A high-efficiency waste incinerator flue gas treatment process

Abstract

The present invention discloses a high-efficiency waste incinerator flue gas treatment process in the field of industrial flue gas purification, comprising the following steps: S1, first introducing hot nitrogen to activate the adsorption bed, spraying a circulating liquid with a pH of 8.5-9.0 through a pre-cooling tower, and then entering the treatment process after the flue gas temperature stabilizes at 175-185°C. The adsorption bed comprises 20 layers of stainless steel wire mesh filled with SNPC material, equipped with an observation window and a pneumatic vibrator. S2, the flue gas is rapidly cooled from 300°C to 80°C by a vortex generator in the pre-cooling tower before entering the adsorption bed. Regeneration is automatically triggered when the dioxin concentration exceeds 1.0ng TEQ / m³. S3, closing the adsorption bed valve and performing microwave pulse radiation regeneration under nitrogen protection. Regeneration is completed when the exhaust CO2 concentration is less than 100ppm, and the adsorption material is cooled to 60°C before being recycled. The present invention uses process synergy to treat flue gas pollutants, improve the removal efficiency of dioxins and heavy metals, and simultaneously achieve the recycling of adsorption materials.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial flue gas purification, and in particular to a high-efficiency waste incinerator flue gas treatment process. Background Art

[0002] With the acceleration of urbanization and the continued expansion of municipal solid waste incineration, flue gas pollutant control faces significant challenges. Traditional waste incineration flue gas treatment generally utilizes a combination of dry deacidification, activated carbon injection, and bag filter dust removal. While this process generally meets emission requirements for conventional pollutants, it suffers from significant technical deficiencies in actual operation. Activated carbon has a limited adsorption capacity for dioxin-like pollutants and easily reaches saturation under complex flue gas composition conditions. It also exhibits poor selectivity for heavy metals such as mercury. Furthermore, existing processes lack precise control over flue gas temperature. When the temperature is between 250°C and 400°C, dioxins are easily resynthesized in the dust removal equipment, severely impacting final emission targets. Furthermore, conventional treatment processes struggle to achieve synergistic pollutant removal and often require multiple, cascaded systems, resulting in complex systems, large footprints, and high operating costs.

[0003] Current improvement technologies are mainly focused on two aspects: optimization of adsorption materials and innovation of process combinations. In terms of materials, researchers have tried to use new adsorbents such as modified activated carbon and molecular sieves. Although the removal efficiency of specific pollutants has been improved to a certain extent, there are still problems such as high cost or difficulty in regeneration. For example, although the zeolite molecular sieves used in some existing technologies have a good adsorption effect on dioxins, the materials are expensive and the structure is easily destroyed at high temperatures; the metal oxide composite adsorbents proposed by other technologies can enhance the capture capacity of heavy metals, but often sacrifice the adsorption performance of organic pollutants. In terms of process, existing technologies mostly improve the purification effect by adding treatment units or extending the residence time, which not only increases energy consumption, but may also lead to new technical bottlenecks, such as equipment corrosion, secondary pollution and other problems.

[0004] Faced with increasingly stringent environmental emission standards, the industry urgently needs to develop efficient, economical, and stable waste incineration flue gas treatment technologies. An ideal technical solution should possess the following characteristics: synergistic removal of dioxins, heavy metals, and acid gases; precise temperature control to inhibit dioxin regeneration; the use of recyclable adsorbent materials to reduce operating costs; and a compact system design with a high degree of automation. These technical requirements pose a comprehensive upgrade challenge to existing processes, necessitating a combination of material modification and process innovation to overcome technical bottlenecks and provide a superior solution for waste incineration flue gas treatment. Summary of the Invention

[0005] The purpose of the present invention is to provide an efficient waste incinerator flue gas treatment process, which solves the technical problems of low dioxin removal rate, poor heavy metal adsorption selectivity, and difficulty in regenerating adsorption materials in traditional waste incineration flue gas treatment.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A high-efficiency waste incinerator flue gas treatment process, characterized by comprising the following steps:

[0008] S1: After starting the incinerator, hot nitrogen is first introduced to activate the adsorption bed. At the same time, the pre-cooling tower spray system is started to adjust the pH of the circulating liquid to 8.5-9.0. When the flue gas temperature stabilizes at 175-185°C, the treatment process is started. The adsorption bed is evenly distributed with 20 layers of stainless steel wire mesh, each layer is filled with SNPC material, and high-temperature resistant glass observation windows are set on both sides of the bed. A pneumatic vibrator is installed at the bottom.

[0009] In step S2, the flue gas enters the pre-cooling tower, where the vortex generator causes the flue gas temperature to drop sharply from 300°C to 80°C. The flue gas then enters the adsorption bed. When the online monitoring shows that the dioxin concentration is greater than 1.0ng TEQ / m³, the regeneration process is triggered.

[0010] S3, close the inlet and outlet valves of the adsorption bed, introduce nitrogen, transfer to the microwave cavity and pulse irradiate, and determine that the regeneration is complete when the CO2 concentration in the exhaust gas is less than 100ppm. After cooling to 60℃, return to the system for recycling.

[0011] According to a preferred embodiment of the present invention, the pre-cooling tower is made of 316L stainless steel and has a vertical tower body with a diameter of 1.2m and a height of 5m. Three sets of staggered vortex generators (blade angle 45°, adjustable speed range 0-2000rpm) are installed in the tower, and a dual-fluid nozzle (aperture 0.3mm, atomization pressure 0.8MPa) is arranged on the top of the tower. The spray liquid is a mixed solution of 10% NaOH and 5% H2O2. A pH online monitor is installed at the bottom of the tower to control the replenishment of the circulating liquid.

[0012] According to a preferred embodiment of the present invention, the microwave regeneration system is connected: a microwave resonant cavity (working frequency 2.45 GHz, maximum power 10 kW) is installed downstream of the adsorption bed, the cavity is lined with a polytetrafluoroethylene anti-corrosion layer, and a sealed transmission between the adsorption bed and the regeneration cavity is achieved through an air lock device. The microwave radiation adopts a pulse mode (working cycle: radiation 10s / interval 20s), and the regenerated exhaust gas is introduced into the secondary combustion chamber for treatment.

[0013] The system assembly and integration steps of the present invention are as follows: a vertical turbulent pre-cooling tower with a diameter of 1.2m and a height of 5m is made of 316L stainless steel, three sets of staggered vortex generators (blade angle 45°, adjustable speed range 0-2000rpm) are installed in the tower, a dual-fluid nozzle (aperture 0.3mm, atomization pressure 0.8MPa) is arranged on the top of the tower, the spray liquid is a mixed solution of 10% NaOH and 5% H2O2, and a pH online monitor is installed at the bottom of the tower to control the replenishment of the circulating liquid; a modular drawer-type adsorption bed (single bed size 1m×0.8m×0 .5m), 20 layers of stainless steel wire mesh (pore size 2mm) are evenly distributed inside, each layer is filled with 2.5cm thick SNPC material (bulk density 0.65g / cm³), high-temperature resistant glass observation windows are set on both sides of the bed, and a pneumatic vibrator (frequency 30Hz) is installed at the bottom to prevent material compaction; the microwave regeneration system is connected to the back of the adsorption bed, using a 2.45GHz microwave resonant cavity (maximum power 10kW), and the cavity is lined with a polytetrafluoroethylene anti-corrosion layer. The air lock device is used to achieve sealed transmission between the adsorption bed and the regeneration cavity, and the regeneration exhaust pipeline is connected to the secondary combustion chamber.

[0014] According to a preferred embodiment of the present invention, in step S1, the temperature of the hot nitrogen is 200° C., the activation time of the adsorption bed is 1 hour, the pore size of the stainless steel wire mesh is 2 mm, the filling thickness of the SNPC material is 2.5 cm, and the bulk density is 0.65 g / cm³; and the vibration frequency of the pneumatic vibrator is 30 Hz.

[0015] During the hot nitrogen activation process of the present invention, high-temperature nitrogen molecules transfer energy through collision, enabling water molecules and volatile organic compounds adsorbed on the surface of the SNPC material to overcome van der Waals forces and desorb. At the same time, carboxyl groups on the surface of the material undergo a decarboxylation reaction at high temperature to form new active sites, and the phenolic hydroxyl groups are partially dehydrated to form a quinone structure. The NaOH in the alkaline spray liquid removes acidic gases such as SO2 through acid-base neutralization reaction, and H2O2 converts NO into NO2 through oxidation. Controlling the temperature at 175-185°C can effectively avoid the resynthesis reaction of dioxins in the temperature range of 250-400°C.

[0016] According to a preferred embodiment of the present invention, in step S2, the flue gas enters the pre-cooling tower at a flow rate of 8000m³ / h; the vortex generator maintains a rotation speed of 1500rpm to make the flue gas temperature drop sharply from 300°C to 80°C within 0.3 seconds; the space velocity of the adsorption bed is 1200h -1 .

[0017] The vortex generator in the present invention generates a strong turbulent effect to achieve rapid heat exchange between high-temperature flue gas and cooling medium. The SNPC material captures dioxins and other macromolecular organic matter through the physical adsorption of the mesoporous SiO2 shell. The Fe3O4 core and Hg 2+Heavy metals such as thiol and thiol undergo chemical complexation to form a stable Fe-O-Hg structure. The thiol groups grafted on the surface of the material combine with heavy metal ions through coordination bonds to form stable compounds such as (RS)2Hg. The amino groups enhance the adsorption capacity of acidic gases through hydrogen bonding. The multi-level pore structure provides graded adsorption space for pollutants of different molecular sizes.

[0018] According to a preferred embodiment of the present invention, in step S3, the nitrogen gas is introduced for 5 minutes, and after being transferred to the microwave cavity, the microwave cavity is irradiated with a power pulse of 5 kW for 15 minutes.

[0019] In the present invention, nitrogen purge removes residual flue gas molecules in the adsorption bed through physical displacement. During microwave regeneration, polar adsorbate molecules undergo dipole rotation in the alternating electric field to generate internal heat. Microwave selective heating causes the adsorbate molecules to transition in vibrational energy levels, thereby weakening their binding force with the adsorbent. The high temperature environment promotes the cleavage and decomposition of the C-Cl bonds in the dioxin molecules. The magnetic loss effect of Fe3O4 generates local hot spots, which further promotes the desorption of the adsorbate. Monitoring the CO2 concentration in the regenerated exhaust gas can accurately determine the degree of regeneration completion.

[0020] According to a preferred embodiment of the present invention, the integrated denitrification flue gas treatment process of the lime kiln further includes: when the dew point temperature at the outlet of the pre-cooling tower is lower than 65°C, the alkali solution spraying volume is automatically increased and an alarm is triggered; if the pressure difference of the adsorption bed exceeds 5kPa, the pneumatic vibrator is immediately started and the material compaction condition is checked; if the bed temperature is detected to be higher than 250°C during the microwave regeneration process, the power supply is immediately cut off and the emergency cooling system is started.

[0021] According to a preferred embodiment of the present invention, the step of modifying the SNPC material comprises:

[0022] S1, walnut shells are crushed and sieved, dried in an oven, and the dried powder is immersed in a mixed solution of 0.5 mol / L thiourea and 1 mol / L urea at a solid-liquid ratio of 1:10, placed in an ultrasonic cell disruptor for treatment, and filtered after completion, washed with deionized water until neutral, and vacuum dried to obtain a precursor; the above precursor is mixed with ferric nitrate nonahydrate at a mass ratio of 5:1, ethanol is added as a dispersion medium, and ball milled, and then transferred to a tube furnace, heated to 400°C under nitrogen protection for pyrolysis, and cooled to obtain an Fe3O4-loaded carbon-based support;

[0023] S2, dispersing the carrier in a mixture of anhydrous ethanol and deionized water, adding ammonia water to adjust the pH to 9.5, slowly adding tetraethyl orthosilicate dropwise, reacting at 50°C under magnetic stirring, centrifuging, washing three times with ethanol, and drying at 60°C to obtain SiO2-coated composite particles;

[0024] S3, placing the composite particles in a quartz boat, placing it in a tube furnace, evacuating it to 0.01 MPa, introducing a H2 / CH4 mixed gas, heating it to 700°C and maintaining it, then switching to pure nitrogen protection and cooling it to 25°C to obtain a carbon-silicon composite material with a multi-level pore structure;

[0025] S4, immersing the composite material in a toluene solution of 3-mercaptopropyltrimethoxysilane, refluxing the solution under nitrogen protection, filtering and rinsing with toluene three times to remove unreacted products, placing the composite material in a plasma treatment apparatus, and introducing ammonia as a nitrogen source to finally obtain the SNPC material.

[0026] According to a preferred embodiment of the present invention, in step S1, the walnut shells are crushed to a particle size of 80-100 mesh and sieved; dried in an 80°C oven for 12 hours; placed in an ultrasonic cell disruptor and treated at a frequency of 40kHz for 2 hours; vacuum dried at 105°C for 6 hours; ball milled with a dispersion medium for 4 hours; and pyrolyzed at 3°C / min to 400°C for 2 hours.

[0027] The doping process of the walnut shell precursor in a thiourea (NH2CSNH2) / urea (CO(NH2)2) mixed solution involves multiple reactions: Under ultrasonic cavitation (40kHz), the thiourea molecules undergo an esterification reaction with the hydroxyl groups in the biomass through the -SH group (R-OH + HS-C=NH2 → RSC=NH2 + H2O). Simultaneously, the amino groups (-NH2) in the urea molecules undergo a nucleophilic substitution reaction with the aromatic rings of the lignin. During the pyrolysis stage (400°C), the doped sulfur atoms are incorporated into the carbon skeleton via a substitution reaction (C+S → CSC), while the nitrogen atoms undergo an insertion reaction to form pyridinic (C5H5N) and pyrrolic (C4H4NH) doping structures. The thermal decomposition of ferric nitrate (Fe(NO3)3·9H2O) undergoes three steps: first, dehydration (100-150℃), then decomposition into Fe2O3 (200-300℃), and finally partial conversion into Fe3O4 (Fe2O3 + C → Fe3O4 + CO↑) in a carbon reducing atmosphere, of which about 15% of Fe 3+ Reduced to Fe 2+ .

[0028] According to a preferred embodiment of the present invention, in step S2, the volume ratio of the anhydrous ethanol to the deionized water is 4:1; the mass ratio of the ethyl orthosilicate to the carrier is 1:5; and the reaction is carried out at 50° C. for 6 hours under magnetic stirring.

[0029] The hydrolysis and polycondensation reaction mechanism of tetraethyl orthosilicate (TEOS) in the present invention is as follows: Under alkaline conditions (pH 9.5), TEOS first hydrolyzes to form Si(OH)4 (Si(OC2H5)4 + 4H2O → Si(OH)4 + 4C2H5OH), followed by dehydration and condensation to form a Si-O-Si network (2Si(OH)4 → (SiO2)n + 4H2O). This process is regulated by interfacial tension, forming a mesoporous structure with a pore size distribution of 2-50nm in an ethanol / water mixed solvent (volume ratio of 4:1). The thickness of the SiO2 layer is precisely controlled by the mass ratio of TEOS to carrier (1:5), and a reaction temperature of 50°C ensures a moderate polycondensation rate and prevents particle agglomeration.

[0030] According to a preferred embodiment of the present invention, in step S3, the flow ratio of the mixed gas H2 / CH4 is 4:1, and the total flow rate is 50 mL / min; the temperature is increased to 700°C at 5°C / min and maintained for 3 hours.

[0031] During the chemical vapor deposition process, a H2 / CH4 mixture (flow ratio 4:1) undergoes a complex reaction at 700°C: CH4 first pyrolyzes (CH4→C+2H2), producing active carbon atoms that diffuse across the surface and fill the material's pores. Simultaneously, H2 reacts with oxygen-containing functional groups on the material's surface (C=O+H2→CH2+H2O), forming new active sites. By controlling the heating rate (5°C / min) and holding time (3h), this process achieves a carbon deposition rate of 15-20wt%, forming a three-level pore structure: micropores (<2nm), mesopores (2-50nm), and macropores (>50nm).

[0032] According to a preferred embodiment of the present invention, in step S4, the reaction is refluxed for 8 hours under nitrogen protection; and the plasma treatment apparatus is used for treatment at a power of 200 W for 30 minutes.

[0033] In the present invention, mercaptosilane ((CH3O)3Si(CH2)3SH) is first hydrolyzed to generate silanol (Si-OH), which then condenses with the silanols on the surface of the material (Si-OH+HO-Si≡→Si-O-Si≡+H2O), with a grafting density of up to 2.5 per nm. 2 During plasma treatment (200W), ammonia is dissociated into NH under the impact of high-energy electrons. x ·(x=1,2) active groups, which are implanted into the carbon matrix through addition reaction (C=C + NH·→CC-NH), forming a doped structure with a nitrogen content of about 5at%, of which pyridinic nitrogen accounts for 60%, pyrrolic nitrogen accounts for 30%, and quaternary nitrogen accounts for 10%.

[0034] The beneficial effects of the present invention are:

[0035] This invention, through its innovative SNPC-modified adsorbent material and optimized treatment process, has achieved remarkable technical results in the field of waste incineration flue gas purification. Firstly, in terms of pollutant removal efficiency, the system demonstrates excellent synergistic processing capabilities, effectively removing not only dioxin-like persistent organic pollutants from flue gas but also harmful components such as heavy metals and acid gases. The unique sulfur-nitrogen co-doping modification technology significantly enhances the adsorbent material's selectivity and adsorption capacity for different pollutants, while the precisely controlled temperature range effectively inhibits dioxin recombination, ensuring stable treatment results.

[0036] Secondly, in terms of system performance, the process achieves continuous and stable operation of flue gas treatment through innovative turbulent precooling technology and a modular adsorption bed design. The rapid cooling characteristics of the precooling tower avoid the temperature control lag inherent in conventional processes. The adsorption bed structure, equipped with an observation window and pneumatic vibrator, facilitates operation and maintenance while preventing material compaction. The introduction of a microwave regeneration system significantly reduces energy consumption while maintaining the long-term performance of the adsorption material, addressing the structural damage caused by traditional thermal regeneration methods.

[0037] Finally, in terms of economic and environmental performance, this technology uses biomass waste as raw material to produce adsorption materials, which not only reduces production costs but also enables resource recycling. The entire process system is compact and highly automated, significantly reducing the need for manual operation and the risk of secondary pollution. Compared to traditional processes, this technology offers greater economic and environmental benefits, providing a more sustainable solution for waste incineration flue gas treatment. DETAILED DESCRIPTION

[0038] The following specific implementation methods are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art may make some non-essential improvements and adjustments to the present application based on the above application content.

[0039] Preparation of SNPC materials: 1 kg of 80-mesh walnut shell powder was dried at 80 °C for 12 hours, immersed in 10 L of a mixed solution containing 0.5 mol / L thiourea and 1 mol / L urea, and ultrasonically treated at 40 kHz for 2 hours. After filtration and washing, the modified precursor was vacuum-dried at 105 °C for 6 hours to obtain the modified precursor; the precursor was ball-milled with 200 g of ferric nitrate nonahydrate for 4 hours, and pyrolyzed at 3 °C / min to 400 °C in a nitrogen atmosphere for 2 hours to obtain a Fe3O4-loaded carbon-based carrier; the carrier was dispersed in a mixture of ethanol and water (4:1) and the mixture was adjusted to obtain a Fe3O4-loaded carbon-based carrier. After adjusting the pH to 9.5, ethyl orthosilicate was slowly added in a mass ratio of 1:5, and the reaction was carried out at 50°C with magnetic stirring for 6 hours. The SiO2-coated composite particles were obtained by centrifugal washing and drying. The composite particles were chemically vapor deposited in a H2 / CH4 (4:1) atmosphere at a temperature of 5°C / min up to 700°C for 3 hours to obtain a hierarchical porous carbon-silicon composite material. Finally, the material was immersed in a 10wt% mercaptosilane toluene solution and refluxed under nitrogen protection for 8 hours. After washing with toluene, it was treated with ammonia for 30 minutes in a 200W plasma treatment instrument to obtain the final SNPC material.

[0040] During the system assembly phase, a 600×500×500mm adsorption bed was constructed from 316L stainless steel. Twenty layers of 2mm-diameter 304 stainless steel mesh were precisely welded inside, with the interlayer spacing set at 25±0.5mm. Each layer was evenly filled with 2.5cm-thick SNPC material, and a vibration-packing method was used to control the bulk density to 0.65±0.02g / cm³. High-temperature-resistant borosilicate glass observation windows (resistant to 300°C) were installed on both sides of the bed, and a pneumatic vibrator with a frequency of 30Hz and an amplitude of 2mm was configured at the bottom. A 1500rpm adjustable vortex generator, equipped with a dual-fluid nozzle (0.3mm aperture) and an online pH monitoring system, was installed in the precooling tower. The microwave regeneration cavity was lined with polytetrafluoroethylene and equipped with a 2.45GHz magnetron and an infrared temperature measurement system. All units were connected via flanges and subjected to a 0.5MPa airtightness test to ensure a leakage rate of less than 0.1% / h.

[0041] System operation phase: During the startup phase, the adsorption bed is activated with 200℃ hot nitrogen (flow rate 100L / min) for 1 hour, and the pre-cooling tower circulation pump is started simultaneously. The pH value of the spray liquid is stabilized at 8.5-9.0 through the automatic dosing system. After the flue gas temperature of the incinerator is stabilized, it is introduced into the treatment system at a flow rate of 8000m³ / h. The vortex generator is maintained at 1500rpm to reduce the flue gas from 300℃ to 80±2℃ within 0.3 seconds. After the flue gas is cooled, it is cooled at a rate of 1200h. -1The air velocity passes through the adsorption bed, and the online dioxin monitor monitors the air velocity in real time. When the concentration is greater than 1.0 ng TEQ / m³, the regeneration process is triggered. During regeneration, the inlet and outlet pneumatic valves are first closed, and nitrogen (99.999% purity) is purged for 5 minutes. After transfer to the microwave cavity, pulse radiation is applied at 5 kW power (10 seconds on / 20 seconds off). The CO2 concentration is monitored by an exhaust gas analyzer. When it is less than 100 ppm, regeneration is determined to be complete. After cooling to 60°C, the system is returned to the system. During operation, if the dew point at the outlet of the pre-cooling tower falls below 65°C, the alkali solution spray rate is automatically increased and an audible and visual alarm is triggered. If the pressure difference between the adsorption bed and the adsorption bed exceeds 5 kPa, the vibrator is immediately activated and a maintenance prompt is issued. During microwave regeneration, if the bed temperature exceeds 250°C, the power is immediately cut off and the water cooling emergency system is activated. Example 2:

[0042] The specific implementation method is the same as that of Example 1, except that the SNPC material is 100 mesh walnut shell powder, ultrasonic treatment is performed for 1.5 hours, and the pyrolysis heating rate is 5°C / min. The TEOS to carrier ratio is 1:8, and the reaction temperature is 40°C. System operation: flue gas flow rate is 6000 m³ / h, vortex speed is 1200 rpm, and cooling time is 0.5 seconds. The adsorption bed space velocity is 1000 h -1 , microwave power 4kW. Example 3:

[0043] The specific implementation method is the same as that of Example 1, except that the SNPC material: H2 / CH4 flow ratio is 2:1, the temperature is raised to 650°C and held for 4 hours, the plasma treatment power is 150W, and the system operation is: nitrogen purge for 8 minutes, microwave irradiation for 10 minutes per cycle, and the regeneration temperature is controlled at 230°C.

[0044] Comparative Example 1

[0045] The specific implementation method is the same as that of Example 1, except that the SNPC material is replaced by commercially available coal-based activated carbon.

[0046] Comparative Example 2

[0047] The specific implementation method is the same as that of Example 1, except that the vortex generator is eliminated and a traditional spray tower (cooling time 3 seconds) is used.

[0048] Comparative Example 3

[0049] The specific implementation method is the same as that of Example 1, except that traditional hot nitrogen regeneration (350° C., 2 h) is adopted.

[0050] Performance Testing

[0051] The above-mentioned preparation processes of Examples 1-3 and Comparative Examples 1-3 were used to treat simulated flue gas containing dioxin (10 ng TEQ / m³), Hg (200 μg / m³), and SO2 (500 ppm), and the data were continuously run for 100 hours.

[0052] Test results: Table 1: Test results of various embodiments and comparative examples

[0053]

[0054] As can be seen from Table 1, the present invention fully demonstrates its technical innovation and significant effects through comparative test data of Examples 1-3 and Comparative Examples 1-3. Compared with the traditional activated carbon process (Comparative Example 1), the SNPC material used in the present invention increases the dioxin removal rate from 85.2% to 99.3%, solving the core problem of insufficient removal efficiency of persistent organic pollutants by traditional processes. This is mainly due to the precisely constructed sulfur / nitrogen co-doping structure and multi-level pore system in the material - sulfur atoms enhance adsorption selectivity through π-π interactions with dioxin molecules, and the alkaline sites generated by nitrogen doping can effectively capture acidic pollutants, while the gradient distribution of micropores-mesopores-macroporous structures provides graded adsorption space for pollutants of different molecular sizes. In terms of heavy metal treatment, the present invention achieves a mercury removal rate of 98.6%, a qualitative leap compared to the traditional process (62.3%). This is attributed to the carefully designed thiol functional groups on the surface of the material and Hg 2+ The specific coordination effect of Fe3O4 (forming a stable Hg-S bond) and the synergistic capture of multiple heavy metals by the Fe3O4 core through chemical adsorption are the key factors influencing the regeneration of adsorbent materials. The innovative microwave pulse regeneration technology of this invention addresses the difficulty in regenerating adsorbent materials, enabling the material to be recycled over 30 times (compared to only 15 times with traditional thermal regeneration). This technology relies on the selective heating properties of microwaves, which only excite the adsorbate molecules without destroying the carrier structure. This, combined with a precise temperature control system (<250°C), prevents sintering and deactivation of the material. Furthermore, the pulsed radiation mode (10s on / 20s off) ensures uniform distribution of heat energy, reducing energy consumption by approximately 48% compared to the traditional thermal regeneration process in Comparative Example 3. Particularly noteworthy is the effective suppression of dioxin resynthesis in the 250-400°C temperature range achieved through turbulent pre-cooling technology (Comparative Example 2 shows a reduction in cooling time from 3 seconds to 0.3 seconds). This breakthrough utilizes a 1500 rpm high-speed vortex generator to enhance gas-liquid mass transfer. Combined with an alkaline oxidizing environment (H₂O₂ / NaOH) with a pH of 8.5-9.0, this technology achieves rapid cooling while simultaneously oxidizing NO to easily treatable NO₂. This integrated design enables the system to achieve a high-volume treatment capacity of 8,000 m³ / h while maintaining a dioxin removal rate exceeding 99%. The entire process, through the in-depth integration of material modification, equipment innovation, and intelligent control, not only overcomes technical bottlenecks associated with traditional technologies, such as the difficulty in synergistic pollutant removal, high operating costs, and poor system stability, but also provides an efficient, economical, and reliable solution for waste incineration flue gas treatment through modular design (e.g., detachable adsorption beds) and automated control (online monitoring and automatic regeneration).

[0055] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A high-efficiency waste incinerator flue gas treatment process, characterized in that: The following steps are involved: S1: After starting the incinerator, hot nitrogen is first introduced to activate the adsorption bed. At the same time, the pre-cooling tower spray system is started to adjust the pH of the circulating liquid to 8.5-9.

0. When the flue gas temperature stabilizes at 175-185°C, the treatment process is started. The adsorption bed is evenly distributed with 20 layers of stainless steel wire mesh, each layer is filled with SNPC material, and high-temperature resistant glass observation windows are set on both sides of the bed. A pneumatic vibrator is installed at the bottom. In step S2, the flue gas enters the pre-cooling tower, where the vortex generator causes the flue gas temperature to drop sharply from 300°C to 80°C. The flue gas then enters the adsorption bed. When the online monitoring shows that the dioxin concentration is greater than 1.0ng TEQ / m³, the regeneration process is triggered. S3, close the inlet and outlet valves of the adsorption bed, introduce nitrogen, transfer to the microwave cavity and pulse irradiate, and determine that the regeneration is complete when the CO2 concentration in the tail gas is less than 100ppm. After cooling to 60℃, return to the system for recycling; The modification steps of the SNPC material include: A1. Walnut shells are crushed and sieved, dried in an oven, and the dried powder is immersed in a mixed solution of 0.5 mol / L thiourea and 1 mol / L urea at a solid-liquid ratio of 1:

10. The powder is then treated in an ultrasonic cell disruptor. After completion, the mixture is filtered, washed with deionized water until neutral, and vacuum dried to obtain a precursor. The precursor is then mixed with ferric nitrate nonahydrate at a mass ratio of 5:1, ball-milled with ethanol as a dispersion medium, and then transferred to a tube furnace. The mixture is heated to 400°C under nitrogen protection and pyrolyzed. After cooling, an Fe3O4-loaded carbon-based support is obtained. A2, the carrier was dispersed in a mixture of anhydrous ethanol and deionized water, ammonia was added to adjust the pH to 9.5, ethyl orthosilicate was slowly added dropwise, and the mixture was reacted at 50°C under magnetic stirring. After centrifugation, the mixture was washed three times with ethanol and dried at 60°C to obtain SiO2-coated composite particles; A3, the composite particles were placed in a quartz boat, placed in a tube furnace, evacuated to 0.01 MPa, and a H2 / CH4 mixed gas was introduced. The temperature was raised to 700°C and maintained, and then switched to pure nitrogen protection and cooled to 25°C to obtain a carbon-silicon composite material with a multi-level pore structure; A4, immersing the composite material in a toluene solution of 3-mercaptopropyltrimethoxysilane, refluxing the solution under nitrogen protection, filtering and rinsing with toluene three times to remove unreacted products, placing the composite material in a plasma treatment apparatus, and introducing ammonia gas.

2. The high-efficiency waste incinerator flue gas treatment process according to claim 1 is characterized in that: In step S1, the temperature of the hot nitrogen is 200°C, the activation time of the adsorption bed is 1 hour, the pore size of the stainless steel wire mesh is 2 mm, the filling thickness of the SNPC material is 2.5 cm, the bulk density is 0.65 g / cm³, and the vibration frequency of the pneumatic vibrator is 30 Hz.

3. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: In step S2, the flue gas enters the pre-cooling tower at a flow rate of 8000 m³ / h; the vortex generator maintains a rotation speed of 1500 rpm to reduce the flue gas temperature from 300°C to 80°C within 0.3 seconds; the air velocity of the adsorption bed is 1200 h -1 .

4. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: In step S3, the nitrogen gas is introduced for 5 minutes, and the mixture is transferred to a microwave cavity and irradiated with a power pulse of 5 kW for 15 minutes.

5. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: The treatment process also includes: when the dew point temperature at the outlet of the pre-cooling tower is lower than 65°C, the alkali solution spray volume is automatically increased and an alarm is triggered; if the pressure difference of the adsorption bed exceeds 5kPa, the pneumatic vibrator is immediately started and the material compaction condition is checked; if the bed temperature is detected to exceed 250°C during microwave regeneration, the power is immediately cut off and the emergency cooling system is started.

6. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: In step A1, the walnut shells are crushed to a particle size of 80-100 mesh and sieved; dried in an 80°C oven for 12 hours; placed in an ultrasonic cell disruptor at a frequency of 40 kHz for 2 hours; vacuum dried at 105°C for 6 hours; ball milled with a dispersion medium for 4 hours; and pyrolyzed at 3°C / min to 400°C for 2 hours.

7. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: In step A2, the volume ratio of the anhydrous ethanol to the deionized water is 4:1; the mass ratio of the ethyl orthosilicate to the carrier is 1:5; and the reaction is carried out at 50° C. for 6 hours under magnetic stirring.

8. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: In step A3, the flow ratio of the H2 / CH4 mixed gas is 4:1, and the total flow rate is 50 mL / min; the temperature is increased to 700°C at 5°C / min and maintained for 3 hours.

9. The high-efficiency waste incinerator flue gas treatment process according to claim 1, characterized in that: In step A4, the reaction was refluxed for 8 hours under nitrogen protection; and the plasma treatment apparatus was used for treatment at a power of 200 W for 30 minutes.

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