Flue gas multi-pollutant cooperative treatment system, treatment method and application

Abstract

The invention discloses a flue gas multi-pollutant cooperative treatment system, a treatment method and application, belongs to the technical field of flue gas purification, and aims to solve the technical problems of short service life and high flue gas requirement of a catalytic filter bag for flue gas treatment. In the treatment system, a catalytic filter bag is arranged in the integrated dust remover; the flue gas inlet section of the dry-process reactor is communicated with an oxidizing agent conveying module for conveying an oxidizing agent into the dry-process reactor, a deacidification agent conveying module for conveying a deacidification agent into the dry-process reactor and an activated carbon conveying module for conveying activated carbon into the dry-process reactor; and the flue gas outlet section of the dry-method reactor is communicated with a reducing agent conveying module for conveying a reducing agent into the integrated dust remover. Compared with the prior art, the process flow can be shortened, the occupied area of equipment is reduced, the power consumption and the consumption of consumables are reduced (economical efficiency), ultralow emission of pollutants (environment friendliness) is guaranteed, the modification cost is low, the service life of the catalytic filter bag is long, operation and maintenance are easy and convenient, and the energy utilization rate is high.

Description

Technical Field

[0001] This invention relates to the field of flue gas purification technology, and in particular to a multi-pollutant synergistic treatment system, treatment method and application for flue gas. Background Technology

[0002] With increasingly stringent pollution control requirements, emission standards for municipal solid waste incineration flue gas are becoming more stringent. For example, some standards require NO... x Hourly average <80 mg / Nm 3 HCl < 10 mg / Nm 3 SO2 < 30 mg / Nm 3 To meet increasingly stringent pollution control requirements, existing flue gas purification processes need to incorporate SCR and wet scrubbing towers, forming a long-chain, segmented process of "SNCR + semi-dry + dry + activated carbon + bag filter + SCR denitrification + wet deacidification." However, this process suffers from drawbacks such as system complexity, high cost, large footprint, high power consumption, and wastewater generation. Furthermore, space constraints make it difficult to adapt to the retrofitting needs of existing facilities, hindering the technological upgrading of older plants.

[0003] To save floor space and reduce operating and equipment investment costs, the industry has begun to explore a new flue gas treatment technology centered on catalytic filter bags. Catalytic filter bags are used to filter catalysts (such as V₂O₅, WO₃, MnO₂). x Loading materials such as PTFE and PPS fibers onto traditional filter bags creates a system that can efficiently and synergistically remove particulate matter and gaseous pollutants (such as NO). x This technology utilizes a multifunctional composite material containing dioxins (and other harmful substances). It can directly replace traditional dust collector filter bags, completing the technological upgrade within the existing equipment framework without requiring additional floor space or large-scale equipment investment.

[0004] Catalytic filter bags are suitable for flue gas environments of 160-260 ℃. When the flue gas temperature is below 200 ℃, a flue gas heating device (SGH or GGH) needs to be added between the SDA and the dust collector flue to heat the flue gas temperature to above 200 ℃ to meet the operating temperature requirements of the catalytic filter bags. However, this heating solution not only increases equipment investment and operating energy consumption, but also makes the heater susceptible to erosion and wear from high-dust flue gas, resulting in high maintenance costs. Furthermore, when the flue gas temperature is below 200 ℃, due to the limitations of catalyst characteristics, SO2 must be strictly controlled to ≤10 mg / Nm³. 3 The humidity must be below 22%; otherwise, it will cause blockage of the ammonium sulfate catalyst ((NH4)HSO4) and loss of active sites, significantly reducing denitrification efficiency and filter bag lifespan. Furthermore, injecting activated carbon at temperatures above 200°C poses a risk of smoldering combustion, creating a safety hazard.

[0005] The current incineration flue gas is subjected to two-stage deacidification by SDA and dry method, and the SDA adopts lime slurry spraying deacidification, which increases the humidity of the flue gas by 2-5%, and due to the limitation of the activity of lime, the SO2 concentration is difficult to be stably lower than 10 mg / Nm 3 The existing process is difficult to meet the stringent requirements of catalytic filter bag application.

[0006] Therefore, to provide a flue gas multi-pollutant efficient synergistic treatment system is a technical problem to be solved by those skilled in the art. SUMMARY

[0007] The application discloses a flue gas multi-pollutant synergistic treatment system, a treatment method and application, to solve the technical problems of short service life of the catalytic filter bag for treating flue gas and high requirements on flue gas in the prior art.

[0008] To solve the above problems, the application adopts the following technical solutions: In a first aspect, the application provides a flue gas multi-pollutant synergistic treatment system, the treatment system comprising, in sequence along the flow direction of the flue gas, a waste heat boiler, a dry method reactor, a flue gas waste heat utilization module, an integrated dust collector and a chimney.

[0009] Specifically, the integrated dust collector is internally provided with a catalytic filter bag; the dry method reactor is connected with an oxidizing agent conveying module for conveying an oxidizing agent into the dry method reactor, a deacidifying agent conveying module for conveying a deacidifying agent into the dry method reactor and an activated carbon conveying module for conveying activated carbon into the dry method reactor at the flue gas inlet section of the dry method reactor; and the dry method reactor is connected with a reducing agent conveying module for conveying a reducing agent into the integrated dust collector at the flue gas outlet section of the dry method reactor.

[0010] Further, the catalytic filter bag is loaded with a composite catalyst, the carrier of the composite catalyst is composed of at least one of TiO2, SiO2, Al2O3 and a molecular sieve, or at least one of a composite composed of two or more of TiO2, SiO2, Al2O3 and a molecular sieve; the active ingredient of the composite catalyst is composed of V2O5 and / or WO3; the dopant of the composite catalyst is composed of at least one of Fe2O3, Nb2O5, CeO2, Sb2O3 and SnO2; the composite catalyst contains 5-20% of the carrier, wherein the content of TiO2 is at least 3-12%, and the content of V2O5 is 1-10% and the content of WO3 is 0.1-8%, and the content of Fe2O3 is 0.1-2%, or the content of Nb2O5 is 1.5-3%, or the content of Sb2O3 is 3-5%, or the content of SnO2 is 2-4%.

[0011] Further, the outlet of the flue gas waste heat utilization module is provided with a main flue and a bypass flue, the bypass flue is provided with a fixed adsorption module, the fixed adsorption module is used to adsorb the regeneration tail gas when the catalytic filter bag is regenerated, and the desorption gas outlet of the fixed adsorption module is connected with the chimney. The outlet of the flue gas waste heat utilization module is connected to a chimney and / or a fixed adsorption module; The inlet end of the bypass flue is arranged on the main flue at the rear side of the outlet of the flue gas waste heat utilization module. Further, the fixed adsorption module comprises a first shutoff valve arranged on the main flue, a second shutoff valve arranged on the bypass flue, and a first control valve connected to the fixed adsorption bed and used for discharging desorption gas, and the first control valve is also connected to the inlet of the dry reactor.

[0012] Further, the outlet of the integrated dust collector is also provided with a hot flue passage connected to a heat device, which is used for recovering heat in the flue gas.

[0013] Further, the oxidant delivery module comprises an ozone generator and a hydrogen peroxide evaporation system; The ozone generation system comprises an oxygen tank used for storing oxygen, a compressed air inlet pipeline used as a backup gas source of oxygen, and the oxygen tank and the compressed air inlet pipeline are connected to the ozone generator, and the ozone generator is connected to a cooling water system; The hydrogen peroxide evaporation system comprises a hydrogen peroxide raw water tank used for storing hydrogen peroxide, a hydrogen peroxide heater used for heating the hydrogen peroxide in the hydrogen peroxide raw water tank, and a hydrogen peroxide buffer tank used for storing gaseous hydrogen peroxide; The outlet of the ozone generator is connected to the outlet of the hydrogen peroxide buffer tank to form an inlet of a mixer, and the mixer is used for fully mixing gaseous ozone and gaseous hydrogen peroxide in a certain proportion and then sending the mixture into the dry reactor.

[0014] Further, the hot flue passage is connected to the hydrogen peroxide heater.

[0015] Further, the reducing agent delivery module comprises an ammonia or ammonia water storage tank used for storing liquid ammonia or ammonia water, an ammonia water evaporator used for evaporating the ammonia water to generate ammonia gas, an ammonia gas buffer tank used for storing gaseous ammonia, and an ammonia gas mixer used for mixing and diluting the ammonia gas with air to a safe concentration and then sending the mixed gas into the integrated dust collector.

[0016] Further, the hot flue passage is connected to the ammonia water evaporator.

[0017] Further, the deacidifying agent delivery module comprises a deacidifying agent storage bin used for storing deacidifying agent, a coarse powder quantitative delivery device used for quantitatively delivering coarse powder deacidifying agent, a fine powder grinding machine used for grinding the coarse powder deacidifying agent into fine powder, a deacidifying agent fine powder bin used for storing the fine powder deacidifying agent, and a fine powder quantitative delivery device used for quantitatively delivering the fine powder deacidifying agent into the dry reactor.

[0018] Further, the activated carbon delivery module comprises an activated carbon raw material storage bin used for storing activated carbon, and an activated carbon quantitative delivery device used for quantitatively delivering the activated carbon into the dry reactor.

[0019] In a second aspect, the application provides a method for treating multiple pollutants in flue gas, which is applied to the flue gas multiple pollutant treatment system of the first aspect, and comprises the following specific steps: Step 100: The flue gas passes through the waste heat boiler to recover the heat carried by the flue gas; Step 200: The flue gas passing out of the waste heat boiler outlet completes the pre-removal of hydrogen chloride, sulfur oxide, heavy metal and dioxin pollutants in the dry method reactor; When the deacidifying agent is baking soda, the particle size of the baking soda is less than 25 μm, and the excess coefficient of the baking soda is 1.05-1.2; when the deacidifying agent is slaked lime, the specific surface area of the slaked lime is greater than 40 m 2 / g, the excess coefficient of the slaked lime is 1.5-2.0; the reaction temperature of the deacidifying agent and the activated carbon is less than 200 ℃, and the residence time of the two in the dry method reactor is 2-4 s; When the original concentration of nitrogen oxide is higher than 300 mg / Nm 3 , the oxidizing agent is introduced into the dry method reactor; Step 300: The particulate matter, deacidifying agent and activated carbon in the flue gas after deacidification and adsorption adhere to the filter bag surface of the catalytic filter bag in the integrated dust collector, and secondary deacidification, secondary adsorption removal of heavy metal and dioxin occur, the reducing agent enters the inner layer of the filter bag, and the reducing agent and nitrogen oxide undergo oxidation-reduction reaction under the action of the catalyst, and then the treated flue gas is discharged; The internal filtration wind speed of the integrated dust collector is 0.6-0.8 m / min, and the pressure difference between the inlet and outlet of the integrated dust collector is 1000-1500 Pa; Step 400: The catalytic filter bag is regenerated every half year, the oxidizing agent is introduced into the dry method reactor, the oxidizing agent passes through the catalytic filter bag to regenerate the composite catalyst in the catalytic filter bag; the inlet flue gas temperature of the dry method reactor during regeneration is greater than or equal to 220 ℃, and the regeneration time is greater than or equal to 24 h.

[0020] Further, in step 200, the oxidizing agent converts the nitrogen monoxide in the flue gas into nitrogen dioxide to improve the catalytic efficiency of the catalytic filter bag on nitrogen oxide.

[0021] Further, in step 400, the oxidizing agent converts the nitrogen monoxide in the flue gas into nitrogen dioxide to make the volume concentration ratio of nitrogen monoxide to nitrogen dioxide be 1-1.5:1, and reduce the ammonium sulfate decomposition temperature.

[0022] Further, in step 400, the volume concentration ratio of ozone to hydrogen peroxide in the oxidizing agent is 0.4-0.6:1, and the volume concentration ratio of ozone to NO in the flue gas is 0.2-0.5:1.

[0023] Further, step 400 further comprises the following specific steps: S410: during regeneration, the bypass flue is opened, and the main flue is closed, so that the regeneration tail gas passes through the adsorption fixing module arranged on the bypass flue; the adsorbent in the fixed adsorption module can be selected from granular activated carbon, molecular sieve or activated coke, and the unit flue gas treatment filling amount of the adsorbent is 100-250 mg / Nm 3 , and the flue gas stays in the fixed bed for 0.3-0.8 s.

[0024] Further, the treatment method further comprises the following steps: Step 500: after regeneration, the adsorbent in the fixed adsorption module is regenerated at least once a year, and each time the regeneration time is 4-8 h; during regeneration of the adsorbent, the bypass flue is opened, and the flue gas heated to 280-350 DEG C passes through the fixed adsorption module, so that the regeneration tail gas adsorbed by the fixed adsorption module is desorbed, and the desorption gas is returned to the dry reactor.

[0025] In a third aspect, the application provides an application of a flue gas multi-pollutant co-processing system and method in waste incineration.

[0026] The technical scheme adopted by the application can achieve the following beneficial effects: By concentrating the addition of the deacidifying agent, the adsorbent and the reducing agent in the dry reactor and the integrated dust collector, integrating the dry deacidification, catalytic filtration and regeneration technologies to form a flue gas purification short process, efficient co-removal of nitrogen oxides, sulfur oxides, hydrogen chloride, heavy metals and dioxin pollutants is achieved, equipment redundancy and flue gas resistance are reduced, thereby making the process compact, significantly reducing equipment investment, land area and operating cost, achieving efficient co-removal of multiple pollutants, and simultaneously meeting the ultra-low emission standard; by regularly adding the oxidizing agent or when the concentration of nitrogen oxides in the flue gas is too high, the catalytic filter bag can be regenerated regularly or the catalytic efficiency of the catalytic filter bag on nitrogen oxides can be improved, the catalytic activity and filtration performance of the catalytic filter bag are restored, the replacement frequency is reduced, the flue gas pollutant emission index is simultaneously improved, and economic performance and environmental protection performance are taken into account. By adding the adsorption fixed bed and its regeneration device, dioxin removal during regeneration of the catalytic filter bag can be achieved, environmental protection risks are reduced, the service life of the adsorbent is prolonged, and the operating cost is reduced. By completely replacing the traditional "SDA (slaked lime slurry) + dry method (slaked lime / baking soda)" deacidification with the high-efficiency dry reactor, using high-activity deacidifying agents (baking soda and high-specificity slaked lime), optimizing the deacidification reaction temperature and increasing the gas-solid contact time, the deacidification efficiency is significantly improved, the high requirement of the catalytic filter bag on the inlet SO2 concentration <10 mg / Nm 3 is met, the utilization rate of the deacidifying agent is improved, and the production of fly ash is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0028] Figure 1 is a schematic diagram of the overall structure of the flue gas multi-pollutant co-processing system provided in Embodiment 1; Figure 2 is a schematic diagram of the structure of the deacidifying agent conveying module in the flue gas multi-pollutant co-processing system provided in Embodiment 1; Figure 3 is a schematic diagram of the structure of the activated carbon conveying module in the flue gas multi-pollutant co-processing system provided in Embodiment 1; Figure 4 is a schematic diagram of the structure of the oxidizing agent conveying module in the flue gas multi-pollutant co-processing system provided in Embodiment 1; Figure 5 is a schematic diagram of the structure of the reducing agent conveying module in the flue gas multi-pollutant co-processing system provided in Embodiment 1; Figure 6 is a schematic diagram of the structure of the fixed adsorption module in the flue gas multi-pollutant co-processing system provided in Embodiment 1; Figure 7 is a schematic diagram of the flow of the flue gas multi-pollutant co-processing method provided in Embodiment 2.

[0029] In the drawings, the reference signs are as follows: 100, waste heat boiler; 200, dry reactor; 300, integrated dust collector; 310, main flue; 320, bypass flue; 330, hot smoke passage; 410, induced draft fan; 420, flue gas waste heat utilization module; 500, chimney; 610, deacidifying agent conveying module; 611, deacidifying agent storage bin; 612, coarse powder quantitative conveying device; 613, fine powder grinder; 614, deacidifying agent fine powder bin; 615, first induced draft fan; 616, fine powder quantitative conveying device; 617, first fan; 620, activated carbon conveying module; 621, activated carbon raw material storage bin; 622, activated carbon quantitative conveying device; 623, second fan; 700, oxidant delivery module; 701, oxygen tank; 702, compressed air inlet pipeline; 703, first pressure reducing valve; 704, cooling water system; 705, ozone generator; 706, second pressure reducing valve; 707, first flow meter; 708, hydrogen peroxide raw water tank; 709, hydrogen peroxide heater; 710, hydrogen peroxide buffer tank; 711, third pressure reducing valve; 712, second flow meter; 713, third fan; 714, mixer; 715, fourth pressure reducing valve; 716, second control valve; 717, fifth flow meter; 800, reducing agent delivery module; 801, ammonia water storage tank; 802, ammonia water evaporator; 803, ammonia gas buffer tank; 804, ammonia gas mixer; 805, dilution fan; 806, third flow meter; 807, third control valve; 808, sixth flow meter; 900, fixed adsorption module; 901, first partition valve; 902, second partition valve; 903, fixed adsorption bed; 904, first control valve; 905, fourth flow meter; 906, heater; 907, fourth control valve. DETAILED DESCRIPTION

[0030] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0031] The terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second" and the like are generally of a kind, and are not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0032] Catalytic filter bag is suitable for flue gas environment of 160-260 ℃. When the flue gas temperature is lower than 200 ℃, a flue gas heating device (SGH or GGH) needs to be added between the SDA and the dust collector flue to heat the flue gas temperature to above 200 ℃ to meet the operating temperature requirements of the catalytic filter bag. However, this heating scheme not only increases equipment investment and operating energy consumption, but also the heater is easily eroded by high dust flue gas, with high maintenance cost. At the same time, when the flue gas temperature is lower than 200 ℃, due to the characteristics of the catalyst, SO2≤10 mg / Nm 3 and humidity <22% need to be strictly controlled, otherwise the catalyst ammonium sulfate ((NH4)HSO4) will be blocked and the active sites will be lost, the denitration efficiency and the service life of the filter bag will be significantly reduced. In addition, when the active carbon is injected above 200 ℃, there is a risk of active carbon smoldering (smoldering), which brings safety hazards. The existing process is difficult to meet the strict requirements of the application of catalytic filter bag.

[0033] The present application improves the acid removal efficiency through a dry reactor, so that the SO2 concentration in the flue gas at the inlet of the integrated dust collector is stably below 10 mg / Nm 3 , by periodically or when the nitrogen oxide concentration in the flue gas is too high, the oxidizing agent can be added to periodically regenerate the catalytic filter bag or improve the catalytic efficiency of the catalytic filter bag to nitrogen oxides, restore the catalytic activity and filtration performance of the catalytic filter bag, reduce its replacement frequency, and simultaneously improve the flue gas pollutant emission index.

[0034] The present application will be described in detail below by combining the accompanying Figures 1 to 7 , a flue gas multi-pollutant co-processing system and processing method and application provided by the present application are described in detail through specific examples and application scenarios.

[0035] Reference is made to Figures 1-6In a first aspect, the present application provides a flue gas multi-pollutant co-processing system. The processing system comprises, in sequence along the flue gas flow direction, a waste heat boiler 100, a dry reactor 200, an integrated dust collector 300, and a chimney 500. In an example, during operation, high-temperature flue gas first enters the waste heat boiler 100, which recovers waste heat and simultaneously reduces the flue gas temperature, creating suitable temperature conditions for subsequent deacidification and dust removal. Subsequently, the flue gas enters the dry reactor 200, where dry deacidification agents (such as lime or baking soda) are injected to react with acidic gases (such as SO2, HCl, etc.) in the flue gas according to the following reactions (1)-(5). Reactions (1)-(3) occur when the deacidification agent is baking soda, and reactions (4)-(5) occur when the deacidification agent is lime, achieving efficient removal of acidic pollutants. The deacidified flue gas, carrying some reaction products and original particulate matter, enters the integrated dust collector 300. The dust collector integrates filtration and secondary reaction functions, removing dust and deacidification byproducts through the outer membrane of the catalytic filter bag, and the filter layer surface can continue to react with unreacted acidic gases, further improving the removal efficiency. The above processing system achieves the co-purification of multiple pollutants (particulate matter, SO x , HCl, etc.); the purified clean flue gas is finally discharged into the atmosphere through the chimney 500.

[0036] 2NaHCO3(s)→Na2CO3(s)+H2O(g)+CO2(g)——(1) Na2CO3(s)+2HCl(g)→2NaCl(s)+H2O(g)+CO2(g)——(2) Na2CO3(s)+SO2(g)+1 / 2O2(g)→Na2SO4(s)+CO2(g)——(3) Ca(OH)2(s)+2HCl(g)→CaCl2(s)+2H2O(g)——(4) Ca(OH)2(s)+SO2(g)+1 / 2O2(g)→CaSO4(s)+H2O(g)——(5) Specifically, the integrated dust collector 300 is equipped with catalytic filter bags, the internal filtration air speed of the integrated dust collector 300 is 0.6-0.8 m / min, and the pressure difference between the inlet and outlet of the integrated dust collector 300 is 1000-1500 Pa. In an example, the integrated dust collector 300 is a bag filter, and the filter bag is a catalytic filter bag. Figure 1As shown, the catalytic filter bag is a composite filter material integrating particulate matter filtering function and catalytic reaction function, the base material of which is a high-temperature-resistant and corrosion-resistant fiber filter material (such as polyphenylene sulfide PPS, polytetrafluoroethylene PTFE or glass fiber), and the filter material surface or interior is loaded with a catalytically active component. The catalytic filter bag realizes efficient capture of flue dust and further removal of acid gases, heavy metals and dioxins, while the catalytic reduction agent (such as ammonia or urea pyrolysis product NH3) reacts with nitrogen oxides (NO x ) in flue gas to generate harmless nitrogen (N2) and water (H2O), realizing integrated and collaborative treatment of deacidification, denitrification and dust removal.

[0037] By using the technical scheme, the integrated dust remover 300 realizes multifunctional integration of dust removal, denitrification and deep purification of residual pollutants by means of the built-in catalytic filter bag, greatly simplifying the flue gas purification system process.

[0038] Specifically, the dry reactor 200 is communicated with a deacidifying agent conveying module 610 for conveying deacidifying agent into the dry reactor 200 and an activated carbon conveying module 620 for conveying activated carbon into the dry reactor 200, the reaction temperature of the deacidifying agent and the activated carbon in the dry reactor 200 is less than 200 ℃, and the residence time of the deacidifying agent and the activated carbon in the dry reactor 200 is 2s-4s; the excess coefficient of baking soda is 1.05-1.2, and the excess coefficient of lime is 1.5-2.0. As shown in the example, Figure 1 As shown, in the working process, the flue gas after waste heat recovery enters the dry reactor 200. In the flue gas inlet section of the dry reactor 200, the deacidifying agent conveying module 610 sprays dry powder deacidifying agent (such as Ca(OH)2 or NaHCO3) into the reactor by compressed air or mechanical injection, for removing SO2, HCl and other acid gases; and the activated carbon conveying module 620 injects activated carbon powder (or particles) with high specific surface area into the dry reactor 200 through a pneumatic conveying system, the activated carbon is in a suspended state in the flue gas, and makes use of its rich microporous structure and surface functional groups to efficiently adsorb trace pollutants in the flue gas. Among them, dioxin pollutants (PCDD / Fs) are enriched on the surface of the activated carbon and carried to the downstream dust remover to be intercepted; elemental mercury (Hg) and oxidized mercury (Hg 2+ ) are fixed by physical adsorption and surface catalytic oxidation. After the activated carbon adsorbs the pollutants, the flue gas enters the integrated dust remover 300, a dust layer containing pollutants is formed on the surface of the filter bag, and is finally intercepted and discharged from the system with fly ash. The Ca(OH)2 particle surface can catalyze the oxidation of part of Hg to Hg 2+ , so that it is more easily adsorbed by activated carbon; and the activated carbon can also serve as a micro-reaction platform for deacidification reaction, prolonging the reaction residence time and improving the overall purification efficiency.

[0039] By using this technical solution, the adsorbent and deacidifying agent are introduced into the dry reactor together, integrating the adsorption process and the deacidification process into the dry reactor. This achieves synergistic purification of acidic gases such as SO2 and HCl with pollutants such as mercury and dioxins, simplifying the system process.

[0040] In some embodiments, the deacidifying agent conveying module 610 includes a deacidifying agent storage silo 611 for storing deacidifying agent, a coarse powder metering conveying device 612 for metering coarse deacidifying agent, a fine powder mill 613 for grinding the coarse deacidifying agent into fine powder, a deacidifying agent fine powder silo 614 for storing deacidifying agent fine powder, a fine powder metering conveying device 616 for metering fine deacidifying agent, a first induced draft fan 615 for transporting fine deacidifying agent from the deacidifying agent fine powder silo 614 to the fine powder metering conveying device 616, and a first blower 617 for conveying the metered fine deacidifying agent to the dry reactor 200. For example, as shown... Figure 1 and Figure 2 As shown, the deacidifying agent (such as NaHCO3 or Ca(OH)2) is first stored in the deacidifying agent storage silo 611, kept dry and moisture-proof to ensure material activity. After the system starts, the coarse powder quantitative conveying device 612 (such as a screw feeder or loss-in-weight feeder) precisely controls the discharge rate of the coarse powder deacidifying agent according to the concentration of acidic gas in the flue gas and the processing load, and continuously and stably conveys it to the fine powder grinding mill 613. In the fine powder grinding mill 613 (such as an air jet mill, ball mill, or impact mill), the coarse powder deacidifying agent is ground into fine powder with smaller particle size and larger specific surface area (baking soda has a particle size of less than 25 μm after grinding, and hydrated lime has a specific surface area greater than 40 m²). 2 / g), significantly improving its reaction rate and removal efficiency with acidic gases such as SO2 and HCl in flue gas. The ground fine powder enters the deacidifying agent fine powder silo 614 through pipeline for temporary storage. This silo is equipped with a level gauge, dust filter element and anti-bridging device (such as pneumatic vibrator or fluidizing plate) to prevent agglomeration and bridging, and ensure smooth material discharge. When fine powder needs to be sprayed, the first induced draft fan 615 (i.e., high negative pressure induced draft fan) is started, and the fine powder deacidifying agent is transported from the fine powder grinder 613 to the deacidifying agent fine powder silo 614 through high negative pressure material extraction, realizing a closed, dust-free and controllable intermediate transfer process. Subsequently, the first blower 617 (such as Roots blower or centrifugal blower) acts as a positive pressure conveying power source, injecting high-pressure clean air into the system, and pushing the metered fine powder deacidifying agent to the flue gas inlet section of the dry reactor 200 through the fine powder metering conveying device 616. Under the action of high-speed airflow, the fine powder of deacidifying agent diffuses fully in the flue and mixes violently with the high-temperature flue gas, resulting in a deacidification reaction and achieving efficient removal of acidic gases.

[0041] The technical scheme is adopted, multi-stage control of coarse powder quantification + grinding + fine powder quantification is ensured, and the particle size and adding amount of the deacidifying agent meet the efficient reaction requirements; the first induced draft fan 615 realizes closed material taking to prevent dust overflow; the first fan 617 provides stable thrust to ensure long-distance and high-resistance conveying; the grinding fineness and injection amount can be flexibly adjusted to adapt to different flue gas conditions and emission standards; the silo buffer design avoids system interruption due to instantaneous demand fluctuations, guarantees continuous operation, realizes efficient, accurate and clean addition of the deacidifying agent, and provides reliable protection for the dry deacidification reaction.

[0042] In some embodiments, the activated carbon conveying module 620 includes an activated carbon raw material storage bin 621 for storing activated carbon, an activated carbon quantitative conveying device 622 for quantitatively conveying activated carbon, and a second fan 623 for conveying the quantitatively conveyed activated carbon to the dry reactor 200. As shown in Figure 1 and Figure 3 The activated carbon powder (or particles) with high adsorption performance is pre-stored in the activated carbon raw material storage bin 621. The storage bin is a closed structure, is equipped with a moisture-proof ventilation device, a material level monitor and an arch breaking device (such as a fluidization plate or a pneumatic vibrator), prevents activated carbon from being humidified and caked or bridged, and ensures smooth and stable discharging. When the system detects that the concentration of trace pollutants such as mercury and dioxin in flue gas increases or enters a high load operation stage, the control system starts the activated carbon adding program. The activated carbon quantitative conveying device 622 (such as a variable frequency screw feeder, a loss-in-weight type feeding scale or a rotary valve) accurately controls the discharging rate of activated carbon according to the preset adding amount or real-time feedback signals, and realizes continuous, uniform and adjustable quantitative supply. The quantitatively conveyed activated carbon enters a conveying pipeline, a high-pressure gas flow is provided by the second fan 623 (usually a Roots blower or a high-pressure centrifugal fan), and the activated carbon is blown to the flue gas inlet section of the dry reactor 200 in a pneumatic conveying manner. The gas flow provided by the second fan 623 not only serves as conveying power, but also promotes the rapid dispersion of activated carbon in the flue, forms a high-concentration suspended cloud, and fully mixes with high-temperature flue gas to achieve efficient adsorption of pollutants in the flue gas.

[0043] The technical scheme is adopted, the activated carbon conveying module 620 realizes rapid response and efficient capture of trace toxic pollutants.

[0044] Specifically, the flue gas inlet section of the dry reactor 200 is communicated with an oxidizing agent conveying module 700 for conveying an oxidizing agent into the dry reactor 200. As shown in Figure 1 and Figure 4 The oxidizing agent conveying module 700 is used to inject an oxidizing agent such as ozone (O3) or hydrogen peroxide. The injection of the oxidizing agent is divided into two cases. One is to regenerate the catalytic filter bag by injecting the oxidizing agent after the system runs for a period of time. The other is to improve the catalytic efficiency of the catalytic filter bag on nitrogen oxides when it is detected that the concentration of nitrogen oxides in the original flue gas is too high.

[0045] By the technical scheme, the catalytic activity and filtering performance of the catalytic filter bag can be recovered by the oxidant delivery module 700, the replacement frequency thereof can be reduced, the catalytic efficiency of nitrogen oxides can be simultaneously improved, the emission index of flue gas pollutants can be improved, and the economic performance and environmental performance can be considered.

[0046] In some embodiments, the oxidant delivery module 700 comprises an ozone generation system and a hydrogen peroxide evaporation system. The ozone generation system comprises an oxygen tank 701 for storing oxygen, a compressed air inlet pipeline 702 as a backup gas source of oxygen, the compressed air inlet pipeline 702 is connected to a high-voltage discharge type ozone generator 705 through a first pressure reducing valve 703, the oxygen tank 701 is also connected to the inlet of the ozone generator 705, the ozone generator 705 is further provided with a cooling water inlet and outlet, and is connected to a cooling water system 704 through a pipeline; the hydrogen peroxide evaporation system is provided with a hydrogen peroxide raw water tank 708 for storing hydrogen peroxide, the hydrogen peroxide in the hydrogen peroxide raw water tank 708 is heated by a hydrogen peroxide heater 709 and then enters a hydrogen peroxide buffer tank 710. The outlet of the ozone generator 705, the outlet of the hydrogen peroxide buffer tank 710 and the inlet of a mixer 714 are connected, the mixer 714 is used to fully mix the gaseous ozone and the gaseous hydrogen peroxide in proportion, the outlet of the ozone generator 705, the outlet of the hydrogen peroxide buffer tank 710 and the inlet of the mixer 714 are respectively provided with a second pressure reducing valve 706 and a first flow meter 707 for reducing the pressure and detecting the flow of the ozone gas, and a third pressure reducing valve 711 and a second flow meter 712 for reducing the pressure and detecting the flow of the hydrogen peroxide gas, the mixer 714 is further provided with a fourth pressure reducing valve 715 for reducing the pressure of the mixed gas and a third fan 713 for sending the mixed gas into the dry reactor 200. For example, Figure 1 and Figure 4As shown, the oxidant delivery module 700 integrates an ozone generation system and a hydrogen peroxide evaporation system, which can independently or cooperatively deliver strong oxidizing gas into the dry method reactor 200, for oxidizing low-valence nitrogen oxides (such as NO) that are difficult to dissolve in water and difficult to remove in flue gas into high-reactivity high-valence nitrogen oxides (such as NO2), to create favorable conditions for subsequent efficient denitration in the integrated dust collector 300. The oxygen source preferably uses a high-purity oxygen tank 701 to improve ozone yield and concentration; when oxygen supply is insufficient or the system needs maintenance, the compressed air inlet pipeline 702 can be switched to as a backup gas source. After being adjusted to an appropriate pressure by the first pressure reducing valve 703, the two gas sources enter the high-voltage discharge ozone generator 705. Under the action of a high-voltage electric field, O2 molecules are decomposed and recombined to generate ozone (O3). The ozone generation process generates a large amount of heat, and to prevent equipment overheating from causing efficiency to drop or damage, the ozone generator 705 is equipped with a cooling water inlet and outlet connected to an external cooling water system 704 (such as a closed cooling tower or a water chiller) to control the temperature of the ozone generator 705 to maintain at 15-35 ℃, achieving continuous heat dissipation and ensuring stable operation. The hydrogen peroxide evaporation system uses a hydrogen peroxide raw water tank 708 to store 20%-35% concentration of hydrogen peroxide solution (H2O2). Liquid H2O2 is pumped into the hydrogen peroxide heater 709 by a delivery pump, rapidly evaporates and decomposes at high temperature to generate gaseous H2O2 and free radicals (·OH, ·HO2, etc.), and then enters the hydrogen peroxide buffer tank 710 for pressure stabilization and gas-liquid separation, ensuring stable output gas pressure and flow. The ozone gas generated by the ozone generator 705 is reduced to a safe delivery pressure by the second pressure reducing valve 706, and the flow is monitored in real time by the first flow meter 707, achieving accurate metering and closed-loop control; the high-temperature gaseous hydrogen peroxide output by the hydrogen peroxide buffer tank 710 is pressure-regulated and flow-monitored by the third pressure reducing valve 711 and the second flow meter 712. The two oxidizing gases then enter the mixer 714, where the volume concentration ratio of ozone to hydrogen peroxide is 0.4-0.6:1, and the volume concentration ratio of ozone to NO in flue gas is 0.2-0.5:1. The mixer uses a multi-stage Venturi or static mixing structure to fully turbulent mix O3 and H2O2 gas, forming a composite oxidant system with super-strong oxidation capacity. Studies have shown that the synergistic effect of O3 and H2O2 can trigger a chain reaction to generate a large amount of hydroxyl radicals (·OH), which can significantly improve the oxidation efficiency of NO and refractory organic matter. The mixed oxidizing gas is further stabilized by the fourth pressure reducing valve 715, and is pushed by the third fan 713 (such as a corrosion-resistant Roots blower or a centrifugal fan) to be delivered to the flue gas inlet section of the dry method reactor 200 through the pipeline and rapidly mixed with high-temperature flue gas.

[0047] The technical scheme has the following beneficial effects: the oxygen and compressed air double-gas-source design ensures continuous and stable operation of the ozone system; the cooling water system effectively controls the temperature, prolonging the service life of the ozone generator; the multi-stage pressure reduction and flow meter configuration realizes on-demand addition of the oxidizing agent, avoiding waste and byproduct generation; the combination of O3 and H2O2 generates ·OH free radicals, significantly improving the oxidation efficiency of NO and organic pollutants; the heating and pressure reduction design prevents H2O2 from condensing or crystallizing, ensuring smooth operation of the system.

[0048] Specifically, the flue gas outlet section of the dry method reactor 200 is connected with a reducing agent delivery module 800 for delivering a reducing agent into the integrated dust collector 300; the outlet section of the integrated dust collector 300 is connected with the chimney 500. As shown in Figure 1 and Figure 5 After the flue gas leaves the dry method reactor 200, the preliminary removal of acid gases (such as SO2 and HCl) and part of trace pollutants (such as Hg and dioxins) has been completed. At this time, the flue gas still contains a certain concentration of nitrogen oxides (NO x The reducing agent delivery module 800 sprays the reducing agent (such as ammonia water or urea solution) into the flue through an atomizing nozzle at the outlet section of the dry method reactor 200, so that the reducing agent is fully mixed with the flue gas. Under the action of high temperature, the reducing agent rapidly decomposes to generate gaseous ammonia (NH3), and the generated NH3 enters the integrated dust collector 300 with the flue gas and reacts with NO x in the integrated dust collector 300 through selective catalytic reduction (SCR) in the built-in catalytic filter bag.

[0049] By using the technical scheme, the integrated dust collector 300 not only has the traditional dust removal function, but also integrates the functions of catalytic denitration, secondary adsorption and reaction, realizing the synergistic deep purification of particulate matter, SO x , NO x , Hg, dioxins and other pollutants, and the cleaned flue gas is finally discharged through the chimney 500.

[0050] In some embodiments, the reducing agent delivery module 800 is provided with a storage tank (such as an ammonia water storage tank 801) for storing liquid ammonia or ammonia water, an ammonia water evaporator 802 for evaporating the ammonia water to generate ammonia gas, an ammonia gas buffer tank 803 for storing the gaseous ammonia, an ammonia gas mixer 804 for mixing and diluting the ammonia gas to a safe concentration, a third flow meter 806 for detecting the mixed gas, and a dilution fan 805 for providing dilution air and delivering the diluted mixed gas to the downstream flue. As shown in Figure 1 andFigure 5 As shown, a 5%–20% concentration of ammonia solution (NH3H2O) is first stored in ammonia storage tank 801. This tank is a closed container under normal or low pressure, equipped with a level gauge, temperature sensor, and safety relief device to prevent evaporation and leakage, ensuring storage safety. When the system requires the addition of a reducing agent, ammonia solution is drawn from the storage tank via a metering pump (such as a diaphragm pump) and quantitatively delivered to the ammonia evaporator 802. The evaporator uses an external heat source (such as steam, waste heat from flue gas, or electric heating) to heat the ammonia solution above its boiling point, allowing it to fully evaporate and decompose. The resulting high-temperature ammonia gas and water vapor mixture enters the ammonia buffer tank 803 for gas-liquid separation and pressure stabilization. The buffer tank serves to stabilize pressure, buffer, and regulate instantaneous flow fluctuations, ensuring a continuous and uniform subsequent ammonia supply. The ammonia gas exiting the buffer tank enters the ammonia mixer 804, where it is mixed with clean air introduced by the dilution fan 805. A dilution fan draws ambient air or preheated air from the boiler to dilute the ammonia gas to a volume concentration below 5% (typically controlled at 3%-4%), below the lower explosive limit (LEL, the explosive limit of ammonia is 15%-28%), ensuring inherent safety during transport and injection. The diluted ammonia gas mixture is then piped to the flue gas outlet section of the dry reactor 200 or the inlet flue of the integrated dust collector 300, where it is thoroughly mixed with the flue gas before entering the catalytic filter bag area. Here, ammonia (NH3) acts as a reducing agent, reacting with nitrogen oxides (NOx) in the flue gas under the action of the catalyst loaded within the catalytic filter bag. x Selective catalytic reduction reaction occurs, achieving efficient denitrification.

[0051] This technical solution uses ammonia water (not anhydrous liquid ammonia) as a reducing agent, resulting in low storage and operational risks. The ammonia gas is transported after being fully diluted to avoid explosions or corrosion caused by excessively high local concentrations. This achieves safe, stable, and precise addition of the reducing agent, providing a reliable guarantee for the efficient denitrification of the catalytic filter bag.

[0052] In some embodiments, the catalytic filter bag is loaded with a composite catalyst. For example, such as... Figure 1 As shown, the composite catalyst, through multi-component synergistic design, not only possesses high-efficiency denitrification (NO)... x In addition to its reducing ability, the composite catalyst also possesses resistance to sulfur and alkali metal poisoning, as well as the function of promoting the decomposition of oxidizing pollutants, thus adapting to long-term stable operation under complex flue gas conditions. Furthermore, this composite catalyst can be loaded onto the fiber surface of the catalytic filter bag via sol-gel method, impregnation method, or co-precipitation method. For example, PPS or PTFE-based filter media can be immersed in a sol solution containing vanadium, tungsten, and molybdenum precursors, and after drying and calcination, a uniform and firm catalytic coating is formed, ensuring that it does not easily fall off during long-term pulse cleaning.

[0053] The technical scheme has the advantages that by loading V2O5-WO3-MoO3 / TiO2 and other composite catalysts on the catalytic filter bag, the denitration efficiency and operation stability are improved, the ability of synergistic treatment of various pollutants is expanded, and the adaptability and reliability of the flue gas multi-pollutant synergistic treatment system are significantly enhanced.

[0054] In some embodiments, the carrier of the composite catalyst is composed of at least one of TiO2, SiO2, Al2O3 and a molecular sieve, or at least one of a composite composed of two or more of TiO2, SiO2, Al2O3 and a molecular sieve; the active component of the composite catalyst is composed of V2O5 and / or WO3; the dopant of the composite catalyst is composed of at least one of Fe2O3, Nb2O5, CeO2, Sb2O3 and SnO2, the catalyst contains 5-20% of the carrier, wherein the content of TiO2 is at least 3-12%, and the content of V2O5 is 1-10% and the content of WO3 is 0.1-8%, and the content of Fe2O3 is 0.1-2%, or the content of Nb2O5 is 1.5-3%, or the content of Sb2O3 is 3-5%, or the content of SnO2 is 2-4%. For example, Figure 1 As shown, the composite catalyst uses a TiO2-SiO2 composite carrier, is prepared by an impregnation method, has a uniform mesoporous structure, and is beneficial to the dispersion of the active component. V2O5 and WO3 are loaded on the carrier as the main active components; and SnO2 is doped as an auxiliary agent. In the process of catalytic denitration, V2O5 serves as the core active component, provides abundant acid sites and redox sites, activates NH3 molecules and promotes the reaction of NH3 with NO x ; WO3 improves the adsorption and stability of NH3; the TiO2-SiO2 composite carrier has good thermal stability and water resistance, and prevents the catalyst from sintering or deactivation in long-term operation. SnO2 forms a solid solution or an interface structure with V2O5 or WO3, adjusts the electronic state of the metal oxide, and enhances the redox capacity of the catalyst; In the long-term operation process, the catalytic filter bag may be deactivated due to the following reasons: dust clogging or covering the active sites; deposition of organic matter on the surface; condensation and coverage of ammonium bisulfate (NH4HSO4) on the catalyst in the low-temperature zone; poisoning of trace heavy metals or chlorides. The filter bag is regenerated at least once a year, and each regeneration time is 4-8 h. During the regeneration, low-concentration ozone (O3) or hydrogen peroxide (H2O2) steam can be introduced to assist in restoring the activity of the catalyst. SnO2 can catalyze the decomposition of ozone, deeply oxidize the accumulated carbon, tar or adsorbed organic pollutants (such as dioxin precursors) on the surface of the filter bag into CO2 and H2O, realize self-cleaning and regeneration, form oxidation active sites on the surface of the catalyst, and O3 can partially oxidize NH4 + in NH4HSO4 or promote the thermal decomposition thereof; realize oxidative cracking at low temperature (200 ℃) rather than simple pyrolysis.

[0055] The catalyst has high denitration efficiency and stable operation in the denitration process, and can support low-temperature catalytic regeneration when the oxidizing agent is introduced into the catalytic filter bag for regeneration, thereby prolonging the service life of the filter bag.

[0056] In some embodiments, the integrated dust collector 300 is provided with a main flue 310 and a bypass flue 320, and the bypass flue 320 is provided with a fixed adsorption module 900 for adsorbing the regeneration tail gas when the catalytic filter bag is regenerated, and the outlet of the fixed adsorption module is connected to the chimney 500. Figure 1 and Figure 6 As shown in the examples of FIGS. 1 and 2, during normal operation of the system, the purified flue gas directly enters the chimney 500 through the main flue 310 to achieve standard emission. At this time, the bypass flue 320 is in a closed state to ensure that the system has the minimum resistance and the highest operating efficiency. When the denitration efficiency decreases due to dust blockage, organic deposition, ammonium bisulfate condensation, or trace heavy metal / chloride poisoning after the catalytic filter bag operates for a period of time, the catalytic filter bag needs to be regenerated online or offline. During the regeneration process, low-concentration ozone or hydrogen peroxide vapor is introduced into the integrated dust collector 300, and an oxidative cracking reaction is carried out under heating or normal temperature conditions to release regeneration tail gas containing volatile organic compounds (VOCs), CO, NO x , SO x , and unreacted ozone. If the tail gas is directly discharged into the chimney, it may cause short-term over-standard emission. Therefore, when the system starts the regeneration program, the flue gas flow is automatically switched: the main flue 310 is closed, and the bypass flue 320 is opened, so that the tail gas generated during the regeneration process does not pass through the main discharge path, but is guided into the fixed adsorption module 900 in the bypass flue 320. The fixed adsorption module 900 is filled with high-performance adsorbents such as modified activated carbon, molecular sieves, basic adsorbents, and activated coke, which can efficiently adsorb O3, VOCs, dioxin substances, and part of the acid gases; harmful pollutants in the regeneration tail gas are gradually adsorbed and trapped when passing through the fixed adsorption module 900, achieving purification treatment. The clean gas stream after adsorption and purification is discharged from the desorption gas outlet of the fixed adsorption module 900 and directly connected to the chimney 500, achieving safe discharge. After the adsorbent is saturated, the fixed adsorption module 900 can be regenerated by desorption. For example, hot nitrogen or steam is used to desorb the adsorbent to release high-concentration pollutant gas, which can be sent to the front-end combustion chamber or a small-sized catalytic oxidation device for complete decomposition; the adsorbent after desorption regains its adsorption capacity and is reused in the next cycle, achieving cyclic utilization.

[0057] The technical scheme has the following beneficial effects: the bypass flue 320 with the fixed adsorption module 900 is arranged, closed loop or semi-closed loop treatment in the catalytic filter bag regeneration process is realized, secondary pollution of the regeneration tail gas to the environment is effectively avoided, continuous emission meeting the standard of the system under all working conditions is ensured, and overall environmental compliance and operation safety are improved.

[0058] In some embodiments, the flue gas waste heat utilization module 420 is further arranged on the main flue 310, and the outlet of the flue gas waste heat utilization module 420 is communicated with the chimney 500 and / or the fixed adsorption module 900. Figure 1 As shown in the figure, the flue gas waste heat utilization module 420 can be a heat pipe heat exchanger, a waste heat boiler economizer, etc., the inlet of which is connected with the main flue 310 at the outlet of the integrated dust collector 300, and is used for recovering the low-grade heat energy remaining in the purified flue gas, for heating boiler feed water, heating, industrial hot water or driving a small power generation system, so as to improve the energy utilization efficiency of the entire flue gas treatment system. During normal operation of the system, the flue gas is purified by the integrated dust collector 300, then enters the flue gas waste heat utilization module 420 through the main flue 310, and the temperature is further reduced to 100-130 DEG C after releasing heat. At this time, according to the system operation requirement, the outlet of the flue gas waste heat utilization module 420 can be selectively communicated with the chimney 500, so that the cooled clean flue gas is directly discharged, which is suitable for normal working conditions without bypass operation; during the regeneration of the catalytic filter bag, the outlet of the flue gas waste heat utilization module 420 is communicated with the bypass flue 320, and the flue gas needs to be heated additionally during the regeneration, so that the flue gas temperature needs to be kept at about 220 DEG C. At this time, the additional heat carried by the flue gas and the tail gas during the regeneration is recovered through the flue gas waste heat utilization module 420, and the tail gas during the regeneration is adsorbed and fixed by the fixed adsorption module 900 in the bypass flue 320.

[0059] The technical scheme has the following beneficial effects: the bypass flue 320 with the fixed adsorption module 900 is arranged, closed loop or semi-closed loop treatment in the catalytic filter bag regeneration process is realized, secondary pollution of the regeneration tail gas to the environment is effectively avoided, continuous emission meeting the standard of the system under all working conditions is ensured, and overall environmental compliance and operation safety are improved.

[0060] In some embodiments, the fixed adsorption module 900 comprises a first partition valve 901 arranged on the main flue 310, a second partition valve 902 and a fixed adsorption bed 903 arranged on the bypass flue 320, a first control valve 904 communicated with the fixed adsorption bed 903 for discharging desorption gas, a fourth flow meter 905 for detecting the flow of heating gas during desorption, and a heater 906 for heating gas; the adsorbent of the fixed adsorption bed 903 can be 2-6 mm granular activated carbon or molecular sieve, and the unit flue gas treatment filling amount of the adsorbent is 100-250 mg / Nm 3The residence time of flue gas in the fixed bed is 0.3-0.8 s. For example, such as... Figure 1 and Figure 6 As shown, this module is integrated into the flue gas path at the outlet of the integrated dust collector 300. It is used to treat the regeneration tail gas during the regeneration of the catalytic filter bags, preventing instantaneous excessive emissions of pollutants. During normal system operation, the flue gas, after being purified by the integrated dust collector 300, flows to the chimney 500 through the main flue duct 310. At this time: the first isolation valve 901 is in the open state, ensuring the main flue is unobstructed; the second isolation valve 902 is in the closed state, isolating the bypass flue duct 320; the first control valve 904 is closed, and the fixed adsorption bed 903 is in standby state. The flue gas flows smoothly through the main flue duct 310, achieving low resistance and high-efficiency emissions. When the catalytic filter bags in the integrated dust collector 300 need to be regenerated (e.g., due to ammonium bisulfate deposition, organic carbon buildup, or active site poisoning leading to a decrease in denitrification efficiency), the system switches to regeneration mode. At this time: the first isolation valve 901 closes, cutting off the emission path of the main flue 310; the second isolation valve 902 opens, guiding the flue gas or regeneration gas flow into the bypass flue 320; the regeneration gas (such as ozone O3, high-temperature flue gas or carrier gas) enters the integrated dust collector 300, performing oxidative or thermal regeneration on the catalytic filter bag, releasing unreacted O3, volatile organic compounds (VOCs), CO, NH3, SO2, etc. x and trace amounts of NO x The regenerated exhaust gas is carried by the airflow into the bypass flue 320 and then into the fixed adsorption bed 903. The fixed adsorption bed is filled with high-performance adsorption materials, such as modified activated carbon, molecular sieves (e.g., 13X or ZSM-5), alkaline impregnated carbon, or alumina. As the regenerated exhaust gas passes through the fixed adsorption bed 903, harmful components are adsorbed and retained stage by stage, achieving purification. The purified gas can be directly discharged or further used in subsequent processes. After the fixed adsorption bed 903 has been running for a period of time, the adsorbent tends to become saturated and desorption regeneration is required. At this time: the second isolation valve 902 is closed to isolate the regeneration gas source; the desorption program is started, and the heater 906 is started to heat the clean gas; the heated gas enters the fixed adsorption bed 903 after being measured by the fourth flow meter 905 for thermal purging; the adsorbed pollutants are desorbed to form high-concentration desorbed gas; the first control valve 904 is opened to deliver the desorbed gas to the outlet of the front-end waste heat boiler or a dedicated oxidation device, where it is completely decomposed into harmless substances such as CO2, H2O, and N2 at high temperatures to avoid secondary pollution.

[0061] This technical solution effectively intercepts pollutants in the regeneration exhaust gas during catalytic filter bag regeneration, avoiding instantaneous emissions exceeding standards and meeting environmental continuous monitoring requirements. Seamless switching between the main and bypass circuits is achieved through the coordinated control of the first isolation valve 901 and the second isolation valve 902, resulting in a high degree of system automation. The fixed adsorption bed 903 is reusable, reducing operating costs. Centralized treatment of desorbed gas enables closed-loop management. The integrated design of the fixed adsorption module 900 with the main flue 310 and bypass flue 320 saves space and facilitates maintenance.

[0062] In some embodiments, the inlet end of the bypass flue 320 is located on the main flue 310 downstream of the outlet of the flue gas waste heat utilization module 420. For example, as shown... Figure 1 As shown, the main flue duct 310 is equipped with a flue gas waste heat recovery module 420. Regardless of whether the flue gas is discharged through the main duct or enters the bypass duct for regeneration, it preferentially passes through the flue gas waste heat recovery module 420 for heat recovery. During normal system operation, the switching valve (such as an electric or pneumatic butterfly valve) on the bypass flue duct 320 is in the closed state, and the purified flue gas flows sequentially through the integrated dust collector 300, the main flue duct 310, the flue gas waste heat recovery module 420, and the chimney 500. During this process, the flue gas waste heat is effectively recovered for heating water supply, heating, or power generation, improving the overall energy efficiency of the system. When it is necessary to regenerate the catalytic filter bag in the integrated dust collector 300 (such as using ozone oxidation for online or offline regeneration), the system automatically switches the operating mode: closing the valve downstream of the main flue duct 310 leading to the chimney; opening the inlet valve of the bypass flue duct 320, thus changing the flue gas flow direction. At this time, the regenerated exhaust gas from the integrated dust collector 300 first enters the flue gas waste heat utilization module 420 through the main flue duct 310 to release residual heat energy. The cooled regenerated exhaust gas then enters the opened bypass flue duct 320 from the outlet of the flue gas waste heat utilization module 420, and then enters the fixed adsorption module 900.

[0063] By adopting this technical solution, the inlet of the bypass flue 320 is set behind the outlet of the flue gas waste heat utilization module 420, realizing the spatiotemporal coordination of heat recovery and pollutant regeneration treatment.

[0064] In some embodiments, the processing system further includes an induced draft fan 410 disposed in the main flue 310, the induced draft fan 410 being located upstream of the flue gas waste heat utilization module 420 in the main flue 310. For example, as... Figure 1As shown, the induced draft fan 410 is installed on the main flue 310 after the integrated dust collector 300 and before the flue gas waste heat utilization module 420 as the negative pressure driving core of the entire flue gas purification system. Its role is to overcome the system resistance in the entire flue gas process, including the pressure drop of the waste heat boiler 100, the dry reactor 200, the integrated dust collector 300, the flue gas waste heat utilization module 420, various conveying pipelines and valves and other equipment, to ensure that the flue gas can flow stably and continuously from the front-end combustion chamber or process equipment to the end chimney 500.

[0065] By adopting the technical solution, after being filtered by the integrated dust collector 300, the flue gas temperature is usually 140-180 ℃, which is within the safe operation temperature range of the induced draft fan, and no additional cooling is required; the flue gas has removed most of the dust, acid components and harmful pollutants, significantly reducing the corrosion, wear and dust accumulation risk of the induced draft fan impeller, prolonging the service life of the equipment; the induced draft fan 410 extracts air in the purification section, so that the front-end dry reactor 200 and the integrated dust collector 300 are in a negative pressure operation state as a whole, which is beneficial to prevent uncleaned flue gas from leaking and ensure the safety of the workshop environment.

[0066] In some embodiments, the integrated dust collector outlet is also provided with a hot smoke passage 330 which is connected to a heat utilization device to recover flue gas waste heat. For example, as shown in Figure 1 As shown, the flue gas after being purified by the integrated dust collector 300 still has a relatively high temperature and has considerable waste heat recovery value. Therefore, a hot smoke passage 330 is arranged at the outlet section of the integrated dust collector 300, which draws high-temperature purified flue gas from the upstream of the main flue 310 or the bypass flue 320 and transports it to an external heat utilization device to realize cascade utilization of energy.

[0067] By adopting the technical solution, by arranging the hot smoke passage 330 and connecting the heat utilization device, not only the comprehensive utilization efficiency of flue gas waste heat is improved, the system energy consumption and carbon emissions are reduced, but also the energy flexibility and economy of the entire flue gas treatment system are enhanced, which is especially suitable for applications such as cogeneration and centralized heating of industrial parks which have high requirements for energy utilization efficiency.

[0068] In some embodiments, the heating devices connected to the hot smoke channel 330 include a hydrogen peroxide heater 709 in the oxidant delivery module 700, an ammonia evaporator 802 in the reducing agent delivery module 800, and a heater 906 in the fixed adsorption module 900. The hot smoke channel 330 includes three branches, which are respectively connected to the above three. The hydrogen peroxide heater 709 is equipped with a fifth flow meter 717 connected to the hot smoke channel 330 for detecting the hot smoke flow rate and a second control valve 716 for opening and closing the corresponding branch of the hot smoke channel 330. The ammonia evaporator 802 is equipped with a sixth flow meter 808 connected to the hot smoke channel 330 for detecting the hot smoke flow rate and a third control valve 807 for opening and closing the corresponding branch of the hot smoke channel 330. The heater 906 is equipped with a fourth control valve 907 connected to the hot smoke channel 330 for opening and closing the corresponding branch of the hot smoke channel 330. For example, Figure 1 and Figures 4-6 As shown, the hot flue gas channel 330 is led out from the main flue gas 310 at the outlet of the integrated dust collector 300, using high-temperature purified flue gas with a temperature of 140-180 ℃ as a heat source. The hot flue gas channel 330 is equipped with a main control valve before each branch and is divided into three independent branches. Each branch is equipped with a dedicated control valve and flow monitoring device to achieve on-demand heating and precise control: The first branch serves the hydrogen peroxide heater 709 (oxidant system). The first branch of the hot flue gas channel 330 is connected to the heating chamber of the hydrogen peroxide heater 709, providing it with the heat energy required for evaporating the H2O2 solution. The second control valve 716 is installed on this branch to open and close the hot flue gas channel 330. It automatically opens when the system needs to start the hydrogen peroxide evaporation function and closes when the addition stops. The fifth flow meter 717 monitors the flow rate of the hot flue gas entering the hydrogen peroxide heater 709 in real time and feeds it back to the central control system to adjust the opening of the second control valve 716 to ensure stable heating. The second branch serves the ammonia evaporator 802 (reducing agent system). The second branch of the hot flue gas passage 330 is connected to the ammonia evaporator 802, providing it with the heat source required for ammonia evaporation. The third control valve 807 controls the on / off state of this branch. It opens when the denitrification system needs ammonia injection and closes otherwise, achieving on-demand heating. The sixth flow meter 808 monitors the hot flue gas flow rate, supports closed-loop control, and ensures that the ammonia evaporation rate is consistent with the flue gas NO₂. x Load matching. The third branch serves heater 906 (fixed adsorption module). The third branch of the hot flue gas passage 330 is connected to heater 906 of fixed adsorption module 900 to provide hot purge gas during adsorption bed desorption and regeneration. The fourth control valve 907 controls the opening and closing of this branch. It is only opened when fixed adsorption bed 903 needs desorption and regeneration, and closed at other times to prevent accidental heat input.

[0069] By adopting the technical scheme, the heat smoke passage 330 realizes distributed and on-demand utilization of flue gas waste heat in multiple subsystems, converts the originally emptied low-grade heat energy into a process heat source, and significantly improves the overall energy efficiency of the system; each branch realizes independent start-stop and precise regulation and control through the control valve (716, 807, 907) and the flow meter (717, 808), and the central control system can dynamically allocate heat according to the running state of each module (such as whether regeneration is needed, whether an oxidizing agent / reducing agent is added), thereby avoiding energy waste.

[0070] Referring to Figure 7 In a second aspect, the application provides a flue gas multi-pollutant co-processing method, which adopts the processing system described above and is applied to flue gas processing of a 500 t / d waste incineration plant. The main parameters of the flue gas of the plant are designed as shown in the following table: Table 1. Main parameters of flue gas (standard condition, dry basis, 11% O2) Firstly, the waste incineration flue gas is sprayed with a reducing agent (ammonia water, urea solution or solid denitration agent) and a desulfurizing agent powder (calcium carbonate, calcium magnesium acetate) in the temperature window of 800-950 ℃ in the incinerator through SNCR (selective non-catalytic reduction denitration technology) and in-furnace desulfurization technology, to complete preliminary removal of nitrogen oxides and sulfur oxides. Then, the high-temperature flue gas with a temperature of about 180 ℃ discharged from the waste heat boiler 100 is introduced into the dry method reactor 200. In the reactor, the flue gas is fully mixed with the baking soda deacidifying agent powder and activated carbon precisely added through the deacidifying agent delivery module 610 and the activated carbon delivery module 620, to implement a preliminary deacidification reaction and efficiently remove heavy metals and dioxin pollutants. The reducing agent delivery module 800 uses 20% ammonia water, which is adjusted to 5% ammonia gas by an ammonia water evaporator, and the ammonia gas is mixed with the high-temperature flue gas at the outlet of the dry method reactor 200 and then enters the integrated dust collector 300. In the integrated dust collector 300, the particulate matters, deacidifying agents and activated carbon in the flue gas adhere to the surface of the filter bag, and further deacidification, heavy metal and dioxin removal reactions occur, and the ammonia molecules enter the inner layer of the filter bag and react with NOx under the action of the catalyst (a V-Sn-Ti catalyst system), to finally realize multi-pollutant co-processing.

[0071] When the integrated dust collector 300 runs for half a year, the inlet temperature of the dry method reactor 200 is increased to 225 ℃ by adjusting the economizer of the waste heat boiler 100, and the catalyst regeneration is completed by continuously running the oxidant delivery module 700 for 24 hours. The oxidant added is a mixture of O3 and H2O2, and the volume concentration ratio of the two is adjusted to 0.5, and the volume concentration ratio of O3 and NO in the flue gas is 0.4, and the oxidant delivery flow is calculated according to formulas (11) and (12). At this time, the NO oxidation rate is about 50%, and it will not be over-oxidized into high-order N2O5 by-products. After oxidation, the proportion of NO and NO2 in the flue gas is about 1:1, which meets the "fast SCR" reaction principle, combined with the addition of Sn2O3 components in the catalyst, which can significantly reduce the thermal decomposition temperature threshold of ammonium sulfate salt from the conventional 350 ℃ to about 200 ℃, thereby effectively activating the catalyst regeneration performance.

[0072] Wherein, if the purpose of the deacidification agent procurement 200 is to form 600 mesh soda fine powder after grinding, and the excess coefficient is 1.1, the flue gas reaction is calculated according to the original concentration and control standard of acid pollutants, and the formula (6) is used to calculate the addition flow of soda of 204 kg / h. If high specific surface area (>40 m 2 / g) is purchased for deacidification reaction, and the excess coefficient is 1.8, the flue gas reaction is calculated according to formula (7), and the addition flow of lime is 147 kg / h.

[0073] F NaHCO3 ={2.62(F SO2in -F SO2out )+2.30(F HClin -F HClout )}×SR Na ——(6) F CaOH2 ={1.16(F SO2in -F SO2out )+1.01(F HClin -F HClout )}×SR Ca ——(7) In the formula: F NaHCO3 , F CaOH2 is the mass flow of the deacidification agent sprayed, unit: kg / h; F SO2in , F HClin is the mass flow of SO2, HCl in the original flue gas, unit: kg / h; F SO2out , F HClout is the mass flow in the clean flue gas, unit: kg / h; SR is the ratio of the actual amount of deacidification agent to the theoretical amount.

[0074] The fly ash deacidification ash yield (i.e. equal to the deacidification reaction product and the over-sprayed deacidification reagent) can be calculated according to the bicarbonate and lime deacidification reaction principle formula (1)-(5). Taking the bicarbonate deacidification ash calculation as an example, the bicarbonate deacidification reaction product is mainly NaCl and Na2SO4, the reaction product calculation formula is seen in (8) and (9), and the bicarbonate over-sprayed amount calculation formula is seen in (10): M NaCl =2.30(F HClin -F HClout )×58.5 / 84——(8) M Na2SO4 =2.62(F SO2in -F SO2out )×142 / 84——(9) M 过量小苏打 =F NaHCO3 ×(SR Na -1)÷S Na R——(10) In the formula: M NaCl , M Na2SO4 is the reaction product of NaCl and Na2SO4, unit is kg / h; M 过量小苏打 is the consumption of over-sprayed bicarbonate, unit is kg / h.

[0075] According to the above formula, through simple calculation, the bicarbonate deacidification ash yield is 155 kg / h. Similarly, the high ratio lime deacidification ash yield is 190 kg / h. In addition, it is known that when the "SDA + dry process" conventional process is used for deacidification, the overage coefficient of ordinary lime is between 2-2.5, if the overage coefficient is calculated as 2, then the fly ash yield of the conventional process is 207 kg / h. Therefore, the fly ash yield of the dry reactor deacidification is reduced by 8-27% compared with the conventional process, thereby saving the treatment cost of fly ash.

[0076] F O3 =(C NO ×48 / 30)×M×Q×0.000001——(11) F H2O2 =(C NO ×18 / 30)×M / N×Q÷C H2O2 ×0.000001——(12) In the formula: F O3 , F H2O2 is the delivery flow of O3 and H2O2, unit is kg / h; C NO is the original concentration of NO in the flue gas, unit is mg / Nm 3 ; Q is the flue gas flow, unit is Nm 3 / h; M and N are the volume concentration ratios of O3 / NO and O3 / H2O2, respectively; C H2O2 is the concentration of H2O2 solution, in %.

[0077] During the regeneration operation of the integrated dust collector 300, the outlet flue of the flue gas waste heat utilization module 420 is switched from the main flue 310 to the bypass flue 320. The flue gas of about 215°C from the dust collector is reduced to 130-150°C by the waste heat utilization system, and then all or part of it enters the fixed adsorption bed 903 to complete the deep purification of the tail flue gas. The particle activated carbon of 2-6 mm is selected in the fixed adsorption bed 903, and the unit flue gas treatment loading of the particle activated carbon is 150 mg / Nm 3 Therefore, the total loading is 150 mg / Nm 3 × 100000 Nm 3 / h × 24 h = 360 kg. After the regeneration of the integrated dust collector 300 is completed, the outlet temperature of the economizer is adjusted to 180°C, and the outlet of the flue gas waste heat utilization module 420 is adjusted to the main flue 310. After the fixed adsorption bed 903 operates for a period of time, the hot flue valve of the adsorbent is opened, and the temperature of the adsorbent is raised to 300°C by the electric heater 906, so as to complete the desorption and regeneration of the adsorbent. The desorption gas contains dioxins and a small amount of acid gas, and is reflowed to the inlet flue of the dry reactor 200 for further purification.

[0078] The present application integrates the dry deacidification, catalytic filtration and regeneration technologies to form a short-range flue gas purification process, realizes efficient and collaborative removal of various pollutants in flue gas, reduces redundant equipment configuration and flue gas resistance, significantly reduces equipment investment, land area and operation cost; the added catalytic filter bag regeneration device can periodically regenerate and process the catalytic filter bag, restore its catalytic activity and filtration performance, reduce the replacement frequency, simultaneously improve the flue gas pollutant emission index, and balance the economy and environmental performance. The regeneration system of the present application is simple to operate, easy to use, and has high regeneration efficiency and significant practical value; the added adsorption fixed bed and its regeneration device can be used for dioxin removal during the regeneration of the catalytic filter bag, reduce environmental protection risk, prolong the service life of the adsorbent, and reduce the operation cost. The present application completely replaces the traditional “SDA (lime slurry) + dry method (lime / baking soda)” deacidification with a high-efficiency dry reactor, significantly improves the deacidification efficiency by using high-activity deacidifying agent (baking soda, high-specific lime), optimizing the deacidification reaction temperature, and increasing the gas-solid contact time, meets the high requirement of the catalytic filter bag on the inlet SO2 concentration <10 mg / Nm 3 , and improves the utilization rate of the deacidifying agent and reduces the production of fly ash. The present application is suitable for the existing rapid technical transformation system design of the incineration plant, can be connected to the process flow of the existing waste incineration plant, shortens the technical transformation period, avoids the loss of long-term shutdown, and is particularly suitable for energy-saving and environmental protection upgrading of old facilities.

[0079] It should be noted that, as used herein, the terms "includes," "including," or "has" are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements is not limited to those elements, but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a... " does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0080] Further, it is to be understood that the scope of the present application is not limited to the exact details of construction, mechanism, or arrangement of parts shown and described, nor exclusively to the exact sequence of steps described, for carrying out the methods described in the application, but one skilled in the art could make various changes, modifications, and substitutions thereto without departing from the application. Also, features described in relation to one example can be combined in other examples.

[0081] The above description is only specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered by the protection scope of the present application.

Claims

1. A multi-pollutant synergistic treatment system for flue gas, characterized in that, The system includes a waste heat boiler (100), a dry reactor (200), an integrated dust collector (300), a waste heat utilization module (420), and a chimney (500) connected in sequence along the flue gas flow direction. The integrated dust collector (300) has a built-in catalytic filter bag; The flue gas inlet section of the dry reactor (200) is connected to an oxidant delivery module (700) for delivering an oxidant into the dry reactor (200), a deacidifying agent delivery module (610) for delivering a deacidifying agent into the dry reactor (200), and an activated carbon delivery module (620) for delivering activated carbon into the dry reactor (200); the flue gas outlet section of the dry reactor (200) is connected to a useful reducing agent delivery module (800), which is used to reduce the flue gas at the outlet of the dry reactor (200).

2. The flue gas multi-pollutant synergistic treatment system according to claim 1, characterized in that, The catalytic filter bag is loaded with a composite catalyst. The support of the composite catalyst is composed of at least one of TiO2, SiO2, Al2O3 and molecular sieve, or at least one of a complex composed of two or more of TiO2, SiO2, Al2O3 and molecular sieve. The active component of the composite catalyst is composed of V2O5 and / or WO3. The dopant of the composite catalyst is composed of at least one of Fe2O3, Nb2O5, CeO2, Sb2O3 and SnO2. The composite catalyst contains 5-20% support, of which TiO2 content is 3-12%, 1-10% V2O5 and / or 0.1-8% WO3, and 0.1-2% Fe2O3 or 1.5-3% Nb2O5 or 3-5% Sb2O3 or 2-4% SnO2.

3. The flue gas multi-pollutant synergistic treatment system according to claim 1, characterized in that, The flue gas waste heat utilization module (420) is provided with a main flue (310) and a bypass flue (320) at its outlet. The bypass flue (320) is provided with a fixed adsorption module (900). The fixed adsorption module (900) is used to adsorb the regeneration tail gas when regenerating the catalytic filter bag. The outlet of the fixed adsorption module (900) is connected to the chimney (500). The outlet of the flue gas waste heat utilization module (420) is connected to the chimney (500) and / or the fixed adsorption module (900). The inlet end of the bypass flue (320) is located on the main flue (310) behind the outlet of the flue gas waste heat utilization module (420).

4. The flue gas multi-pollutant synergistic treatment system according to claim 3, characterized in that, The fixed adsorption module (900) includes a first isolation valve (901) located in the main flue (310), a second isolation valve (902) located in the bypass flue (320), and a fixed adsorption bed (903). The fixed adsorption bed (903) is provided with a first control valve (904) for discharging desorbed gas. The first control valve (904) is also connected to the inlet of the dry reactor (200).

5. The flue gas multi-pollutant synergistic treatment system according to claim 1, characterized in that, The integrated dust collector (300) is also provided with a hot flue gas channel (330) at its outlet. The hot flue gas channel (330) is connected to a heat recovery device to recover heat from the flue gas.

6. The flue gas multi-pollutant synergistic treatment system according to claim 5, characterized in that, The oxidant delivery module (700) includes an ozone generation system and a hydrogen peroxide evaporation system; The ozone generation system includes an oxygen tank (701) for storing and supplying oxygen, and a compressed air inlet pipe (702) for serving as a backup oxygen source. The oxygen tank (701) and the compressed air inlet pipe (702) are connected to an ozone generator (705), which is connected to a cooling water system (704). The hydrogen peroxide evaporation system includes a hydrogen peroxide raw water tank (708) for storing hydrogen peroxide, a hydrogen peroxide heater (709) for heating the hydrogen peroxide in the hydrogen peroxide raw water tank (708), and a hydrogen peroxide buffer tank (710) for storing gaseous hydrogen peroxide. The outlet of the ozone generator (705) is connected to the outlet of the hydrogen peroxide buffer tank (710) and the inlet of the mixer (714). The mixer (714) is used to fully mix gaseous ozone and gaseous hydrogen peroxide in proportion and then send them into the dry reactor (200). And / or, the hot flue (330) is connected to the hydrogen peroxide heater (709). And / or, the reducing agent delivery module (800) includes a storage tank (801) for storing liquid ammonia or ammonia water, an ammonia water evaporator (802) for evaporating ammonia water to generate ammonia gas, an ammonia gas buffer tank (803) for storing gaseous ammonia, and an ammonia gas mixer (804) for mixing ammonia gas with air and diluting it to a safe concentration before sending the mixed gas into the integrated dust collector (300). And / or, the hot flue (330) is connected to the ammonia evaporator (802); And / or, the deacidifying agent delivery module (610) includes a deacidifying agent storage silo (611) for storing deacidifying agent, a coarse powder metering delivery device (612) for metering coarse powder deacidifying agent, a fine powder mill (613) for grinding coarse powder deacidifying agent into fine powder, a deacidifying agent fine powder silo (614) for storing deacidifying agent fine powder, and a fine powder metering delivery device (616) for metering fine powder deacidifying agent into the dry reactor (200). And / or, the activated carbon delivery module (620) includes an activated carbon raw material storage bin (621) for storing activated carbon and an activated carbon metering delivery device (622) for metering activated carbon into the dry reactor (200).

7. A method for synergistic treatment of multiple pollutants in flue gas, characterized in that, The system for synergistic treatment of multiple pollutants in flue gas according to any one of claims 1-6 includes the following specific steps: Step 100: The flue gas passes through the waste heat boiler (100) to recover the heat carried by the flue gas; Step 200: The flue gas from the waste heat boiler (100) undergoes pre-removal of hydrogen chloride, sulfur oxides, heavy metals and dioxin-like pollutants in the dry reactor (200); When the deacidifying agent is baking soda, the particle size of the baking soda is less than 25 μm, and the excess coefficient of the baking soda is 1.05-1.2; when the deacidifying agent is slaked lime, the specific surface area of ​​the slaked lime is greater than 40 m². 2 / g, the excess coefficient of slaked lime is 1.5-2.0; the reaction temperature of deacidifying agent and activated carbon is less than 200 ℃, and the residence time of both in the dry reactor (200) is 2-4 s; When the original concentration of nitrogen oxides is higher than 300 mg / Nm 3 At that time, an oxidant is introduced into the dry reactor (200); Step 300: After the reducing agent is evenly mixed with the flue gas at the outlet of the dry reactor (200), it enters the integrated dust collector (300). The reducing agent used is ammonia. Particulate matter, deacidifying agent, and activated carbon in the flue gas within the integrated dust collector (300) adhere to the surface of the catalytic filter bag to form a filter cake, further undergoing the removal of acidic gases, heavy metals, and dioxins. Meanwhile, ammonia enters the inner layer of the catalytic filter bag and, under the action of the catalyst, reacts with NO... x An oxidation-reduction reaction occurs, and the flue gas purified by the integrated dust collector (300) enters the flue gas waste heat utilization module (420). The internal filtration velocity of the integrated dust collector (300) is 0.6-0.8 m / min, and the pressure difference between the inlet and outlet of the integrated dust collector (300) is 1000-1500 Pa. Step 400: Regenerate the catalytic filter bag every six months by introducing an oxidant into the dry reactor (200) so that the oxidant passes through the catalytic filter bag to regenerate the composite catalyst in the catalytic filter bag; during regeneration, the inlet flue gas temperature of the dry reactor (200) is greater than or equal to 220 ℃, and the regeneration time is greater than or equal to 24 h.

8. The method for synergistic treatment of multiple pollutants in flue gas according to claim 7, characterized in that, In step 200, the oxidant converts nitric oxide in the flue gas into nitrogen dioxide to improve the catalytic efficiency of the catalytic filter bag for nitrogen oxides. In step 400, the oxidant converts nitric oxide in the flue gas into nitrogen dioxide, so that the volume ratio of nitric oxide to nitrogen dioxide is 1-1.5:1, and lowers the decomposition temperature of ammonium sulfate; And / or, in step 400, the volume concentration ratio of ozone to hydrogen peroxide gas in the oxidant is 0.4-0.6:1, and the volume concentration ratio of ozone to NO in the flue gas is 0.2-0.5:

1.

9. The method for synergistic treatment of multiple pollutants in flue gas according to claim 7, characterized in that, Step 400 also includes the following specific steps: S410: During regeneration, open the bypass flue (320) and close the main flue (310) to allow the regeneration exhaust gas to pass through the adsorption and fixation module (900) installed on the bypass flue; the adsorbent in the fixation adsorption module (900) can be granular activated carbon, molecular sieve, or activated coke, and the adsorbent unit flue gas treatment loading is 100-250 mg / Nm³. 3 The residence time of flue gas in the fixed bed is 0.3-0.8 s; The processing method further includes the following steps: Step 500: After regeneration, the adsorbent in the fixed adsorption module (900) shall be regenerated at least once a year, and the regeneration time shall be 4-8 hours each time. When regenerating the adsorbent, the bypass flue (320) shall be opened to allow the flue gas heated to 280-350°C to pass through the fixed adsorption module (900) so that the regenerated tail gas adsorbed by the fixed adsorption module (900) shall be desorbed and the desorbed gas shall be returned to the dry reactor (200).

10. Application of a multi-pollutant synergistic treatment system and method for flue gas in waste incineration.

Images