A method and system for removing VOCs based on microwave-light modified catalyst

Abstract

The present invention provides a method and system for removing VOCs based on a microwave-light-modified catalyst, which belongs to the field of atmospheric pollution control. In the present invention, a microwave-light-modified removal coupling reactor is first used to activate a modified composite catalyst, and then the modified composite catalyst is used to induce free radicals / active components to degrade a variety of typical VOCs in industrial tail gas into CO2 and H2O. The removal process is green and pollution-free. The microwave-light-modified removal coupling reactor developed by the present invention can realize the simultaneous activation and modification of the catalyst and the advanced oxidation of pollutants in one reactor. Therefore, the device has outstanding comprehensive advantages such as simple and compact structure, short process flow, high mass transfer efficiency, high efficiency of simultaneous removal of pollutants and green and environmentally friendly process. It is a new industrial VOCs tail gas purification method and system with broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of air pollution control, and specifically relates to a method and system for removing VOCs by activating free radicals using an ultraviolet-microwave synergistic modified magnetic catalyst. Background Art

[0002] VOCs (volatile organic compounds) can cause temporary or permanent damage to organs such as the respiratory tract, blood, and liver (including blood disorders and cancer). Waste incineration and industrial production generate a variety of organic waste gases, primarily including hydrocarbons, alcohols, acids, aldehydes, ketones, and amines. These organic waste gases can also cause serious air pollution. Therefore, the research and development of economical, efficient, and environmentally friendly VOC removal technologies and equipment is a key issue in the environmental field.

[0003] The main technologies for removing VOCs from industrial waste gas include catalytic combustion, condensation recovery, adsorption, direct combustion, plasma degradation and absorption. Among them, the catalytic combustion method heats and converts exhaust gas into harmless and odorless CO2 and H2O through catalytic combustion. This method has a low ignition temperature, high purification rate, easy operation, and a small footprint. It is suitable for treating high-temperature or high-concentration VOCs, but the catalyst is easily poisoned and deactivated. The activated carbon adsorption method has high removal efficiency, simple and reliable technology, and low initial investment, but the activated carbon needs to be replaced frequently, which increases the loading, unloading, transportation, and replacement procedures, leading to increased operating costs. The direct combustion method uses auxiliary fuels such as gas or oil to heat the mixed gas, decomposing harmful substances into harmless substances under high temperature. This method has simple process and low investment, and is suitable for high-concentration and low-volume exhaust gases, but has high safety technology and operational requirements. The plasma degradation method has the advantages of a simple process flow, easy control, and thorough degradation, but has disadvantages such as high energy consumption and poor reliability of key equipment. The condensation recovery method is suitable for treating exhaust gases with high VOC concentrations, small gas volumes, and low temperatures, but requires complex refrigeration equipment and consumes a lot of energy. It is mainly used in certain industries such as petrochemicals, pharmaceuticals, and printing and dyeing. Common absorption methods include physical absorption and oxidative absorption, which involve introducing waste gas into an absorption liquid for separation or oxidation treatment. These methods suffer from complex process flows and high equipment investment. Consequently, despite the development of various VOCs removal technologies, each one has limitations in its scope of application and drawbacks. Therefore, the continued development of cost-effective, efficient, and environmentally friendly VOCs removal technologies and equipment holds significant scientific and industrial value.

[0004] In addition, in the exhaust gas of many industrial production units, two or more VOCs are often present in the airflow at the same time. Many existing removal technologies and equipment are developed for the removal of a single VOC, which has disadvantages such as large initial investment and complex process flow, as well as high operating energy consumption and high costs. In comparison, the simultaneous removal of multiple VOCs in a single device can effectively reduce the complexity of the device and process, reduce investment and operating energy consumption / costs, and has good development prospects and engineering application value. At present, multiple VOCs and multiple pollutants simultaneous removal technologies have been developed both domestically and internationally.

[0005] Among various common simultaneous removal technologies, free radical advanced oxidation (FRA) offers comprehensive advantages such as strong oxidation capacity and a green and environmentally friendly process, making it a promising technology for the simultaneous removal of multiple VOCs. However, the development of existing FRA technologies has been relatively slow. The main problems can be summarized as follows: (I) The use of separate electrochemical, photochemical, and microwave activation technologies suffers from low energy utilization efficiency and activation efficiency (generally requiring the use of other catalysts or activators); (II) Ultrasonic and thermal activation technologies suffer from low radical activation efficiency and low pollutant removal efficiency, and are usually used only as auxiliary enhancement measures in conjunction with other technologies; (III) Transition metal ion activation technologies suffer from difficulties in separating and recovering transition metal ions and secondary pollution; and (IV) Transition metal oxide activation technologies suffer from the easy decomposition and inactivation of metal oxides in acidic solutions. These four key issues are the main bottlenecks or obstacles hindering the large-scale industrial application of FRA technologies for the simultaneous removal of multiple VOCs. Furthermore, extensive scientific research and industrial practice have confirmed that mass transfer is the primary rate-determining step in gas-solid multiphase modification processes. Therefore, using conventional reactors to modify catalysts often results in disadvantages such as bulky reactors and high operating energy consumption. Further research and development of efficient multiphase modification reactors capable of achieving excellent mixing and enhanced mass transfer is needed. Summary of the Invention

[0006] To address the above technical issues, the present invention provides a method and system for removing VOCs by free radical activation using a UV-microwave-synergistically modified magnetic catalyst. In this method, a modified composite catalyst is first activated using a microwave-light-modified degassing coupled reactor. The modified composite catalyst then induces free radicals / active components to degrade various typical VOCs in industrial exhaust gas into CO2 and H2O. The microwave-light-modified degassing coupled reactor developed in this invention enables simultaneous catalyst activation and modification and pollutant advanced oxidation within a single reactor.

[0007] The basic principles of the method and system described in the present invention are:

[0008] (1) Catalyst modification process: First, in the modification area (A1), microwave / ultraviolet light is used to activate the modified catalyst (Co x Cu y Fe z O j / Biochar) to prepare a catalyst with expanded pores and increased specific surface area, and to generate abundant oxygen- and nitrogen-containing active sites on its surface. The above multi-step modification process can be expressed by the following equation (1):

[0009]

[0010] (2) The process of activating the oxidant with modified catalyst to generate free radicals and active components: Using the modified catalyst (Co x Cu y Fe z O j / Biochar) synergistically activates microwave / ultraviolet light to activate O3 / H2O2 / S2O8 in the free radical advanced oxidation degradation zone (A2). 2- Produces highly reactive free radicals / components (mainly SO4 - OH, HO2, O, O3 and O2 1 ), the specific process can be expressed by the following equation (2):

[0011]

[0012] (3) Simultaneous removal of pollutants: using highly oxidizing free radicals / active components (such as SO4 - OH, HO2, O, O3 and O2 1 ) can simultaneously oxidize and remove multiple VOCs from industrial exhaust gases, degrading VOCs into CO2 and H2O, thereby achieving the simultaneous removal of multiple pollutants. The entire removal process is green and pollution-free. The specific process can be expressed as follows:

[0013] VOCs+SO4 - ·+·OH+·O+O2 1 +O3+HO2·→H2O+CO2 (3)

[0014] The catalyst that loses its activity after the reaction can be returned to the modification zone (A1) of the microwave-light modification decoupling reactor (3) after magnetic separation and recovery, and regenerated through the activation modification process shown in the above equation (1), so as to regain new activated free radical properties, thereby realizing the recycling of the catalyst.

[0015] Based on the above principles, the present invention proposes a method for removing VOCs based on microwave-light modified catalysts, the specific steps are as follows:

[0016] I. The industrial waste gas / air mixture enters the catalyst feeder 1 from the waste gas / air inlet a of the catalyst feeder, and the catalyst enters the catalyst feeder 1 from the catalyst inlet b of the catalyst feeder. After being thoroughly mixed in the catalyst feeder 1, the industrial waste gas / air and catalyst enter the bottom of the microwave-light modification and removal coupled reactor 3 through the total catalyst inlet e of the microwave-light modification and removal coupled reactor, and are then sprayed into the modification zone A1 through the bottom lift nozzle 2. The microwave radiator 4 arranged in the modification zone (A1) begins to emit microwaves, and after the lateral catalyst impact nozzle 5 and the circulating fan 9 are fully activated, they can draw the suspended catalyst in the modification zone A1 to achieve synchronous impact, thereby achieving intense mixing. At the same time as the microwave emitter 4 is activated, the UV lamp in the photochemical barrier modification device 7 is also synchronously activated to emit UV light, and the lateral atomized solution impact nozzle 6 simultaneously sprays the atomized (NH4)2CO3 / H2O2 mixed solution, which synergistically activates the modified magnetic catalyst with the microwave / UV light, thereby achieving rapid pore expansion and loading of active sites on the catalyst. When the catalyst is sprayed by the lateral catalyst impact nozzle 5 and hits the quartz partition protective sleeve 8 of the photochemical barrier modification device 7, violent collision and friction will occur, which can greatly improve the heat and mass transfer efficiency and is beneficial to improving the modification efficiency of the catalyst.

[0017] II. After being modified in the modification zone A1, the catalyst continues to enter the free radical advanced oxidation degradation zone A2 to induce peroxide and O3 to produce highly active free radicals / components to oxidize and degrade VOCs. The ozone distributor 12 first sprays a certain concentration of O3, while the peroxide solution atomizer 13 sprays a certain concentration of H2O2 / S2O8 2- Mixed solution. After the UV lamp 16 is started, it radiates 254nm ultraviolet light and microwaves to activate O3 / H2O2 / S2O8 in a coordinated manner. 2- Produces highly reactive free radicals / components, mainly SO4 - OH, HO2, O, O3 and O2 1 , oxidative degradation of VOCs. VOCs can be oxidatively degraded into CO2 and H2O by these multiple active free radicals / components, and the removal process is green and pollution-free. The gas-solid mixture after pollutant removal is subjected to gas-solid separation in the magnetic separator 17. The separated catalyst is fed back into the catalyst feeder 1 through the catalyst feeder regeneration catalyst inlet i through the bypass circulation system, and is finally fed back into the microwave-light modification removal coupling reactor 3 for modification and regeneration. The separated CO2 and H2O are discharged into the atmosphere through the magnetic separator gas outlet h. Furthermore, the total inlet concentration of VOCs in industrial exhaust gas is not more than 80,000 mg / m 3The VOCs are one of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene, or a mixture of two or more of the above pollutants.

[0018] Furthermore, the catalyst is a composite carbon-based metal oxide catalyst (Co x Cu y Fe z O j / Biochar), and the optimized loading range of the three metal components is 1wt% to 15wt%. The saturation magnetization intensity of the catalyst needs to be maintained at 15emug -1 ~90emug -1 to ensure good magnetic separation and recovery.

[0019] The present invention also provides a microwave-photocatalytic VOC removal system based on a microwave-photocatalytic VOC removal method. The system comprises a microwave-photocatalytic VOC removal coupled reactor 3, which is divided into a modification zone A1 and a free radical advanced oxidation degradation zone A2. Multiple microwave emitters 4 are provided on the sidewalls of both modification zone A1 and free radical advanced oxidation degradation zone A2. Modification zone A1, located below the microwave-photocatalytic VOC removal coupled reactor 3, is equipped with multiple microwave emitters 4, multiple bottom lift nozzles 2, multiple lateral catalyst impact nozzles 5, lateral atomized solution impact nozzles 6, a photochemical barrier modification device 7, and a quartz partition protective sleeve 8. Free radical advanced oxidation degradation zone A2, located above modification zone A1, is equipped with multiple microwave emitters 4, a UV lamp 16, an ozone distributor 12, and a peroxide solution atomizer 13. The ozone distributor 12 is connected to the ozone supply tank 14, while the peroxide solution atomizer 13 is connected to the peroxide solution storage tower 15. The bottom of the microwave-light modification and removal coupled reactor 3 is equipped with a microwave-light modification and removal coupled reactor catalyst main inlet e and a microwave-light modification and removal coupled reactor catalyst main outlet f. The bottom of the modification zone A1 is connected to the circulation piping system for the lateral catalyst impact nozzles and the lateral atomized solution impact nozzles on both sides. The circulation piping system is equipped with a circulation fan 9, a mixed solution storage tank 10, and a solution pump 11.

[0020] Furthermore, the bypass circulation system is equipped with a bypass blower 18, a high-temperature steam cleaning device 19, and a nitrogen-protected high-temperature regeneration device 20. The high-temperature steam cleaning device 19 can spray high-temperature, high-pressure steam at 100°C to 220°C and 0.5 MPa to 5 MPa to flush and clean residue from the catalyst surface and pores. The nitrogen-protected high-temperature regeneration device 20 provides high-purity nitrogen and performs preliminary high-temperature activation and regeneration of the catalyst at temperatures between 300°C and 600°C.

[0021] Furthermore, the microwave emitters 4 in the microwave-light modification decoupling reactor 3 are arranged in series, with a transverse spacing and a longitudinal spacing M1 both between 12 cm and 60 cm, and the transverse and longitudinal spacings are the same.

[0022] Furthermore, the longitudinal and lateral spacing M2 between the bottom lift nozzles 2 at the bottom of the microwave-light modification and desorption coupled reactor 3 is equal, ranging from 8 cm to 20 cm. The initial airflow velocity of the bottom lift nozzles is between 15 m / s and 40 m / s to ensure sufficient airflow levitation force to lift the catalyst, but not too high, resulting in a short residence time of the catalyst within the modification zone A1. Side catalyst impact nozzles 5 are arranged on both sides of the modification zone A1 of the microwave-light modification and desorption coupled reactor 3 for spraying catalyst powder, while side atomized solution impact nozzles 6 are arranged for spraying atomized modification solution. The side catalyst impact nozzles 5 and side atomized solution impact nozzles 6 are arranged in a spaced-apart arrangement, with longitudinal and lateral spacing M3 ranging from 20 cm to 60 cm, and the longitudinal and lateral spacing is equal. The initial airflow velocity of the side catalyst impact nozzles 5 is between 40 m / s and 110 m / s to ensure sufficient impact force. The initial velocity of the airflow from the lateral atomized solution impingement nozzle 6 is between 50 m / s and 90 m / s to ensure sufficient atomization and mixing. The distance L1 between the lateral catalyst impingement nozzle 5 and the lateral atomized solution impingement nozzle 6 and the photochemical barrier modification device 7 is maintained between 60 cm and 300 cm to ensure sufficient acceleration distance for the catalyst particles. However, the injection distance cannot be too long, as this will result in insufficient injection and impact strength for the catalyst particles.

[0023] Furthermore, the microwave-optical modification and decomposition coupled reactor 3 is provided with a modification zone A1 and a free radical advanced oxidation degradation zone A2. Modification zone A1 is located below free radical advanced oxidation degradation zone A2. The height H1 of modification zone A1 ranges from 100 cm to 300 cm, while the height H2 of free radical advanced oxidation degradation zone A2 ranges from 80 cm to 200 cm. The UV lamps in free radical advanced oxidation degradation zone A2 are arranged in a sequential arrangement, with an optimized longitudinal and transverse spacing M4 between 6 cm and 18 cm. The effective wavelength of the UV light ranges from 180 nm to 280 nm.

[0024] Furthermore, the microwave radiation power density inside the modification area A1 needs to be maintained at 800W / m 3 ~4000W / m 3 The microwave radiation power density inside the free radical advanced oxidation degradation zone A2 needs to be maintained at 300W / m 3 ~900W / m 3 The UV radiation power density inside the modification area A1 needs to be maintained at 60W / m3 ~240W / m 3 The UV radiation power density inside the free radical advanced oxidation degradation zone A2 needs to be maintained at 60W / m 3 ~200W / m 3 between.

[0025] Furthermore, in the (NH4)2CO3 / H2O2 mixed solution ejected from the side atomizing solution impact nozzle 6 in the microwave-light modification and desorption coupled reactor 3, the (NH4)2CO3 concentration must be maintained between 0.05mol / L and 1.2mol / L, while the H2O2 concentration must be maintained between 0.3mol / L and 2.4mol / L. The O3 concentration ejected from the ozone distributor is in the range of 100ppm to 800ppm. The H2O2 / S2O8 ejected from the peroxide solution atomizer 13 is 2- In the mixed solution, the concentration of H2O2 should be maintained between 0.8mol / L and 2.5mol / L, while the concentration of S2O8 2- The concentration needs to be maintained between 0.1mol / L and 0.8mol / L.

[0026] Furthermore, the photochemical barrier modification device (7) is internally composed of two ultraviolet light sources, 185nm and 254nm. The two ultraviolet light sources are arranged in sequence with a spacing M5 kept the same, and the optimal spacing is between 1cm and 8cm.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Existing similar free radical advanced oxidation technologies for removing VOCs generally have various deficiencies. For example, high-energy free radical activation removal technologies such as electrochemistry, ultraviolet light and microwaves have deficiencies such as low energy utilization efficiency and low free radical activation efficiency. Transition metal ion activation removal technology has problems such as difficulty in recovering metal ions and secondary pollution. Thermal activation, ultrasound and metal oxide activation removal technologies have difficulties such as low free radical yield and low pollutant removal efficiency, and are usually only used in combination as auxiliary means of other activation technologies. The present invention proposes to use microwaves, ultraviolet light and carbon-based composite metal oxides to synergistically activate multi-oxidants to induce multiple highly active free radicals / components, and oxidatively remove multiple gaseous VOCs. This method can effectively overcome the deficiencies of the above-mentioned single activation removal technology, realize the synergistic effect of multiple activation removal technologies, and has extremely high multi-pollutant removal capabilities (all six VOCs can achieve 100% removal), with good development prospects.

[0029] (2) Existing catalyst modification technologies and pollutant removal technologies usually have complex modification processes and equipment, resulting in long process flows and complex equipment, which in turn leads to huge initial investment and operating costs. Therefore, the development of energy-saving and low-carbon modification and removal technologies with low energy consumption, low cost and short process flows is an important topic and development direction in this field. The microwave-light modification and removal coupled reactor developed in the present invention can achieve rapid one-step modification and efficient removal of multiple pollutants in one reactor. It has outstanding advantages such as simple modification and removal equipment and short process flows, and has good industrial application prospects.

[0030] (3) The solid catalyst modification and pollutant removal processes are both gas-solid heterogeneous processes. In the complex heterogeneous modification and removal reaction process, the oxidation rate of free radicals is often extremely fast, so the multiphase mass transfer process is usually the rate-controlling step of the entire modification and removal process. How to simply and efficiently enhance the mass transfer process is the key to achieving efficient modification and efficient pollutant removal. However, the mass transfer efficiency of the fixed bed reactor and fluidized bed reactor commonly used in this field is low and cannot meet the requirements of industrial applications. The microwave-light modification and removal coupling reactor developed by the present invention is simultaneously equipped with a lateral catalyst impact nozzle, a lateral atomized solution impact nozzle and a photochemical barrier modification device, which can achieve violent collisions between catalyst particles and atomized droplets at the same time, thereby having extremely high enhanced mixing and mass transfer performance, and thus can achieve efficient simultaneous removal of multiple pollutants (the simultaneous removal efficiency of six VOCs can be as high as 100%).

[0031] In summary, the modification and removal system developed in the present invention has outstanding comprehensive advantages such as simple and compact structure, short process flow, high mass transfer efficiency, high simultaneous pollutant removal efficiency and green and environmentally friendly process. It is a new industrial exhaust VOCs purification method and system with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 .Schematic diagram of the structure of the microwave-light coupled modified catalyst induced free radical removal VOCs technology and device in an embodiment of the present invention.

[0033] Figure 2 .Schematic diagram of the arrangement and dimensions of the microwave emitter of the microwave-light modified decoupling reactor according to an embodiment of the present invention.

[0034] Figure 3 . Schematic diagram of the bottom lift nozzle arrangement and dimensions of the microwave-light modified decoupling reactor according to an embodiment of the present invention.

[0035] Figure 4 .Schematic diagram of the arrangement and dimensions of the lateral catalyst impact nozzle and the lateral atomized solution impact nozzle in an embodiment of the present invention.

[0036] Figure 5 . Schematic diagram of the arrangement and dimensions of the UV lamps in the free radical advanced oxidation degradation zone (A2) of an embodiment of the present invention.

[0037] Figure 6 . Schematic diagram of the light source arrangement and dimensions of the photochemical blocking modification device according to an embodiment of the present invention.

[0038] Figure 1: Catalyst feeder 2. Bottom lift nozzle 3. Microwave-photomodification removal coupled reactor 3-1 Side wall of microwave-photomodification removal coupled reactor 4. Microwave emitter 5. Lateral catalyst impact nozzle 6. Lateral atomized solution impact nozzle 7. Photochemical barrier modification device 8. Quartz partition protective cover 9. Circulating fan 10. Mixed solution storage tank 11. Solution pump 12. Ozone distributor 13. Peroxide solution atomizer 14. Ozone supply tank 15. Peroxide solution storage tower 16. UV lamp 17. Magnetic separator 18. Bypass fan 19. High-temperature steam cleaning device 20. Nitrogen protection high-temperature regeneration device 21. 185nm vacuum UV lamp 22. 254nm short-wave UV lamp

[0039] a. Catalyst feeder exhaust gas / air inlet b. Catalyst feeder catalyst inlet c. Catalyst circulation left outlet d. Catalyst circulation right outlet e. Microwave-light modification and decoupling reactor catalyst total inlet f. Microwave-light modification and decoupling reactor catalyst total outlet g. Magnetic separator catalyst outlet h. Magnetic separator gas outlet i. Catalyst feeder regeneration catalyst inlet DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0041] The present invention proposes a method for removing VOCs based on microwave-light modified catalyst, the specific steps are as follows:

[0042] I. The industrial waste gas / air mixture enters the catalyst feeder 1 from the waste gas / air inlet a of the catalyst feeder, and the catalyst enters the catalyst feeder 1 from the catalyst inlet b of the catalyst feeder. After being thoroughly mixed in the catalyst feeder 1, the industrial waste gas / air and catalyst enter the bottom of the microwave-light modification and removal coupled reactor 3 through the total catalyst inlet e of the microwave-light modification and removal coupled reactor, and are then sprayed into the modification zone A1 through the bottom lift nozzle 2. The microwave radiator 4 arranged in the modification zone (A1) begins to emit microwaves, and after the lateral catalyst impact nozzle 5 and the circulating fan 9 are fully activated, they can draw the suspended catalyst in the modification zone A1 to achieve synchronous impact, thereby achieving intense mixing. At the same time as the microwave emitter 4 is activated, the UV lamp in the photochemical barrier modification device 7 is also synchronously activated to emit UV light, and the lateral atomized solution impact nozzle 6 simultaneously sprays the atomized (NH4)2CO3 / H2O2 mixed solution, which synergistically activates the modified magnetic catalyst with the microwave / UV light, thereby achieving rapid pore expansion and loading of active sites on the catalyst. When the catalyst is sprayed by the lateral catalyst impact nozzle 5 and hits the quartz partition protective sleeve 8 of the photochemical barrier modification device 7, violent collision and friction will occur, which can greatly improve the heat and mass transfer efficiency and is beneficial to improving the modification efficiency of the catalyst.

[0043] II. After being modified in the modification zone A1, the catalyst continues to enter the free radical advanced oxidation degradation zone A2 to induce peroxide and O3 to produce highly active free radicals / components to oxidize and degrade VOCs. The ozone distributor 12 first sprays a certain concentration of O3, while the peroxide solution atomizer 13 sprays a certain concentration of H2O2 / S2O8 2- Mixed solution. After the UV lamp 16 is started, it radiates 254nm ultraviolet light and microwaves to activate O3 / H2O2 / S2O8 in a coordinated manner. 2- Produces highly reactive free radicals / components, mainly SO4 - OH, HO2, O, O3 and O2 1 , oxidative degradation of VOCs. VOCs can be oxidatively degraded into CO2 and H2O by these multiple active free radicals / components, and the removal process is green and pollution-free. The gas-solid mixture after pollutant removal is subjected to gas-solid separation in the magnetic separator 17. The separated catalyst is fed back into the catalyst feeder 1 through the catalyst feeder regeneration catalyst inlet i through the bypass circulation system, and is finally fed back into the microwave-light modification removal coupling reactor 3 for modification and regeneration. The separated CO2 and H2O are discharged into the atmosphere through the magnetic separator gas outlet h. Furthermore, the total inlet concentration of VOCs in industrial exhaust gas is not more than 80,000 mg / m 3 The VOCs are one of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene, or a mixture of two or more of the above pollutants.

[0044] Furthermore, the catalyst is a composite carbon-based metal oxide catalyst (Co x Cu y Fe z O j / Biochar), and the optimized loading range of the three metal components is 1wt% to 15wt%. The saturation magnetization intensity of the catalyst needs to be maintained at 15emug -1 ~90emug -1 to ensure good magnetic separation and recovery.

[0045] In the (NH4)2CO3 / H2O2 mixed solution ejected from the side atomized solution impact nozzle 6 in the microwave-light modification and desorption coupled reactor 3, the (NH4)2CO3 concentration must be maintained between 0.05mol / L and 1.2mol / L, while the H2O2 concentration must be maintained between 0.3mol / L and 2.4mol / L. The O3 concentration ejected from the ozone distributor ranges from 100ppm to 800ppm. The H2O2 / S2O8 ejected from the peroxide solution atomizer 13 2- In the mixed solution, the concentration of H2O2 should be maintained between 0.8mol / L and 2.5mol / L, while the concentration of S2O8 2- The concentration needs to be maintained between 0.1mol / L and 0.8mol / L.

[0046] The total inlet concentration of VOCs in industrial exhaust gas is not more than 80,000 mg / m 3 The VOCs are one of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene, or a mixture of two or more of the above pollutants.

[0047] The catalyst is a composite carbon-based metal oxide catalyst (Co x Cu y Fe z O j / Biochar), and the optimized loading range of the three metal components is 1wt% to 15wt%. The saturation magnetization intensity of the catalyst needs to be maintained at 15emug -1 ~90emug -1 to ensure good magnetic separation and recovery.

[0048] Based on the above-mentioned method of removing VOCs by activating free radicals using a UV-microwave synergistic modified magnetic catalyst, the present invention also discloses a system for removing VOCs by activating free radicals using a UV-microwave synergistic modified magnetic catalyst.

[0049] like Figure 1 As shown, the microwave-light modification and decomposition coupled reactor 3 is divided into a modification zone A1 and a free radical advanced oxidation degradation zone A2, and multiple microwave emitters 4 are installed on the inner sidewalls of both modification zone A1 and free radical advanced oxidation degradation zone A2. Modification zone A1 is located below the microwave-light modification and decomposition coupled reactor 3. In addition to the multiple microwave emitters 4, the interior is also equipped with multiple bottom lift nozzles 2, multiple lateral catalyst impact nozzles 5, lateral atomized solution impact nozzles 6, a photochemical barrier modification device 7, and a quartz partition protective sleeve 8.

[0050] Free radical advanced oxidation degradation zone A2 is located above modification zone A1. In addition to multiple microwave emitters 4, it also houses a UV lamp 16, an ozone distributor 12, and a peroxide solution atomizer 13. The ozone distributor 12 is connected to an ozone supply tank 14, while the peroxide solution atomizer 13 is connected to a peroxide solution storage tower 15. The bottom of the microwave-photoelectric modification and removal coupled reactor 3 is equipped with a microwave-photoelectric modification and removal coupled reactor catalyst main inlet e and a microwave-photoelectric modification and removal coupled reactor catalyst main outlet f. The bottom of modification zone A1 is connected to a circulation piping system for lateral catalyst impact nozzles and lateral atomized solution impact nozzles on both sides. The circulation piping system is equipped with a circulation fan 9, a mixed solution storage tank 10, and a solution pump 11.

[0051] like Figure 2 As shown, the microwave emitters 4 in the microwave-light modification decoupling reactor 3 are arranged in series, and the transverse spacing and the longitudinal spacing M1 are both between 12 cm and 60 cm, and the transverse and longitudinal spacings are the same.

[0052] like Figure 3 As shown, the longitudinal and lateral spacing M2 between the bottom lift nozzles 2 at the bottom of the microwave-light modification and decoupling reactor 3 is equal, ranging from 8 cm to 20 cm. The initial airflow velocity of the bottom lift nozzles is between 15 m / s and 40 m / s to ensure sufficient airflow levitation force to lift the catalyst, but not too high as to shorten the catalyst's residence time in the modification zone A1.

[0053] like Figure 4As shown, lateral catalyst impact nozzles 5 are arranged on both sides of the modification zone A1 of the microwave-light modification and desorption coupled reactor 3 for spraying catalyst powder, while lateral atomized solution impact nozzles 6 are used to spray atomized modified solution. The lateral catalyst impact nozzles 5 and lateral atomized solution impact nozzles 6 are arranged in a spaced-apart arrangement, with longitudinal and lateral spacing M3 both between 20 cm and 60 cm, and the longitudinal and lateral spacings are the same. The initial airflow velocity of the lateral catalyst impact nozzle 5 is between 40 m / s and 110 m / s to ensure sufficient impact force. The initial airflow velocity of the lateral atomized solution impact nozzle 6 is between 50 m / s and 90 m / s to ensure sufficient atomization and mixing force.

[0054] like Figure 1 As shown, the distance L1 between the lateral catalyst impact nozzle 5 and the lateral atomized solution impact nozzle 6 and the photochemical barrier modification device 7 is maintained between 60cm and 300cm to ensure that the catalyst particles have sufficient acceleration distance, but the injection distance cannot be too long, otherwise the catalyst particles will not be able to reach the injection and impact intensity.

[0055] like Figure 1 As shown, the height H1 of the modification zone A1 is between 100 cm and 300 cm, and the height H2 of the free radical advanced oxidation degradation zone A2 is between 80 cm and 200 cm.

[0056] like Figure 5 As shown, the UV lamps in the free radical advanced oxidation degradation zone A2 are arranged in a sequential manner, and the optimized range of the longitudinal and transverse spacing M4 is between 6 cm and 18 cm, and the effective wavelength range of the UV light is between 180 nm and 280 nm.

[0057] The microwave radiation power density inside the modification area (A1) needs to be maintained at 800W / m 3 ~4000W / m 3 The microwave radiation power density inside the free radical advanced oxidation degradation zone (A2) needs to be maintained at 300W / m 3 ~900W / m 3 The UV radiation power density inside the modification area (A1) must be maintained at 60W / m 3 ~240W / m 3 The UV radiation power density inside the free radical advanced oxidation degradation zone (A2) must be maintained at 60W / m 3 ~200W / m 3 between.

[0058] like Figure 1As shown, the bypass circulation system is equipped with a bypass blower 18, a high-temperature steam cleaning device 19, and a nitrogen-protected high-temperature regeneration device 20. The high-temperature steam cleaning device 19 can spray high-temperature, high-pressure steam at 100°C to 220°C and 0.5 MPa to 5 MPa to flush and clean residue from the catalyst surface and pores. The nitrogen-protected high-temperature regeneration device 20 can provide high-purity nitrogen and perform preliminary high-temperature activation and regeneration of the catalyst at temperatures between 300°C and 600°C.

[0059] like Figure 6 As shown, the photochemical barrier modification device 7 is composed of two UV light sources, 185nm and 254nm. The two UV light sources are arranged in sequence with a spacing M5 kept constant, and the optimal spacing is between 1cm and 8cm.

[0060] The following is an example of the device removing six pollutants, including benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene, simultaneously under different conditions:

[0061] Example 1:

[0062] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the ultraviolet wavelengths in the modification zone (A1) are 254 nm and 185 nm, and the ultraviolet wavelength in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 800 W / m 3 , UV light power is 60W / m 3 The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 200W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.05mol / L, and the H2O2 concentration is 0.3mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 200ppm, the H2O2 concentration is 0.8mol / L, and the S2O8 2- The concentration is 0.1mol / L. The catalyst dosage is 150mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0063] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 58.1%, 39.9%, 35.8%, 39.4%, 33.3%, and 29.5%, respectively.

[0064] Example 2:

[0065] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the wavelength of ultraviolet light in the modification zone (A1) is 254 nm and 185 nm, and the wavelength of ultraviolet light in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1200 W / m 3 , UV light power is 80W / m 3 The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 200W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.05mol / L, and the H2O2 concentration is 0.3mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 200ppm, the H2O2 concentration is 0.8mol / L, and the S2O8 2- The concentration is 0.1mol / L. The catalyst dosage is 150mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0066] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 68.4%, 47.1%, 45.3%, 42.9%, 41.0%, and 34.2%, respectively.

[0067] Example 3:

[0068] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the wavelength of ultraviolet light in the modification zone (A1) is 254 nm and 185 nm, and the wavelength of ultraviolet light in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1200 W / m 3 , UV light power is 80W / m 3The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 200W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.1mol / L, and the H2O2 concentration is 0.5mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 200ppm, the H2O2 concentration is 0.8mol / L, and the S2O8 2- The concentration is 0.1mol / L. The catalyst dosage is 150mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0069] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 77.2%, 56.9%, 55.7%, 62.4%, 61.3%, and 44.9%, respectively.

[0070] Example 4:

[0071] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the wavelength of ultraviolet light in the modification zone (A1) is 254 nm and 185 nm, and the wavelength of ultraviolet light in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1200 W / m 3 , UV light power is 80W / m 3 The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 200W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.2mol / L, and the H2O2 concentration is 0.8mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 300ppm, the H2O2 concentration is 0.8mol / L, and the S2O8 2- The concentration is 0.1mol / L. The catalyst dosage is 150mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0072] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 85.7%, 68.9%, 65.4%, 72.9%, 71.1%, and 54.9%, respectively.

[0073] Example 5:

[0074] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the ultraviolet wavelengths in the modification zone (A1) are 254 nm and 185 nm, and the ultraviolet wavelength in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1600 W / m 3 , UV light power is 120W / m 3 The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 240W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.2mol / L, and the H2O2 concentration is 0.8mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 300ppm, the H2O2 concentration is 0.8mol / L, and the S2O8 2- The concentration is 0.2mol / L. The catalyst dosage is 200mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0075] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 91.8%, 80.4%, 79.1%, 86.7%, 79.9%, and 68.8%, respectively.

[0076] Example 6:

[0077] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the ultraviolet wavelengths in the modification zone (A1) are 254 nm and 185 nm, and the ultraviolet wavelength in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1600 W / m 3 , UV light power is 120W / m 3The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 240W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.2mol / L, and the H2O2 concentration is 1.2mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 400ppm, the H2O2 concentration is 0.8mol / L, and the S2O8 2- The concentration is 0.2mol / L. The catalyst dosage is 200mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0078] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 96.4%, 89.2%, 86.5%, 91.5%, 84.8%, and 79.7%, respectively.

[0079] Example 7:

[0080] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the ultraviolet wavelengths in the modification zone (A1) are 254 nm and 185 nm, and the ultraviolet wavelength in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1600 W / m 3 , UV light power is 120W / m 3 The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 240W / m 3 , UV light power is 80W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.2mol / L, and the H2O2 concentration is 1.2mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 400ppm, the H2O2 concentration is 1.2mol / L, and the S2O8 2- The concentration is 0.3 mol / L. The catalyst dosage is 300 mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600 mg / m 3 .

[0081] The preliminary results of numerical simulation and small-scale tests are as follows: the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 100%, 96.8%, 93.7%, 98.4%, 91.8%, and 89.6%, respectively.

[0082] Example 8:

[0083] M1 is 25 cm, M2 is 8 cm, M3 is 40 cm, M4 is 6 cm, M5 is 2 cm, L1 is 80 cm, H1 is 120 cm, H2 is 100 cm, the ultraviolet wavelengths in the modification zone (A1) are 254 nm and 185 nm, and the ultraviolet wavelength in the free radical advanced oxidation degradation zone (A2) is 254 nm. The microwave radiation power density in the modification zone (A1) is 1600 W / m 3 , UV light power is 150W / m 3 The microwave radiation power density in the free radical advanced oxidation degradation zone (A2) is 240W / m 3 , UV light power is 120W / m 3 The initial velocity of the bottom lift nozzle airflow is 20m / s, the initial velocity of the lateral catalyst impact nozzle airflow is 40m / s, and the initial velocity of the lateral atomized solution impact nozzle airflow is 50m / s. The (NH4)2CO3 concentration in the modification zone (A1) is 0.2mol / L, and the H2O2 concentration is 1.2mol / L. The O3 concentration in the free radical advanced oxidation degradation zone (A2) is 400ppm, the H2O2 concentration is 1.2mol / L, and the S2O8 2- The concentration is 0.5mol / L. The catalyst dosage is 300mg / L. The concentrations of benzene, toluene, xylene, styrene, trichloroethylene and chlorobenzene in industrial tail gas are all 600mg / m 3 .

[0084] The preliminary results of numerical simulation and small-scale tests are that the simultaneous removal efficiencies of benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene can reach 100%, 100%, 100%, 100%, 100%, and 100%, respectively.

[0085] The method described in the present invention can achieve simultaneous removal efficiencies of 100%, 100%, 100%, 100%, 100%, 100%, and 100% for benzene, toluene, xylene, styrene, trichloroethylene, and chlorobenzene, respectively. It has extremely high simultaneous removal efficiency of multiple pollutants, can achieve simultaneous removal of single or multiple gaseous VOCs, and does not generate wastewater or waste liquid. It can well meet the current strict ultra-low emission requirements and has extremely significant technical competitive advantages.

[0086] The embodiments described are preferred implementations of the present invention, but the present invention is not limited to the above implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the scope of protection of the present invention.

Claims

1. A method for removing VOCs based on microwave-light modified catalyst, characterized in that: The steps of the method are as follows: I. The industrial waste gas / air mixed flow enters the catalyst feeder (1) from the waste gas / air inlet (a) of the catalyst feeder, and the catalyst enters the catalyst feeder (1) from the catalyst inlet (b) of the catalyst feeder; the industrial waste gas / air and the catalyst are fully mixed in the catalyst feeder (1) and then enter the bottom of the microwave-light modification and removal coupling reactor (3) through the total catalyst inlet (e) of the microwave-light modification and removal coupling reactor, and then are sprayed into the modification zone (A1) through the bottom lift nozzle (2); the microwave emitter (4) arranged in the modification zone (A1) starts to emit microwaves, and the lateral catalyst impact nozzle (5) and the circulation fan (9) are all started and then the modification zone ( A1) achieves synchronous collision and intense mixing of the suspended catalyst; when the microwave emitter (4) is started, the ultraviolet lamp in the photochemical barrier modification device (7) is also started synchronously to emit ultraviolet light, and the side atomized solution impact nozzle (6) simultaneously sprays the atomized (NH4)2CO3 / H2O2 mixed solution, and synergistically activates the modified magnetic catalyst with the microwave / ultraviolet light, thereby achieving rapid pore expansion of the catalyst and loading of active sites; when the catalyst is sprayed by the side catalyst impact nozzle (5) onto the quartz partition protective sleeve (8) of the photochemical barrier modification device (7), violent collision and friction are generated, thereby improving the heat and mass transfer efficiency and the catalyst modification efficiency; II. After being modified in the modification zone (A1), the catalyst continues to enter the free radical advanced oxidation degradation zone (A2) to induce peroxides and O3 to produce highly active free radicals / components to oxidatively degrade VOCs; the ozone distributor (12) first sprays a certain concentration of O3, and the peroxide solution atomizer (13) sprays a certain concentration of H2O2 / S2O8 2- Mixed solution; after the UV lamp (16) is turned on, 254 nm ultraviolet radiation is radiated and microwaves are used to synergistically activate O3 / H2O2 / S2O8 2- Producing highly active free radicals / components, including SO4 - •,•OH, HO2,•,•O, O3 and O2 1 , oxidative degradation of VOCs; VOCs are oxidatively degraded into CO2 and H2O by multiple active free radicals / components; the gas-solid mixture after pollutant removal is subjected to gas-solid separation in a magnetic separator (17); the separated catalyst is fed back into the catalyst feeder (1) through the catalyst regeneration inlet (i) of the catalyst feeder through a bypass circulation system, and is finally fed back into the microwave-light modification removal coupling reactor (3) for modification and regeneration; the separated CO2 and H2O are discharged into the atmosphere through the gas outlet (h) of the magnetic separator.

2. The method for removing VOCs based on microwave-light modified catalyst according to claim 1, characterized in that: The catalyst is a composite carbon-based metal oxide catalyst synthesized with biochar as carrier and cobalt, copper and iron as multi-metal active components. x Cu y Fe z O j / Biochar, the optimized loading range of the three metal components is 1wt%~15wt%, and the saturation magnetization intensity of the catalyst is maintained at 15 emug -1 ~90 emug -1 between.

3. The method for removing VOCs based on microwave-light modified catalyst according to claim 2, characterized in that: The initial velocity of the airflow of the bottom lift nozzle (2) is between 15m / s and 40m / s, the initial velocity of the airflow of the lateral catalyst impact nozzle (5) is between 40m / s and 110m / s; the initial velocity of the airflow of the lateral atomized solution impact nozzle (6) is between 50m / s and 90m / s; the microwave radiation power density inside the modification zone (A1) is maintained at 800W / m 3 ~4000W / m 3 The microwave radiation power density inside the free radical advanced oxidation degradation zone (A2) is maintained at 300 W / m 3 ~900 W / m 3 The UV radiation power density inside the modified area (A1) is maintained at 60 W / m 3 ~240 W / m 3 The UV radiation power density inside the free radical advanced oxidation degradation zone (A2) was maintained at 60 W / m 3 ~200 W / m 3 between.

4. The method for removing VOCs based on microwave-light modified catalyst according to claim 1, characterized in that: In the (NH4)2CO3 / H2O2 mixed solution sprayed from the side atomizing solution impact nozzle (6), the (NH4)2CO3 concentration is maintained between 0.05 mol / L and 1.2 mol / L, while the H2O2 concentration is maintained between 0.3 mol / L and 2.4 mol / L; the O3 concentration sprayed from the ozone distributor is in the range of 100 ppm to 800 ppm; the H2O2 / S2O8 sprayed from the peroxide solution atomizer (13) is in the range of 100 ppm to 800 ppm. 2- In the mixed solution, the concentration of H2O2 should be maintained between 0.8 mol / L and 2.5 mol / L, while the concentration of S2O8 2- The concentration must be maintained between 0.1 mol / L and 0.8 mol / L; the total inlet concentration of VOCs in the industrial exhaust gas is not greater than 80,000 mg / m 3 .

5. The system for removing VOCs based on microwave-light modified catalyst according to claim 1, characterized in that: The microwave-light modification and decomposition coupling reactor (3) is divided into a modification zone (A1) and a free radical advanced oxidation degradation zone (A2) from bottom to top; a plurality of microwave emitters (4) are provided on the inner sidewalls of the modification zone (A1) and the free radical advanced oxidation degradation zone (A2); a plurality of bottom lift nozzles (2) are provided at the bottom of the modification zone (A1), and a plurality of lateral catalyst impact nozzles (5) and lateral atomized solution impact nozzles (6) are installed on the sidewalls; a photochemical blocking modification device (7) is provided in the middle of the modification zone (A1), and the photochemical blocking modification device (7) A quartz partition protective sleeve (8) is provided on the top; an ultraviolet lamp (16), an ozone distributor (12) and a peroxide solution atomizer (13) are provided inside the free radical advanced oxidation degradation zone (A2); the ozone distributor (12) is connected to the ozone gas supply tank (14), and the peroxide solution atomizer (13) is connected to the peroxide solution storage tower (15); the bottom and top of the microwave-light modification and removal coupling reactor (3) are respectively provided with a microwave-light modification and removal coupling reactor catalyst total inlet (e) and a microwave-light modification and removal coupling reactor catalyst total outlet (f).

6. The system according to claim 5, characterized in that: The bottom sides of the modification zone (A1) are connected to the circulation pipeline system of the lateral catalyst impact nozzle (5) and the lateral atomized solution impact nozzle (6); the circulation pipeline system is provided with a circulation fan (9), a mixed solution storage tank (10) and a solution pump (11), a high-temperature steam cleaning device (19) and a nitrogen protection high-temperature regeneration device (20); the required high-temperature steam cleaning device (19) can spray high-temperature and high-pressure steam of 100°C to 220°C and 0.5 MPa to 5 MPa to flush and clean the residues on the catalyst surface / pores; the nitrogen protection high-temperature regeneration device (20) provides high-purity nitrogen and performs preliminary high-temperature activation and regeneration of the catalyst in the range of 300°C to 600°C.

7. The system according to claim 5, wherein: The microwave emitters (4) are arranged in a row, and the transverse spacing and longitudinal spacing M1 are equal, and both are between 12 cm and 60 cm; the longitudinal and transverse spacing M2 between the bottom lift nozzles (2) are equal, and both are between 8 cm and 20 cm; the lateral catalyst impact nozzles (5) and the lateral atomized solution impact nozzles (6) are arranged in a row at intervals, and the longitudinal and transverse spacing M3 are equal, and both are between 20 cm and 60 cm; the spacing L1 between the lateral catalyst impact nozzles (5) and the lateral atomized solution impact nozzles (6) and the photochemical barrier modification device (7) is maintained between 60 cm and 300 cm.

8. The system according to claim 5, wherein: The height H1 of the modification zone (A1) is between 100 cm and 300 cm, and the height H2 of the free radical advanced oxidation degradation zone (A2) is between 80 cm and 200 cm; the ultraviolet lamps in the free radical advanced oxidation degradation zone (A2) are arranged in a sequential manner, with the longitudinal and transverse spacing M4 being equal, and the range of M4 is between 6 cm and 18 cm, and the effective wavelength range of ultraviolet light is between 180 nm and 280 nm; the photochemical blocking modification device (7) is internally composed of two ultraviolet light sources of 185 nm and 254 nm; the two ultraviolet light sources are arranged in sequence, and the spacing M5 remains the same and is between 1 cm and 8 cm.

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