Method and equipment for dephosphorization and desulfurization of yellow phosphorus tail gas

Abstract

The present invention discloses a method and apparatus for dephosphorization and desulfurization of yellow phosphorus tail gas, aiming to address the technical problem of efficiently removing phosphorus-containing and sulfur-containing pollutants from yellow phosphorus tail gas. The method comprises: passing the yellow phosphorus tail gas through a dephosphorization device to remove phosphorus-containing substances from the yellow phosphorus tail gas, wherein the dephosphorization device utilizes a first catalytic flue gas treatment device; passing the dephosphorized flue gas through an organic sulfur hydrolysis and conversion device to convert organic sulfur in the dephosphorized flue gas into H2S, wherein the organic sulfur hydrolysis and conversion device utilizes a second catalytic flue gas treatment device; and passing the organic sulfur hydrolysis and conversion flue gas through a desulfurization device to remove H2S from the organic sulfur hydrolysis and conversion flue gas, wherein the desulfurization device utilizes a third catalytic flue gas treatment device. This method achieves efficient and continuous treatment of phosphorus-containing and sulfur-containing pollutants from yellow phosphorus tail gas.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic flue gas treatment, and in particular to a method and equipment for dephosphorization and desulfurization of yellow phosphorus tail gas, and a catalytic flue gas treatment device. Background Art

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

[0003] On the other hand, yellow phosphorus tail gas is a process gas mainly containing carbon monoxide, which is discharged after the phosphorus collection process in the electric furnace yellow phosphorus production process. In addition to CO, this gas usually also contains impurities such as P4, CO2, PH3, O2, COS, CS2, H2S, water vapor, HF, etc. At present, the main methods for purifying yellow phosphorus tail gas are:

[0004] 1) Water washing method: The yellow phosphorus tail gas is introduced into a water washing tower to remove most of the dust and fluoride, phosphide, and sulfide;

[0005] 2) Alkali washing method: The yellow phosphorus tail gas is introduced into the alkaline washing tower and washed with NaOH solution to remove a large amount of acidic gases such as H2S and CO2 in the tail gas;

[0006] 3) Temperature swing adsorption (TSA) method: using temperature changes to control the adsorption and desorption process, adsorption at low temperature, desorption and regeneration at high temperature, mainly used for dephosphorization;

[0007] 4) Pressure swing adsorption (PSA): uses pressure changes to control the adsorption and desorption process, with high-pressure adsorption and low-pressure desorption and regeneration. It 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 oxidizes the pH3 in yellow phosphorus tail gas into elemental phosphorus and water using a selective catalyst at 200-300°C and near atmospheric pressure by precisely controlling the amount of oxygen.

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

[0010] At present, most manufacturers adopt a combination of water washing and alkaline washing processes. A small number of manufacturers, based on the water washing and alkaline washing processes, also add temperature swing adsorption (TSA), pressure swing adsorption (PSA), DePOx continuous catalytic oxidation dephosphorization process, and chemical oxidant oxidation process. Summary of the Invention

[0011] The purpose of the present invention is to provide a novel method and equipment for dephosphorization and desulfurization of yellow phosphorus tail gas, so as to solve the technical problem of efficiently removing phosphorus-containing pollutants and sulfur-containing pollutants in yellow phosphorus tail gas.

[0012] In addition, another object of the present invention is to provide a catalytic flue gas treatment device, which can be used in, but not limited to, the above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization methods and equipment, to solve the technical problem of secondary pollution caused by the generation of sulfur dioxide during the catalytic oxidation of H2S.

[0013] The first aspect provides a method for dephosphorization and desulfurization of yellow phosphorus tail gas, comprising: passing the yellow phosphorus tail gas into a dephosphorization device to remove phosphorus-containing substances in the yellow phosphorus tail gas, the dephosphorization device adopts a first catalytic flue gas treatment device, the first catalytic flue gas treatment device comprises a first reactor, during operation, the yellow phosphorus tail gas enters the first reactor from the air inlet of the first reactor and then passes through the first catalyst and is discharged from the exhaust port of the first reactor to become dephosphorized flue gas, PH3 and P4 in the yellow phosphorus tail gas react on the first catalyst to form phosphorus oxide and phosphoric acid when passing through the first catalyst, and when the first catalyst is washed and regenerated, the phosphorus oxide and the phosphoric acid enter the regeneration liquid sprayed on the first catalyst and are discharged from the drain port of the first reactor; passing the dephosphorized flue gas 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, the second catalytic flue gas treatment device comprises a second reactor, during operation, the dephosphorized flue gas enters the air inlet of the second reactor The organic sulfur hydrolysis-converted flue gas enters the second reactor, passes through the second catalyst, and is then discharged from the exhaust port of the second reactor to become organic sulfur hydrolysis-converted flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed and converted into H2S when passing through the second catalyst. The organic sulfur hydrolysis-converted flue gas is passed into a desulfurization device to remove H2S from the organic sulfur hydrolysis-converted flue gas. The desulfurization device adopts a third catalytic flue gas treatment device. The third catalytic flue gas treatment device includes a third reactor. During operation, the organic sulfur hydrolysis-converted flue gas enters the third reactor from the air inlet of the third reactor, passes through the third catalyst, and is then discharged from the exhaust port of the third reactor to become desulfurized flue gas. The H2S in the organic sulfur hydrolysis-converted flue gas reacts on the third catalyst to form elemental S and sulfuric acid when passing through the third catalyst. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacting with water. When the third catalyst is washed and regenerated, the elemental S and the sulfuric acid enter the regeneration liquid sprayed on the third catalyst and are discharged from the drain port of the third reactor.

[0014] The second aspect is a yellow phosphorus tail gas dephosphorization and desulfurization device, comprising: a dephosphorization device for receiving yellow phosphorus tail gas and removing phosphorus-containing substances in the yellow phosphorus tail gas, the dephosphorization device adopts a first catalytic flue gas treatment device, the first catalytic flue gas treatment device comprises a first reactor, when working, the yellow phosphorus tail gas enters the first reactor from the air inlet of the first reactor and then passes through the first catalyst and is discharged from the exhaust port of the first reactor to become dephosphorized flue gas, PH3 and P4 in the yellow phosphorus tail gas react on the first catalyst to form phosphorus oxide and phosphoric acid when passing through the first catalyst, when the first catalyst is washed and regenerated, the phosphorus oxide and the phosphoric acid enter the regeneration liquid sprayed on the first catalyst and are discharged from the drain port of the first reactor; an organic sulfur hydrolysis conversion device for receiving the dephosphorized flue gas and converting the organic sulfur in the dephosphorized flue gas into H2S, the organic sulfur hydrolysis conversion device adopts a second catalytic flue gas treatment device, the second catalytic flue gas treatment device comprises a second reactor, when working, the dephosphorized flue gas enters the air inlet of the second reactor The second reactor then passes through the second catalyst and is then discharged from the exhaust port of the second reactor to become organic sulfur hydrolysis conversion flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed and converted into H2S when passing through the second catalyst. A desulfurization device is used to receive the organic sulfur hydrolysis conversion flue gas and remove H2S from the organic sulfur hydrolysis conversion flue gas. The desulfurization device adopts a third catalytic flue gas treatment device, and the third catalytic flue gas treatment device includes a third reactor. During operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor from the air inlet of the third reactor, passes through the third catalyst, and is then discharged from the exhaust port of the third reactor to become desulfurized flue gas. The H2S in the organic sulfur hydrolysis conversion flue gas reacts on the third catalyst to form elemental S and sulfuric acid when passing through the third catalyst. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacting with water. When the third catalyst is washed and regenerated, the elemental S and the sulfuric acid enter the regeneration liquid sprayed on the third catalyst and are then discharged from the drain port of the third reactor.

[0015] The above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization method and equipment adopts 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, CS2) into H2S through catalytic hydrolysis; the third stage catalytically oxidizes H2S to elemental S. The entire treatment process can achieve efficient and continuous treatment of phosphorus-containing pollutants and sulfur-containing pollutants in yellow phosphorus tail gas through the selective reaction of the catalyst. In addition, in order to address the problem that elemental S is easily oxidized to form sulfur dioxide, thereby causing secondary pollution, the third catalyst can further catalytically oxidize sulfur dioxide and react with water to form sulfuric acid, thereby avoiding the problem of sulfur dioxide emissions.

[0016] More specifically, the above-mentioned three-stage catalytic flue gas treatment has the following coupling effects: First, phosphides (especially PH3 and P4) are inherently toxic and will poison subsequent catalysts (phosphides such as PH3 and P4 have strong reducing and coordination properties. When they come into contact with the catalyst surface, they are prone to chemical adsorption and chemical reactions with the active sites of the catalyst, thereby occupying or covering the active sites of the catalyst). Therefore, by preferentially removing phosphides, the activity and service life of the subsequent second and third catalysts can be effectively protected. Secondly, organic sulfur is uniformly converted into H2S through catalytic hydrolysis in the second stage. Compared with organic sulfides such as COS and CS2, H2S is more easily catalytically oxidized, which can significantly improve the desulfurization efficiency of the third stage. Finally, the temperature gradient and chemical reaction characteristics of the entire treatment chain form a good synergistic effect.

[0017] According to a third aspect, a catalytic flue gas treatment device is provided, comprising: a reaction system for removing H2S from the flue gas to be treated by reaction, comprising at least one reactor, the reactor having an air inlet, an exhaust port, a liquid discharge port and a catalyst located in the reactor, the reactor being provided with a regeneration liquid spraying device for washing and regenerating the catalyst, wherein during operation, the flue gas to be treated enters the reactor from the air inlet of the reactor, passes through the catalyst and is discharged from the exhaust port of the reactor to become treated flue gas, and the H2S in the flue gas to be treated reacts on the catalyst to form elemental S and sulfuric acid when passing through the catalyst, the sulfuric acid being generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacting with water, and when the catalyst is washed and regenerated, the elemental S and the sulfuric acid enter the regeneration liquid sprayed on the catalyst and are discharged from the liquid discharge port of the reactor; A liquid circulation system comprises at least one regeneration liquid tank and a regeneration liquid circulation control pipe network connected between the at least one regeneration liquid tank and each reactor, wherein the regeneration liquid circulation control pipe network comprises an output side control pipe network, an input side control pipe network and a regeneration liquid driving device, wherein the output side control pipe network can introduce the regeneration liquid in the selected regeneration liquid tank into the regeneration liquid spraying device of the selected reactor, and the input side control pipe network can introduce the regeneration liquid output from the discharge port of the selected reactor into the selected regeneration liquid tank, and the regeneration liquid driving device can provide the required power to the regeneration liquid; a flue gas conveying system comprises an air intake pipe network and an exhaust pipe network, wherein the air intake pipe network comprises an air intake main pipe and various air intake branches respectively connecting the air intake main pipe to the air intake ports of each reactor, and each air intake branch pipe is respectively provided with an on-off control mechanism, and the exhaust pipe network comprises an exhaust main pipe and various exhaust branches respectively connecting the exhaust main pipe to the exhaust ports of each reactor.

[0018] The catalytic flue gas treatment device integrates a reaction system, a regeneration liquid circulation system, and a flue gas delivery system. The catalyst converts H2S into elemental S. To address the problem of elemental S being easily oxidized to form sulfur dioxide, which can cause secondary pollution, the catalyst further catalytically oxidizes the sulfur dioxide and reacts it with water to form sulfuric acid, thus avoiding sulfur dioxide emissions. Furthermore, the regeneration liquid circulation system achieves directional delivery and recovery of the regeneration liquid through a circulation control network, providing flexible operation. The flue gas delivery system's intake and exhaust pipe network design enables multiple reactors to operate in parallel, facilitating maintenance and overhaul. It can be used in applications including, but not limited to, the aforementioned yellow phosphorus tail gas dephosphorization and desulfurization methods and equipment.

[0019] 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 partially given in the following description, partially become apparent from the following description, or be learned through practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings that constitute a part of this specification are used to assist in understanding the present invention. The contents provided in the drawings and the related descriptions in this specification can be used to explain the present invention, but do not constitute improper limitations on the present invention.

[0021] Figure 1 This is a schematic diagram of a yellow phosphorus tail gas dephosphorization and desulfurization device according to an embodiment of the present invention.

[0022] Figure 2 for Figure 1 A partial enlarged view of the desulfurization unit.

[0023] Figure 3 for Figure 1 Schematic diagram of the specific structure of the desulfurization unit.

[0024] Figure 4 This is a schematic diagram of a pre-desulfurization device in a yellow phosphorus tail gas dephosphorization and desulfurization device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention is described clearly and completely below with reference to the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be noted that:

[0026] The technical solutions and technical features provided in each section, including the following description, may be combined with each other unless they conflict. In addition, where possible, these technical solutions, technical features, and related combinations may be assigned specific technical themes and protected by relevant patents.

[0027] The embodiments of the present invention involved in the following description are generally only a part of the embodiments rather than all the embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of patent protection.

[0028] The terms "include," "comprising," "having," and any variations thereof in this specification, the corresponding claims, and related parts are intended to cover non-exclusive inclusions. Other related terms and units are to be reasonably interpreted based on the relevant content provided in this specification.

[0029] Figure 1 This is a schematic diagram of a yellow phosphorus tail gas dephosphorization and desulfurization device according to an embodiment of the present invention. Figure 1 As shown, a yellow phosphorus tail gas dephosphorization and desulfurization device mainly includes: a dephosphorization device 7, an organic sulfur hydrolysis conversion device 8 and a desulfurization device 9.

[0030] The dephosphorization device 7 is used to receive yellow phosphorus tail gas and remove phosphorus-containing substances in 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 air inlet of the first reactor 71, passes through the first catalyst, and is then discharged from the exhaust port of the first reactor 71 to become dephosphorized flue gas. 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. When the first catalyst is washed and regenerated, the phosphorus oxides and the phosphoric acid enter the regeneration liquid sprayed on the first catalyst and are discharged from the drain port of the first reactor 71.

[0031] 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, and the second catalytic flue gas treatment device includes a second reactor 81. During operation, the dephosphorized flue gas enters the second reactor 81 from the air inlet of the second reactor 81, passes through the second catalyst, and is discharged from the exhaust port of the second reactor 81 to become organic sulfur hydrolysis conversion flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed and converted into H2S when passing through the second catalyst.

[0032] The desulfurization device 9 is used to receive the organic sulfur hydrolysis conversion flue gas and remove H2S from the organic sulfur hydrolysis conversion flue gas. The desulfurization device 9 adopts a third catalytic flue gas treatment device, and the third catalytic flue gas treatment device includes a third reactor 91. During operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor 91 from the air inlet of the third reactor 91, passes through the third catalyst, and is then discharged from the exhaust port of the third reactor 91 to become desulfurized flue gas. The H2S in the organic sulfur hydrolysis conversion flue gas reacts on the third catalyst to form elemental S and sulfuric acid when passing through the third catalyst. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacting with water. When the third catalyst is washed and regenerated, the elemental S and the sulfuric acid enter the regeneration liquid sprayed on the third catalyst and are discharged from the drain port of the third reactor 91.

[0033] The above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization equipment adopts 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, CS2) into H2S through catalytic hydrolysis; the third stage catalytically oxidizes H2S to elemental S. The entire treatment process can achieve efficient and continuous treatment of phosphorus-containing pollutants and sulfur-containing pollutants in yellow phosphorus tail gas through the selective reaction of the catalyst. In addition, in order to address the problem that elemental S is easily oxidized to form sulfur dioxide, thereby causing secondary pollution, the third catalyst can further catalytically oxidize sulfur dioxide and react with water to form sulfuric acid, thereby avoiding the problem of sulfur dioxide emissions.

[0034] More specifically, the above-mentioned three-stage catalytic flue gas treatment has the following coupling effects: First, phosphides (especially PH3 and P4) are inherently toxic and will poison subsequent catalysts (phosphides such as PH3 and P4 have strong reducing and coordination properties. When they come into contact with the catalyst surface, they are prone to chemical adsorption and chemical reactions with the active sites of the catalyst, thereby occupying or covering the active sites of the catalyst). Therefore, by preferentially removing phosphides, the activity and service life of the subsequent second and third catalysts can be effectively protected. Secondly, organic sulfur is uniformly converted into H2S through catalytic hydrolysis in the second stage. Compared with organic sulfides such as COS and CS2, H2S is more easily catalytically oxidized, which can significantly improve the desulfurization efficiency of the third stage. Finally, the temperature gradient and chemical reaction characteristics of the entire treatment chain form a good synergistic effect.

[0035] like Figure 1As shown, the above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization equipment can also include a leaching pretreatment device, which is arranged before the dephosphorization device 7. The leaching pretreatment device is used to perform leaching pretreatment on the yellow phosphorus tail gas before sending it into the dephosphorization device 7; the leaching pretreatment 7 includes a first leaching system 1 and / or a second leaching system 2. The first leaching system 1 is used to perform water leaching treatment on the yellow phosphorus tail gas, and the second leaching system 2 is used to perform alkaline solution leaching treatment on the yellow phosphorus tail gas.

[0036] Specifically, in this embodiment, the elution pretreatment 7 includes a first elution system 1 and a second elution system 2, the first elution system 1 includes a two-stage first elution tower, the second elution system 2 includes a one-stage second elution tower, and the second elution tower is arranged in series after the two-stage first elution tower.

[0037] The elution pretreatment device is mainly used to remove large particulate matter and some water-soluble gaseous pollutants in yellow phosphorus tail gas. Water elution treatment can preliminarily remove some phosphorus- and sulfur-containing compounds, and alkaline solution elution treatment can further remove acidic gases, thereby reducing the load of subsequent treatment.

[0038] In addition, a gas-liquid separator 3 and a gas heating device are sequentially provided between the elution pretreatment device and the dephosphorization device 7. The gas-liquid separator 3 is used to separate the gas and liquid. The separated yellow phosphorus tail gas can first enter the gas separation cylinder 4, which can shunt the yellow phosphorus tail gas as needed. For example, the gas separation cylinder 4 can shunt a portion of the yellow phosphorus tail gas to a gas tank for storage (the yellow phosphorus tail gas in the gas tank can be used for combustion) and shunt a portion of the yellow phosphorus tail gas to the gas heating device.

[0039] The gas separation cylinder 4 is arranged after the gas-liquid separation device 3 and before the gas heating device, and can divert the yellow phosphorus tail gas according to actual needs, which not only realizes the rational use of resources but also avoids overload of subsequent catalytic treatment devices.

[0040] 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 use the yellow phosphorus tail gas output by the desulfurization device 9 to preheat the yellow phosphorus tail gas output by the gas cylinder 4. The function of the heater 6 is to use external water vapor to further heat the yellow phosphorus tail gas preheated by the heat exchanger 5.

[0041] The gas heating device adopts a two-stage heating method of a heat exchanger 5 and a heater 6. This design not only saves energy but also ensures that the yellow phosphorus gas entering the dephosphorization device 7 reaches a suitable reaction temperature.

[0042] 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 passes through the first elution system (including two-stage first elution towers) for water elution treatment and the second elution system (including one-stage second elution tower) for alkaline solution elution treatment, and then enters the gas separation cylinder 4 after separation by the gas-liquid separation device 3. The gas separation cylinder 4 diverts part of the yellow phosphorus tail gas to the gas tank for storage for combustion, and the other part is heated by the heat exchanger 5 (preheated by the yellow phosphorus tail gas output by the desulfurization device 9) and the heater 6, and then 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 and converted 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.

[0043] It should be pointed out that the above-mentioned first catalytic flue gas treatment device, the second catalytic flue gas treatment device and the third catalytic flue gas treatment device all use catalytic methods to treat flue gas. From the perspective of process principles, each of them is not a brand new technology (for example, in the field of natural gas purification, there is already a technology for catalytic hydrolysis of organic sulfur into hydrogen sulfide), but the key lies in the combination method and the selection of suitable catalysts and operating process parameters based on the combined process.

[0044] In this embodiment, the operating conditions of the first reactor are:

[0045] 1) First catalyst formula:

[0046] The first catalyst is mainly composed of the following components in parts by weight:

[0047] Nano PdO particles: 0.8-1.2 parts;

[0048] Nano-PtO2 particles: 0.4-0.6 parts;

[0049] CeO2: 3.5-4.5 parts;

[0050] V2O5: 2.5-3.5 parts;

[0051] Activated carbon carrier: 90-93 parts;

[0052] 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;

[0053] 2) Operating parameters of the first reactor: operate at 100-120°C and control the space velocity to 1000-2000h -1 , the O2 concentration in the gas phase is 5-8% (v / v%), and the moisture content is less than 2% (v / v%).

[0054] It can be seen that the first catalyst is mainly composed of nano-PdO particles, nano-PtO2 particles, CeO2, V2O5 and activated carbon carrier, wherein 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 the conditions of 100-120℃ and the space velocity of 1000-2000h -1 , it operates under the conditions of O2 concentration in the gas phase 5-8% (v / v%) and moisture content less than 2% (v / v%).

[0055] The first catalyst, composed primarily of nanoscale PdO and PtO2, exhibits excellent catalytic performance, effectively catalyzing the oxidation of PH3 and P4. CeO2, with its excellent oxygen storage and release properties and redox properties, provides active oxygen for the reaction. V2O5 enhances the catalyst's sulfur tolerance. The activated carbon support provides a large surface area, facilitating the dispersion of active components and the adsorption of reactants. This overall formulation achieves highly efficient catalytic oxidation of phosphorus-containing pollutants.

[0056] Specifically, CeO2 has a unique fluorite crystal structure, Ce ions can be reversibly converted between +3 and +4 valence states, while lattice oxygen can freely enter and exit the lattice to form 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 reduce to Ce 3+ This oxygen storage and release process can be expressed as: This property enables CeO2 to regulate the local oxygen concentration, continuously providing active oxygen for the catalytic oxidation reaction, thereby maintaining stable catalytic activity. The oxygen vacancies on the CeO2 surface can serve as active sites, promoting the activation of oxygen molecules and improving the catalytic oxidation efficiency.

[0057] V2O5 forms a VOV structure in the catalyst, which offers strong resistance to sulfur poisoning. When sulfur-containing compounds come into contact with the catalyst, the sulfates formed on the V2O5 surface readily decompose, preventing the accumulation of stable sulfides on the catalyst surface, thereby preventing permanent deactivation of active sites. Furthermore, a strong interaction between V2O5 and CeO2 forms a Ce-OV bridge structure, further enhancing the catalyst's redox performance and sulfur resistance. During catalyst regeneration, V2O5 also aids in the oxidative removal of sulfides, enabling the catalyst to maintain its high activity.

[0058] The reaction formulas involved in the first reactor are: 4PH3+8O2→2P2O5+6H2O; P4+5O2→P2O5;

[0059] P2O5+3H2O→2H3PO4.

[0060] In this embodiment, the operating conditions of the second reactor are:

[0061] 1) Second catalyst formula:

[0062] The second catalyst is mainly composed of the following components in parts by weight:

[0063] CeO2: 5-7 parts;

[0064] V2O5: 3-4 parts;

[0065] MoO3: 2-3 parts;

[0066] γ-Al2O3 carrier: 86-90 parts;

[0067] Among them, 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;

[0068] 2) Second reactor operating parameters: operate at 70-90°C, control the space velocity to 1000-2000h -1 , the moisture content is 15-20% (v / v%).

[0069] It can be seen that the second catalyst is mainly composed of CeO2, V2O5, MoO3 and γ-Al2O3 carrier, wherein 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. Under the conditions of 70-90℃ and the space velocity of 1000-2000h -1 , and operate under the condition of moisture content 15-20% (v / v%).

[0070] CeO2 through Ce 4+ / Ce 3+ Valence conversion provides sufficient redox active sites and forms a stable Ce-OV structure with V2O5 to enhance anti-poisoning ability; V2O5 provides appropriate acidic sites to promote hydrolysis reaction, and its V-OH group 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 a Mo-O-Ce structure with other components; the γ-Al2O3 carrier has a large specific surface area (>200m 2 / g) and a suitable pore structure ensure 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 an optimal balance between acidic sites and redox sites, achieving efficient and stable hydrolysis conversion of organic sulfur under low-temperature conditions.

[0071] The hydrolysis conversion process includes the following reaction formulas: COS+H2O=H2S+CO2 and CS2+2H2O=2H2S+CO2.

[0072] In this embodiment, the operating conditions of the third reactor are:

[0073] 1) The third catalyst formula:

[0074] The third catalyst is mainly composed of the following components in parts by weight:

[0075] Fe2O3: 3-5 parts;

[0076] CuO: 2-3 parts;

[0077] MnO2: 1-2 parts;

[0078] Activated carbon carrier: 90-94 parts;

[0079] Among them, 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;

[0080] 2) Operation parameters of the third reactor:

[0081] Run at 65-85℃, control the airspeed to 800-1500h -1 , the O2 concentration in the gas phase is 3-5% (v / v%), and the moisture content is 2-8% (v / v%).

[0082] The third catalyst is mainly composed of Fe2O3, CuO, MnO2 and activated carbon carrier, wherein 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. Under the conditions of 65-85℃ and the space velocity of 800-1500h -1 , it operates under the conditions of O2 concentration of 3-5% (v / v%) and moisture content of 2-8% (v / v%) in the gas phase.

[0083] The third catalyst is actually divided into a first component and a second component. The first component, which includes Fe2O3, CuO, and MnO2, is used to catalyze the reaction of H2S and oxygen in the flue gas to produce elemental sulfur. The second component, which includes an activated carbon carrier, is used to further catalyze the oxidation of sulfur dioxide produced by the reaction of elemental sulfur and oxygen, and react it with water to produce sulfuric acid.

[0084] Fe2O3 is the main active component, through Fe 3+ / Fe 2+ Valence cycle catalyzes H2S oxidation; CuO through Cu 2+ / Cu + The conversion enhances electron transfer efficiency, while 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, enabling the selective oxidation of H2S to elemental sulfur at low temperatures (65-85°C). The appropriate oxygen concentration and moisture during the reaction help maintain the catalytic cycle and inhibit over-oxidation.

[0085] Activated carbon not only serves as a carrier, providing a large surface area for dispersing the active components, but more importantly, its surface oxygen-containing functional groups play a key role in the second-stage reaction. When a small amount of elemental sulfur is over-oxidized to form SO2, the oxygen-containing functional groups on the activated carbon surface catalyze further oxidation of the SO2, which is then converted to sulfuric acid in the presence of water, achieving deep desulfurization. This dual-functional catalytic system ensures efficient H2S removal at low temperatures while also treating SO2 generated during the process, demonstrating the holistic and advanced nature of the catalyst design.

[0086] It can be seen that the three-stage catalytic flue gas treatment implemented by the above-mentioned yellow phosphorus tail gas dephosphorization and desulfurization equipment belongs to low-temperature catalytic technology (the first reactor is operated at 100-120°C, the second reactor is operated at 70-90°C, and the third reactor is operated at 65-85°C), and the temperature of the three-stage catalytic flue gas treatment is reduced step by step. This temperature gradient design reduces energy consumption (heater 6 can use a steam heater, and the steam source required by the steam heater is already available in the yellow phosphorus manufacturer and can be used directly; and the yellow phosphorus tail gas does not need to be heated except for heater 6), while avoiding the catalyst sintering and deactivation that may be caused by excessive temperature.

[0087] Figure 2 for Figure 1 A partial enlarged view of the desulfurization unit. Figure 3 for Figure 1 Schematic diagram of the specific structure of the desulfurization device. Figure 2-Figure 3 As shown, the above desulfurization device specifically includes: reaction system, regeneration liquid circulation system and flue gas transportation system. Figure 1 It can be seen that the above-mentioned dephosphorization device also includes a reaction system, a regeneration liquid circulation system and a flue gas conveying system. The following description will focus on the reaction system, regeneration liquid circulation system and flue gas conveying system of the desulfurization device.

[0088] like Figure 2-Figure 3 As shown, the reaction system of the desulfurization device is used to react and remove H2S in the flue gas to be treated, and includes at least one reactor (i.e., the third reactor 91). The reactor has an air inlet, an exhaust port, a liquid discharge port and a catalyst located in the reactor (i.e., the third catalyst). The reactor is provided with a regeneration liquid spraying device for washing and regenerating the catalyst. During operation, the flue gas to be treated enters the reactor from the air inlet of the reactor, passes through the catalyst, and is then discharged from the exhaust port of the reactor to become treated flue gas. When passing through the catalyst, the H2S in the flue gas to be treated reacts on the catalyst to form elemental S and sulfuric acid. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacts with water. When the catalyst is washed and regenerated, the elemental S and the sulfuric acid enter the regeneration liquid sprayed on the catalyst and are discharged from the liquid discharge port of the reactor.

[0089] The regeneration liquid circulation system 92 includes at least one regeneration liquid tank 921 and a regeneration liquid circulation control pipeline network connected between the at least one regeneration liquid tank 921 and each reactor. The regeneration liquid circulation control pipeline network has an output side control pipeline network 922, an input side control pipeline network 923 and a regeneration liquid driving device. The output side control pipeline network 922 can introduce the regeneration liquid in the selected regeneration liquid tank 921 into the regeneration liquid spraying device of the selected reactor. The input side control pipeline network 923 can introduce the regeneration liquid output from the discharge port of the selected reactor into the selected regeneration liquid tank 921. The regeneration liquid driving device can provide the required power to the regeneration liquid.

[0090] The flue gas delivery system 93 includes an air intake network 931 and an exhaust network 932. The air intake network 931 includes an air intake main pipe and air intake branches that connect the air intake main pipe to the air inlets of each reactor respectively. Each air intake branch has an on-off control mechanism. The exhaust network 932 includes an exhaust main pipe and exhaust branches that connect the exhaust main pipe to the exhaust ports of each reactor respectively.

[0091] Among them, each air intake branch pipe has a bending portion 933 that extends downward, then turns back and extends upward. When it is necessary to cut off the air intake of the flue gas in the selected air intake branch pipe, a liquid sealing liquid is injected into the corresponding bending portion 933 through the liquid inlet structure provided on the corresponding bending portion to form a liquid seal for the bending portion. When it is necessary to conduct the air intake of the flue gas in the selected air intake branch pipe, the liquid sealing liquid in the corresponding bending portion is discharged through the liquid discharge structure provided on the corresponding bending portion 933.

[0092] The above structure of the desulfurization device can refer to the relevant structures of the catalytic flue gas desulfurization equipment disclosed in the patent documents of the applicant, such as CN214764545U, CN114653202A, and CN114797450A. The desulfurization device of the present invention and the catalytic flue gas desulfurization equipment in these patent documents have similar working processes.

[0093] However, in the desulfurization device of the present invention, the height of the intake side of the bend 933 on each intake branch pipe is set higher than the height of the exhaust side of the bend 933 (see Figure 2 The height difference between the air inlet side of the bent portion 933 and the air outlet side of the bent portion 933 is H. In addition, the liquid level of the sealing liquid injected into the bent portion 933 can rise to the air outlet side of the bent portion 933 and overflow from the channel on the air outlet side of the bent portion 933 to the air inlet of the corresponding reactor.

[0094] Setting the inlet side of the bend 933 on each inlet branch pipe higher than the outlet side makes it easier to control the level of the sealing liquid injected into the bend 933 (the overflow point height of the channel on the outlet side of the bend 933) and ensures that the overflow direction is always toward the reactor's air inlet, preventing the sealing liquid from flowing back into the inlet manifold. This design makes the flow direction of the sealing liquid more controllable and improves the reliability and safety of the liquid seal.

[0095] Furthermore, the liquid inlet structure of the bend 933 on each inlet branch pipe is connected to the at least one regeneration liquid tank via a liquid sealing liquid delivery pipeline system. The output-side control pipeline network 922 comprises an output-side main pipe and output-side branches connecting the output-side main pipe to the regeneration liquid spray device of each reactor. Each output-side branch is equipped with a regeneration liquid delivery control valve 924. A liquid sealing liquid delivery manifold 925 branches off from the pipeline on each output-side branch before the corresponding regeneration liquid delivery control valve 924. Each liquid delivery manifold is connected to the liquid inlet structure of the bend 933 on the inlet branch pipe of the corresponding reactor via a corresponding liquid sealing liquid delivery control valve 925 provided on the liquid delivery manifold. The liquid inlet structure is a liquid inlet interface provided on the pipeline on the exhaust side of the corresponding bend 933.

[0096] In this way, when the catalyst in the selected reactor needs to be washed and regenerated, the regeneration liquid in the selected regeneration liquid tank is guided to the regeneration liquid spraying device of the selected reactor through the regeneration liquid circulation system. During this process, the liquid sealing liquid delivery control valve corresponding to the selected reactor is first opened for a period of time to allow the liquid level of the liquid sealing liquid injected into the corresponding bend to rise to the overflow height on the exhaust side of the bend and then the liquid sealing liquid is discharged from the channel on the exhaust side of the bend to the air inlet of the corresponding reactor, thereby maintaining the liquid level of the liquid sealing liquid injected into the corresponding bend below the overflow height on the exhaust side of the bend. Then, the liquid sealing liquid delivery control valve corresponding to the selected reactor is closed and the regeneration liquid delivery control valve corresponding to the selected reactor is ensured to be opened.

[0097] By first opening the sealing liquid delivery control valve corresponding to the selected reactor for a period of time, the liquid level of the sealing liquid injected into the corresponding bend is raised to the overflow height on the exhaust side of the bend and the sealing liquid is discharged from the channel on the exhaust side of the bend to the air inlet of the corresponding reactor, thereby keeping the liquid level of the sealing liquid injected into the corresponding bend below the overflow height on the exhaust side of the bend. Then, the sealing liquid delivery control valve corresponding to the selected reactor is closed and the regeneration liquid delivery control valve corresponding to the selected reactor is ensured to be opened. This not only can accurately control the liquid level of the sealing liquid and prevent the sealing liquid from flowing back into the air intake manifold, thereby ensuring the reliability and safety of the liquid seal, but also simultaneously drive the sealing liquid and the regeneration liquid through the regeneration liquid driving device.

[0098] As mentioned above, the yellow phosphorus tail gas dephosphorization and desulfurization equipment of the above embodiment operates as follows: the yellow phosphorus tail gas first undergoes a water rinse treatment through a first rinsing system and an alkaline solution rinse treatment through a second rinsing system. After separation by a gas-liquid separator 3, it enters a gas distributor 4. The gas distributor 4 diverts part of the yellow phosphorus tail gas to a gas tank for storage and combustion. The remaining part, after being heated by a heat exchanger 5 and a heater 6, sequentially enters a dephosphorization unit 7, an organic sulfur hydrolysis and conversion unit 8, and a desulfurization unit 9, and is ultimately discharged as desulfurized flue gas. Experiments have found that after water washing and alkali washing, the yellow phosphorus tail gas still contains a relatively large amount of inorganic sulfur (H2S) and organic sulfur (COS, CS2, etc.). The composition and content of these sulfides depend on the nature and quality of the raw materials. H2S reacts with oxygen to form elemental sulfur, which is a yellow solid that deposits on the surface of the first catalyst, increasing the resistance of the first catalyst layer.

[0099] Therefore, the yellow phosphorus tail gas dephosphorization and desulfurization equipment according to another embodiment of the present invention improves the above yellow phosphorus tail gas dephosphorization and desulfurization equipment by adding a pre-desulfurization device before the dephosphorization device 7 .

[0100] Figure 4 This is a schematic diagram of a pre-desulfurization device in a yellow phosphorus tail gas dephosphorization and desulfurization equipment according to an embodiment of the present invention. Figure 4As shown, the pre-desulfurization device 10 adopts a liquid-phase absorption process, the core principle of which is to use a proprietary liquid-phase desulfurizer in the desulfurization tower 101 to absorb H2S into a rich liquid; the rich liquid (stored in the rich liquid tank 102) is regenerated by contact with air in the ejector 103, and after being restored to a lean liquid, it is returned to the desulfurization tower 101 for use through the lean liquid tank 104.

[0101] This liquid-phase desulfurizer can utilize a mixed solution of sodium carbonate and sodium arsenite. During the absorption process, it reacts with H2S to form NaHS and NaHCO3. Subsequently, an oxidation regeneration reaction occurs in the ejector upon contact with air, simultaneously releasing elemental sulfur. The NaOH generated during the regeneration process reacts with CO2 in the air to regenerate Na2CO3, thereby enabling the recycling of the liquid-phase desulfurizer. The pre-desulfurization device 10 can operate at room temperature and pressure, offering simple operation and high efficiency. Sodium arsenite (NaAsO2), the active component (typically added in a few grams per liter), acts as a catalyst, improving regeneration efficiency and reaction rate. It is reduced to arsenite upon absorbing H2S and oxidized back to sodium arsenite upon contact with air, repeating this cycle.

[0102] Of course, the pre-desulfurization device can also use the same desulfurization device as the desulfurization device 9. In an optional embodiment, the desulfurization device 9 is a desulfurization tower, and multiple reactors are distributed in the desulfurization tower, some of which serve as reactors of the pre-desulfurization device, and the other part serve as reactors of the desulfurization device 9.

[0103] The above describes the relevant contents of the present invention. Based on this description, a person skilled in the art will be able to implement the present invention. Based on the above content of this specification, all other embodiments obtained by a person skilled in the art without making any creative efforts should fall within the scope of the present invention.

Claims

1. A method for dephosphorization and desulfurization of yellow phosphorus tail gas, characterized by: include: Passing yellow phosphorus tail gas into a dephosphorization device to remove phosphorus-containing substances in the yellow phosphorus tail gas, the dephosphorization device adopts a first catalytic flue gas treatment device, the first catalytic flue gas treatment device comprising a first reactor, during operation, the yellow phosphorus tail gas enters the first reactor from an air inlet, passes through a first catalyst, and is then discharged from an exhaust port of the first reactor to become dephosphorized flue gas, PH3 and P4 in the yellow phosphorus tail gas react on the first catalyst when passing through the first catalyst to form phosphorus oxides and phosphoric acid, and when the first catalyst is washed and regenerated, the phosphorus oxides and the phosphoric acid enter a regeneration liquid sprayed on the first catalyst and are then discharged from a liquid outlet of the first reactor; Passing the dephosphorized flue gas into an organic sulfur hydrolysis conversion device to convert organic sulfur in the dephosphorized flue gas into H2S, wherein the organic sulfur hydrolysis conversion device adopts a second catalytic flue gas treatment device, and the second catalytic flue gas treatment device includes a second reactor. During operation, the dephosphorized flue gas enters the second reactor from the air inlet of the second reactor, passes through the second catalyst, and is then discharged from the exhaust port of the second reactor to become organic sulfur hydrolysis conversion flue gas. The organic sulfur in the dephosphorized flue gas is hydrolyzed and converted into H2S when passing through the second catalyst. The organic sulfur hydrolysis conversion flue gas is passed into a desulfurization device to remove H2S in the organic sulfur hydrolysis conversion flue gas. The desulfurization device adopts a third catalytic flue gas treatment device, and the third catalytic flue gas treatment device includes a third reactor. During operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor from the air inlet of the third reactor, passes through the third catalyst, and is then discharged from the exhaust port of the third reactor to become desulfurized flue gas. When passing through the third catalyst, the H2S in the organic sulfur hydrolysis conversion flue gas reacts on the third catalyst to form elemental S and sulfuric acid. The sulfuric acid is generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacting with water. When the third catalyst is washed and regenerated, the elemental S 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 operating conditions of the first reactor are: 1) First catalyst formula: The first catalyst is formed by uniformly mixing the following components in parts by weight: 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°C and control the space velocity to 1000-2000h -1 , the O2 concentration in the gas phase is 5-8% (v / v%), and the moisture content is less than 2% (v / v%).

2. The method for dephosphorization and desulfurization of yellow phosphorus tail gas as claimed in claim 1, wherein: The operating conditions of the second reactor are: 1) Second catalyst formula: The second catalyst is formed by uniformly mixing the following components in parts by weight: CeO2: 5-7 parts; V2O5: 3-4 parts; MoO3: 2-3 parts; γ-Al2O3 carrier: 86-90 parts; Among them, 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) Second reactor operating parameters: operate at 70-90°C, control the space velocity to 1000-2000h -1 , the moisture content is 15-20% (v / v%).

3. The method for dephosphorization and desulfurization of yellow phosphorus tail gas as claimed in claim 1, wherein: The operating conditions of the third reactor are: 1) The third catalyst formula: The third catalyst is formed by uniformly mixing the following components in parts by weight: Fe2O3: 3-5 parts; CuO: 2-3 parts; MnO2: 1-2 parts; Activated carbon carrier: 90-94 parts; Among them, 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) Operation parameters of the third reactor: Run at 65-85℃, control the airspeed to 800-1500h -1 , the O2 concentration in the gas phase is 3-5% (v / v%), and the moisture content is 2-8% (v / v%).

4. The method for dephosphorization and desulfurization of yellow phosphorus tail gas according to any one of claims 1 to 3, wherein: The yellow phosphorus tail gas is subjected to leaching pretreatment before being sent to the dephosphorization device; the leaching pretreatment includes passing the yellow phosphorus tail gas into a first leaching system for water leaching treatment and / or passing the yellow phosphorus tail gas into a second leaching system for alkaline solution leaching treatment.

5. The method for dephosphorization and desulfurization of yellow phosphorus tail gas as claimed in claim 4, wherein: The yellow phosphorus tail gas after the leaching pretreatment is subjected to gas-liquid separation treatment and heating in succession, and then sent to the dephosphorization device.

6. Yellow phosphorus tail gas dephosphorization and desulfurization equipment, characterized by: include: A dephosphorization device for receiving yellow phosphorus tail gas and removing phosphorus-containing substances from the yellow phosphorus tail gas, wherein the dephosphorization device adopts a first catalytic flue gas treatment device, and the first catalytic flue gas treatment device includes a first reactor. During operation, the yellow phosphorus tail gas enters the first reactor from the air inlet, passes through the first catalyst, and is then discharged from the exhaust port of the first reactor to become dephosphorized flue gas. 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. When the first catalyst is washed and regenerated, 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. an organic sulfur hydrolysis conversion device for receiving the dephosphorized flue gas and converting the organic sulfur in the dephosphorized flue gas into H2S; the organic sulfur hydrolysis conversion device adopts a second catalytic flue gas treatment device, the second catalytic flue gas treatment device comprising a second reactor; during operation, the dephosphorized flue gas enters the second reactor from the air inlet, passes through the second catalyst, and is 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 and converted into H2S when passing through the second catalyst; a desulfurization device for receiving the organic sulfur hydrolysis conversion flue gas and removing H2S from the organic sulfur hydrolysis conversion flue gas, the desulfurization device adopts a third catalytic flue gas treatment device, the third catalytic flue gas treatment device includes a third reactor, during operation, the organic sulfur hydrolysis conversion flue gas enters the third reactor from the air inlet of the third reactor, passes through the third catalyst, and is then discharged from the exhaust port of the third reactor to become desulfurized flue gas, the H2S in the organic sulfur hydrolysis conversion flue gas reacts on the third catalyst to form elemental S and sulfuric acid when passing through the third catalyst, the sulfuric acid is generated by further catalytic oxidation of sulfur dioxide generated by the reaction of the elemental S with oxygen and reacting with water, and when the third catalyst is washed and regenerated, the elemental S 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 operating conditions of the first reactor are: 1) First catalyst formula: The first catalyst is formed by uniformly mixing the following components in parts by weight: 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°C and control the space velocity to 1000-2000h -1 , the O2 concentration in the gas phase is 5-8% (v / v%), and the moisture content is less than 2% (v / v%).

7. The yellow phosphorus tail gas dephosphorization and desulfurization equipment according to claim 6, characterized in that:

1. The operating conditions of the second reactor are: 1) Second catalyst formula: The second catalyst is formed by uniformly mixing the following components in parts by weight: CeO2: 5-7 parts; V2O5: 3-4 parts; MoO3: 2-3 parts; γ-Al2O3 carrier: 86-90 parts; Among them, 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) Second reactor operating parameters: operate at 70-90°C, control the space velocity to 1000-2000h -1 , moisture content is 15-20% (v / v%); 2. The operating conditions of the third reactor are: 1) The third catalyst formula: The third catalyst is formed by uniformly mixing the following components in parts by weight: Fe2O3: 3-5 parts; CuO: 2-3 parts; MnO2: 1-2 parts; Activated carbon carrier: 90-94 parts; Among them, 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) Operation parameters of the third reactor: Run at 65-85℃, control the airspeed to 800-1500h -1 , the O2 concentration in the gas phase is 3-5% (v / v%), and the moisture content is 2-8% (v / v%).

8. The yellow phosphorus tail gas dephosphorization and desulfurization equipment according to claim 6, characterized in that: It includes a leaching pretreatment device, which is arranged before the dephosphorization device. The leaching pretreatment device is used to perform leaching pretreatment on the yellow phosphorus tail gas before sending it into the dephosphorization device; the leaching pretreatment includes a first leaching system and / or a second leaching system. The first leaching system is used to perform water leaching treatment on the yellow phosphorus tail gas, and the second leaching system is used to perform alkaline solution leaching treatment on the yellow phosphorus tail gas.

9. The yellow phosphorus tail gas dephosphorization and desulfurization equipment according to claim 8, characterized in that: The first elution system comprises at least two stages of first elution towers, and the second elution system comprises at least one stage of second elution tower, wherein the second elution tower is arranged in series after the at least two stages of first elution towers; And / or, a gas-liquid separation device and a gas heating device are sequentially arranged between the elution pretreatment device and the dephosphorization device.

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