Fly ash dioxin rapid catalytic decomposition method and device based on in-situ Joule heat

Abstract

The invention provides a fly ash dioxin rapid catalytic decomposition method and device based on in-situ Joule heat, and belongs to the technical field of fly ash treatment. The in-situ Joule heat-based fly ash dioxin rapid catalytic decomposition method comprises the following steps: introducing current into a mixed material of a Ni / NHPC catalyst and fly ash in a closed environment to carry out in-situ Joule heat treatment, and cooling after the treatment is finished to realize the catalytic decomposition of the fly ash dioxin, the treatment process is carried out in a device for quickly catalyzing and decomposing the dioxin in the fly ash based on the in-situ Joule heat. According to the fly ash treated by the in-situ Joule heat-based fly ash dioxin rapid catalytic decomposition device, most of toxic substances are fixedly sealed in the sealed cavity, the concentration of gas-phase pollutants is extremely low and reaches the zero emission standard, a flue gas purification device does not need to be additionally arranged, the overall process layout of fly ash treatment is greatly optimized, and the treatment cost is reduced. And the complexity and the operation cost of the system are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of fly ash treatment, and particularly relates to a method and device for rapidly catalytically decomposing dioxins in fly ash based on in-situ Joule heat. Background Art

[0002] With the improvement of people's living standards and the change of consumption concepts, the output of domestic waste shows an increasing trend year by year. Fly ash generated during the incineration process is rich in harmful substances such as dioxins, heavy metals, and soluble chlorides, which pose a threat to the human body and the environment and have been listed in the national hazardous waste list (HW18). Therefore, how to harmlessly dispose of fly ash is an important factor restricting the high-quality development of the waste incineration industry and a necessary measure to promote the "waste-free city". Among them, the problem of dioxin pollution control is particularly urgent.

[0003] Dioxins are the general term for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), with a total of 210 homologues, 17 of which are toxic, and 2,3,7,8-tetrachlorodibenzo-p-dioxin has the strongest toxicity. The demand for harmless disposal of fly ash is extremely urgent. Developing and improving dioxin detoxification technology is an important prerequisite for realizing the safe disposal and resource utilization of incinerated fly ash.

[0004] Existing fly ash dioxin degradation technologies are mainly divided into two categories: one is the high-temperature decomposition dioxin technology, including high-temperature sintering (700 - 1200 °C), high-temperature melting (1200 - 1600 °C) / vitrification (1100 - 1500 °C), and cement rotary kiln heat treatment technology (above 1400 °C). While decomposing dioxins, it can effectively solidify heavy metals and realize the resource utilization of fly ash. However, this method has the disadvantages of high energy consumption, easy volatilization of low-boiling heavy metals, and easy regeneration of dioxins in the low-temperature zone. The other is the low-temperature thermal decomposition technology, that is, dioxin removal is achieved through atmosphere regulation, pressure control, reagent addition, etc., mainly including hydrothermal treatment, mechanochemical degradation technology, and low-temperature catalytic pyrolysis. The hydrothermal treatment technology uses a reaction kettle to provide a suitable temperature (200 - 374 °C) and high-pressure (4 - 22 MPa) environment to promote the dissolution and dechlorination of dioxins in fly ash, but there are also problems such as immature technology, high energy consumption, and difficult waste liquid treatment; the mechanochemical degradation technology applies mechanical force to fly ash at room temperature to promote the effective decomposition of dioxins in fly ash, but this method has problems such as high energy consumption, low disposal volume, and long treatment cycle.

[0005] The low-temperature catalytic pyrolysis technology can decompose 99% of the dioxins in fly ash at a low temperature (<500°C) in an anoxic or anaerobic atmosphere. The low-temperature thermal decomposition method has mild reaction conditions and relatively low energy consumption, and the reaction products can be recycled, such as being used in building materials, cement production, etc., to realize the secondary utilization of waste and has good development potential. However, during the low-temperature thermal decomposition process, the generation and decomposition of dioxins exist simultaneously. Only when the decomposition rate exceeds the generation rate will the dioxin concentration in fly ash gradually decrease. The decomposition rate and generation rate of fly ash dioxins are easily affected by the fly ash components. CaO and Ca(OH) in fly ash 2 can promote the decomposition of highly chlorinated dioxins in fly ash; while the carbon source and chlorine source in fly ash will cause the regeneration of dioxins, and some metals such as Cu, Zn, Mg, etc. will also play a catalytic role and accelerate the synthesis of dioxins. The main way of dioxin generation under an inert atmosphere is precursor synthesis. During the waste incineration process, chlorinated precursor substances such as chlorobenzene and chlorophenol will be generated. These precursors undergo heterogeneous catalytic reactions on the surface of various metal oxides in fly ash to generate dioxins. And the fly ash components change with the changes in waste composition, incineration conditions, flue gas purification systems, etc. Therefore, it is difficult to ensure the stable compliance of fly ash dioxin concentration only by optimizing the operating conditions. How to further reduce the energy consumption of fly ash dioxin detoxification while ensuring the stable compliance of fly ash dioxin concentration has very important environmental protection significance.

[0006] At present, the Joule heating technology has received extensive attention due to its advantages such as high efficiency and low energy consumption. Patent CN118417286A discloses a method for rapid detoxification and resource utilization of municipal solid waste incineration fly ash based on Joule heat. This method aims at the complex characteristics of fly ash components, conducts multi-stage pretreatment on fly ash to recover chlorides and calcium carbonate. Then, according to the Joule heat technology, high-temperature treatment of fly ash by Joule heat is carried out. Then, according to the characteristics of fly ash after Joule heat treatment, subsequent treatment is carried out. The fly ash after high-temperature activation is used as an active cementitious material to prepare high-performance solid waste-based cement, and finally, fly ash detoxification, resource recovery, and high-value utilization are realized. The operation method proposed in this patent is to carry out solid-liquid separation on the acid washing solution after pickling municipal solid waste incineration fly ash, add sodium carbonate to the acid washing solution for hardness removal treatment, and then carry out mechanical compression evaporation crystallization to obtain potassium chloride and sodium chloride. According to the mass ratio of 40-50:25-35:20-30, the dried pickled fly ash, sodium chloride, and petroleum coke are sequentially added to a ball mill for mechanical ball milling treatment, and then the obtained mixed powder is compression molded and placed in the Joule heat generation section of a Joule heat flash evaporation device. After high-temperature discharge treatment (above 3000°C), the heavy metal-rich steam is condensed and collected, the dioxins contained in the compressed material are degraded under high-temperature conditions, and the petroleum coke is converted into graphene, and finally, detoxified and activated fly ash is obtained. Finally, the detoxified and activated fly ash and heavy metals are subjected to resource treatment and then utilized. However, this method essentially belongs to a high-temperature decomposition technology, which has high requirements for equipment and processes and is difficult to achieve low-temperature and high-efficiency detoxification of fly ash dioxins.

[0007] Patent CN118904889A discloses a method and device for decomposing dioxins in fly ash and co-curing heavy metals. Using nitrogen-doped hierarchical porous carbon material NHPC as a carrier, firmly anchor metallic nickel Ni to form a Ni / NHPC catalyst. Mix the Ni / NHPC catalyst and fly ash and place them in the first kiln body of a two-stage rotary kiln, and conduct low-temperature pyrolysis treatment for 30 min in pure N 2 gas at a pyrolysis temperature of 300 °C; after the treatment, enter the second kiln body of the two-stage rotary kiln for rapid cooling to achieve low-temperature thermal decomposition of the dioxins in the fly ash. However, the method of heating the material in this invention has problems of low efficiency and high energy consumption, and it is difficult to achieve low-energy consumption decomposition of dioxins in fly ash at low temperatures.

[0008] Therefore, this invention proposes a method and device for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat. Summary of the Invention

[0009] To solve the problems of low treatment efficiency, high energy consumption, and easy generation of secondary pollution in the treatment of dioxins in fly ash in the prior art, this invention proposes a method and device for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat to achieve rapid, efficient, and harmless treatment of dioxins in fly ash.

[0010] To achieve the above object, this invention provides the following technical solutions:

[0011] One of the technical solutions of this invention:

[0012] A method for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat, passing an electric current through the mixed material of Ni / NHPC catalyst and fly ash in a closed environment for in-situ Joule heat treatment, and cooling after the treatment is completed to achieve catalytic decomposition of dioxins in fly ash.

[0013] Further, in the in-situ Joule heat treatment, the current intensity is 1-10 A, the temperature is 300 °C, and the time is 30 min.

[0014] The in-situ Joule heat treatment of this invention is a technology that directly supplies heat to a chemical reaction by using the Joule heat generated when an electric current flows through a conductive catalyst. It has extremely high energy conversion efficiency and extremely fast heating rate, and due to the existence of an electric field, it can effectively change the reaction performance and enhance the activity of the catalyst.

[0015] Further, the addition amount of the Ni / NHPC catalyst is 1% of the mass of the fly ash. For example, for 100 g of fly ash, 1 g of Ni / NHPC catalyst needs to be added.

[0016] Further, the Ni / NHPC catalyst is prepared by using the foaming method to prepare the NHPC support and then loading Ni onto the NHPC support through an ultrasonic-assisted reduction method, which specifically includes the following steps:

[0017] S1: Prepare the NHPC support

[0018] 1.1: Before the experiment starts, weigh 12 g of corncob, 36 g of ammonium oxalate monohydrate, and 12 g of potassium bicarbonate respectively. Place the above materials in a ceramic mortar and grind them into a mixed powder;

[0019] 1.2: Then place the mixed powder in a quartz boat and put it into a tube furnace, and introduce N at a rate of 300 mL / min 2 , and introduce it for 10 min to exhaust the air in the reaction device;

[0020] 1.3: Subsequently, run the tube furnace. Under the atmosphere of N at 200 mL / min 2 , heat it from room temperature to 900 °C at a rate of 10 °C / min and keep it for 1 h;

[0021] 1.4: Then cool it to room temperature to obtain a black solid powder; dissolve the obtained powder in 500 mL of deionized water, add 10 mL of concentrated hydrochloric acid (concentration 37%) at the same time, and stir it at a rotation speed of 400 r / min at room temperature for 12 h;

[0022] 1.5: Then filter and wash it with deionized water until the pH of the filtrate is approximately 7. Collect the filter residue, dry and grind it to obtain the NHPC support.

[0023] S2: Prepare the Ni / NHPC catalyst by using the ultrasonic-assisted reduction method

[0024] 2.1: Weigh 100 mg of Ni(NO 3 ) 2 ·6H 2 O and place it in a beaker, add 10 mL of deionized water, and stir evenly to obtain a Ni(NO 3 ) 2 ·6H 2 O solution with a concentration of 10 mg / mL;

[0025] 2.1: Weigh 180 mg of the NHPC prepared in step S1 into a 100 mL beaker, add 20 mL of deionized water, and ultrasonicate for 30 min to make it evenly dispersed in water;

[0026] 2.3: Slowly drop the prepared Ni(NO 3 ) 2 ·6H 2 O solution into the NHPC aqueous solution, and assist with ultrasonic oscillation during the process to ensure Ni 2+Uniform distribution. After the dropping is completed, the mixed solution is ultrasonically treated for 30 min to uniformly adsorb Ni 2+ onto the surface of the carbon material;

[0027] 2.4: Measure 10 mL of a 1 mg / mL NaBH 4 solution and slowly drop it into the above solution while assisting with ultrasonic oscillation. During this process, the Ni adsorbed on the surface of the carbon material will be 2+ reduced, and ultrasonic treatment will continue for 40 min;

[0028] 2.5: After the ultrasonic treatment, wash and filter with deionized water, collect the filter residue, and dry it in an oven to obtain a Ni / NHPC catalyst with a theoretical Ni loading of 5%.

[0029] The present invention uses a novel Ni / NHPC catalyst to induce dechlorination of dioxins in fly ash at low temperature (<350 °C) while enhancing the decomposition of dioxin precursors, achieving the purpose of highly efficient detoxification (>95%) of dioxins in fly ash at low temperature (<350 °C). The main principle of low-temperature thermal decomposition of dioxins in fly ash is hydrodechlorination: active H atoms react with Cl atoms on the aromatic ring, and chlorine is removed and combines with H atoms to form HCl. The doped metal Ni in the Ni / NHPC catalyst can promote the dissociation and activation of H atoms in the reaction system, reduce the dechlorination activation energy of the target molecule, and increase the dechlorination rate of dioxins. In addition, the hierarchical porous carbon material (HPC) has a three-dimensional structure with interconnected micropores, mesopores, and macropores, providing numerous channels with low resistance and short paths for mass transfer. NHPC obtained by nitrogen doping treatment can further adjust the electronic structure of HPC, enhance the interaction between the active metal and HPC, form an M-N 4 coordination structure to firmly anchor active metal atoms and promote their highly dispersed state, and can adsorb and fix heavy metals in the fluffy sponge-like structure of the NHPC material, reducing heavy metal leaching, thereby effectively solidifying heavy metals in fly ash.

[0030] The second technical solution of the present invention:

[0031] A device for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat, which is used to implement the above-mentioned method for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat. The device for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat includes a sealed reactor, a power supply system, a control system, and a material inlet and outlet system. The sealed reactor includes a sealed cavity; an upper electrode and a lower electrode are respectively installed at the upper and lower ends of the sealed cavity; a temperature sensor is arranged inside the sealed cavity, and a liquid cooling system is arranged outside the sealed cavity; the power supply system is electrically connected to the upper electrode and the lower electrode; the control system is electrically connected to the temperature sensor inside the sealed cavity through the power supply system; the material inlet and outlet system includes a feed port and a discharge port. The upper electrode is provided with a feed port, and the feed port is controlled by a feed valve; the discharge port is arranged at the lower electrode of the sealed cavity, and an exhaust valve is further arranged on one side of the lower electrode of the sealed cavity.

[0032] Further, the sealed cavity is a quartz sealed cavity, and both the upper electrode and the lower two electrodes of the sealed cavity are carbon rod electrodes.

[0033] Further, the upper electrode of the sealed cavity is connected to the negative pole of the power supply system, and the lower electrode of the sealed cavity is connected to the positive pole of the power supply system.

[0034] Further, the power supply system has a function of current regulation and can accurately control the current intensity according to the reaction requirements.

[0035] Further, the control system is connected to the temperature sensor inside the sealed cavity through the power supply system, and automatically adjusts the current output of the power supply system according to the monitored temperature data to realize the intelligent control of the reaction process.

[0036] Further, the feed port of the material inlet and outlet system is used to add mixed materials into the sealed cavity, and the discharge port of the material inlet and outlet system is used to take out the treated fly ash products.

[0037] Further, the feed valve connecting the feed port and the upper electrode of the sealed cavity and the exhaust valve further arranged on one side of the lower electrode of the sealed cavity are both used for sealing to prevent gas leakage during the reaction process.

[0038] Further, the liquid cooling system outside the sealed cavity is used to rapidly cool the mixed materials to prevent the low-temperature regeneration of dioxins.

[0039] Further, the method for realizing the rapid catalytic decomposition of dioxins in fly ash by using the device for rapid catalytic decomposition of dioxins in fly ash based on in-situ Joule heat includes the following steps:

[0040] Mix the Ni / NHPC catalyst with fly ash to obtain a mixed material. Load the mixed material into the feed port of the material inlet and outlet system, open the feed valve, and allow the mixed material to enter the interior of the sealed cavity. Fill carbon rods at the upper and lower ends of the sealed cavity as the upper electrode and the lower electrode, connect the power supply system for in-situ Joule heat treatment, and control the heating temperature of the in-situ Joule heat treatment according to the temperature data monitored by the temperature sensor inside the sealed cavity through the control system. After the heating is completed, turn off the power supply system, open the liquid cooling system outside the sealed cavity, and after the cooling is completed, open the exhaust valve to discharge the waste gas. Then open the discharge port of the material inlet and outlet system to collect the waste material for subsequent safe disposal or resource utilization.

[0041] Compared with the prior art, the present invention has the following advantages and technical effects:

[0042] (1) When treating fly ash by traditional heating methods, heat is usually transferred from an external heat source to the fly ash, and the heat transfer path is relatively long, which easily leads to the problem of low heat transfer efficiency. According to Joule's law, in the in-situ Joule heat treatment of the present invention, when an electric current passes through the material mixed with fly ash and the Ni / NHPC catalyst, the electric current encounters resistance, thereby generating Joule heat, which causes the material to heat up rapidly, greatly shortening the heating time. At the same time, since the conduction of the electric current in the material is relatively uniform, the heat distribution is also relatively uniform, avoiding the problems of local overheating or insufficient heating caused by temperature gradients in traditional heating methods, and improving the consistency and stability of the treatment.

[0043] (2) The in-situ Joule heat treatment technology of the present invention can directly convert electrical energy into heat energy for heating the material, thereby reducing the energy loss caused by heat conduction, heat convection, and heat radiation between the traditional heating method and the surrounding environment, significantly improving the efficiency of heating the material, and effectively reducing the energy consumption of heating the material.

[0044] (3) The rapid catalytic decomposition method of fly ash dioxins based on in-situ Joule heat of the present invention utilizes the in-situ Joule heat treatment technology, which can achieve the efficient decomposition of fly ash dioxins under the combined action of an electric field, a temperature field, and a catalyst. The in-situ Joule heat treatment technology and the Ni / NHPC catalyst act synergistically, capable of quickly heating the material to the optimal active temperature of the catalyst, enabling the catalyst to rapidly exert its function and reducing the activation energy of the dioxin decomposition reaction. When an electric current flows through the catalyst, it will stimulate the proton migration on the catalyst surface, collide and interact with the molecules in the catalytic process, promote the activation of thermodynamically stable molecules, thereby improving the catalytic reaction performance; in addition, the electric field is also prone to interact with the catalyst, reactants, intermediates or products, etc., affecting the adsorption and desorption processes and intensities, resulting in a greatly improved removal efficiency of dioxins. In addition, the in-situ Joule heat treatment technology is used to rapidly and uniformly heat the Ni / NHPC catalyst and fly ash mixture, effectively reducing the energy loss generated during heating.

[0045] (4) For the fly ash disposed of by the device for the rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat of the present invention, most of the toxic substances are sealed in the sealed cavity, and the concentration of its gaseous pollutants is extremely low, reaching the standard approaching zero emissions. There is no need to additionally equip a flue gas purification device, greatly optimizing the overall process layout of fly ash treatment and reducing the complexity and operating cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0047] Figure 1 It is a schematic diagram of the principle of the rapid catalytic decomposition method of fly ash dioxins based on in-situ Joule heat of the present invention;

[0048] Figure 2 It is a schematic structural diagram of the device for the rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat of the present invention, wherein, 1 - feed inlet, 2 - feed valve, 3 - upper electrode, 4 - sealed cavity, 5 - mixed material, 6 - liquid cooling system, 7 - lower electrode, 8 - exhaust valve, 9 - discharge port, 10 - power supply system, 11 - control system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation embodiments of the present invention.

[0050] It should be understood that the terms used in this invention are only for describing specific embodiments and are not intended to limit the invention. Additionally, for the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0051] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0052] Without departing from the scope or spirit of this invention, various improvements and changes can be made to the specific embodiments of the specification of this invention, which are obvious to those skilled in the art. Other embodiments obtained from the specification of this invention are obvious to those skilled in the art. The specification and examples of this invention are merely exemplary.

[0053] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0054] An embodiment of this invention provides a method for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat. A mixed material of Ni / NHPC catalyst and fly ash is subjected to in-situ Joule heat treatment by passing an electric current in a closed environment, and after the treatment is completed, it is cooled to achieve the catalytic decomposition of fly ash dioxins.

[0055] In a preferred embodiment of this invention, the current intensity in the in-situ Joule heat treatment is 1 - 10 A, the temperature is 300 °C, and the time is 30 min.

[0056] The method for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat of this invention utilizes the in-situ Joule heat treatment technology to achieve the efficient decomposition of fly ash dioxins under the combined action of an electric field, a temperature field, and a catalyst. The schematic diagram of the invention principle is shown in Figure 1 .

[0057] In-situ Joule heat treatment is a technology that directly supplies heat to chemical reactions by using the Joule heat generated when an electric current flows through a conductive catalyst. It has extremely high energy conversion efficiency and extremely fast heating rate, and due to the presence of an electric field, it can effectively change the reaction performance and enhance the activity of the catalyst. Increasing the current intensity, increasing the reaction temperature, and prolonging the treatment time can all accelerate the heating rate, enabling the fly ash to reach the reaction temperature faster, thereby improving the decomposition efficiency of dioxins. However, the energy consumption will also increase, and more heat-resistant equipment and materials may be required, and the treatment cycle becomes longer, thus increasing the complexity and operating cost of the system.

[0058] In a preferred embodiment of the present invention, the addition amount of the Ni / NHPC catalyst is 1% of the mass of the fly ash. For example, for 100 g of fly ash, 1 g of the Ni / NHPC catalyst needs to be added.

[0059] In a preferred embodiment of the present invention, the Ni / NHPC catalyst is prepared by using the foaming method to prepare the NHPC carrier, and then Ni is loaded into the NHPC carrier by an ultrasonic-assisted reduction method, specifically including the following steps:

[0060] S1: Prepare the NHPC carrier

[0061] 1.1: Before the experiment starts, weigh 12 g of corncob, 36 g of ammonium oxalate monohydrate, and 12 g of potassium bicarbonate respectively. Place the above materials in a ceramic mortar and grind them into a mixed powder;

[0062] 1.2: Then place the mixed powder in a quartz boat and put it into a tube furnace, and introduce N at a rate of 300 mL / min 2 , and introduce it for 10 min to exhaust the air in the reaction device;

[0063] 1.3: Subsequently, operate the tube furnace. Under the atmosphere of N at 200 mL / min 2 , heat from room temperature to 900 °C at a rate of 10 °C / min and hold for 1 h;

[0064] 1.4: Then cool to room temperature to obtain a black solid powder; dissolve the obtained powder in 500 mL of deionized water, add 10 mL of concentrated hydrochloric acid (concentration 37%) at the same time, and stir at a rotation speed of 400 r / min at room temperature (25 ± 2 °C) for 12 h;

[0065] 1.5: Then filter and wash with deionized water until the pH of the filtrate is approximately 7. Collect the filter residue, dry and grind it to obtain the NHPC carrier.

[0066] S2: Prepare the Ni / NHPC catalyst by ultrasonic-assisted reduction method

[0067] 2.1: Weigh 100 mg of Ni(NO 3 )2 ·6H 2 O was placed in a beaker, and 10 mL of deionized water was added and stirred evenly to obtain a Ni(NO 3 ) 2 ·6H 2 O solution;

[0068] 2.1: Weigh 180 mg of NHPC prepared in step S1 into a 100 mL beaker, add 20 mL of deionized water, and ultrasonicate for 30 min to uniformly disperse it in water;

[0069] 2.3: Slowly drip the prepared Ni(NO 3 ) 2 ·6H 2 O solution into the NHPC aqueous solution, and assist ultrasonic oscillation during the process to ensure that Ni 2+ is evenly distributed. After the dripping is completed, ultrasonicate the mixed solution for 30 min to evenly adsorb Ni 2+ onto the surface of the carbon material;

[0070] 2.4: Measure 10 mL of 1 mg / mL NaBH 4 solution and slowly drip it into the above solution, while assisting ultrasonic oscillation. During this process, the Ni 2+ adsorbed on the surface of the carbon material will be reduced, and continue to ultrasonicate for 40 min;

[0071] 2.5: After the ultrasonication is completed, wash and filter with deionized water, collect the filter residue, and dry it in an oven to obtain a Ni / NHPC catalyst with a theoretical Ni loading of 5%.

[0072] The embodiment of the present invention also proposes a device for rapid catalytic decomposition of fly ash dioxin based on in-situ Joule heat. The structural schematic diagram is shown in Figure 2, wherein, 1 - feed inlet, 2 - feed valve, 3 - upper electrode, 4 - sealed cavity, 5 - mixed material, 6 - liquid cooling system, 7 - lower electrode, 8 - exhaust valve, 9 - discharge port, 10 - power supply system, 11 - control system. This device is used to implement the above-mentioned method for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat. The device for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat includes a sealed reactor, a power supply system, a control system, and a material inlet and outlet system; the sealed reactor includes a sealed cavity 4 for encapsulating the mixed material 5. The upper and lower ends of the sealed cavity 4 are respectively equipped with an upper electrode 3 and a lower electrode 7. A temperature sensor is arranged inside the sealed cavity 4, and a liquid cooling system 6 is arranged outside the sealed cavity 4. The power supply system 10 is electrically connected to the upper electrode 3 and the lower electrode 7. The control system 11 is electrically connected to the temperature sensor inside the sealed cavity 4 through the power supply system 10. The material inlet and outlet system includes a feed inlet 1 and a discharge port 9. The upper electrode 3 is provided with the feed inlet 1, and the feed inlet 1 is controlled by the feed valve 2. The discharge port 9 is arranged at the lower electrode 7, and an exhaust valve 8 is also arranged on one side of the lower electrode 7.

[0073] In a preferred embodiment of the present invention, the sealed cavity is a quartz sealed cavity, and the electrodes at the upper and lower ends of the sealed cavity are carbon rod electrodes.

[0074] In a preferred embodiment of the present invention, the upper electrode 3 of the sealed cavity 4 is connected to the negative pole of the power supply system 10, and the lower electrode 7 of the sealed cavity 4 is connected to the positive pole of the power supply system 10.

[0075] In a preferred embodiment of the present invention, the power supply system 10 has a current adjustment function and can accurately control the current intensity according to the reaction requirements.

[0076] In a preferred embodiment of the present invention, the control system 11 is connected to the temperature sensor inside the sealed cavity 4 through the power supply system 10, and automatically adjusts the current output of the power supply system 10 according to the monitored temperature data to achieve intelligent control of the reaction process.

[0077] In a preferred embodiment of the present invention, the feed inlet 1 of the material inlet and outlet system is used to add the mixed material 5 into the sealed cavity, and the discharge port 9 of the material inlet and outlet system is used to take out the treated fly ash product.

[0078] In a preferred embodiment of the present invention, both the feed valve 2 and the exhaust valve 8 are used for sealing to prevent gas leakage during the reaction process.

[0079] In a preferred embodiment of the present invention, the liquid cooling system 6 outside the sealed cavity 4 is used to rapidly cool the mixed material 5 to prevent the low-temperature regeneration of dioxins.

[0080] In a preferred embodiment of the present invention, the method for rapidly catalytically decomposing dioxins in fly ash by using the device for rapidly catalytically decomposing dioxins in fly ash based on in-situ Joule heat comprises the following steps:

[0081] Mix the Ni / NHPC catalyst with fly ash to obtain a mixed material 5. Load the mixed material 5 into the feed port 1 of the material inlet and outlet system. Open the feed valve 2 to enable the mixed material 5 to enter the interior of the sealed cavity 4. Fill carbon rods at the upper and lower ends of the sealed cavity 4 as the upper electrode 3 and the lower electrode 7. Connect the power supply system 10 for in-situ Joule heat treatment. Turn on the power supply system 10 to apply a direct current of 1 A, and control the heating temperature of the in-situ Joule heat treatment according to the temperature data monitored by the temperature sensor inside the sealed cavity 4 through the control system 11. Heat the mixed material 5 to 300 °C and maintain it for 30 min. After heating is completed, turn off the power supply system 10. Open the liquid cooling system 6 outside the sealed cavity 4 to rapidly cool the mixed material 5 until the temperature is below 100 °C to prevent the low-temperature regeneration of dioxins. After cooling is completed, open the exhaust valve 8 to discharge the waste gas. Then open the discharge port 9 of the material inlet and outlet system to collect the waste material for subsequent safe disposal or resource utilization.

[0082] In the embodiment of the present invention, the dioxin concentration is measured by gas chromatography-high resolution mass spectrometry (GC-HRMS), and the treatment efficiency of dioxins is calculated by the formula (η is the treatment efficiency of dioxins, C 1 is the concentration of dioxins in fly ash before in-situ Joule heat treatment, C 2 is the concentration of dioxins in fly ash after in-situ Joule heat treatment). The heavy metal leaching rate is measured by using inductively coupled plasma optical emission spectrometry (ICP-OES) to measure the heavy metal content in the acid washing solution of fly ash after acid washing, and the gaseous pollutants are measured by gas chromatography-mass spectrometry (GC-MS).

[0083] The technical solution of the present invention will be further described below through examples.

[0084] Example 1

[0085] The concentration of dioxins in the municipal solid waste incineration fly ash treated in this example is 6.2 μg I-TEQ / kg.

[0086] (1) Mix 1 g of Ni / NHPC catalyst evenly with 100 g of collected municipal solid waste incineration fly ash to obtain a mixed material 5;

[0087] (2) Mix the Ni / NHPC catalyst with the fly ash to obtain the mixed material 5. Load the mixed material 5 into the feed port 1 of the material inlet and outlet system. Open the feed valve 2 to allow the mixed material 5 to enter the interior of the quartz sealed cavity 4. Fill carbon rods as the upper and lower electrodes at the upper and lower ends of the quartz sealed cavity 4. Connect the upper electrode 3 to the negative pole of the power supply system 10, and connect the lower electrode 7 to the positive pole of the power supply system 10. Turn on the power supply system 10 for in-situ Joule heat treatment. Apply a direct current of 1 A by turning on the power supply system 10, and control the heating temperature of the in-situ Joule heat treatment according to the temperature data monitored by the temperature sensor inside the sealed cavity 4 through the control system 11. Heat the mixed material 5 to 300 °C and maintain it for 30 min. After heating is completed, turn off the power supply system 10. Open the liquid cooling system 6 outside the sealed cavity 4 to quickly cool the mixed material 5 until the temperature is below 100 °C to prevent the reformation of dioxins at low temperatures. After cooling is completed, open the exhaust valve 8 to discharge the waste gas. Then open the discharge port 9 of the material inlet and outlet system to collect the waste materials for subsequent safe disposal or resource utilization.

[0088] (3) Detect the raw municipal solid waste incineration fly ash before treatment and the fly ash product (waste material) taken out in step (2) after treatment. The results are shown in Table 1.

[0089] Table 1 Detection results of the fly ash product (waste material) after treatment in Example 1

[0090] Test items Before treatment After treatment Dioxin concentration (μg I-TEQ / kg) 6.2 0.28 Treatment efficiency (%) - 95.5 Energy consumption (kWh / kg fly ash) - 0.35 Heavy metal leaching rate (%) - Below detection limit <![CDATA[Gas-phase pollutant concentration (mg / m 3 )]]> Below detection limit

[0091] As can be seen from Table 1, at a current intensity of 1 A, the in-situ Joule heat treatment technology can effectively catalytically decompose dioxins in fly ash, with a treatment efficiency reaching 95.5%, low energy consumption, and an extremely low heavy metal leaching rate. No obvious gaseous pollutants were detected, indicating that the method in the embodiment of the present invention has good environmental friendliness.

[0092] Example 2

[0093] The concentration of dioxins in the municipal solid waste incineration fly ash selected in this example is 6.8 μg I-TEQ / kg.

[0094] (1) Mix 1 g of Ni / NHPC catalyst evenly with 100 g of the collected municipal solid waste incineration fly ash to obtain the mixed material 5;

[0095] (2) Mix the Ni / NHPC catalyst with fly ash to obtain a mixed material 5. Load the mixed material 5 into the feed port 1 of the material inlet and outlet system. Open the feed valve 2 to allow the mixed material 5 to enter the interior of the quartz sealed cavity 4. Fill carbon rods at the upper and lower ends of the quartz sealed cavity 4 as the upper and lower electrodes. Connect the upper electrode 3 to the negative pole of the power supply system 10 and the lower electrode 7 to the positive pole of the power supply system 10. Turn on the power supply system 10 for in-situ Joule heat treatment. Apply a DC current of 5 A by turning on the power supply system 10, and control the heating temperature of the in-situ Joule heat treatment according to the temperature data monitored by the temperature sensor inside the sealed cavity 4 through the control system 11. Heat the mixed material 5 to 300 °C and maintain it for 30 min. After heating is completed, turn off the power supply system 10. Open the liquid cooling system 6 outside the sealed cavity 4 to rapidly cool the mixed material 5 until the temperature is below 100 °C to prevent the low-temperature regeneration of dioxins. After cooling is completed, open the exhaust valve 8 to discharge the waste gas. Then open the discharge port 9 of the material inlet and outlet system to collect the waste materials for subsequent safe disposal or resource utilization.

[0096] (3) Detect the raw municipal solid waste incineration fly ash before treatment and the fly ash product (waste material) taken out after treatment in step (2). The dioxin concentration is measured by gas chromatography-high resolution mass spectrometry (GC-HRMS), and the treatment efficiency of dioxins is calculated by the formula (η is the treatment efficiency of dioxins, C 1 is the concentration of dioxins in fly ash before in-situ Joule heat treatment, C 2 is the concentration of dioxins in fly ash after in-situ Joule heat treatment). The heavy metal leaching rate is measured by determining the heavy metal content in the acid washing solution of fly ash after pickling using inductively coupled plasma optical emission spectrometry (ICP-OES), and the gaseous pollutants are measured by gas chromatography-mass spectrometry (GC-MS). The results are shown in Table 2.

[0097] Table 2 Detection results of the fly ash product (waste material) after treatment in Example 2

[0098]

[0099]

[0100] As can be seen from Table 2, at a current intensity of 5 A, the treatment efficiency of dioxins in fly ash is further increased to 97.8%. The energy consumption increases slightly but is still at a low level, and the heavy metal leaching rate is extremely low, and no obvious gaseous pollutants are detected. The results of Example 2 of the present invention show that the in-situ Joule heat treatment technology at a medium current intensity has a higher decomposition efficiency and good energy consumption control ability.

[0101] Example 3

[0102] In this example, the concentration of dioxins in the municipal solid waste incineration fly ash selected is 7.1 μg I-TEQ / kg.

[0103] (1) Mix 1 g of Ni / NHPC catalyst evenly with 100 g of the collected municipal solid waste incineration fly ash to obtain the mixed material 5.

[0104] (2) After mixing the Ni / NHPC catalyst and the fly ash to obtain the mixed material 5, load the mixed material 5 into the feed port 1 of the material inlet and outlet system, open the feed valve 2, so that the mixed material 5 enters the inside of the quartz sealed cavity 4. Fill carbon rods as the upper and lower electrodes at the upper and lower ends of the quartz sealed cavity 4. The upper electrode 3 is connected to the negative pole of the power supply system 10, and the lower electrode 7 is connected to the positive pole of the power supply system 10. Turn on the power supply system 10 for in-situ Joule heat treatment. Turn on the power supply system 10 to apply a DC current of 10 A, and control the heating temperature of the in-situ Joule heat treatment according to the temperature data monitored by the temperature sensor inside the sealed cavity 4 through the control system 11. Heat the mixed material 5 to 300 °C and maintain it for 30 min. After heating is completed, turn off the power supply system 10, open the liquid cooling system 6 outside the sealed cavity 4, and quickly cool the mixed material 5 until it is below 100 °C to prevent the low-temperature regeneration of dioxins. After cooling is completed, open the exhaust valve 8 to discharge the waste gas. Then open the discharge port 9 of the material inlet and outlet system to collect the waste material for subsequent safe disposal or resource utilization.

[0105] (3) Detect the raw municipal solid waste incineration fly ash before treatment and the fly ash product (waste material) taken out after treatment in step (2). Among them, the concentration of dioxins is measured by gas chromatography-high resolution mass spectrometry (GC-HRMS), and the treatment efficiency of dioxins is calculated by the formula (η is the treatment efficiency of dioxins, C 1 is the concentration of dioxins in the fly ash before in-situ Joule heat treatment, C 2 is the concentration of dioxins in the fly ash after in-situ Joule heat treatment). The heavy metal leaching rate is measured by using inductively coupled plasma optical emission spectrometry (ICP-OES) to measure the heavy metal content in the acid washing solution of the fly ash after acid washing, and the gaseous pollutants are measured by gas chromatography-mass spectrometry (GC-MS). The results are shown in Table 3.

[0106] Table 3 Detection results of the fly ash product (waste material) after treatment in Example 3

[0107]

[0108]

[0109] As can be seen from Table 3, at a current intensity of 10 A, the treatment efficiency of dioxins in fly ash reaches 98.9%. Although the energy consumption still increases to some extent, it is overall within a controllable range. The results of Example 3 show that the in-situ Joule heat treatment technology at high current intensity can efficiently decompose dioxins in fly ash, and no obvious gaseous pollutants are detected, indicating that this method can effectively avoid secondary pollution while efficiently treating dioxins in fly ash.

[0110] Comparative Example 1

[0111] The concentration of dioxins in the municipal solid waste incineration fly ash selected in this comparative example is 7.1 μg I-TEQ / kg.

[0112] (1) 1 g of Ni / NHPC catalyst was mixed evenly with 100 g of the collected municipal solid waste incineration fly ash to obtain a mixed material 5;

[0113] (2) After the Ni / NHPC catalyst and fly ash were mixed to obtain the mixed material 5, the mixed material 5 was loaded into the feed port 1 of the material inlet and outlet system. The feed valve 2 was opened to allow the mixed material 5 to enter the interior of the quartz sealed cavity 4. Carbon rods were filled at the upper and lower ends of the quartz sealed cavity 4 as the upper and lower electrodes. The upper electrode 3 was connected to the negative pole of the power supply system 10, and the lower electrode 7 was connected to the positive pole of the power supply system 10. The power supply system 10 was turned on for in-situ Joule heat treatment. The power supply system 10 was turned on to apply a direct current of 30 A, and the heating temperature of the in-situ Joule heat treatment was controlled by the control system 11 according to the temperature data monitored by the temperature sensor inside the sealed cavity 4. The mixed material 5 was heated to 300 °C and maintained for 30 min. After the heating was completed, the power supply system 10 was turned off, and the liquid cooling system 6 outside the sealed cavity 4 was opened to quickly cool the mixed material 5 until it was below 100 °C to prevent the low-temperature regeneration of dioxins. After the cooling was completed, the exhaust valve 8 was opened to discharge the waste gas. Then, the discharge port 9 of the material inlet and outlet system was opened to collect the waste material for subsequent safe disposal or resource utilization.

[0114] (3) The raw municipal solid waste incineration fly ash before treatment and the fly ash product (waste material) taken out after the treatment in step (2) were detected. Among them, the dioxin concentration was measured by gas chromatography-high resolution mass spectrometry (GC-HRMS), and the treatment efficiency of dioxins was calculated by the formula (η is the treatment efficiency of dioxins, C 1 is the concentration of dioxins in fly ash before in-situ Joule heat treatment, C 2 is the concentration of dioxins in fly ash after in-situ Joule heat treatment). The heavy metal leaching rate was measured by using inductively coupled plasma optical emission spectrometry (ICP-OES) to measure the heavy metal content in the acid washing solution of fly ash after acid washing, and the gaseous pollutants were measured by gas chromatography-mass spectrometry (GC-MS). The results are shown in Table 4.

[0115] Test Results of Fly Ash Products (Waste) after Treatment in Comparative Example 1

[0116]

[0117]

[0118] As can be seen from Table 4, at a current intensity of 30 A, the in-situ Joule heating technology can more efficiently catalyze the decomposition of dioxins in fly ash, with a treatment efficiency reaching 99.9%. No obvious gaseous pollutants were detected. The treatment effect is not much different from that of Example 3, but the energy consumption also increases accordingly, indicating that the method in Comparative Example 1 does not meet the requirements of reducing the system complexity and operating cost.

[0119] Comparative Example 2

[0120] The concentration of dioxins in the municipal solid waste incineration fly ash selected in this comparative example is 7.1 μg I-TEQ / kg.

[0121] (1) Mix 1 g of Ni / NHPC catalyst evenly with 100 g of the collected municipal solid waste incineration fly ash to obtain mixed material 5;

[0122] (2) After mixing the Ni / NHPC catalyst and fly ash to obtain mixed material 5, load mixed material 5 into the feed port 1 of the material inlet and outlet system. Open the feed valve 2 to allow mixed material 5 to enter the interior of the quartz sealed cavity 4. Fill carbon rods as the upper and lower electrodes at the upper and lower ends of the quartz sealed cavity 4. The upper electrode 3 is connected to the negative pole of the power supply system 10, and the lower electrode 7 is connected to the positive pole of the power supply system 10. Turn on the power supply system 10 for in-situ Joule heat treatment. Turn on the power supply system 10 to apply a DC current of 10 A, and control the heating temperature of the in-situ Joule heat treatment according to the temperature data monitored by the temperature sensor inside the sealed cavity 4 through the control system 11. Heat mixed material 5 to 500 °C and maintain it for 30 min. After heating is completed, turn off the power supply system 10. Open the liquid cooling system 6 outside the sealed cavity 4 to rapidly cool mixed material 5 until the temperature is below 100 °C to prevent the low-temperature regeneration of dioxins. After cooling is completed, open the exhaust valve 8 to discharge the waste gas. Then open the discharge port 9 of the material inlet and outlet system to collect the waste for subsequent safe disposal or resource utilization.

[0123] (3) Test the raw municipal solid waste incineration fly ash before treatment and the fly ash products (waste) taken out after treatment in step (2). The concentration of dioxins is measured by gas chromatography-high resolution mass spectrometry (GC-HRMS), and the treatment efficiency of dioxins is calculated by the formula (η is the treatment efficiency of dioxins, C 1 is the concentration of fly ash dioxins before in-situ Joule heat treatment, C 2Calculated from the concentration of dioxins in fly ash after in-situ Joule heat treatment, the heavy metal leaching rate was measured by using inductively coupled plasma optical emission spectrometry (ICP-OES) to determine the heavy metal content in the pickling solution after pickling fly ash, and the gaseous pollutants were measured by gas chromatography-mass spectrometry (GC-MS). The results are shown in Table 5.

[0124] Table 5 Detection results of fly ash products (waste materials) before and after treatment in Comparative Example 2

[0125]

[0126]

[0127] As can be seen from Table 5, at a current intensity of 10 A and a reaction temperature of 500 °C, the in-situ Joule heat technology can more efficiently catalyze the decomposition of dioxins in fly ash, with a treatment efficiency of 99.93%, and no obvious gaseous pollutants were detected. The treatment effect is not much different from that of Example 3, but the energy consumption also increases accordingly, indicating that the method in Comparative Example 2 also does not meet the requirements of reducing the system complexity and operating cost.

[0128] Comparative Example 3

[0129] The concentration of dioxins in the municipal solid waste incineration fly ash selected in this comparative example was 7.1 μg I-TEQ / kg.

[0130] (1) 1 g of Ni / NHPC catalyst was mixed evenly with 100 g of the collected municipal solid waste incineration fly ash to obtain a mixed material 5;

[0131] (2) After mixing the Ni / NHPC catalyst and fly ash to obtain the mixed material 5, the mixed material 5 was loaded into the feed port 1 of the material inlet and outlet system, the feed valve 2 was opened, so that the mixed material 5 entered the interior of the quartz sealed cavity 4. Carbon rods were filled as the upper and lower electrodes at the upper and lower ends of the quartz sealed cavity 4. The upper electrode 3 was connected to the negative pole of the power supply system 10, and the lower electrode 7 was connected to the positive pole of the power supply system 10. The power supply system 10 was turned on for in-situ Joule heat treatment. The power supply system 10 was turned on to apply a direct current of 10 A, and the heating temperature of the in-situ Joule heat treatment was controlled by the control system 11 according to the temperature data monitored by the temperature sensor inside the sealed cavity 4. The mixed material 5 was heated to 300 °C and maintained for 60 min. After the heating was completed, the power supply system 10 was turned off, and the liquid cooling system 6 outside the sealed cavity 4 was turned on to quickly cool the mixed material 5 until it was below 100 °C to prevent the low-temperature regeneration of dioxins. After the cooling was completed, the exhaust valve 8 was opened to discharge the waste gas, and then the discharge port 9 of the material inlet and outlet system was opened to collect the waste material for subsequent safe disposal or resource utilization.

[0132] (3) The raw municipal solid waste incineration fly ash before treatment and the fly ash product (waste) taken out after the treatment in step (2) are detected. Among them, the dioxin concentration is measured by gas chromatography-high resolution mass spectrometry (GC-HRMS), and the treatment efficiency of dioxin is calculated by the formula (η is the treatment efficiency of dioxin, C 1 is the concentration of dioxin in fly ash before in-situ Joule heat treatment, C 2 is the concentration of dioxin in fly ash after in-situ Joule heat treatment). The heavy metal leaching rate is measured by determining the heavy metal content in the acid washing solution of fly ash after pickling using inductively coupled plasma optical emission spectrometry (ICP-OES), and the gaseous pollutants are measured by gas chromatography-mass spectrometry (GC-MS). The results are shown in Table 6.

[0133] Table 6 Detection results of fly ash products (wastes) before and after treatment in Comparative Example 3

[0134]

[0135]

[0136] As can be seen from Table 6, at a current intensity of 10 A and a reaction temperature of 300 °C, when the reaction time is extended to 60 minutes, the decomposition efficiency of dioxin in fly ash can be further improved, and the treatment efficiency is close to complete decomposition (99.97%), and the treatment effect is not much different from that of Example 3, but the energy consumption also increases accordingly, indicating that the method in Comparative Example 3 does not meet the requirements of reducing the system complexity and operating cost.

[0137] Through the monitoring results of Examples 1 to 3 and Comparative Examples 1 to 3, the following conclusions can be drawn:

[0138] 1. The method of the present invention can effectively decompose dioxin in fly ash at different current intensities, with high treatment efficiency and low energy consumption.

[0139] 2. With the increase of the current intensity, the treatment efficiency of dioxin is further improved, but the energy consumption also increases slightly. In the current intensity range of 1 A to 10 A, this method shows good environmental friendliness and economy.

[0140] 3. The experimental results show that the method of the present invention can achieve efficient decomposition of dioxin in fly ash under low-temperature conditions, and at the same time can effectively solidify heavy metals and avoid secondary pollution, with broad application prospects.

[0141] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat, characterized in that: The mixture of Ni / NHPC catalyst and fly ash is subjected to in-situ Joule heat treatment by passing electric current in a closed environment, and then cooled after the treatment to achieve catalytic decomposition of dioxins in the fly ash.

2. The method for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat according to claim 1, characterized in that: The in-situ Joule heat treatment has a current intensity of 1-10A, a temperature of 300°C and a time of 30 minutes.

3. The method for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat according to claim 1, characterized in that: The addition amount of the Ni / NHPC catalyst is 1% of the mass of the fly ash.

4. A device for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat, characterized in that: The method for rapidly catalytically decomposing fly ash dioxins based on in-situ Joule heat according to any one of claims 1 to 3 is used, wherein the device for rapidly catalytically decomposing fly ash dioxins based on in-situ Joule heat comprises: a closed reactor, a power supply system, a control system and a material inlet and outlet system; The closed reactor comprises a sealed cavity, an upper electrode and a lower electrode are respectively installed at the upper and lower ends of the sealed cavity; a temperature sensor is arranged inside the sealed cavity, and a liquid cooling system is arranged outside the sealed cavity; The power supply system is electrically connected to the upper electrode and the lower electrode; The control system is electrically connected to the temperature sensor inside the sealed cavity through the power supply system; The material inlet and outlet system includes a feed port and a discharge port. The upper electrode is provided with a feed port, and the discharge port is provided at the lower electrode. An exhaust valve is also provided on one side of the lower electrode.

5. The device for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat according to claim 4, characterized in that: The sealed cavity is a quartz sealed cavity, and the upper electrode and the lower electrode are both carbon rod electrodes.

6. The device for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat according to claim 4, characterized in that: The method for realizing the rapid catalytic decomposition of fly ash dioxins by using the device for rapid catalytic decomposition of fly ash dioxins based on in-situ Joule heat comprises the following steps: A mixed material is obtained by mixing the Ni / NHPC catalyst with fly ash, and the mixed material is loaded into the feed port of the material inlet and outlet system, and the feed valve is opened to allow the mixed material to enter the sealed cavity, and carbon rods are filled into the upper and lower ends of the sealed cavity as the upper electrode and the lower electrode, and the power supply system is turned on for in-situ Joule heat treatment, and the heating temperature of the in-situ Joule heat treatment is controlled by the control system according to the temperature data monitored by the temperature sensor inside the sealed cavity, and the power supply system is turned off after the heating is completed, and the liquid cooling system outside the sealed cavity is opened, and the exhaust valve is opened after the cooling is completed to discharge the exhaust gas, and then the discharge port of the material inlet and outlet system is opened to collect and process the waste.

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