantly reducing the reaction energy barrier of subsequent SO2 reduction by CH4. This solves the problems of high reduction energy barrier and difficult start-up in traditional processes, and successfully produces high-concentration H2S gas in the reactor, thus providing high-quality raw materials for the subsequent conversion and preparation of sulfur.

[0032] (2) This invention innovatively adopts a segmented and graded feeding design, with the raw material gas added step by step along the process flow, resulting in an iterative amplification trend in the reaction scale and H2S concentration, maximizing the utilization of the heat and space inside the reactor. Each newly introduced raw material gas encounters and is catalytically induced by the newly generated and larger amount of H2S in the previous stage, promoting the efficient conversion of SO2 and the stepwise amplification of H2S generation between stages. In addition, this invention can directly use the cold raw material gas introduced step by step to directly mix and cool the high-temperature gas generated in the previous stage, so that the catalytic reaction temperature after the start-up reaction is stabilized within the optimal reaction range.

[0033] (3) The end product of the H2S production device of the present invention is high-concentration H2S gas, which can be directly connected to the existing Claus process in industry after cooling. The process coupling is high and the elemental sulfur recovery efficiency is high, providing a new technical means for the high-value utilization of sulfur resources in SO2. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the H2S production apparatus of the present invention.

[0035] Figure 2 This is a schematic diagram of the sulfur preparation system of the present invention.

[0036] Figure 3 This is a schematic diagram of the gas distribution component of the present invention.

[0037] Figure 4 This is a schematic diagram of the structure of the mesh support plate of the present invention.

[0038] Explanation of markings in the diagram: 1-Reactor body, 1.1-Discharge port, 1.2-Hand hole, 1.3-Temperature detection port, 1.4-Solid slag discharge port, 1.5-Heating and insulation layer; 2-Multi-stage feeding module, 2.1-Feed inlet, 2.1.1-First-stage feed inlet, 2.1.2-Second-stage feed inlet, 2.1.3-Third-stage feed inlet, 2.1.4-Fourth-stage feed inlet, 2.2-Gas distribution component, 2.2.1-Main pipe, 2.2.2-Annular pipe, 2.2.3-Branch pipe; 3-Multi-stage catalytic module, 3.1-Mesh support plate, 3.2-Catalyst layer, 3.2.1-Primary catalytic layer, 3.2.2-Secondary catalytic layer, 3.2.3-Tertiary catalytic layer, 3.2.4-Quaternary catalytic layer; 4-Cooling heat exchange unit; 5-Claus process reaction unit. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0040] In this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] Where there is no conflict, the following embodiments and features described herein may be combined with each other.

[0043] In the following embodiments, unless otherwise specified, the raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art. Unless otherwise specified, the functional components or structures are conventional components or conventional structures used in the art to achieve the corresponding functions.

[0044] Example 1: This embodiment provides an H2S production device based on flue gas SO2 stepped iterative scale-up, a sulfur preparation system including the device, and a matching sulfur preparation method. Wherein, as... Figure 1 As shown, the H2S production device in this embodiment specifically includes a reactor body 1, a multi-stage feeding module 2, and a multi-stage catalytic module 3.

[0045] In this embodiment, the reactor body 1 has a discharge port 1.1 at the top for discharging high-concentration H2S products and a solid waste discharge port 1.4 at the bottom for discharging solid waste. Temperature detection ports 1.3 are provided between adjacent catalyst layers 3.2 in the reactor body 1 for segmented monitoring of the reaction temperature within the reactor body 1. A heating and insulation layer 1.5 is provided on the outer wall of the reactor body 1 for heat preservation.

[0046] The multi-stage feed module 2 in this embodiment is used to introduce SO2-CH4 feed gas in stages. The multi-stage feed module 2 specifically includes several feed ports 2.1 independently arranged from bottom to top along the reactor body 1, and a gas distribution component 2.2 located inside the reactor body 1 and connected to each feed port 2.1.

[0047] The multi-stage catalytic module 3 in this embodiment is used to amplify the amount of H2S generated in a stepwise iteration. The multi-stage catalytic module 3 specifically includes a mesh support plate 3.1 disposed between adjacent gas distribution components 2.2 and a catalyst layer 3.2 filled on the mesh support plate 3.1.

[0048] In this embodiment, the feed inlet 2.1 has at least three inlets, which, from bottom to top, are a primary feed inlet 2.1.1, a secondary feed inlet 2.1.2, and a tertiary feed inlet 2.1.3. The catalyst layer 3.2 correspondingly includes at least a primary catalyst layer 3.2.1 and a secondary catalyst layer 3.2.2. The primary catalyst layer 3.2.1 is located between the primary feed inlet 2.1.1 and the secondary feed inlet 2.1.2, and the gas flow outlet of the primary feed inlet 2.1.1 points towards the primary catalyst layer 3.2.1. The secondary catalyst layer 3.2.2 is located between the secondary feed inlet 2.1.2 and the tertiary feed inlet 2.1.3, and the gas flow outlet of the secondary feed inlet 2.1.2 points towards the secondary catalyst layer 3.2.2.

[0049] like Figure 2 As shown, the sulfur preparation system in this embodiment includes an H2S production unit, a cooling and heat exchange unit 4, and a Claus process reaction unit 5. The cooling and heat exchange unit 4 is connected to the discharge port 1.1 of the reactor body 1 and is used to cool the H2S gas generated by the H2S production unit. The cooling and heat exchange unit 4 can specifically adopt commonly used industrial indirect heat exchangers (shell-and-tube, coaxial, finned tube, plate), mixing heat exchangers (gas scrubbing tower, spray cooler, jet heat exchanger), regenerative heat exchangers, etc. The Claus process reaction unit 5 is connected to the outlet of the cooling and heat exchange unit 4 and is used to convert the cooled H2S into sulfur. The Claus process reaction unit 5 can be an existing industrial Claus process.

[0050] The sulfur preparation method in this embodiment is based on the above-described sulfur preparation system and specifically includes the following steps: S1, Initial reaction stage: SO2-CH4 feed gas is introduced through the primary feed inlet 2.1.1, and the start-up reaction takes place in the primary catalyst layer 3.2.1 to generate product gas containing H2S. SO2-CH4 feed gas accounts for 10-15% of the total feed volume, and the molar ratio of CH4 to SO2 in the SO2-CH4 feed gas is controlled at 0.7-0.8. The start-up reaction temperature is 700-800 ℃.

[0051] S2, Step-by-Step Feeding Scale-Up Stage: SO2-CH4 feed gas is introduced through the secondary feed inlet 2.1.2. The newly introduced feed gas undergoes a reduction reaction in the secondary catalyst layer 3.2.2, where it reacts with the H2S generated in the primary catalyst layer 3.2.1 to further produce H2S product gas. The SO2-CH4 feed gas accounts for 16-20% of the total feed gas, and the molar ratio of CH4 to SO2 in the SO2-CH4 feed gas is controlled at 0.7-0.8.

[0052] The process involves further staged input of SO2-CH4 feed gas, which induces a reduction reaction between the newly introduced feed gas and the newly generated H2S from the previous stage in the corresponding catalyst layer 3.2, thereby further iterating and scaling up the production of H2S product gas. The reduction reaction temperature is 650-700 ℃.

[0053] S4, Sulfur Recovery Stage: The final generated H2S gas flows out from the emission port 1.1, is cooled by the cooling and heat exchange unit 4, and is then transported to the downstream Claus process reaction unit 5 to generate sulfur, thereby realizing the step-by-step iterative scale-up of flue gas SO2 to produce sulfur.

[0054] Example 2: This embodiment provides an H2S production device based on flue gas SO2 stepped iterative scale-up, a sulfur preparation system including the device, and a matching sulfur preparation method. Specifically, the H2S production device in this embodiment includes a reactor body 1, a multi-stage feeding module 2, and a multi-stage catalytic module 3.

[0055] Compared with Example 1, such as Figure 3As shown, the gas distribution component 2.2 in this embodiment specifically includes a main pipe 2.2.1, a ring pipe 2.2.2, and several branch pipes 2.2.3. The main pipe 2.2.1 is connected to the inlet 2.1, the ring pipe 2.2.2 is connected to the main pipe 2.2.1, and the several branch pipes 2.2.3 are arranged outward in a radiating pattern along the ring pipe 2.2.2. Each of the main pipe 2.2.1, the ring pipe 2.2.2, and the branch pipes 2.2.3 is provided with an outlet with a diameter of 5-8 mm. The outlets are arranged at a downward 30° angle, and the horizontal spacing between the outlets is 35-45 mm.

[0056] like Figure 4 As shown, the center of the mesh support plate 3.1 in this embodiment is provided with a detachable perforated plate for easy loading of catalyst. The mesh diameter of the mesh support plate 3.1 is 5-8 mm, and the opening ratio is 35-40%. The reactor body 1 is provided with hand holes 1.2 for unloading at corresponding positions at the bottom of the catalyst layer 3.2, and the diameter of the hand holes 1.2 is 150-200 mm.

[0057] Example 3: This embodiment provides an H2S production device based on flue gas SO2 stepped iterative scale-up, a sulfur preparation system including the device, and a matching sulfur preparation method. Specifically, the H2S production device in this embodiment includes a reactor body 1, a multi-stage feeding module 2, and a multi-stage catalytic module 3.

[0058] The H2S production device in this embodiment mainly includes: ① Reactor body 1: Multiple catalytic layers 3.2 are arranged sequentially along the material flow direction inside the reactor body, serving as the core area for the gas reduction reaction.

[0059] ② Multi-stage feeding module 2: includes multiple independent feed inlets installed on the reactor body 1 for introducing raw material gas in stages and batches. The multi-stage feeding module 2 includes at least a primary feed inlet 2.1.1, a secondary feed inlet 2.1.2, and a tertiary feed inlet 2.1.3.

[0060] ③ Multi-stage catalytic module 3: Located inside the reactor body 1 and corresponding to the multi-stage feed module 2, the multi-stage catalytic module 3 includes at least a primary catalytic layer 3.2.1 and a secondary catalytic layer 3.2.2.

[0061] ④ Gas outlet: The exhaust port 1.1 at the end of the reactor body 1 is used to discharge the H2S gas generated in the reaction.

[0062] In this embodiment, the gas flow outlet of the primary feed inlet 2.1.1 points to the primary catalyst layer 3.2.1, and the secondary feed inlet 2.1.2 is located downstream of the primary catalyst layer 3.2.1 and upstream of the secondary catalyst layer 3.2.2.

[0063] In this embodiment, a cooling heat exchange unit 4 is connected downstream of the discharge port 1.1, and the outlet of the cooling heat exchange unit 4 is connected to the downstream Claus process reaction unit 5.

[0064] In this embodiment, a gas distribution assembly 2.2 is arranged inside the reactor body 1 via a multi-stage feed inlet. The main pipe 2.2.1 of the gas distribution assembly 2.2 connects to the internal annular pipe 2.2.2, and the annular pipe 2.2.2 has 8-10 branch pipes 2.2.3 arranged outward in a scattering pattern. The gas distribution assembly 2.2 has vent holes with a diameter of 5-8 mm, positioned at a downward 30° angle, with a horizontal spacing of 35-45 mm, ensuring that the raw material gas can be uniformly distributed in the catalyst layer 3.2 within the reactor body after entering through the gas distribution assembly 2.2.

[0065] In this embodiment, a perforated support plate 3.1 is provided at the bottom of each catalyst layer 3.2 in the reactor. The perforated support plate 3.1 has a mesh size of 5-8 mm and an open area of ​​35-40%, and a detachable perforated plate with a diameter of 480-500 mm is provided in the center to facilitate the filling of each catalyst layer. Each catalyst layer 3.2 has a hand hole 1.2 at the bottom, with a diameter of 150-200 mm, mainly used for unloading the catalyst.

[0066] In this embodiment, temperature detection ports 1.3 are provided between adjacent catalyst layers 3.2 in the reactor body 1 for segmented monitoring of the reaction temperature inside the reactor body 1.

[0067] In this embodiment, the SO2 reduction catalyst packed in the catalyst layer 3.2 is a commercially available active γ-alumina. Those skilled in the art can modify the active γ-alumina using conventional methods such as hydrothermal treatment and impregnation. The modifying components used include commonly used active metals such as Ti / Zr, Co / Mo, or Ni / Mo.

[0068] This embodiment utilizes the aforementioned apparatus for the staged iterative scale-up of SO2 production from flue gas to produce sulfur. Specifically, based on the chemical principle of "sulfur-driven sulfur production" through H2S self-amplification, this embodiment employs a staged, segmented feeding of SO2 feed gas, and promotes the efficient reduction and conversion of SO2 under the induction of H2S. The specific steps include: (1) Start-up reaction stage: SO2-CH4 feed gas with a set ratio is introduced through the primary feed port 2.1.1 and the start-up reaction is carried out in the primary catalyst layer 3.2.1 to generate product gas containing H2S.

[0069] (2) Secondary iterative amplification stage: After monitoring that the primary catalyst layer 3.2.1 stably produces H2S products, SO2-CH4 feed gas with a set ratio is introduced from the secondary feed inlet 2.1.2. The newly introduced feed gas, under the combined action of the H2S produced in the primary catalyst layer 3.2.2 and the secondary catalyst layer 3.2.1, undergoes efficient reduction and conversion to produce more H2S product gas.

[0070] (3) Multi-stage scale-up stage: After the H2S generated in the secondary catalyst layer 3.2.2 stabilizes, SO2-CH4 feed gas with a set ratio is introduced sequentially from the tertiary feed port 2.1.3 and the quaternary feed port 2.1.4. The newly introduced feed gas and the newly generated H2S in the previous stage undergo an induced reduction reaction in the corresponding catalyst layer 3.2, and further iterates and scales up to generate new H2S product gas.

[0071] (4) Sulfur recovery stage: The final generated H2S gas flows out from the emission port 1.1, and after being cooled, it is transported to the downstream Claus process to react and generate elemental sulfur, thereby realizing the step-by-step iterative scale-up of flue gas SO2 to produce sulfur.

[0072] Example 4: This embodiment is used to treat low-concentration SO2 flue gas generated from industrial flue gas, focusing on verifying the start-up and cascade scale-up performance of the device under low-concentration conditions. The parameters of the feed gas are as follows: the initial concentration of SO2 in the flue gas is 2.0 vol%, and the molar ratio of reducing agent CH4 to SO2 is controlled at 0.75.

[0073] First stage (start-up reaction): 12% of the total flow rate of feed gas was introduced through the primary feed inlet 2.1.1, and the initial reaction temperature of the primary catalyst layer 3.2.1 was controlled at 750 ℃. After the reaction stabilized, the selectivity of H2S in the primary outlet gas stream was measured to reach 92%.

[0074] Second stage (secondary scale-up): Maintaining a stable primary feed, open the secondary feed inlet 2.1.2 and introduce 18% of the feed gas. Under the self-amplification-induced effect of H2S generated in the primary stage, the reaction in the secondary catalyst layer 3.2.2 can proceed efficiently by maintaining a reaction temperature of 650 ℃.

[0075] The third stage (multi-stage iterative scale-up): After the H2S gas flow generated by the secondary catalyst layer 3.2.2 stabilizes, following the same induced scale-up logic, 28% and 42% of the feed gas are sequentially introduced through the tertiary feed inlet 2.1.3 and the quaternary feed inlet 2.1.4, respectively. Each newly introduced feed gas encounters and is catalytically induced by the newly generated, larger amount of H2S from the previous stage, promoting efficient SO2 conversion and a stepwise scale-up of H2S generation between stages.

[0076] Operating results: In the mixed gas flowing out of outlet 1.1, the total SO2 conversion rate reached 98.5%, and the H2S selectivity was as high as 98.2%. After cooling, the gas was introduced into the downstream Claus process, and the total sulfur recovery rate reached 98.1%.

[0077] Example 5: This embodiment is used to treat high-concentration SO2 flue gas generated during non-ferrous metal smelting and other processes, focusing on verifying the dilution and regulation effect of multi-stage segmented feeding on the exothermic reaction process. Feed gas parameters: initial SO2 concentration in the flue gas is 20.0 vol%, and the molar ratio of CH4 to SO2 is controlled at 0.76.

[0078] First stage (start-up reaction): 12% of the total flow rate of raw material gas is introduced through the primary feed inlet 2.1.1. Due to the high concentration, the reaction temperature of the primary catalyst layer 3.2.1 rises to 800 ℃ after startup.

[0079] The second stage (scale-up with stepped feed): Secondary feed inlet 2.1.2, tertiary feed inlet 2.1.3, and quaternary feed inlet 2.1.4 are opened sequentially, introducing 18%, 28%, and 42% cold feed gas respectively. The introduced cold feed gas is used to directly mix and cool the high-temperature gas generated in the previous stage, stabilizing the temperature of each catalyst layer 3.2 within the optimal reaction range of 650~700℃.

[0080] Results: Through the strong induction of H2S and the utilization of stepwise reaction heat, the formation of byproducts COS and CS2 was successfully suppressed. The total SO2 conversion rate at emission port 1.1 was 99.1%, and the outlet gas contained almost no byproducts, greatly reducing the catalytic hydrolysis pressure on the downstream Claus process.

[0081] Example 6: This embodiment aims to verify the advantages of H2S self-amplification and sulfur-promoting mechanism in reducing the start-up energy barrier of subsequent reaction stages and system energy consumption. Feed gas parameters: The initial SO2 concentration in the flue gas is 3.5 vol%, and the molar ratio of CH4 to SO2 is controlled at 0.75.

[0082] First-stage start-up: Initial feed gas is introduced through the first-stage feed port 2.1.1, and the first-stage catalyst layer 3.2.1 is heated to 800 °C using external auxiliary electric heating to overcome the initial high energy barrier, and the reaction begins and stably produces H2S.

[0083] No additional heating iteration: After H2S gas flows into the subsequent catalyst layer, the external auxiliary heating power of each subsequent stage is reduced to 75% of its original value. The secondary feed inlet 2.1.2, tertiary feed inlet 2.1.3, and quaternary feed inlet 2.1.4 are opened sequentially. Under the chemically induced catalytic effect of the existing H2S, the start-up energy barrier of subsequent reactions is significantly reduced, and the reaction can be automatically triggered at 650 °C. Furthermore, the exothermic reaction maintains the system's self-thermal equilibrium.

[0084] Operating results: The SO2 conversion rate at emission outlet 1.1 remained stable at 97.8%. Compared with the traditional single-stage, one-time feed reduction process, the device of this invention reduces the external heating energy consumption of the system by 25% due to the low-temperature start-up and self-heating auxiliary operation of the later stages.

[0085] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An H2S production device based on flue gas SO2 stepped iterative scale-up, comprising a reactor body (1), characterized in that, The H2S production unit also includes a multi-stage feeding module (2) and a multi-stage catalytic module (3); The multi-stage feeding module (2) is used to introduce SO2-CH4 raw material gas in stages. Specifically, it includes several feed ports (2.1) independently set from bottom to top along the reactor body (1), and a gas distribution component (2.2) set in the reactor body (1) and connected to each feed port (2.1). The multi-stage catalytic module (3) is used to amplify the amount of H2S generated in a stepwise iteration. Specifically, it includes a mesh support plate (3.1) disposed between adjacent gas distribution components (2.2) and a filling material in the mesh support plate (3.1). 3.1) on the catalyst layer (3.2).

2. The H2S production device based on flue gas SO2 stepped iterative scale-up as described in claim 1, characterized in that, The top of the reactor body (1) is provided with a discharge port (1.1) for discharging high concentration H2S products. The bottom of the reactor body (1) is provided with a solid slag discharge port (1.4) for discharging solid waste slag.

3. The H2S production device based on flue gas SO2 stepped iterative scale-up as described in claim 1, characterized in that, The feed inlet (2.1) has at least three parts, which are, from bottom to top, a primary feed inlet (2.1.1), a secondary feed inlet (2.1.2) and a tertiary feed inlet (2.1.3). The catalyst layer (3.2) includes at least a primary catalyst layer (3.2.1) and a secondary catalyst layer (3.2.2). The primary catalyst layer (3.2.1) is located between the primary feed inlet (2.1.1) and the secondary feed inlet (2.1.2), and the gas flow outlet of the primary feed inlet (2.1.1) points towards the primary catalyst layer (3.2.1). The secondary catalyst layer (3.2.2) is located between the secondary feed inlet (2.1.2) and the tertiary feed inlet (2.1.3), and the gas flow outlet of the secondary feed inlet (2.1.2) points towards the secondary catalyst layer (3.2.2).

4. The H2S production device based on flue gas SO2 stepped iterative scale-up as described in claim 1, characterized in that, The gas distribution component (2.2) specifically includes: The main pipeline (2.2.1) is connected to the feed inlet (2.1); The ring pipe (2.2.2) is connected to the main pipe (2.2.1); Several branch pipes (2.2.3) are arranged in a radiating pattern outward from the ring pipe (2.2.2); The main pipe (2.2.1), the ring pipe (2.2.2), and the branch pipe (2.2.3) are all equipped with vent holes with a diameter of 5-8 mm. The vent holes are arranged obliquely downward and the horizontal spacing between the vent holes is 35-45 mm.

5. The H2S production device based on flue gas SO2 stepped iterative scale-up as described in claim 1, characterized in that, The center of the mesh support plate (3.1) is provided with a detachable perforated plate for easy loading of catalyst; The mesh support plate (3.1) has a mesh diameter of 5-8 mm and an opening rate of 35-40%.

6. The H2S production device based on flue gas SO2 stepped iterative scale-up as described in claim 1, characterized in that, The reactor body (1) is provided with hand holes (1.2) for unloading at corresponding positions at the bottom of the catalyst layer (3.2). The diameter of the hand hole (1.2) is 150-200 mm.

7. The H2S production device based on flue gas SO2 stepped iterative scale-up as described in claim 1, characterized in that, The reactor body (1) has temperature detection ports (1.3) between adjacent catalyst layers (3.2). A heating and insulation layer (1.5) is provided on the outer wall of the reactor body (1).

8. A sulfur preparation system, characterized in that, The H2S production device based on the step-by-step iterative scale-up of flue gas SO2 as described in any one of claims 1 to 7 further includes: The cooling heat exchange unit (4) is connected to the discharge port (1.1) of the reactor body (1) and is used to cool H2S; Claus process reaction unit (5) is connected to the outlet of cooling heat exchange unit (4) to convert H2S into sulfur.

9. A method for preparing sulfur, characterized in that, The preparation method is carried out using the sulfur preparation system according to claim 8; the preparation method includes the following steps: S1, Initial reaction stage: SO2-CH4 feed gas is introduced through the primary feed inlet (2.1.1) and the reaction is initiated in the primary catalyst layer (3.2.1) to generate product gas containing H2S. S2, Step-by-Step Feeding Scale-Up Stage: SO2-CH4 feed gas is introduced through the secondary feed inlet (2.1.2). The newly introduced feed gas undergoes a reduction reaction in the secondary catalyst layer (3.2.2) in conjunction with the H2S generated in the primary catalyst layer (3.2.1) to further produce H2S product gas. Further, SO2-CH4 feed gas is introduced in stages, so that the newly introduced feed gas and the newly generated H2S in the previous stage can undergo an induced reduction reaction in the corresponding catalyst layer (3.2), and the production of H2S product gas can be further scaled up iteratively. S4, Sulfur Recovery Stage: The final generated H2S gas flows out from the discharge port (1.1), is cooled by the cooling heat exchange unit (4), and is then transported to the downstream Claus process reaction unit (5) to generate sulfur, thereby realizing the step-by-step iterative scale-up of flue gas SO2 to produce sulfur.

10. A method for preparing sulfur according to claim 9, characterized in that, In steps S1 and S2, the molar ratio of CH4 to SO2 in the SO2-CH4 feed gas is controlled at 0.7~0.8; In step S1, the SO2-CH4 feed gas accounts for 10-15% of the total feed rate, and the temperature for starting the reaction is 700-800℃. In step S2, the SO2-CH4 feed gas accounts for 16-20% of the total feed amount, and the reduction reaction temperature is 650-700℃.

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