Catalytic flue gas treatment device and yellow phosphorus tail gas purification system

Abstract

The application discloses a kind of catalytic flue gas treatment device and yellow phosphorus tail gas purification system, to solve the technical problem that catalytic flue gas treatment device needs longer time to be placed and dried after catalyst washing regeneration, affects the working efficiency of catalytic flue gas treatment device.For reaction system, regeneration liquid circulation system and flue gas conveying system;It also includes drying system, the drying system includes first air blower, heater and drying gas distribution pipe network, the first air blower and the heater are connected with each reactor by the drying gas distribution pipe network, so that the airflow generated by the first air blower is heated by the heater to form drying gas and enter the reactor after catalyst washing regeneration and pass through the catalyst in the reactor, when the drying gas passes through the catalyst, the regeneration liquid attached to the catalyst evaporates and is discharged from the reactor after catalyst washing regeneration along with the flow of the drying gas.The drying time of the catalyst is shortened.

Description

Technical Field

[0001] This invention relates to the field of flue gas treatment technology, specifically to a catalytic flue gas treatment device, a yellow phosphorus tail gas purification system, and a flue gas purification system. Background Technology

[0002] To remove sulfur dioxide from flue gas, the applicant has developed catalytic flue gas treatment technology. For example, the applicant discloses catalytic flue gas desulfurization equipment in patent documents with publication numbers CN214764545U, CN114653202A, and CN114797450A. However, their applications are limited to sulfur dioxide removal.

[0003] On the other hand, yellow phosphorus tail gas is a process gas mainly containing carbon monoxide discharged after the phosphorus collection process in the electric furnace yellow phosphorus production process. Besides CO, this gas typically contains impurities such as P4, CO2, PH3, O2, COS, CS2, H2S, water vapor, and HF. Currently, the main purification methods for yellow phosphorus tail gas include:

[0004] 1) Water washing method: Introducing the yellow phosphorus tail gas into a water washing tower can remove most of the dust, fluorides, phosphorides, and sulfides;

[0005] 2) Alkaline washing method: The yellow phosphorus tail gas is introduced into the alkaline washing tower and washed with NaOH solution, which can remove a large amount of acidic gases such as H2S and CO2 from the tail gas.

[0006] 3) Temperature-switched adsorption (TSA) method: This method uses temperature changes to control the adsorption and desorption processes. It involves adsorption at low temperatures and desorption and regeneration at high temperatures, and is mainly used for dephosphorization.

[0007] 4) Pressure Swing Adsorption (PSA): This method uses pressure changes to control the adsorption and desorption processes. It involves high-pressure adsorption and low-pressure desorption and regeneration, and is mainly used to remove H2S and CO2 from yellow phosphorus tail gas.

[0008] 5) DePOx continuous catalytic oxidation dephosphorization process: a continuous treatment process that uses selective catalysts to oxidize PH3 in yellow phosphorus tail gas into elemental phosphorus and water under conditions of 200-300℃ and near atmospheric pressure by precisely controlling the amount of oxygen.

[0009] 6) For phosphine and hydrogen sulfide in yellow phosphorus tail gas, there are also ferric chloride method, sodium hypochlorite oxidation method, concentrated sulfuric acid absorption method, and hydrogen peroxide oxidation method. These all use chemical oxidants (FeCl3, NaClO, H2SO4, H2O2) to oxidize PH3 and H2S into harmless or easily treatable products, and therefore can be collectively referred to as chemical oxidant oxidation methods.

[0010] Currently, most manufacturers use a combination of water washing and alkaline washing processes. A small number of manufacturers, in addition to water washing and alkaline washing, also add temperature swing adsorption (TSA), pressure swing adsorption (PSA), DePOx continuous catalytic oxidation dephosphorization process, and chemical oxidant oxidation process as needed.

[0011] In its prior patent application (application number 202411874384X) entitled "Method and Equipment for Dephosphorization and Desulfurization of Yellow Phosphorus Tail Gas," the applicant provides a novel method and equipment for dephosphorization and desulfurization of yellow phosphorus tail gas (see the detailed description in the specific embodiments section of this specification). This method employs a three-stage catalytic flue gas treatment: the first stage converts PH3 and P4 into controllable phosphorus oxides and phosphoric acid through catalytic oxidation; the second stage converts organic sulfur (such as COS and CS2) into H2S through catalytic hydrolysis; and the third stage catalytically oxidizes H2S into elemental sulfur. The entire treatment process, through the selective reaction of the catalyst, achieves efficient and continuous treatment of phosphorus-containing and sulfur-containing pollutants in the yellow phosphorus tail gas. Furthermore, addressing the problem that elemental sulfur is easily oxidized to sulfur dioxide, causing secondary pollution, the third catalyst can further catalytically oxidize sulfur dioxide and react it with water to produce sulfuric acid, thereby avoiding sulfur dioxide emissions.

[0012] The dephosphorization and desulfurization method and equipment for yellow phosphorus tail gas still have the following problems: the dephosphorization unit (first catalytic flue gas treatment unit) requires a low moisture content to operate, but the first catalyst of the first catalytic flue gas treatment unit has a high moisture content after washing and regeneration. If the first catalyst is allowed to stand and dry to reach the operating conditions of the first catalytic flue gas treatment unit, it will take a long time, which will affect the working efficiency of the dephosphorization unit. Summary of the Invention

[0013] The purpose of this invention is to provide a catalytic flue gas treatment device and a yellow phosphorus tail gas purification system to solve the technical problem that the catalyst in the catalytic flue gas treatment device (such as the first catalytic flue gas treatment device in the yellow phosphorus tail gas purification system) needs to be left to stand and dry for a long time after washing and regeneration, which affects the working efficiency of the catalytic flue gas treatment device.

[0014] In a first aspect, a catalytic flue gas treatment apparatus is provided, comprising: a reaction system including at least one reactor, the reactor having an inlet, an outlet, a drain outlet, and a catalyst located within the reactor; the reactor being provided with a regenerated liquid spraying device for washing and regenerating the catalyst; during operation, the flue gas to be treated enters the reactor through the inlet, passes through the catalyst, and then exits from the outlet as treated flue gas; the target pollutants in the flue gas to be treated undergo an oxidation reaction on the catalyst to form target products when passing through it; during the washing and regeneration of the catalyst, the target products adhering to the catalyst enter the regenerated liquid sprayed on the catalyst and are then discharged from the drain outlet of the reactor; and a regenerated liquid circulation system including at least one regenerated liquid tank and a regenerated liquid circulation control network connecting the at least one regenerated liquid tank and each reactor, the regenerated liquid circulation control network having an output-side control network, an input-side control network, and a regenerated liquid driving device; the output-side control network can drive selected... The regenerated liquid in the regenerated liquid tank is introduced into the regenerated liquid spraying device of the selected reactor. The input-side control network can introduce the regenerated liquid output from the discharge port of the selected reactor into the selected regenerated liquid tank. The regenerated liquid driving device can provide the required power to the regenerated liquid. The flue gas conveying system includes an inlet network and an exhaust network. The inlet network is used to introduce the flue gas to be treated into the inlet of the selected reactor. The exhaust network is used to output the treated flue gas from the exhaust port of the selected reactor. In addition, a drying system is included. The drying system includes a first blower, a heater, and a drying gas distribution network. The first blower and the heater are connected to each reactor through the drying gas distribution network, so that the airflow generated by the first blower is heated by the heater to form drying gas, which enters the reactor after catalyst washing and regeneration and passes through the catalyst in the reactor. When the drying gas passes through the catalyst, the regenerated liquid attached to the catalyst evaporates and is discharged from the reactor after catalyst washing and regeneration with the flow of the drying gas.

[0015] Secondly, a yellow phosphorus tail gas purification system is provided, comprising: passing the yellow phosphorus tail gas into a dephosphorization device to remove phosphorus-containing substances from the yellow phosphorus tail gas, wherein the dephosphorization device employs a first catalytic flue gas treatment device, the first catalytic flue gas treatment device comprising a first reactor, wherein during operation, the yellow phosphorus tail gas enters the first reactor from the inlet, passes through a first catalyst, and is then discharged from the exhaust port of the first reactor as dephosphorized flue gas; wherein PH3 and P4 in the yellow phosphorus tail gas react on the first catalyst to form phosphorus oxides and phosphoric acid when passing through the first catalyst, and during the washing and regeneration of the first catalyst, the phosphorus oxides and phosphoric acid enter the regeneration liquid sprayed on the first catalyst and are then discharged from the drain port of the first reactor; and passing the dephosphorized flue gas into an organic sulfur hydrolysis conversion device to convert the organic sulfur in the dephosphorized flue gas into H2S, wherein the organic sulfur hydrolysis conversion device employs a second catalytic flue gas treatment device, the second catalytic flue gas treatment device comprising a second reactor, wherein during operation, the dephosphorized flue gas enters the second reactor from the inlet, passes through a second catalyst, and is then discharged from the exhaust port of the first reactor as dephosphorized flue gas. The exhaust gas from the second reactor is discharged as organic sulfur hydrolysis conversion flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed into H2S when passing through the second catalyst. The organic sulfur hydrolysis conversion flue gas is then passed into a desulfurization device to remove the H2S. The desulfurization device is a third catalytic flue gas treatment device, which includes a third reactor. During operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor through the inlet, passes through the third catalyst, and then exits from the exhaust port of the third reactor as desulfurized flue gas. The H2S in the organic sulfur hydrolysis conversion flue gas reacts on the third catalyst to form elemental sulfur and sulfuric acid. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide produced by the reaction of elemental sulfur with oxygen and then reacting with water. When the third catalyst is washed and regenerated, the elemental sulfur and the sulfuric acid enter the regeneration liquid sprayed on the third catalyst and are then discharged from the outlet of the third reactor. The first catalytic flue gas treatment device is the catalytic flue gas treatment device of the first aspect described above.

[0016] By integrating a drying system into a catalytic flue gas treatment unit, heated drying gas is used to directly pass through the catalyst to accelerate the evaporation of the attached regenerated liquid. This effectively solves the technical problem of the need for long-term static drying after catalyst washing and regeneration. It not only significantly shortens the catalyst drying time and improves the unit's working efficiency, but also ensures that the catalyst is always in optimal working condition through precise control of the drying system, thus improving the reliability and stability of the entire treatment system. At the same time, this technical solution has universal applicability and can be promoted and applied to catalytic flue gas treatment units that require periodic catalyst regeneration.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0018] The accompanying drawings, which form part of this specification, are used to aid in understanding the invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the invention, but do not constitute an undue limitation of the invention.

[0019] Figure 1 This is a schematic diagram of a yellow phosphorus tail gas purification system according to an embodiment of the present invention.

[0020] Figure 2 for Figure 1 A partial enlarged view of the flue gas driven device.

[0021] Figure 3 for Figure 1 A partially enlarged view of the dephosphorization unit. Detailed Implementation

[0022] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0023] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0024] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0025] The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0026] Figure 1 This is a schematic diagram of a yellow phosphorus tail gas purification system according to an embodiment of the present invention. Figure 1 As shown, the yellow phosphorus tail gas purification system mainly includes: dephosphorization device 7, organic sulfur hydrolysis conversion device 8, and desulfurization device 9.

[0027] The dephosphorization device 7 is used to receive yellow phosphorus tail gas and remove phosphorus-containing substances from the yellow phosphorus tail gas. The dephosphorization device 7 adopts a first catalytic flue gas treatment device, which includes a first reactor 71. During operation, the yellow phosphorus tail gas enters the first reactor 71 from the inlet, passes through the first catalyst, and is discharged from the exhaust port of the first reactor 71 as dephosphorized flue gas. When the yellow phosphorus tail gas passes through the first catalyst, the PH3 and P4 react on the first catalyst to form phosphorus oxide and phosphoric acid. When the first catalyst is washed and regenerated, the phosphorus oxide and phosphoric acid enter the regeneration liquid sprayed on the first catalyst and are discharged from the drain port of the first reactor 71.

[0028] The organic sulfur hydrolysis conversion device 8 is used to receive the dephosphorized flue gas and convert the organic sulfur in the dephosphorized flue gas into H2S. The organic sulfur hydrolysis conversion device 8 adopts a second catalytic flue gas treatment device. The second catalytic flue gas treatment device includes a second reactor 81. When working, the dephosphorized flue gas enters the second reactor 81 from the inlet, passes through the second catalyst, and is discharged from the exhaust port of the second reactor 81 as organic sulfur hydrolysis conversion flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed into H2S when passing through the second catalyst.

[0029] The desulfurization device 9 is used to receive the organic sulfur hydrolysis conversion flue gas and remove H2S from it. The desulfurization device 9 adopts a third catalytic flue gas treatment device, which includes a third reactor 91. During operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor 91 through the inlet, passes through the third catalyst, and is then discharged from the exhaust port of the third reactor 91 as desulfurized flue gas. When the H2S in the organic sulfur hydrolysis conversion flue gas passes through the third catalyst, it reacts on the third catalyst to form elemental sulfur and sulfuric acid. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide produced by the reaction of elemental sulfur with oxygen and then reacting with water. When the third catalyst is washed and regenerated, the elemental sulfur and the sulfuric acid enter the regeneration liquid sprayed on the third catalyst and are discharged from the outlet of the third reactor 91.

[0030] The aforementioned dephosphorization and desulfurization equipment for yellow phosphorus tail gas employs a three-stage catalytic flue gas treatment method: the first stage converts PH3 and P4 into controllable phosphorus oxides and phosphoric acid through catalytic oxidation; the second stage converts organic sulfur (such as COS and CS2) into H2S through catalytic hydrolysis; and the third stage catalytically oxidizes H2S into elemental sulfur. The entire treatment process, through the selective reaction of the catalyst, achieves efficient and continuous treatment of phosphorus- and sulfur-containing pollutants in the yellow phosphorus tail gas. Furthermore, addressing the issue of elemental sulfur being easily oxidized to sulfur dioxide, thus causing secondary pollution, the third catalyst further catalytically oxidizes sulfur dioxide and reacts it with water to form sulfuric acid, thereby avoiding sulfur dioxide emissions.

[0031] More specifically, the three-stage catalytic flue gas treatment described above exhibits the following coupling effects: First, phosphides (especially PH3 and P4) are inherently toxic and can poison subsequent catalysts (PH3 and P4 phosphides possess strong reducing and coordination properties; when they come into contact with the catalyst surface, they readily undergo chemical adsorption and reaction with the catalyst's active sites, thereby occupying or covering these sites). Therefore, preferentially removing phosphides effectively protects the activity and lifespan of the subsequent second and third catalysts. Second, organic sulfur is uniformly converted to H2S through the second-stage catalytic hydrolysis. Compared to organic sulfur compounds such as COS and CS2, H2S is more easily catalytically oxidized, significantly improving the desulfurization efficiency of the third stage. Finally, the temperature gradient and chemical reaction characteristics of the entire treatment chain create a good synergistic effect.

[0032] like Figure 1 As shown, the above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization equipment may further include a scrubbing pretreatment device. The scrubbing pretreatment device is located before the dephosphorization device 7. The scrubbing pretreatment device is used to scrub the yellow phosphorus tail gas before sending it into the dephosphorization device 7. The scrubbing pretreatment includes a first scrubbing system 1 and / or a second scrubbing system 2. The first scrubbing system 1 is used to perform water scrubbing treatment on the yellow phosphorus tail gas, and the second scrubbing system 2 is used to perform alkaline solution scrubbing treatment on the yellow phosphorus tail gas.

[0033] Specifically, in this embodiment, the rinsing pretreatment includes a first rinsing system 1 and a second rinsing system 2. The first rinsing system 1 includes two-stage first rinsing towers, and the second rinsing system 2 includes a first-stage second rinsing tower. The second rinsing tower is connected in series after the two-stage first rinsing towers.

[0034] The scrubbing pretreatment unit is mainly used to remove large particulate matter and some water-soluble gaseous pollutants from yellow phosphorus tail gas. Water scrubbing can initially remove some phosphorus and sulfur compounds, while alkaline solution scrubbing can further remove acidic gases, thereby reducing the load on subsequent treatments.

[0035] Furthermore, a gas-liquid separation device 3 and a gas heating device are sequentially arranged between the rinsing pretreatment device and the dephosphorization device 7. The function of the gas-liquid separation device 3 is to achieve gas-liquid separation. The separated yellow phosphorus tail gas can first enter the gas distribution cylinder 4, which can divert the yellow phosphorus tail gas as needed. For example, the gas distribution cylinder 4 can divert a portion of the yellow phosphorus tail gas to a gas holder for storage (the yellow phosphorus tail gas in the gas holder can be used for combustion) and divert a portion of the yellow phosphorus tail gas to the gas heating device.

[0036] The gas separator 4 is located after the gas-liquid separator 3 and before the gas heating device. It can divert the yellow phosphorus tail gas according to actual needs, which not only realizes the rational use of resources, but also avoids overloading of subsequent catalytic treatment devices.

[0037] In this embodiment, the gas heating device specifically includes a heat exchanger 5 and a heater 6. The function of the heat exchanger 5 is to preheat the yellow phosphorus tail gas output from the desulfurization device 9 using the yellow phosphorus tail gas output from the gas distribution cylinder 4, and the function of the heater 6 is to further heat the yellow phosphorus tail gas preheated by the heat exchanger 5 using external water vapor.

[0038] The gas heating device adopts a two-stage heating method using heat exchanger 5 and heater 6. This design not only saves energy but also ensures that the yellow phosphorus gas entering the dephosphorization unit 7 reaches the appropriate reaction temperature.

[0039] In summary, the working process of the above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization equipment is as follows: the yellow phosphorus tail gas first undergoes water scrubbing treatment in the first scrubbing system (including two-stage first scrubbing towers) and alkaline solution scrubbing treatment in the second scrubbing system (including a first-stage second scrubbing tower). After being separated by the gas-liquid separation device 3, it enters the gas distribution cylinder 4. The gas distribution cylinder 4 diverts part of the yellow phosphorus tail gas to the gas holder for storage and combustion, while the other part is heated by the heat exchanger 5 (using the yellow phosphorus tail gas output from the desulfurization device 9 for preheating) and the heater 6, and then sequentially enters the dephosphorization device 7 (PH3 and P4 react on the first catalyst to form phosphorus oxide and phosphoric acid), the organic sulfur hydrolysis conversion device 8 (organic sulfur is hydrolyzed into H2S on the second catalyst), and the desulfurization device 9 (H2S reacts on the third catalyst to form elemental S and sulfuric acid), and is finally discharged as desulfurized flue gas.

[0040] It should be noted that the first, second, and third catalytic flue gas treatment devices mentioned above all use catalytic methods to treat flue gas. From the perspective of process principle, they are not entirely new technologies (for example, there is already a technology in the field of natural gas purification that catalytically hydrolyzes organic sulfur into hydrogen sulfide). However, the key lies in the combination method and the selection of appropriate catalysts and operating process parameters based on the combined process.

[0041] In this embodiment, the operating conditions of the first reactor are:

[0042] 1) First catalyst formulation:

[0043] The first catalyst is mainly composed of the following components in parts by weight, uniformly mixed:

[0044] Nano-PdO particles: 0.8-1.2 parts;

[0045] Nano PtO2 particles: 0.4-0.6 parts;

[0046] CeO2: 3.5-4.5 parts;

[0047] V2O5: 2.5-3.5 parts;

[0048] Activated carbon carrier: 90-93 parts;

[0049] The weight ratio of nano-PdO particles to nano-PtO2 particles is (1.8-2):1, and the weight ratio of CeO2 to V2O5 is (1.2-1.5):1.

[0050] 2) Operating parameters of the first reactor: operate at 100-120℃, with a space velocity controlled at 1000-2000 h⁻¹. -1 The O2 concentration in the gas phase is 5-8% (v / v%), and the moisture content is less than 2% (v / v%).

[0051] It can be seen that the first catalyst mainly consists of nano-PdO particles, nano-PtO2 particles, CeO2, V2O5, and an activated carbon support. The weight ratio of nano-PdO to nano-PtO2 is controlled at (1.8-2):1, and the weight ratio of CeO2 to V2O5 is controlled at (1.2-1.5):1. Under conditions of 100-120℃ and a space velocity of 1000-2000 h⁻¹, the catalyst was successfully applied. -1 It operates under conditions where the O2 concentration in the gas phase is 5-8% (v / v%) and the moisture content is less than 2% (v / v%).

[0052] In the first catalyst, nano-sized PdO and PtO2 serve as the main active components, exhibiting excellent oxidation catalytic performance and efficiently catalyzing the oxidation conversion of PH3 and P4. CeO2 possesses good oxygen storage and release properties and redox performance, providing active oxygen for the reaction. V2O5 enhances the catalyst's sulfur resistance. The activated carbon support provides a large specific surface area, which is beneficial for the dispersion of active components and the adsorption of reactants. The overall formulation design achieves highly efficient catalytic oxidation of phosphorus-containing pollutants.

[0053] Specifically, CeO2 has a unique fluorite-type crystal structure, where Ce ions can reversibly switch between +3 and +4 valence states, while lattice oxygen can freely enter and exit the lattice, forming oxygen vacancies. Under oxygen-rich conditions, CeO2 can absorb and store oxygen.3+ Oxidized to Ce 4+ Under hypoxic conditions, Ce 4+ It will release oxygen and be reduced to Ce. 3+ This oxygen storage and release process can be represented as: This property allows CeO2 to regulate the local oxygen concentration, continuously providing active oxygen for the catalytic oxidation reaction, thereby maintaining stable catalytic activity. Oxygen vacancies on the CeO2 surface can serve as active sites, promoting the activation of oxygen molecules and improving catalytic oxidation efficiency.

[0054] V₂O₅ forms a VOV structure in the catalyst, which exhibits strong resistance to sulfur poisoning. When sulfur-containing compounds come into contact with the catalyst, the sulfates formed on the V₂O₅ surface are easily decomposed, preventing the accumulation of stable sulfides and thus avoiding permanent deactivation of active sites. Furthermore, a strong interaction exists between V₂O₅ and CeO₂, forming a Ce-OV bridging structure, which further enhances the catalyst's redox performance and sulfur resistance. During catalyst regeneration, V₂O₅ also contributes to the oxidative removal of sulfides, enabling the catalyst to maintain high activity continuously.

[0055] The first reactor involves the following reaction formulas: 4PH3 + 8O2 → 2P2O5 + 6H2O; P4 + 5O2 → P2O5;

[0056] P2O5 + 3H2O → 2H3PO4.

[0057] In this embodiment, the operating conditions of the second reactor are:

[0058] 1) Second catalyst formulation:

[0059] The second catalyst is mainly composed of the following components in parts by weight, uniformly mixed:

[0060] CeO2: 5-7 parts;

[0061] V2O5: 3-4 parts;

[0062] MoO3: 2-3 parts;

[0063] γ-Al2O3 support: 86-90 parts;

[0064] The weight ratio of CeO2 to V2O5 is (1.6-1.8):1, and the weight ratio of V2O5 to MoO3 is (1.4-1.6):1.

[0065] 2) Operating parameters of the second reactor: operate at 70-90℃, with a space velocity controlled at 1000-2000 h⁻¹. -1 The moisture content is 15-20% (v / v%).

[0066] It can be seen that the second catalyst mainly consists of CeO2, V2O5, MoO3, and γ-Al2O3 support, with a CeO2 to V2O5 weight ratio of (1.6-1.8):1 and a V2O5 to MoO3 weight ratio of (1.4-1.6):1. Under conditions of 70-90℃ and a space velocity of 1000-2000 h⁻¹, [the catalyst was successfully tested]. -1 It operates under conditions where the moisture content is 15-20% (v / v%).

[0067] CeO2 through Ce 4+ / Ce 3+ Valence state transitions provide ample redox active sites and form a stable Ce-OV structure with V₂O₅, enhancing resistance to poisoning; V₂O₅ provides appropriate acidic sites to promote hydrolysis, and its V-OH groups can activate water molecules to accelerate the hydrolysis process; MoO₃ not only through Mo 6+ It provides additional Lewis acid sites to enhance hydrolysis activity, effectively inhibits sulfur poisoning, and forms Mo-O-Ce structures with other components; the γ-Al2O3 support, through its large specific surface area (>200m²), provides additional Lewis acid sites to enhance hydrolysis activity, effectively inhibits sulfur poisoning, and forms Mo-O-Ce structures with other components; 2 The appropriate pore structure ensures high dispersion of the active components, while providing excellent mechanical strength and thermal stability. The precise ratio of the three active components (CeO2:V2O5=(1.6-1.8):1, V2O5:MoO3=(1.4-1.6):1) ensures the optimal balance between acidic sites and redox sites, achieving efficient and stable hydrolytic conversion of organic sulfur under low temperature conditions.

[0068] The hydrolysis and conversion process includes the following reaction formulas: COS + H2O = H2S + CO2 and CS2 + 2H2O = 2H2S + CO2.

[0069] In this embodiment, the operating conditions of the third reactor are as follows:

[0070] 1) Third catalyst formulation:

[0071] The third catalyst is mainly composed of the following components in parts by weight, uniformly mixed:

[0072] Fe2O3: 3-5 parts;

[0073] CuO: 2-3 parts;

[0074] MnO2: 1-2 parts;

[0075] Activated carbon carrier: 90-94 parts;

[0076] The weight ratio of Fe2O3 to CuO is (1.5-1.8):1, and the weight ratio of CuO to MnO2 is (1.8-2.0):1.

[0077] 2) Operating process parameters of the third reactor:

[0078] Operate at 65-85℃, with a controlled airspeed of 800-1500 h⁻¹. -1 The O2 concentration in the gas phase is 3-5% (v / v%), and the moisture content is 2-8% (v / v%).

[0079] The third catalyst mainly consists of Fe₂O₃, CuO, MnO₂, and an activated carbon support, with the weight ratio of Fe₂O₃ to CuO being (1.5-1.8):1, and the weight ratio of CuO to MnO₂ being (1.8-2.0):1. The catalyst operates at 65-85℃ with a space velocity of 800-1500 h⁻¹. -1 It operates under conditions of 3-5% (v / v%) O2 concentration and 2-8% (v / v%) moisture content in the gas phase.

[0080] The third catalyst is actually divided into two components: a first type and a second type. The first type of component contains Fe2O3, CuO, and MnO2, which is used to catalytically react H2S and oxygen in the flue gas to produce elemental sulfur. The second type of component contains an activated carbon support, which is used to further catalytically oxidize the sulfur dioxide generated by the reaction of elemental sulfur with oxygen and then react it with water to produce sulfuric acid.

[0081] Fe2O3 is the main active component, through Fe 3+ / Fe 2+ Valence state cycling catalyzes H2S oxidation; CuO via Cu 2+ / Cu + The conversion enhances electron transfer efficiency; MnO2 provides additional redox sites. The precise ratio of the three oxides (Fe2O3:CuO = (1.5-1.8):1, CuO:MnO2 = (1.8-2.0):1) forms a highly efficient multi-metal oxide composite system, achieving selective oxidation of H2S to elemental sulfur under low-temperature conditions (65-85℃). During the reaction, appropriate oxygen concentration and moisture content help maintain the catalytic cycle and inhibit over-oxidation.

[0082] Activated carbon not only serves as a carrier, providing a large specific surface area for dispersing active components, but more importantly, its surface oxygen-containing functional groups play a crucial role in the second-stage reaction. When a small amount of elemental sulfur is over-oxidized to SO2, the oxygen-containing functional groups on the activated carbon surface can catalyze the further oxidation of SO2, converting it into sulfuric acid in the presence of moisture, thereby achieving deep desulfurization. This bifunctional catalytic system ensures both efficient removal of H2S and treatment of SO2 generated during the process under low-temperature conditions, demonstrating the holistic and advanced nature of the catalyst design.

[0083] It is evident that the three-stage catalytic flue gas treatment achieved by the aforementioned yellow phosphorus tail gas dephosphorization and desulfurization equipment belongs to low-temperature catalytic technology (the first reactor operates at 100-120℃, the second reactor at 70-90℃, and the third reactor at 65-85℃). Furthermore, the temperature of the three-stage catalytic flue gas treatment decreases step by step. This temperature gradient design reduces energy consumption (heater 6 can be a steam heater, and the steam source required for the steam heater is readily available at the yellow phosphorus production plant and can be used directly; and apart from heater 6, the yellow phosphorus tail gas does not need to be heated further), while avoiding catalyst sintering and deactivation that may be caused by excessively high temperatures.

[0084] The aforementioned desulfurization unit specifically includes: a reaction system, a regenerated liquid circulation system, and a flue gas conveying system. Of course, in conjunction with... Figure 1 As can be seen, the aforementioned dephosphorization unit also includes a reaction system, a regenerated liquid circulation system, and a flue gas conveying system. The following section will focus on explaining the reaction system, regenerated liquid circulation system, and flue gas conveying system of the desulfurization unit.

[0085] The desulfurization unit's reaction system is used to remove H2S from the flue gas to be treated. It includes at least one reactor (i.e., the third reactor 91), which has an air inlet, an exhaust outlet, a liquid outlet, and a catalyst (i.e., the third catalyst) located in the reactor. The reactor is equipped with a regeneration liquid spraying device for washing and regenerating the catalyst. During operation, the flue gas to be treated enters the reactor through the air inlet, passes through the catalyst, and then exits from the exhaust outlet of the reactor as treated flue gas. When the H2S in the flue gas to be treated passes through the catalyst, it reacts on the catalyst to form elemental sulfur and sulfuric acid. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide produced by the reaction of elemental sulfur with oxygen and then reacting with water. When washing and regenerating the catalyst, the elemental sulfur and the sulfuric acid enter the regeneration liquid sprayed on the catalyst and are then discharged from the reactor's liquid outlet.

[0086] The regenerated liquid circulation system includes at least one regenerated liquid tank and a regenerated liquid circulation control network connecting the at least one regenerated liquid tank and each reactor. The regenerated liquid circulation control network has an output-side control network, an input-side control network, and a regenerated liquid driving device. The output-side control network can guide the regenerated liquid in the selected regenerated liquid tank to the regenerated liquid spraying device of the selected reactor. The input-side control network can guide the regenerated liquid output from the drain outlet of the selected reactor to the selected regenerated liquid tank. The regenerated liquid driving device can provide the required power to the regenerated liquid.

[0087] A flue gas conveying system includes an intake pipe network and an exhaust pipe network. The intake pipe network includes an intake manifold and intake branch pipes that connect the intake manifold to the intake ports of each reactor. Each intake branch pipe has an on / off control mechanism. The exhaust pipe network includes an exhaust manifold and exhaust branch pipes that connect the exhaust manifold to the exhaust ports of each reactor.

[0088] Each intake branch pipe has a bend that extends downwards, then bends back and extends upwards. When it is necessary to cut off the intake of flue gas in the selected intake branch pipe, liquid seal liquid is injected into the corresponding bend through the liquid inlet structure set on the corresponding bend to form a liquid seal. When it is necessary to open up the intake of flue gas in the selected intake branch pipe, the liquid seal liquid in the corresponding bend is discharged through the liquid outlet structure set on the corresponding bend.

[0089] The above-described structure of the desulfurization device can be referenced to the relevant structures in the catalytic flue gas desulfurization equipment disclosed by the applicant in patent documents with publication numbers CN214764545U, CN114653202A, and CN114797450A. The working process of the desulfurization device in this invention is similar to that of the catalytic flue gas desulfurization equipment in these patent documents.

[0090] As mentioned above, the working process of the yellow phosphorus tail gas dephosphorization and desulfurization equipment in the above embodiment is as follows: the yellow phosphorus tail gas first undergoes water washing treatment through the first washing system and alkaline solution washing treatment through the second washing system. After separation by the gas-liquid separator 3, it enters the gas distribution cylinder 4. The gas distribution cylinder 4 diverts part of the yellow phosphorus tail gas to the gas holder for storage and combustion, while the other part is heated by the heat exchanger 5 and the heater 6, and then sequentially enters the dephosphorization device 7, the organic sulfur hydrolysis conversion device 8, and the desulfurization device 9, finally being discharged as desulfurized flue gas. Experiments have found that after water washing and alkaline washing, the yellow phosphorus tail gas still contains a large amount of inorganic sulfur (H2S) and organic sulfur (COS, CS2, etc.). The composition and content of these sulfides depend on the properties and quality of the raw materials. H2S reacts with oxygen to generate elemental sulfur, which is a yellow solid and will deposit on the surface of the first catalyst, increasing the resistance of the first catalyst layer.

[0091] Therefore, the dephosphorization and desulfurization equipment for yellow phosphorus tail gas in another embodiment of the present invention improves upon the above-mentioned dephosphorization and desulfurization equipment for yellow phosphorus tail gas by adding a pre-desulfurization device before the dephosphorization device 7.

[0092] The pre-desulfurization unit can adopt the liquid phase absorption process. Its core principle is to use a proprietary liquid phase desulfurizing agent to absorb H2S in the desulfurization tower to become rich liquid. The rich liquid (stored in the rich liquid tank) is regenerated by contacting air in the ejector and restored to lean liquid. After being returned to the desulfurization tower for use through the lean liquid tank, it is used again.

[0093] This liquid-phase desulfurizing agent can use a mixed solution of sodium carbonate and sodium arsenite. During absorption, it reacts with HS to generate NaHS and NaHCO3. Subsequently, upon contact with air in the injector, it undergoes an oxidative regeneration reaction, simultaneously releasing elemental sulfur. The NaOH generated during regeneration reacts with CO in the air to regenerate NaCO3, thus achieving the recycling of the liquid-phase desulfurizing agent. This pre-desulfurization unit can operate at ambient temperature and pressure, featuring simple operation and high efficiency. Sodium arsenite (NaAsO), as the active component (typically added at a dosage of a few grams per liter), acts as a catalyst to improve regeneration efficiency and reaction rate: it is reduced to arsenite during HS absorption and oxidized back to sodium arsenite upon contact with air, thus repeating the cycle.

[0094] Of course, the pre-desulfurization unit can also use the same desulfurization unit as the desulfurization unit. In an optional embodiment, the desulfurization unit is a desulfurization tower, which contains multiple reactors, some of which serve as reactors for the pre-desulfurization unit and others as reactors for the desulfurization unit.

[0095] like Figure 1 As shown, in the aforementioned yellow phosphorus tail gas purification system, a flue gas driving device 10 is provided before the scrubbing pretreatment device. This device includes at least two induced draft fans 11 connected in parallel between the total flue gas inlet pipe and the total flue gas outlet pipe. Each induced draft fan 11 has valves at its inlet and outlet. Currently, switching between the induced draft fans 11 is achieved by controlling the opening and closing of these valves. The inventors have discovered that these valves are difficult to completely seal, and yellow phosphorus tail gas is a flammable, explosive, and highly toxic gas. When switching between the induced draft fans is achieved by controlling the opening and closing of these valves, backflow can easily occur, posing a certain safety hazard.

[0096] In one embodiment of the present invention, the flue gas driving device is improved by adjusting the flue gas driving device to be positioned between the scrubbing pretreatment device and the dephosphorization device 7. Furthermore, as... Figure 2As shown, the inlet of each of the two induced draft fans 11 is connected to the total flue gas input pipe through an independently installed first anti-reverse liquid seal device 12, and the outlet of each of the at least two induced draft fans 11 is connected to the total flue gas output pipe through a uniformly installed second anti-reverse liquid seal device 13.

[0097] The first anti-reverse liquid seal device 12 includes a first closed liquid storage tank. The upper part of the first closed liquid storage tank is provided with a first vertical guide tube. The bottom of the first vertical guide tube is immersed below the liquid surface of the first closed liquid storage tank. The upper part of the first vertical guide tube is connected to the flue gas main input pipe. The shell of the first closed liquid storage tank is provided with a first exhaust port above the liquid surface of the first closed liquid storage tank. The first exhaust port is connected to the air inlet of the corresponding induced draft fan.

[0098] The second anti-reverse liquid seal device 13 includes a second closed liquid storage tank. The upper part of the second closed liquid storage tank is provided with a second vertical guide tube corresponding to each of the at least two induced draft fans. The bottom of each second vertical guide tube is immersed below the liquid surface of the second closed liquid storage tank. The upper part of each second vertical guide tube is connected to the exhaust port of the corresponding induced draft fan. The shell of the second closed liquid storage tank is provided with a second exhaust port above the liquid surface of the first closed liquid storage tank. The second exhaust port is connected to the flue gas total output pipe.

[0099] The flue gas drive unit 10 adopts a two-fan, one-standby-one-operation mode. The flue gas delivery process is as follows: the yellow phosphorus tail gas to be treated first passes through the first closed liquid storage tank of the first check-back liquid seal device 12. The flue gas enters from the upper part of the first vertical guide tube, passes through the part of the bottom of the first vertical guide tube submerged below the liquid surface, and after passing through the liquid seal, enters the air inlet of the operating induced draft fan 11 from the first exhaust port. After being pressurized by the induced draft fan 12, the flue gas enters the second check-back liquid seal device 13 from the exhaust port, passes through the upper part of the second vertical guide tube corresponding to the induced draft fan 12, passes through the part of the bottom of the second vertical guide tube submerged below the liquid surface of the second closed liquid storage tank, and finally enters the total flue gas output pipe from the second exhaust port. When the operating induced draft fan 11 needs maintenance or replacement, the standby induced draft fan 11 starts to take over the delivery task. The independent first check-back liquid seal 12 ensures the safety and reliability of the induced draft fan 11 switching process.

[0100] The advantages of this design are: by setting an independent first check seal 12 at the inlet of the induced draft fan 11, gas backflow can be completely prevented when the induced draft fan is stopped; by setting a uniform second check seal 13 at the outlet of the induced draft fan 11, downstream gas backflow can be prevented and equipment investment can be reduced.

[0101] Figure 3 for Figure 1 A partially enlarged view of the dephosphorization unit. (See attached image.) Figure 3 As shown, the first catalytic flue gas treatment device includes a drying system, which comprises a first blower 14 and a heater 15 (each corresponding to the first reactor 71, specifically for use). Figure 1 The heater 6 in the middle, when each first reactor is working, the flue gas to be treated is first heated by the heater 71 corresponding to the first reactor before entering the first reactor) and the drying gas distribution network, the first blower 14 and the heater 15 are connected to each first reactor 71 through the drying gas distribution network, so that the airflow generated by the first blower 14 is heated by the heater 15 to form drying gas and enters the first reactor 71 after the first catalyst is washed and regenerated, and passes through the first catalyst in the first reactor 71. When the drying gas passes through the first catalyst, the regenerated liquid attached to the first catalyst evaporates and is discharged from the first reactor 71 after the catalyst is washed and regenerated with the flow of the drying gas.

[0102] In addition, the drying gas delivery network includes a drying gas delivery pipeline that mixes the drying gas discharged from the first reactor after the first catalyst is washed and regenerated with the flue gas to be treated from other first reactors.

[0103] The working principle of the aforementioned drying system is as follows: An airflow is generated by a first blower, heated by a heater to form drying gas. This drying gas then enters the first reactor after the first catalyst has been washed and regenerated via a drying gas distribution network. This causes the regenerated liquid adhering to the first catalyst to evaporate and be discharged with the drying gas. Simultaneously, the discharged drying gas mixes with the flue gas to be treated from other first reactors through the drying gas distribution network. This design can quickly dry the washed and regenerated first catalyst, improving the efficiency of the dephosphorization unit, and the mixing process fully utilizes the heat from the drying gas.

[0104] The heater 15 has a dual function: on the one hand (during the first catalyst washing and regeneration cycle), it heats the airflow generated by the first blower to form drying gas, ensuring it has sufficient heat to enter the first reactor 71 after washing and regeneration, thereby evaporating and carrying away the regenerated liquid adhering to the first catalyst; on the other hand (during the first reactor's operating cycle), it heats the flue gas to be treated, ensuring that the temperature of the flue gas entering each first reactor 71 meets the requirements of the catalytic reaction. This dual-function design ensures both the drying effect of the first catalyst and the normal progress of the catalytic reaction.

[0105] In addition, the first catalytic flue gas treatment device also includes an oxygen supplementation system, which includes a second blower 16, an airflow regulating device 17, and an oxygen supplementation gas distribution network. The second blower 16 and the airflow regulating device 17 are connected to each first reactor through the oxygen supplementation gas distribution network, so that the airflow generated by the second blower 16 is adjusted by the airflow regulating device 17 to form oxygen supplementation gas and enter the flue gas to be treated in the corresponding first reactor. The oxygen concentration in the oxygen supplementation gas is greater than the oxygen concentration in the flue gas to be treated before mixing the oxygen supplementation gas.

[0106] The oxygen-supplementing gas is air. The airflow regulating device 17 includes a main pipeline and a bypass pipeline connected in parallel. A first shut-off valve, a flow regulating valve, and a second shut-off valve are connected in series on the main pipeline, and a third shut-off valve is provided on the bypass pipeline.

[0107] The airflow regulating device 17 adopts a dual-circuit design with a main pipeline and a bypass pipeline connected in parallel. The main pipeline is equipped with a first shut-off valve, a flow regulating valve, and a second shut-off valve in sequence, while the bypass pipeline is equipped with a third shut-off valve. This structure not only enables precise flow control through the flow regulating valve in the main pipeline, but also provides a fast passage through the bypass pipeline. At the same time, the dual-circuit design provides an operation backup function, and each valve can be maintained and replaced independently, which improves the reliability and maintenance convenience of the system while ensuring the regulation accuracy.

[0108] In addition, each first reactor is provided with at least two layers of first catalyst, and the oxygen supplementation gas distribution network can introduce oxygen supplementation gas into the inlet side space of the at least two layers of first catalyst respectively.

[0109] By setting at least two layers of first catalyst in each first reactor and using an oxygen supply gas distribution network to introduce oxygen supply gas into the inlet space of each catalyst layer, a multi-level oxygen supply and catalytic reaction process is achieved. This layered oxygen supply design not only ensures that each catalyst layer receives sufficient oxygen supply, improving the uniformity and efficiency of the catalytic reaction, but also enables more precise reaction control by adjusting the amount of oxygen supplied to each layer, effectively improving the overall catalytic conversion effect.

[0110] In addition, the oxygen supplementation system also includes an air tank 18 that is connected in series between the second blower 16 and the airflow regulating device.

[0111] By connecting an air reservoir 18 in series between the second blower 16 and the airflow regulating device, the airflow pulsation from the second blower can be effectively buffered and stabilized. At the same time, the air reservoir, as an air storage device, can balance system pressure fluctuations and provide a stable air source for the airflow regulating device. This design not only improves the operational stability of the oxygen supplementation system, but also makes the airflow regulation more precise and controllable, thereby ensuring the safe and reliable operation of the entire system.

[0112] The working principle of the above-mentioned oxygen supplementation system is as follows: the second blower 16 generates airflow, which is regulated by the main pipeline (including the first shut-off valve, the flow regulating valve and the second shut-off valve) set in parallel. The airflow is then introduced into the air inlet space of at least two layers of the first catalyst in each first reactor through the oxygen supplementation gas distribution pipeline. At the same time, an air tank 18 is set between the second blower 16 and the airflow regulating device 17. This design avoids the safety hazards that may be caused by mixed oxygen supplementation outside the first reactor 71 by directly supplementing oxygen inside the first reactor 71 and precisely controlling the flow and distribution of oxygen supplementation gas. In addition, the setting of the air tank 18 can reduce airflow fluctuations and ensure the stability of oxygen supplementation.

[0113] The foregoing has described the relevant content of the present invention. Those skilled in the art will be able to implement the present invention based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of the present invention.

Claims

1. A catalytic flue gas treatment device, comprising: A reaction system includes at least one reactor, which has an air inlet, an exhaust outlet, a liquid outlet, and a catalyst located in the reactor. The reactor is equipped with a regeneration liquid spraying device for washing and regenerating the catalyst. During operation, the flue gas to be treated enters the reactor through the air inlet, passes through the catalyst, and is then discharged from the exhaust outlet of the reactor as treated flue gas. The target pollutants in the flue gas to be treated undergo an oxidation reaction on the catalyst to form target products when passing through the catalyst. During the washing and regeneration of the catalyst, the target products adhering to the catalyst enter the regeneration liquid sprayed on the catalyst and are then discharged from the liquid outlet of the reactor. A regenerated liquid circulation system includes at least one regenerated liquid tank and a regenerated liquid circulation control network connecting the at least one regenerated liquid tank and each reactor. The regenerated liquid circulation control network has an output-side control network, an input-side control network, and a regenerated liquid driving device. The output-side control network can guide the regenerated liquid in the selected regenerated liquid tank to the regenerated liquid spraying device of the selected reactor. The input-side control network can guide the regenerated liquid output from the drain outlet of the selected reactor to the selected regenerated liquid tank. The regenerated liquid driving device can provide the required power to the regenerated liquid. A flue gas conveying system includes an inlet pipe network and an exhaust pipe network. The inlet pipe network is used to introduce the flue gas to be treated into the inlet of a selected reactor, and the exhaust pipe network is used to output the treated flue gas from the exhaust port of the selected reactor. Its features are: It also includes a drying system, which comprises a first blower, a heater, and a drying gas distribution network. The first blower and the heater are connected to each reactor through the drying gas distribution network, so that the airflow generated by the first blower is heated by the heater to form drying gas, which enters the reactor after catalyst washing and regeneration and passes through the catalyst in the reactor. When the drying gas passes through the catalyst, the regenerated liquid attached to the catalyst evaporates and is discharged from the reactor after catalyst washing and regeneration with the flow of the drying gas. The reaction system includes at least two reactors, and the drying system includes heaters corresponding to these reactors. When each reactor is in operation, the flue gas to be treated is first heated by the heater corresponding to that reactor before entering that reactor. The drying gas distribution network includes a drying gas delivery pipeline that mixes the drying gas discharged from the reactor after catalyst washing and regeneration with the flue gas to be treated from other reactors. The target pollutant is a phosphorus-containing substance; when the phosphorus-containing substance in the flue gas to be treated passes through the catalyst, it reacts on the catalyst to form phosphorus oxide and phosphoric acid. When the catalyst is washed and regenerated, the phosphorus oxide and phosphoric acid enter the regeneration liquid sprayed on the catalyst and are discharged from the drain port of the reactor.

2. The catalytic flue gas treatment device as described in claim 1, characterized in that: The flue gas to be treated is yellow phosphorus tail gas.

3. The catalytic flue gas treatment device as described in claim 2, characterized in that: The yellow phosphorus tail gas is yellow phosphorus tail gas that has undergone rinsing pretreatment; the rinsing pretreatment includes passing the yellow phosphorus tail gas into a first rinsing system for water rinsing treatment and / or passing the yellow phosphorus tail gas into a second rinsing system for alkaline solution rinsing treatment.

4. A yellow phosphorus tail gas purification system, characterized in that: include: The yellow phosphorus tail gas is passed into a dephosphorization device to remove phosphorus-containing substances from the yellow phosphorus tail gas. The dephosphorization device adopts a first catalytic flue gas treatment device, which includes a first reactor. During operation, the yellow phosphorus tail gas enters the first reactor from the inlet, passes through the first catalyst, and is discharged from the exhaust port of the first reactor as dephosphorized flue gas. When the yellow phosphorus tail gas passes through the first catalyst, the PH3 and P4 in the yellow phosphorus tail gas react on the first catalyst to form phosphorus oxide and phosphoric acid. When the first catalyst is washed and regenerated, the phosphorus oxide and phosphoric acid enter the regeneration liquid sprayed on the first catalyst and are discharged from the drain port of the first reactor. The dephosphorized flue gas is passed into an organic sulfur hydrolysis conversion device to convert the organic sulfur in the dephosphorized flue gas into H2S. The organic sulfur hydrolysis conversion device adopts a second catalytic flue gas treatment device, which includes a second reactor. During operation, the dephosphorized flue gas enters the second reactor from the inlet, passes through the second catalyst, and is then discharged from the exhaust port of the second reactor as organic sulfur hydrolysis conversion flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed into H2S when passing through the second catalyst. The organic sulfur hydrolysis conversion flue gas is passed into a desulfurization device to remove H2S from the organic sulfur hydrolysis conversion flue gas. The desulfurization device adopts a third catalytic flue gas treatment device, which includes a third reactor. During operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor from the inlet, passes through the third catalyst, and is discharged from the exhaust port of the third reactor as desulfurized flue gas. When the H2S in the organic sulfur hydrolysis conversion flue gas passes through the third catalyst, it reacts on the third catalyst to form elemental sulfur and sulfuric acid. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide produced by the reaction of elemental sulfur with oxygen and then reacting with water. When the third catalyst is washed and regenerated, the elemental sulfur and the sulfuric acid enter the regeneration liquid sprayed on the third catalyst and are discharged from the drain port of the third reactor. The first catalytic flue gas treatment device adopts the catalytic flue gas treatment device as described in any one of claims 1-3; and the first catalytic flue gas treatment device further includes an oxygen supplementation system for directly supplementing oxygen inside the first reactor. The oxygen supplementation system includes a second blower, an airflow regulating device, and an oxygen supplementation gas distribution network. The second blower and the airflow regulating device are connected to each first reactor through the oxygen supplementation gas distribution network, so that the airflow generated by the second blower is adjusted by the airflow regulating device to form oxygen supplementation gas and enter the flue gas to be treated in the corresponding first reactor. The oxygen concentration in the oxygen supplementation gas is greater than the oxygen concentration in the flue gas to be treated before mixing with the oxygen supplementation gas.

5. The yellow phosphorus tail gas purification system as described in claim 4, characterized in that: The operating conditions of the first reactor are: 1) First catalyst formulation: The first catalyst is mainly composed of the following components in parts by weight, uniformly mixed: Nano-PdO particles: 0.8-1.2 parts; Nano PtO2 particles: 0.4-0.6 parts; CeO2: 3.5-4.5 parts; V2O5: 2.5-3.5 parts; Activated carbon carrier: 90-93 parts; The weight ratio of nano-PdO particles to nano-PtO2 particles is (1.8-2):1, and the weight ratio of CeO2 to V2O5 is (1.2-1.5):

1. 2) Operating parameters of the first reactor: operate at 100-120℃, with a space velocity controlled at 1000-2000 h⁻¹. -1 The O2 concentration in the gas phase is 5-8% (v / v%), and the moisture content is less than 2% (v / v%). The operating conditions for the second reactor are: 1) Second catalyst formulation: The second catalyst is mainly composed of the following components in parts by weight, uniformly mixed: CeO2: 5-7 parts; V2O5: 3-4 parts; MoO3: 2-3 parts; γ-Al2O3 support: 86-90 parts; The weight ratio of CeO2 to V2O5 is (1.6-1.8):1, and the weight ratio of V2O5 to MoO3 is (1.4-1.6):

1. 2) Operating parameters of the second reactor: operate at 70-90℃, with a space velocity controlled at 1000-2000 h⁻¹. -1 The moisture content is 15-20% (v / v%). The operating conditions of the third reactor are as follows: 1) Third catalyst formulation: The third catalyst is mainly composed of the following components in parts by weight, uniformly mixed: Fe2O3: 3-5 parts; CuO: 2-3 parts; MnO2: 1-2 parts; Activated carbon carrier: 90-94 parts; The weight ratio of Fe2O3 to CuO is (1.5-1.8):1, and the weight ratio of CuO to MnO2 is (1.8-2.0):

1. 2) Operating process parameters of the third reactor: Operate at 65-85℃, with a controlled airspeed of 800-1500 h⁻¹. -1 The O2 concentration in the gas phase is 3-5% (v / v%), and the moisture content is 2-8% (v / v%).

6. The yellow phosphorus tail gas purification system as described in claim 4, characterized in that: The device includes a rinsing pretreatment unit, which is installed before the dephosphorization unit. The rinsing pretreatment unit is used to rinsing pretreat the yellow phosphorus tail gas before it is sent into the dephosphorization unit. The rinsing pretreatment unit includes a first rinsing system and / or a second rinsing system. The first rinsing system is used to perform water rinsing treatment on the yellow phosphorus tail gas, and the second rinsing system is used to perform alkaline solution rinsing treatment on the yellow phosphorus tail gas.

7. The yellow phosphorus tail gas purification system as described in claim 6, characterized in that: The first rinsing system includes at least two stages of first rinsing towers, and the second rinsing system includes at least one stage of second rinsing towers, with the second rinsing towers connected in series after the at least two stages of first rinsing towers.

Images