A honeycomb ceramic plasma degradation device and degradation method for SF6

Abstract

The invention relates to the technical field of sulfur hexafluoride degradation and discloses a honeycomb ceramic plasma degradation device for SF6, comprising a DBD reactor, a gas supply unit being arranged on the left side of the DBD reactor, a power supply unit being arranged at the bottom of the DBD reactor, and a processing unit being arranged on the right side of the DBD reactor, wherein the DBD reactor and the gas supply unit are connected via a gas pipe, and the DBD reactor and the power supply unit are electrically connected; the device breaks away from the traditional single-tube structure of the inner electrode and adopts a novel detachable honeycomb ceramic structure as the inner electrode of the reactor; the porous structure thereof provides a good channel for the flow and distribution of gas, and the porous channel facilitates the adsorption of catalysts and decomposition products, and can effectively promote the degradation process; at the same time, the honeycomb ceramic is used as the inner electrode in a detachable design, and the inner electrode tube is inserted into a slightly larger hole in the middle of the honeycomb ceramic, which facilitates the installation, cleaning and maintenance of the device and reduces the operating cost.

Description

Technical Field

[0001] The present invention relates to the technical field of sulfur hexafluoride degradation, and in particular to a device and a method for degrading SF6 using honeycomb ceramic plasma. Background Art

[0002] SF6, with its excellent insulation and arc-extinguishing properties, is widely used in electrical equipment such as gas-insulated circuit breakers, transmission pipelines, insulated substations, and transformers. Due to its high global warming potential (GWP), SF6 is listed as one of the six greenhouse gases with restricted emissions. It is highly stable in the atmosphere, has a long lifespan, and is difficult to degrade naturally. With the rapid development of the power industry, SF6 usage has increased annually. However, SF6 leaks occur annually in power systems due to equipment maintenance and replacement, and the direct release of SF6 waste gas has a serious impact on the environment. Currently, the main emission reduction measures include replacing SF6 with environmentally friendly gases (low-GWP gases), SF6 recovery and recycling, and SF6 waste gas degradation technologies. SF6 degradation technologies offer the advantages of high efficiency and low energy consumption. SF6 degradation methods include thermal decomposition, photocatalysis, and plasma. Plasma methods utilize active species such as high-energy electrons, ions, and free radicals in the plasma to react with SF6 molecules, rapidly dissociating them. Among them, the dielectric barrier discharge (DBD) plasma method has the advantages of high degradation rate, high energy efficiency, reliable discharge and simple device, and is widely used in treating waste gas.

[0003] Prior art has used DBD plasma technology to degrade SF6, analyzing the effects of various input voltages, background gases, and catalyst types and sizes on SF6 degradation. Using glass beads as catalysts in these experiments resulted in low degradation efficiency, with a high SO2F2 content and a low SO2 content in the degradation products. However, using γ-Al2O3 as a catalyst resulted in a high SO2 content and suppressed the formation of SO2F2 and SOF2. These results indicate that different filler materials influence the distribution of degradation products, with metal oxides such as γ-Al2O3 improving this distribution. Currently, the inner electrode in coaxial DBD plasmas for SF6 degradation always uses a single-tube structure, and the filler material must completely fill the entire DBD reactor, which impacts economic costs. While numerous factors influence the SF6 degradation rate, different inner electrode structures can also affect the SF6 degradation rate. However, this issue has not been extensively explored, making it valuable for research. At the same time, the internal electrode structure in the current DBD plasma technology for SF6 degradation is too simple, and different internal electrode structures will also affect the SF6 degradation rate. At the same time, in order to change the filling form of the catalyst and reduce the operating cost, the catalyst adsorption method can be used to solve this problem. Therefore, a honeycomb ceramic plasma SF6 degradation device and degradation method are proposed to solve the above problems. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a device and method for degrading SF6 using honeycomb ceramic plasma, which has the advantages of significantly improving the degradation rate of SF6 and being green and environmentally friendly, and solves the problems mentioned in the above background technology.

[0005] In order to achieve the above-mentioned purpose of significantly improving the degradation rate of SF6 and being green and environmentally friendly, the present invention provides the following technical solution: a honeycomb ceramic plasma degradation device for SF6, comprising a DBD reactor, a gas supply unit is provided on the left side of the DBD reactor, a power supply unit is provided at the bottom of the DBD reactor, and a processing unit is provided on the right side of the DBD reactor;

[0006] The DBD reactor is connected to the gas supply unit via an air pipe, the DBD reactor is electrically connected to the power supply unit, and the DBD reactor is connected to the processing unit via an air pipe;

[0007] The DBD reactor includes an outer electrode, a detachable honeycomb ceramic inner electrode is clamped inside the outer electrode, the detachable honeycomb ceramic inner electrode is composed of a honeycomb ceramic and an inner electrode tube, the honeycomb ceramic has an inner electrode tube hole, the honeycomb ceramic has a catalyst hole, the inner electrode tube is clamped inside the inner electrode tube hole, and the inner electrode tube hole size is larger than the catalyst hole size;

[0008] A sealing connector is provided on the outer surface of the outer electrode, and the sealing connector is used to seal the air supply unit and the air pipe of the processing unit.

[0009] Preferably, the gas supply unit includes a gas distributor, the gas inlet of the gas distributor is connected to an SF6 gas supply bottle and an Ar gas supply bottle through an air pipe, the outer surfaces of the air pipes connecting the SF6 gas supply bottle, the Ar gas supply bottle and the gas distributor are all provided with pressure reducing valves, and the outer surface of the air pipe connecting the gas distributor and the DBD reactor is provided with an electromagnetic flowmeter and a solenoid valve.

[0010] Preferably, the power supply unit includes a plasma power supply, one side of the plasma power supply is electrically connected to a voltage regulator, and the other side of the plasma power supply is fixedly connected to an oscilloscope.

[0011] Preferably, the processing unit includes an alkali solution treatment tank, the top of the alkali solution treatment tank is fixedly connected with an air outlet pipe, the alkali solution treatment tank is filled with alkali solution, and the right air pipe of the DBD reactor is inserted into the alkali solution.

[0012] Preferably, the number of the inner electrode tube hole is one, the diameter of the inner electrode tube hole is 0.6 cm, the number of the catalyst holes is eight, the diameter of the eight catalyst holes is 0.4 cm, the eight catalyst holes are evenly distributed in a circular shape on the outer surface of the inner electrode tube hole, and the length of the inner electrode tube is 35 cm.

[0013] Preferably, the degradation method of SF6 by honeycomb ceramic plasma degradation comprises the following specific steps:

[0014] S1: Clamp the inner electrode tube into the tube hole of the inner electrode tube so that the honeycomb ceramic is located in the middle of the inner electrode tube;

[0015] S2: Prepare Cu(NO3)2 powder, add water to the Cu(NO3)2 powder, and stir it evenly without precipitation to obtain a Cu(NO3)2 aqueous solution;

[0016] S3: The detachable honeycomb ceramic inner electrode is completely immersed in a Cu(NO3)2 aqueous solution, evaporated in a water bath, and calcined at high temperature to decompose into a CuO catalyst, which is evenly attached to the catalyst pores;

[0017] S4: The outer electrode is sleeved on the outer surface of the detachable honeycomb ceramic inner electrode, and the two ends of the outer electrode are connected to the gas distribution device and the alkali solution treatment tank using flanges. The outer electrode is connected to the plasma power supply using a high-voltage wire;

[0018] S5: The SF6 gas supply cylinder and the Ar gas supply cylinder are connected to the gas distribution instrument through the gas pipe, and the voltage regulator and the oscilloscope are connected to the plasma power supply through wires;

[0019] S6: Open the pressure reducing valves at the gas pipes of the SF6 gas supply cylinder and the Ar gas supply cylinder. The pressure reducing valves control the input openings of SF6 and Ar. According to the ratio of SF6 and Ar set by the gas distributor, they are mixed inside the gas distributor to form a uniform mixed gas.

[0020] S7: The mixed gas flow rate is controlled by an electromagnetic flow meter and a solenoid valve to deliver the mixed gas into the DBD reaction;

[0021] S8: Start the plasma power supply. Under the action of the high-voltage electric field, the mixed gas in the catalyst pores is broken down to generate plasma. Active substances such as high-energy electrons, ions and free radicals in the plasma collide and react with SF6 molecules. The CuO catalyst synergistically plays a catalytic role in the plasma environment, promoting the degradation process of SF6 gas.

[0022] S9: After degradation, first close the pressure reducing valve at the SF6 gas supply bottle to keep the DBD reactor running stably. After 10 minutes, turn off the plasma power supply and continue to introduce Ar to discharge the gas in the DBD reactor into the alkali solution in the alkali solution treatment pool for tail gas treatment and discharge it through the outlet pipe.

[0023] S10: Finally, close the pressure reducing valve at the Ar gas supply bottle.

[0024] Compared with the prior art, the present invention provides a device and method for SF6 degradation using honeycomb ceramic plasma, which has the following beneficial effects:

[0025] 1. This honeycomb ceramic plasma degradation device for SF6 breaks the traditional single-tube structure of the inner electrode and adopts a novel detachable honeycomb ceramic structure as the inner electrode of the reactor. Its porous structure provides a good channel for the flow and distribution of gas. The porous channel helps the adsorption of catalysts and decomposition products, which can effectively promote the degradation process. At the same time, the honeycomb ceramic is used as the inner electrode in a detachable design. The inner electrode tube is inserted into the slightly larger hole in the middle of the honeycomb ceramic, which facilitates the installation, cleaning and maintenance of the device and reduces operating costs.

[0026] 2. This honeycomb ceramic plasma degradation method for SF6 utilizes Cu(NO3)2 powder as a precursor. After evaporation in a water bath and high-temperature calcination, it is converted into a CuO catalyst, which adheres to the porous channels of the honeycomb ceramic. The CuO catalyst, in conjunction with the plasma, promotes the dissociation of SF6. Simultaneously, the catalyst surface serves as a site for the active species to react with SF6 molecules, accelerating the degradation reaction. The presence of the CuO catalyst tends to produce SO2 as a degradation product, effectively suppressing the formation of harmful gases such as SO2F2. The exhaust gas is treated in an alkaline solution treatment tank, which absorbs and neutralizes most of the acidic gases, effectively preventing the resulting acidic gases from posing a threat to humans and the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of a honeycomb ceramic plasma degradation device for SF6 proposed in the present invention;

[0028] Figure 2 This is a schematic diagram of the gas supply unit of a honeycomb ceramic plasma SF6 degradation device proposed in the present invention;

[0029] Figure 3 This is a schematic diagram of a DBD reactor for a honeycomb ceramic plasma degradation of SF6 proposed in the present invention;

[0030] Figure 4 This is a schematic diagram of a processing unit of a honeycomb ceramic plasma degradation device for SF6 proposed in the present invention;

[0031] Figure 5 This is a schematic diagram of a power supply unit of a honeycomb ceramic plasma SF6 degradation device proposed in the present invention;

[0032] Figure 6 This is a detailed structural diagram of a DBD reactor for a honeycomb ceramic plasma degradation of SF6 proposed in the present invention;

[0033] Figure 7 This is a schematic diagram of a honeycomb ceramic plasma degradation device for SF6 proposed by the present invention.

[0034] In the figure: 1DBD reactor, 101 outer electrode, 102 detachable honeycomb ceramic inner electrode, 1021 inner electrode tube hole, 1022 catalyst hole, 1023 honeycomb ceramic, 1024 inner electrode tube, 103 sealing connector, 2 gas supply unit, 201 gas distribution instrument, 202SF6 gas supply bottle, 203Ar gas supply bottle, 204 pressure reducing valve, 205 electromagnetic flowmeter, 206 solenoid valve, 3 power supply unit, 301 plasma power supply, 302 voltage regulator, 303 oscilloscope, 4 processing unit, 401 alkali solution treatment tank, 402 gas outlet pipe. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Example 1: Please refer to Figure 1-7A honeycomb ceramic plasma degradation device for SF6 includes a DBD reactor 1, a gas supply unit 2 is provided on the left side of the DBD reactor 1, a power supply unit 3 is provided at the bottom of the DBD reactor 1, and a processing unit 4 is provided on the right side of the DBD reactor 1.

[0037] The DBD reactor 1 is connected to the gas supply unit 2 via a gas pipe, is electrically connected to the power supply unit 3, and is connected to the processing unit 4 via a gas pipe. The DBD reactor 1 includes an outer electrode 101, with a removable honeycomb ceramic inner electrode 102 secured thereto. The removable honeycomb ceramic inner electrode 102 comprises a honeycomb ceramic 1023 and an inner electrode tube 1024. The honeycomb ceramic 1023 defines an inner electrode tube pore 1021, which also defines a catalyst pore 1022. The inner electrode tube 1024 is secured within the inner electrode tube pore 1021, and the inner electrode tube pore 1021 is larger than the catalyst pore 1022. The honeycomb ceramic 1023 has a large specific surface area and porosity, which facilitates uniform gas distribution and flow. The porous structure also serves as a catalyst carrier, effectively improving SF6 degradation efficiency. Furthermore, the main component of honeycomb ceramics is Al2O3, which can provide more active sites for the catalyst and accelerate the degradation reaction. Because the CuO catalyst has excellent catalytic activity, it can catalyze the decomposition of SF6 molecules, reduce the reaction activation energy, and accelerate the degradation reaction. The degradation products tend to produce SO2 and other substances that are easy to handle.

[0038] Furthermore, a sealing connector 103 is provided on the outer surface of the outer electrode 101, which is used to seal the gas pipe between the gas supply unit 2 and the processing unit 4. There is one inner electrode tube hole 1021 with a diameter of 0.6 cm. There are eight catalyst holes 1022 with a diameter of 0.4 cm each. The eight catalyst holes 1022 are evenly distributed in a circular shape on the outer surface of the inner electrode tube hole 1021. The inner electrode tube 1024 is 35 cm long.

[0039] Secondly, the gas supply unit 2 includes a gas distributor 201, the gas inlet of the gas distributor 201 is connected to the SF6 gas supply bottle 202 and the Ar gas supply bottle 203 through a gas pipe. The outer surface of the gas pipe connecting the SF6 gas supply bottle 202, the Ar gas supply bottle 203 and the gas distributor 201 is provided with a pressure reducing valve 204, and the outer surface of the gas pipe connecting the gas distributor 201 and the DBD reactor 1 is provided with an electromagnetic flowmeter 205 and an electromagnetic valve 206.

[0040] Furthermore, the power supply unit 3 includes a plasma power supply 301 . One side of the plasma power supply 301 is electrically connected to a voltage regulator 302 , and the other side of the plasma power supply 301 is fixedly connected to an oscilloscope 303 .

[0041] In addition, the processing unit 4 includes an alkali solution treatment tank 401, the top of which is fixedly connected to an air outlet pipe 402. The alkali solution treatment tank 401 is filled with alkali solution, and the right air pipe of the DBD reactor 1 is inserted into the alkali solution.

[0042] The honeycomb ceramic plasma degradation method for SF6 comprises the following specific steps:

[0043] S1: clamp the inner electrode tube 1024 into the inner electrode tube hole 1021 so that the honeycomb ceramic 1023 is located in the middle of the inner electrode tube 1024;

[0044] S2: Prepare 5.64g of Cu(NO3)2 powder, add 150ml of water to the Cu(NO3)2 powder, and stir it evenly without precipitation to obtain a Cu(NO3)2 aqueous solution;

[0045] S3: The removable honeycomb ceramic inner electrode 102 is completely immersed in a Cu(NO3)2 aqueous solution, evaporated to dryness in a 100°C water bath, and then baked in a 150°C oven for 8 hours to completely evaporate the water. Finally, it is calcined in a tube furnace at 500°C for 4 hours, causing the CuO catalyst to uniformly adhere to the catalyst pores 1022 and the CuO to uniformly adhere to the porous channels of the honeycomb ceramic 1023. Through the synergistic effect of DBD plasma technology and catalysts, efficient SF6 waste gas degradation is achieved. The degradation products tend to produce easily treatable SO2, which can be directly discharged after alkaline solution treatment, reducing environmental pollution. This is an efficient and environmentally friendly waste gas treatment technology. The presence of CuO significantly improves the SF6 degradation rate and achieves a certain degree of product selectivity, making the SF6 degradation products more likely to produce easily treatable substances such as SO2, while effectively suppressing the formation of other difficult-to-treat products such as SOF2, SO2F2, and SOF4.

[0046] S4: The outer electrode 101 is sleeved on the outer surface of the detachable honeycomb ceramic inner electrode 102, and the two ends of the outer electrode 101 are connected to the gas distribution device 201 and the alkali solution treatment tank 401 using flanges 104. The outer electrode 101 is connected to the plasma power supply 301 using a high-voltage wire;

[0047] S5: The SF6 gas supply cylinder 202 and the Ar gas supply cylinder 203 are connected to the gas distribution instrument 201 through the gas pipe, and the voltage regulator 302 and the oscilloscope 303 are connected to the plasma power supply 301 through the wire;

[0048] S6: Open the pressure reducing valve 204 at the gas pipes of the SF6 gas supply bottle 202 and the Ar gas supply bottle 203. The pressure reducing valve 204 controls the input opening of SF6 and Ar. According to the SF6 and Ar ratio set by the gas distributor 201, the ratio is 2% SF6 and 98% Ar. The gas is fully mixed inside the gas distributor to form a uniform mixed gas.

[0049] S7: The mixed gas flow rate is controlled by the electromagnetic flowmeter 205 and the electromagnetic valve 206 at a rate of 300 ml / min, and the mixed gas is delivered to the DBD reactor 1;

[0050] S8: Start the plasma power supply 301, the discharge gap is 3mm, and under the action of the high-voltage electric field, the mixed gas in the catalyst hole 1022 is broken down to generate plasma. Active substances such as high-energy electrons, ions and free radicals in the plasma collide and react with SF6 molecules. The CuO catalyst synergistically plays a catalytic role in the plasma environment, promoting the degradation process of SF6 gas.

[0051] S9: After degradation, first close the pressure reducing valve 204 at the SF6 gas supply bottle 202 to keep the DBD reactor 1 running stably. After 10 minutes, turn off the plasma power supply 301 and continue to introduce Ar to discharge the gas in the DBD reactor 1 into the alkali solution in the alkali solution treatment tank 401 for tail gas treatment and discharge through the outlet pipe 402; the tail gas is discharged into the atmosphere after being treated in the alkali solution treatment tank 401, which can effectively avoid the impact on human body and environment.

[0052] S10: Finally, close the pressure reducing valve 204 at the Ar gas supply cylinder 203.

[0053] Table 1 Experimental data of the ratio of Cu(NO3)2 powder mass to aqueous solution volume of 5.64g:150ml

[0054]

[0055] In summary, this honeycomb ceramic plasma degradation device for SF6 features a removable honeycomb ceramic inner electrode structure with porous channels that facilitate uniform gas distribution and catalyst adsorption. CuO is uniformly deposited into the porous channels of the honeycomb ceramic inner electrode by methods such as water bath evaporation. The CuO catalyst reduces the activation energy required for SF6 dissociation, accelerating the degradation reaction. The CuO catalytic action and the enhanced effect of the DBD plasma significantly improve the SF6 degradation rate. Furthermore, the presence of the CuO catalyst reduces the formation of harmful products in the degradation products, effectively improving their distribution. Furthermore, the device generates no secondary pollution during the SF6 degradation process, thus complying with environmental requirements.

[0056] Furthermore, the exhaust gas is treated in the alkaline solution treatment tank 401 and then discharged into the atmosphere, effectively preventing any impact on the human body and the environment. This technical solution breaks away from the traditional single internal electrode structure and catalyst attachment method. Honeycomb ceramics are used as the internal electrode material, and their porous channels serve as attachment points for the CuO catalyst. Through the synergistic action of plasma and catalyst, efficient SF6 degradation is achieved. Furthermore, the product produced by the CuO catalyst degradation is predominantly SO2, making it easy to handle and absorb through the alkaline solution without causing any harm to humans or the environment.

[0057] Example 2: Please refer to Figure 1-7 A honeycomb ceramic plasma degradation device for SF6 includes a DBD reactor 1, a gas supply unit 2 is provided on the left side of the DBD reactor 1, a power supply unit 3 is provided at the bottom of the DBD reactor 1, and a processing unit 4 is provided on the right side of the DBD reactor 1.

[0058] Among them, the DBD reactor 1 is connected to the gas supply unit 2 through an air pipe, the DBD reactor 1 is electrically connected to the power supply unit 3, and the DBD reactor 1 is connected to the processing unit 4 through an air pipe. The DBD reactor 1 includes an outer electrode 101, and a detachable honeycomb ceramic inner electrode 102 is clamped inside the outer electrode 101. The detachable honeycomb ceramic inner electrode 102 is composed of a honeycomb ceramic 1023 and an inner electrode tube 1024. An inner electrode tube hole 1021 is opened inside the honeycomb ceramic 1023, and a catalyst hole 1022 is opened inside the honeycomb ceramic 1023. The inner electrode tube 1024 is clamped inside the inner electrode tube hole 1021, and the size of the inner electrode tube hole 1021 is larger than the size of the catalyst hole 1022. The structure of honeycomb ceramic 1023 has a large specific surface area and porosity, which facilitates uniform gas distribution and flow. The porous structure also serves as a catalyst carrier, effectively improving the efficiency of SF6 degradation. Furthermore, honeycomb ceramics, primarily composed of Al2O3, provide more active sites for the catalyst, accelerating the degradation reaction. The CuO catalyst possesses excellent catalytic activity, catalyzing the decomposition of SF6 molecules, reducing the activation energy of the reaction and accelerating the degradation reaction. The degradation products tend to produce easily handled substances such as SO2.

[0059] Furthermore, a sealing connector 103 is provided on the outer surface of the outer electrode 101, which is used to seal the gas pipe between the gas supply unit 2 and the processing unit 4. There is one inner electrode tube hole 1021 with a diameter of 0.6 cm. There are eight catalyst holes 1022 with a diameter of 0.4 cm each. The eight catalyst holes 1022 are evenly distributed in a circular shape on the outer surface of the inner electrode tube hole 1021. The inner electrode tube 1024 is 35 cm long.

[0060] Secondly, the gas supply unit 2 includes a gas distributor 201, the gas inlet of the gas distributor 201 is connected to the SF6 gas supply bottle 202 and the Ar gas supply bottle 203 through a gas pipe. The outer surface of the gas pipe connecting the SF6 gas supply bottle 202, the Ar gas supply bottle 203 and the gas distributor 201 is provided with a pressure reducing valve 204, and the outer surface of the gas pipe connecting the gas distributor 201 and the DBD reactor 1 is provided with an electromagnetic flowmeter 205 and an electromagnetic valve 206.

[0061] Furthermore, the power supply unit 3 includes a plasma power supply 301 . One side of the plasma power supply 301 is electrically connected to a voltage regulator 302 , and the other side of the plasma power supply 301 is fixedly connected to an oscilloscope 303 .

[0062] In addition, the processing unit 4 includes an alkali solution treatment tank 401, the top of which is fixedly connected to an air outlet pipe 402. The alkali solution treatment tank 401 is filled with alkali solution, and the right air pipe of the DBD reactor 1 is inserted into the alkali solution.

[0063] The honeycomb ceramic plasma degradation method for SF6 comprises the following specific steps:

[0064] S1: clamp the inner electrode tube 1024 into the inner electrode tube hole 1021 so that the honeycomb ceramic 1023 is located in the middle of the inner electrode tube 1024;

[0065] S2: Prepare 8.46g of Cu(NO3)2 powder, add 150ml of water to the Cu(NO3)2 powder, and stir it evenly without precipitation to obtain a Cu(NO3)2 aqueous solution;

[0066] S3: The removable honeycomb ceramic inner electrode 102 is completely immersed in a Cu(NO3)2 aqueous solution, evaporated to dryness in a 100°C water bath, and then baked in a 150°C oven for 8 hours to completely evaporate the water. Finally, it is calcined in a tube furnace at 500°C for 4 hours to uniformly adhere the CuO catalyst to the catalyst pores 1022. The CuO is then uniformly attached to the porous channels of the honeycomb ceramic 1023. Through the synergistic effect of DBD plasma technology and the catalyst, efficient SF6 waste gas degradation is achieved. The degradation products tend to produce easily treatable SO2, which can be directly discharged after alkaline solution treatment, reducing environmental pollution. This is an efficient and environmentally friendly waste gas treatment technology. The presence of CuO significantly improves the SF6 degradation rate and has a certain degree of product selectivity, making the SF6 degradation products more likely to produce easily treatable substances such as SO2, while effectively suppressing the formation of other difficult-to-treat products such as SOF2, SO2F2, and SOF4.

[0067] S4: The outer electrode 101 is sleeved on the outer surface of the detachable honeycomb ceramic inner electrode 102, and the two ends of the outer electrode 101 are connected to the gas distribution device 201 and the alkali solution treatment tank 401 using flanges 104. The outer electrode 101 is connected to the plasma power supply 301 using a high-voltage wire;

[0068] S5: The SF6 gas supply cylinder 202 and the Ar gas supply cylinder 203 are connected to the gas distribution instrument 201 through the gas pipe, and the voltage regulator 302 and the oscilloscope 303 are connected to the plasma power supply 301 through the wire;

[0069] S6: Open the pressure reducing valve 204 at the gas pipes of the SF6 gas supply bottle 202 and the Ar gas supply bottle 203. The pressure reducing valve 204 controls the input opening of SF6 and Ar. According to the SF6 and Ar ratio set by the gas distributor 201, the ratio is 2% SF6 and 98% Ar. The gas is fully mixed inside the gas distributor to form a uniform mixed gas.

[0070] S7: The mixed gas flow rate is controlled by the electromagnetic flowmeter 205 and the electromagnetic valve 206 at a rate of 300 ml / min, and the mixed gas is delivered to the DBD reactor 1;

[0071] S8: Start the plasma power supply 301, the discharge gap is 3mm, and under the action of the high-voltage electric field, the mixed gas in the catalyst hole 1022 is broken down to generate plasma. Active substances such as high-energy electrons, ions and free radicals in the plasma collide and react with SF6 molecules. The CuO catalyst synergistically plays a catalytic role in the plasma environment, promoting the degradation process of SF6 gas.

[0072] S9: After degradation, first close the pressure reducing valve 204 at the SF6 gas supply bottle 202 to keep the DBD reactor 1 running stably. After 10 minutes, turn off the plasma power supply 301 and continue to introduce Ar to discharge the gas in the DBD reactor 1 into the alkali solution in the alkali solution treatment tank 401 for tail gas treatment and discharge through the outlet pipe 402; the tail gas is discharged into the atmosphere after being treated in the alkali solution treatment tank 401, which can effectively avoid the impact on human body and environment.

[0073] S10: Finally, close the pressure reducing valve 204 at the Ar gas supply cylinder 203.

[0074] Table 2 Experimental data of the ratio of Cu(NO3)2 powder mass to aqueous solution volume of 8.46g:150ml

[0075]

[0076] In summary, this honeycomb ceramic plasma degradation device for SF6 features a removable honeycomb ceramic inner electrode structure with porous channels that facilitate uniform gas distribution and catalyst adsorption. CuO is uniformly deposited into the porous channels of the honeycomb ceramic inner electrode by methods such as water bath evaporation. The CuO catalyst reduces the activation energy required for SF6 dissociation, accelerating the degradation reaction. The CuO catalytic action and the enhanced effect of the DBD plasma significantly improve the SF6 degradation rate. Furthermore, the presence of the CuO catalyst reduces the formation of harmful products in the SF6 degradation products, effectively improving the distribution of degradation product content. Furthermore, the device generates no secondary pollution during the SF6 degradation process, thus complying with environmental requirements.

[0077] Furthermore, the exhaust gas is treated in the alkaline solution treatment tank 401 and then discharged into the atmosphere, effectively preventing any impact on the human body and the environment. This technical solution breaks away from the traditional single internal electrode structure and catalyst attachment method. Honeycomb ceramics are used as the internal electrode material, and their porous channels serve as attachment points for the CuO catalyst. Through the synergistic action of plasma and catalyst, efficient SF6 degradation is achieved. Furthermore, the product produced by the CuO catalyst degradation is predominantly SO2, making it easy to handle and absorb through the alkaline solution without causing any harm to humans or the environment.

[0078] Example 3: Please refer to Figure 1-7 A honeycomb ceramic plasma degradation device for SF6 includes a DBD reactor 1, a gas supply unit 2 is provided on the left side of the DBD reactor 1, a power supply unit 3 is provided at the bottom of the DBD reactor 1, and a processing unit 4 is provided on the right side of the DBD reactor 1.

[0079] The DBD reactor 1 is connected to the gas supply unit 2 via a gas pipe, is electrically connected to the power supply unit 3, and is connected to the processing unit 4 via a gas pipe. The DBD reactor 1 includes an outer electrode 101, with a removable honeycomb ceramic inner electrode 102 secured thereto. The removable honeycomb ceramic inner electrode 102 comprises a honeycomb ceramic 1023 and an inner electrode tube 1024. The honeycomb ceramic 1023 defines an inner electrode tube pore 1021, which also defines a catalyst pore 1022. The inner electrode tube 1024 is secured within the inner electrode tube pore 1021, and the inner electrode tube pore 1021 is larger than the catalyst pore 1022. The honeycomb ceramic 1023 has a large specific surface area and porosity, which facilitates uniform gas distribution and flow. The porous structure also serves as a catalyst carrier, effectively improving SF6 degradation efficiency. Furthermore, the main component of honeycomb ceramics is Al2O3, which can provide more active sites for the catalyst and accelerate the degradation reaction. Because the CuO catalyst has excellent catalytic activity, it can catalyze the decomposition of SF6 molecules, reduce the reaction activation energy, accelerate the degradation reaction, and the degradation products tend to generate SO2 and other substances that are easy to handle.

[0080] Furthermore, a sealing connector 103 is provided on the outer surface of the outer electrode 101, which is used to seal the gas pipe between the gas supply unit 2 and the processing unit 4. There is one inner electrode tube hole 1021 with a diameter of 0.6 cm. There are eight catalyst holes 1022 with a diameter of 0.4 cm each. The eight catalyst holes 1022 are evenly distributed in a circular shape on the outer surface of the inner electrode tube hole 1021. The inner electrode tube 1024 is 35 cm long.

[0081] Secondly, the gas supply unit 2 includes a gas distributor 201, the gas inlet of the gas distributor 201 is connected to the SF6 gas supply bottle 202 and the Ar gas supply bottle 203 through a gas pipe. The outer surface of the gas pipe connecting the SF6 gas supply bottle 202, the Ar gas supply bottle 203 and the gas distributor 201 is provided with a pressure reducing valve 204, and the outer surface of the gas pipe connecting the gas distributor 201 and the DBD reactor 1 is provided with an electromagnetic flowmeter 205 and an electromagnetic valve 206.

[0082] Furthermore, the power supply unit 3 includes a plasma power supply 301 . One side of the plasma power supply 301 is electrically connected to a voltage regulator 302 , and the other side of the plasma power supply 301 is fixedly connected to an oscilloscope 303 .

[0083] In addition, the processing unit 4 includes an alkali solution treatment tank 401, the top of which is fixedly connected to an air outlet pipe 402. The alkali solution treatment tank 401 is filled with alkali solution, and the right air pipe of the DBD reactor 1 is inserted into the alkali solution.

[0084] The honeycomb ceramic plasma degradation method for SF6 comprises the following specific steps:

[0085] S1: clamp the inner electrode tube 1024 into the inner electrode tube hole 1021 so that the honeycomb ceramic 1023 is located in the middle of the inner electrode tube 1024;

[0086] S2: Prepare 11.28g of Cu(NO3)2 powder, add 150ml of water to the Cu(NO3)2 powder, and stir it evenly without precipitation to obtain a Cu(NO3)2 aqueous solution;

[0087] S3: The removable honeycomb ceramic inner electrode 102 is completely immersed in a Cu(NO3)2 aqueous solution, evaporated to dryness in a 100°C water bath, and then baked in a 150°C oven for 8 hours to completely evaporate the water. Finally, it is calcined in a tube furnace at 500°C for 4 hours, causing the CuO catalyst to uniformly adhere to the catalyst pores 1022 and the CuO to uniformly adhere to the porous channels of the honeycomb ceramic 1023. Through the synergistic effect of DBD plasma technology and catalysts, efficient SF6 waste gas degradation is achieved, and the degradation products tend to produce easily treatable SO2. After alkaline solution treatment, they can be directly discharged, reducing environmental pollution. This is an efficient and environmentally friendly waste gas treatment technology. The presence of CuO significantly improves the SF6 degradation rate and has a certain product selectivity, making the SF6 degradation products more likely to produce easily treatable substances such as SO2, while effectively suppressing the formation of other difficult-to-treat products such as SOF2, SO2F2, and SOF4.

[0088] S4: The outer electrode 101 is sleeved on the outer surface of the detachable honeycomb ceramic inner electrode 102, and the two ends of the outer electrode 101 are connected to the gas distribution device 201 and the alkali solution treatment tank 401 using flanges 104. The outer electrode 101 is connected to the plasma power supply 301 using a high-voltage wire;

[0089] S5: The SF6 gas supply cylinder 202 and the Ar gas supply cylinder 203 are connected to the gas distribution instrument 201 through the gas pipe, and the voltage regulator 302 and the oscilloscope 303 are connected to the plasma power supply 301 through the wire;

[0090] S6: Open the pressure reducing valve 204 at the gas pipes of the SF6 gas supply bottle 202 and the Ar gas supply bottle 203. The pressure reducing valve 204 controls the input opening of SF6 and Ar. According to the SF6 and Ar ratio set by the gas distributor 201, the ratio is 2% SF6 and 98% Ar. The gas is fully mixed inside the gas distributor to form a uniform mixed gas.

[0091] S7: The mixed gas flow rate is controlled by the electromagnetic flowmeter 205 and the electromagnetic valve 206 at a rate of 300 ml / min, and the mixed gas is delivered to the DBD reactor 1;

[0092] S8: Start the plasma power supply 301, the discharge gap is 3mm, and under the action of the high-voltage electric field, the mixed gas in the catalyst hole 1022 is broken down to generate plasma. Active substances such as high-energy electrons, ions and free radicals in the plasma collide and react with SF6 molecules. The CuO catalyst synergistically plays a catalytic role in the plasma environment, promoting the degradation process of SF6 gas.

[0093] S9: After degradation, first close the pressure reducing valve 204 at the SF6 gas supply bottle 202 to keep the DBD reactor 1 running stably. After 10 minutes, turn off the plasma power supply 301 and continue to introduce Ar to discharge the gas in the DBD reactor 1 into the alkali solution in the alkali solution treatment tank 401 for tail gas treatment and discharge through the outlet pipe 402; the tail gas is discharged into the atmosphere after being treated in the alkali solution treatment tank 401, which can effectively avoid the impact on human body and environment.

[0094] S10: Finally, close the pressure reducing valve 204 at the Ar gas supply cylinder 203.

[0095] Table 3 Experimental data of the ratio of Cu(NO3)2 powder mass to aqueous solution volume of 11.28g:150ml

[0096]

[0097] In summary, this honeycomb ceramic plasma degradation device for SF6 features a removable honeycomb ceramic inner electrode structure with porous channels that facilitate uniform gas distribution and catalyst adsorption. CuO is uniformly deposited into the porous channels of the honeycomb ceramic inner electrode by methods such as water bath evaporation. The CuO catalyst reduces the activation energy required for SF6 dissociation, accelerating the degradation reaction. The CuO catalytic action and the enhanced effect of the DBD plasma significantly improve the SF6 degradation rate. Furthermore, the presence of the CuO catalyst reduces the formation of harmful products in the degradation products, effectively improving their distribution. Furthermore, the device generates no secondary pollution during the SF6 degradation process, thus complying with environmental requirements.

[0098] Furthermore, the exhaust gas is treated in the alkaline solution treatment tank 401 and then discharged into the atmosphere, effectively preventing any impact on the human body and the environment. This technical solution breaks away from the traditional single internal electrode structure and catalyst attachment method. Honeycomb ceramics are used as the internal electrode material, and their porous channels serve as attachment points for the CuO catalyst. Through the synergistic action of plasma and catalyst, efficient SF6 degradation is achieved. Furthermore, the product produced by the CuO catalyst degradation is predominantly SO2, making it easy to handle and absorb through the alkaline solution without causing any harm to humans or the environment.

[0099] Comparative experiments were conducted with different Cu(NO3)2 powder masses, using a 150ml aqueous solution. Comparisons across multiple experiments revealed that when the Cu(NO3)2 powder mass was 5.64g, the concentration of the Cu(NO3)2 powder in the solution was too low, preventing the CuO from completely adhering to the porous channels of the honeycomb ceramics after subsequent water-bath evaporation and high-temperature calcination, resulting in a maximum SF6 degradation rate of only 77.6%. When the Cu(NO3)2 powder mass was 11.28g, the aqueous solution concentration was likely too high, leading to partial crystallization during the water-bath evaporation process, which affected the experimental results. The maximum degradation rate was 78.9%. Based on the above, a Cu(NO3)2 aqueous solution was prepared using 8.46g of Cu(NO3)2 powder and 150ml of water. At an input power of 100W, the maximum degradation rate was 97.0%, with SO2 accounting for the highest proportion of the degradation products. Most of the acidic gases could be directly absorbed by alkaline solutions.

[0100] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0101] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A honeycomb ceramic plasma degradation device for SF6, comprising a DBD reactor (1), characterized in that: A gas supply unit (2) is provided on the left side of the DBD reactor (1), a power supply unit (3) is provided at the bottom of the DBD reactor (1), and a processing unit (4) is provided on the right side of the DBD reactor (1); The DBD reactor (1) is connected to the gas supply unit (2) via an air pipe, the DBD reactor (1) is electrically connected to the power supply unit (3), and the DBD reactor (1) is connected to the processing unit (4) via an air pipe; The DBD reactor (1) comprises an outer electrode (101), a detachable honeycomb ceramic inner electrode (102) is clamped inside the outer electrode (101), the detachable honeycomb ceramic inner electrode (102) is composed of a honeycomb ceramic (1023) and an inner electrode tube (1024), an inner electrode tube hole (1021) is provided inside the honeycomb ceramic (1023), a catalyst hole (1022) is provided inside the honeycomb ceramic (1023), the inner electrode tube (1024) is clamped inside the inner electrode tube hole (1021), and the size of the inner electrode tube hole (1021) is larger than the size of the catalyst hole (1022); A sealing connector (103) is provided on the outer surface of the outer electrode (101), and the sealing connector (103) is used to seal the air pipe of the air supply unit (2) and the processing unit (4); The catalyst holes (1022) are evenly distributed in an annular shape on the outer surface of the inner electrode tube hole (1021).

2. The honeycomb ceramic plasma degradation device for SF6 according to claim 1, characterized in that: The gas supply unit (2) comprises a gas distribution instrument (201), the gas inlet of the gas distribution instrument (201) is connected to an SF6 gas supply bottle (202) and an Ar gas supply bottle (203) via a gas pipe, the outer surface of the gas pipes connecting the SF6 gas supply bottle (202) and the Ar gas supply bottle (203) to the gas distribution instrument (201) are all provided with a pressure reducing valve (204), and the outer surface of the gas pipe connecting the gas distribution instrument (201) to the DBD reactor (1) is provided with an electromagnetic flowmeter (205) and an electromagnetic valve (206).

3. The honeycomb ceramic plasma degradation device for SF6 according to claim 1, characterized in that: The power supply unit (3) comprises a plasma power supply (301), one side of the plasma power supply (301) is electrically connected to a voltage regulator (302), and the other side of the plasma power supply (301) is fixedly connected to an oscilloscope (303).

4. The honeycomb ceramic plasma degradation device for SF6 according to claim 1, characterized in that: The processing unit (4) includes an alkali solution treatment tank (401), the top of the alkali solution treatment tank (401) is fixedly connected to an air outlet pipe (402), the alkali solution treatment tank (401) is filled with alkali solution, and the right air pipe of the DBD reactor (1) is inserted into the alkali solution.

5. The honeycomb ceramic plasma degradation device for SF6 according to claim 1, characterized in that: The sealing connection piece (103) is a flange.

6. The method for degrading SF6 by using honeycomb ceramic plasma according to any one of claims 1 to 5, characterized in that: The specific steps of degradation are: S1: clamping the inner electrode tube (1024) into the inner electrode tube hole (1021) so that the honeycomb ceramic (1023) is located in the middle of the inner electrode tube (1024); S2: Prepare Cu(NO3)2 powder, add water to the Cu(NO3)2 powder, and stir it evenly without precipitation to obtain a Cu(NO3)2 aqueous solution; S3: The detachable honeycomb ceramic inner electrode (102) is completely immersed in a Cu(NO3)2 aqueous solution, evaporated in a water bath, and calcined at high temperature to decompose into a CuO catalyst, which is uniformly attached to the catalyst pores (1022); S4: The outer electrode (101) is sleeved on the outer surface of the detachable honeycomb ceramic inner electrode (102), and the two ends of the outer electrode (101) are connected to the gas distribution device (201) and the alkali solution treatment tank (401) using flanges (104). The outer electrode (101) is connected to the plasma power supply (301) using a high-voltage wire; S5: The SF6 gas supply bottle (202) and the Ar gas supply bottle (203) are connected to the gas distribution device (201) through a gas pipe, and the voltage regulator (302) and the oscilloscope (303) are connected to the plasma power supply (301) through electric wires; S6: Open the pressure reducing valve (204) at the gas pipe of the SF6 gas supply bottle (202) and the Ar gas supply bottle (203), control the input opening of SF6 and Ar through the pressure reducing valve (204), and mix them inside the gas distribution device (201) according to the ratio of SF6 and Ar set by the gas distribution device (201) to form a uniform mixed gas; S7: The mixed gas flow rate is controlled by the electromagnetic flow meter (205) and the electromagnetic valve (206), and the mixed gas is delivered to the DBD reactor (1); S8: starting the plasma power supply (301). Under the action of the high voltage electric field, the mixed gas in the catalyst hole (1022) is broken down to generate plasma. Active substances such as high-energy electrons, ions and free radicals in the plasma collide and react with SF6 molecules. The CuO catalyst synergistically plays a catalytic role in the plasma environment, promoting the degradation process of SF6 gas. S9: After degradation, first close the pressure reducing valve (204) at the SF6 gas supply bottle (202) to keep the DBD reactor (1) running stably. After 10 minutes, turn off the plasma power supply (301) and continue to introduce Ar to discharge the gas in the DBD reactor (1) into the alkali solution in the alkali solution treatment pool (401) for tail gas treatment and discharge through the outlet pipe (402); S10: Finally, close the pressure reducing valve (204) at the Ar gas supply bottle (203).

Images