Device and method for treating organic waste gas by double dielectric barrier discharge plasma excitation catalytic gas phase reaction

Abstract

The present invention discloses a device and method for treating organic waste gas by double dielectric barrier discharge plasma excitation catalytic gas phase reaction. The device comprises a reactor cylinder, one end of the reactor cylinder is provided with a gas inlet and the other end is provided with a gas outlet; it also comprises at least one reaction unit arranged on the gas path in the reactor cylinder, the reaction unit comprises a plasma discharge unit and a catalyst unit arranged in sequence along the gas path; the distance between the plasma discharge unit and the catalyst unit is 5 to 10 cm. The organic waste gas to be treated is treated by the plasma discharge unit and the catalyst unit in sequence or alternately by the plasma discharge unit and the catalyst unit, and the purified waste gas is discharged. The present invention solves the problems of low purification efficiency and high energy consumption of the existing single plasma waste gas treatment technology and plasma coordinated catalytic waste gas treatment equipment.

Description

Technical Field

[0001] The invention relates to the technical field of organic waste gas treatment, and in particular to a device for treating organic waste gas by using double dielectric barrier discharge plasma to excite catalytic gas phase reaction. Background Art

[0002] Low-temperature plasma can treat organic waste gas by using high-energy electrons and active substances to destroy pollutant molecules at room temperature and pressure, but there are many problems, such as low mineralization rate, high energy consumption, and the presence of NOx and ozone by-products. In recent years, researchers at home and abroad have combined plasma with catalysts to improve treatment effects and energy utilization, and reduce the generation of by-products. Research data shows that under a certain energy density, different reactor types and catalyst parameters are used for different types of pollutants. Compared with the single low-temperature plasma technology, the energy efficiency of low-temperature plasma synergistic catalytic technology is greatly improved.

[0003] For example, the Chinese invention patent document with publication number CN 105457488A discloses a device and method for removing nitrogen oxides by using a catalyst combined with plasma. The flue gas and ammonia are mixed and passed to the gas inlet at the bottom of the reactor. The reactor is a double-medium layer structure. A layer of metal mesh is wrapped around the outer side of the outer medium tube as an outer electrode. A metal inner electrode is arranged inside the inner medium tube. The inner electrode is connected to the positive electrode of the power supply, and the outer electrode is connected to the negative electrode of the power supply to form a plasma generator. In the middle of the reactor, a partition with vents is arranged in the cavity between the outer medium tube and the inner medium tube, and a catalyst Fe-Cu / CNTs is added to the partition. The mixed gas is denitrated by the combined action of the catalyst and plasma in the reactor.

[0004] The role of catalysts in plasma technology is mainly reflected in the following aspects: when the catalyst is in the plasma field, it is called a one-stage plasma synergistic catalytic reactor. The polarization of the catalyst surface will enhance the discharge and form a field strength enhancement area on the surface. The catalyst will adsorb volatile organic compounds, which will prolong the time of synergistic degradation and facilitate the removal of pollutants. When the catalyst is outside the plasma field, it is called a two-stage plasma synergistic catalytic reactor. In this reactor, the exhaust gas molecules react on the catalyst, which can reduce the activation energy of the reaction of high-energy active particles in the plasma. At the same time, the discharge parameters of the discharge module are stable, and the system engineering design is relatively convenient.

[0005] Although significant progress has been made in the treatment of organic waste gas with low-temperature plasma technology, the technology still has problems such as high energy consumption and low VOCs treatment efficiency at low power consumption. For this reason, current research is mainly focused on plasma synergistic catalysis, using high-energy active substances generated by plasma modules to deeply oxidize and decompose VOCs in catalysts to meet the safety, efficiency and economic requirements required by engineering applications. Since the current plasma synergistic catalytic technology mainly studies the catalytic oxidation process, it mainly uses the oxidation effect of ozone byproducts and uses ozone catalysts to form ozone synergistic catalytic reactions. In order to achieve the target efficiency of waste gas treatment, the system energy consumption is relatively high. Summary of the invention

[0006] The present invention provides a device for treating organic waste gas by dual-dielectric barrier discharge plasma-excited catalytic gas phase reaction, which solves the problems of low purification efficiency and high energy consumption of existing single plasma waste gas treatment technology and plasma-coordinated catalytic waste gas treatment equipment.

[0007] A device for treating organic waste gas by double dielectric barrier discharge plasma excitation catalytic gas phase reaction, comprising a reactor cylinder, one end of which is provided with a gas inlet and the other end of which is provided with a gas outlet; and at least one reaction unit arranged on a gas path in the reactor cylinder, wherein the reaction unit comprises a plasma discharge unit and a catalyst unit arranged in sequence along the gas path; and the distance between the plasma discharge unit and the catalyst unit is 5 to 10 cm.

[0008] The present invention adopts a high-frequency power-driven dual-dielectric barrier discharge as a plasma source and a two-stage catalyst setting method, and adjusts the distance between the catalyst and the plasma discharge area. The adjusted distance is 5 to 10 cm, so that the gas reaches the catalyst after a very short stay time (0.1s) after discharge. At this time, the energy of the high-energy substances in the gas is less attenuated, and the main purification reaction is transferred to the catalyst unit. After colliding with the catalyst, the catalyst has a charge defect, which stimulates the catalytic reaction, making the system catalytic oxidation reaction more efficient, and the target efficiency and energy consumption of exhaust gas treatment are greatly reduced. The spacing is further preferably 5 to 8 cm; the most preferred is 5 cm.

[0009] The present invention has found that the closer the distance between the discharge area and the catalyst is, the shorter the time it takes for the active intermediates generated by the discharge to reach the catalyst, the smaller the energy decay of the active intermediates, and the higher the electron temperature on the catalyst surface. Once the electron temperature of the catalyst is increased, more free electron-hole pairs are generated, and its catalytic activity is also increased, thereby further catalyzing the degradation of organic matter and improving the degradation efficiency.

[0010] The present invention adjusts the distance between the plasma unit and the catalyst unit to control the residence time of the exhaust gas after discharge so that it reaches the catalyst surface within 0.1s. The electron temperature decay of the exhaust gas molecules is less, and the catalyst contacts the exhaust gas to generate more free electron-hole pairs, which stimulates the catalyst to produce higher catalytic activity, thereby further catalytically degrading organic matter and improving degradation efficiency.

[0011] Preferably, the gas in the reactor cylinder flows axially along the cylinder; the reaction unit is arranged on a cross section perpendicular to the gas flow direction, and a plurality of reaction units are stacked in sequence along a direction perpendicular to the gas flow direction.

[0012] Further preferably, sequentially stacked reaction units are arranged on at least two radial cross sections along the gas flow direction. The gas to be treated can be subjected to discharge treatment and catalyst treatment alternately.

[0013] Preferably, the plasma discharge unit is a plurality of tubular electrode assemblies stacked in sequence in a direction perpendicular to the gas flow direction or a plurality of plate electrode assemblies stacked in sequence in a direction perpendicular to the gas flow direction.

[0014] A preferred form of a plasma discharge unit, the tubular electrode assembly comprises a ground electrode core rod and a high-voltage electrode core rod arranged in parallel in the same vertical plane, and barrier dielectric tubes respectively wrapped around the ground electrode core rod and the high-voltage electrode core rod; the areas between the barrier dielectric tubes in a single tubular electrode assembly and the areas between the barrier dielectric tubes of adjacent tubular electrode assemblies are both discharge areas, and the discharge areas are for gas to pass through; all the ground electrode core rods are connected in parallel and then grounded, and all the high-voltage electrode core rods are connected in parallel and then externally connected to a high-frequency high-voltage power supply.

[0015] Furthermore, among all the electrode core rods, the ground electrode core rods and the high voltage electrode core rods are arranged alternately, and the electrode core rods on both sides are ground electrode core rods. The electrode core is one of a metal conductor electrode, a copper electrode, conductive graphite, etc.; the dielectric layer is made of quartz.

[0016] Another preferred embodiment of a plasma discharge unit, wherein the plate-type electrode assembly of the plasma discharge unit comprises a high-voltage electrode plate and a grounding electrode plate which are arranged in parallel and horizontally, and a blocking dielectric layer which is arranged on both sides of the high-voltage electrode plate and the grounding electrode plate respectively; the blocking dielectric layers of a single plate-type electrode assembly and the blocking dielectric layers of adjacent plate-type electrode assemblies are the discharge areas, and the discharge areas are for gas to pass through; all the grounding electrode plates are connected in parallel and then grounded; and all the high-voltage electrode plates are connected in parallel and then externally connected to a high-frequency high-voltage power supply.

[0017] Furthermore, among all the electrode plates, the ground electrode plates and the high-voltage electrode plates are arranged alternately, and the electrode plates on both sides are ground electrode plates. The high-voltage electrode plate is one of a metal plate, a copper plate, a conductive graphite plate, etc.; and the barrier dielectric layer is a quartz plate.

[0018] Preferably, the catalyst unit uses a supported catalyst, which is distributed on a cross section parallel to the plasma discharge unit; the catalyst unit is slidably mounted on the inner wall of the reactor cylinder. The catalyst position is adjustable, which facilitates adjustment of the spacing between the catalyst unit and the plasma discharge unit according to actual working conditions. The catalyst is cut into a plate shape that is adapted to the size of the electrode unit, distributed on a cross section parallel to the plasma discharge unit, and the plate surface is perpendicular to the axis of the cylinder.

[0019] The present invention also provides a method for treating organic waste gas by double dielectric barrier discharge plasma excitation catalytic gas phase reaction, which is preferably implemented by the device of the present invention, comprising the following steps:

[0020] In the reactor equipment, the organic waste gas to be treated is sequentially or alternately treated by the plasma discharge unit and the catalyst unit, and the purified waste gas is discharged; the distance between the plasma discharge unit and the catalyst unit is 5 to 10 cm.

[0021] The plasma discharge unit adopts a high-frequency high-voltage power supply, with a discharge voltage of 15000V and above and a frequency of 10kHz and above. The high-voltage AC power supply with a repetition frequency of 15000V and above 10kHz drives a planar discharge effect.

[0022] Preferably, the flow rate of the organic waste gas to be treated through the plasma discharge unit and the catalyst unit is 0.5-1.0 m / s.

[0023] Preferably, the organic pollutants in the organic waste gas to be treated are ethyl acetate, toluene or methyl mercaptan.

[0024] The present invention uses a high-voltage AC power supply of 15000V and a repetition frequency of more than 10kHz to drive a sequentially arranged tubular double dielectric barrier discharge reactor, so that the reactor can obtain a uniform discharge effect on the entire plane, and the exhaust gas can obtain energy uniformly when passing through the reactor. Electrons, as light particles, are driven by a high-frequency alternating electric field and accelerated by the electric field, and some electrons are separated from molecules. At this time, the electron temperature of the exhaust gas molecules is relatively high, and the electron temperature is between 1 and 20 eV, which is equivalent to 10,000 to 200,000 K (Kelvin).

[0025] The catalyst used in the catalyst assembly is a supported catalyst. The carrier is a foamed metal, cordierite or other similar structural materials as a catalyst carrier, titanium dioxide, manganese dioxide or other low-temperature active catalyst as a target catalyst, which is supported on the carrier, and the catalyst itself is an existing catalyst.

[0026] The present invention is based on the existing plasma cooperative catalytic technology, adopts a low-temperature plasma driving process of approximately planar discharge, adopts a two-stage catalyst setting method, and sets a flat-plate catalyst in parallel at the rear of the discharge plane at a distance of 5 to 10 cm from the discharge plane. The empty tower wind speed is controlled at 0.5 to 1.0 m / s, so that the catalyst maintains a high-voltage discharge safety protection distance, and the residence time of the exhaust gas before reaching the catalyst after discharge is less than 0.1 s. The high-energy substances carried by the exhaust gas through the discharge reaction are used to contact the catalyst, so that defects appear in the electronic structure of the catalyst, which has an effect similar to that of a photocatalyst under ultraviolet radiation, catalytically oxidizes organic molecules, and makes the degradation rate of characteristic pollutants of organic waste gas (such as ethyl acetate, toluene, methyl mercaptan and other substances) reach 80 to 90%.

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

[0028] This technical solution uses the high energy generated by the plasma reactor to reach the catalyst in a very short time. The smaller the energy decay of the active intermediate, the higher the electron temperature on the catalyst surface. Once the electron temperature of the catalyst is increased, more free electron-hole pairs are generated, which stimulates the catalyst to produce higher catalytic activity, thereby further catalytically degrading organic matter and improving degradation efficiency. Under this reaction system, the exhaust gas treatment system can be operated at 2 to 5 W / (m 3 / h exhaust gas), that is, every 1000m 3 / h waste gas treatment system with an installed power of 2 to 5kW, the degradation rate of ethyl acetate and toluene can reach 80 to 90%, and the removal rate of reducing odorous waste gases such as landfill leachate and sewage station regulating tanks can reach more than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of an implementation mode of the device of the present invention.

[0030] Figure 2 yes Figure 1 The schematic diagram of the structure of the reactor unit in the embodiment shown.

[0031] Figure 3 yes Figure 2 Schematic diagram of a single set of electrode structures in the reactor unit shown.

[0032] Figure 4 yes Figure 2 Schematic diagram of the electrode structure in the reactor unit shown.

[0033] Figure 5 It is a structural schematic diagram of another embodiment of the device of the present invention.

[0034] Figure 6 Figure 5 The schematic diagram of the structure of the reactor unit in the embodiment shown.

[0035] Figure 7 yes Figure 6 Schematic diagram of a single set of electrode structures in the reactor unit shown.

[0036] Figure 8 yes Figure 6 Schematic diagram of the electrode structure in the reactor unit shown.

[0037] Fig. 9 This is the process flow chart of VOCs waste gas treatment.

[0038] Fig.10 Toluene degradation efficiency of catalysts at different positions.

[0039] Fig.11 Ethyl acetate degradation efficiency of catalysts at different positions.

[0040] Figures 1 to 9 The reference numerals shown in the figure are as follows:

[0041] 1- Reactor body 2- Air inlet 3- Air outlet

[0042] 4-Reaction unit

[0043] 41- plasma discharge unit 42- catalyst unit 43- outer frame

[0044] 411-high voltage electrode 412-ground electrode 413-discharge area

[0045] 414-Dielectric barrier DETAILED DESCRIPTION

[0046] Example 1

[0047] like Figure 1 to Figure 4 As shown, a two-stage exhaust gas treatment device includes a reactor cylinder 1 and a plurality of reaction units 4 arranged in the reactor cylinder 1. The reaction cylinder has an air inlet 3 at one axial end and an air outlet 3 at the other end, and the gas in the cylinder flows axially.

[0048] The structure of the reaction unit 4 in this embodiment is as follows Figure 2 As shown, it includes an outer frame 43, a plasma discharge unit 41 and a catalyst unit 42 fixed in the outer frame 43, and the plasma discharge unit 41 and the catalyst unit 42 are arranged in sequence along the gas flow direction.

[0049] The structure of the plasma discharge unit 41 is as follows: Figure 4 As shown, it includes a plurality of single groups of electrodes arranged in sequence perpendicular to the airflow direction, each single group of electrodes ( Figure 3 ) includes a high-voltage electrode 411 and a grounding electrode 412. In this embodiment, the high-voltage electrode is a rod-shaped metal electrode core, and the grounding electrode is a tubular quartz dielectric tube. The metal electrode core passes through the center of the quartz dielectric tube. The quartz dielectric tubes of a single group of electrodes and the quartz dielectric tubes of adjacent single groups of electrodes are the discharge gaps 413, and the gas passes through the discharge gaps. In all metal electrode cores, the grounding electrode cores and the high-voltage electrode cores are arranged alternately, and the electrode cores at the bottom and top layers are grounding electrodes. All grounding electrodes are connected in parallel and then grounded, and all high-voltage electrodes are connected in parallel and then connected to a high-frequency high-voltage power supply. The high-frequency high-voltage power supply uses a 15000V, 10kHz or higher frequency high-voltage power supply, which can be set to adjustable frequency and power. The catalyst unit uses foam metal, cordierite or other similar structural materials as a catalyst carrier, and cuts out a flat plate with a thickness of about 20 mm that is equivalent to the plane of the above-mentioned discharge reactor. Titanium dioxide, manganese dioxide or other low-temperature active catalysts are used as target catalysts and loaded on the carrier. The catalyst is arranged behind the discharge assembly. The surface of the catalyst plate is perpendicular to the axis of the cylinder and is arranged behind the discharge assembly along the gas flow direction. The gas passes through the catalyst. The distance l between the catalyst and the discharge assembly is 5 to 10 cm. This distance refers to the distance between the rightmost side of the discharge unit and the leftmost side of the catalyst unit. The catalyst plate is first fixed on the catalyst frame. The catalyst frame can be installed on the inner wall of the reactor cylinder through a sliding mechanism and can slide a certain distance along the axial direction of the cylinder to facilitate the adjustment of the distance between the catalyst and the discharge assembly.

[0050] For small or experimental test equipment, a single reaction unit can be used, installed on the gas path section between the inlet and outlet of the cylinder to pass the exhaust gas with modulated concentration and air volume, and a synchronous sampling device can be set at the inlet and outlet of the equipment to detect and analyze the composition, concentration and removal rate of the exhaust gas and treated tail gas.

[0051] For large equipment, the following can be used: Figure 1 In the arrangement shown, multiple reaction sections are set along the gas flow direction, and multiple reaction units are stacked in each reaction section. The stacking here means that the reaction units are stacked in sequence from bottom to top on the radial cross-section of the reactor cylinder. Multiple reaction units in the same reaction section are connected in parallel, and the reaction units in adjacent reaction sections are connected in series, so that the exhaust gas can be repeatedly purified.

[0052] The waste gas with modulated concentration and air volume is introduced, and synchronous sampling devices are set at the air inlet and outlet of the equipment to detect and analyze the composition, concentration and removal rate of the waste gas and the treated tail gas.

[0053] Example 2

[0054] like Figures 5 to 8 As shown, the difference from Example 1 is that the plasma discharge unit structure used is different. In this embodiment, a plate-shaped double dielectric barrier discharge is used, such as Figure 6 to Figure 8 shown.

[0055] The structure of the reaction unit 4 in this embodiment is as follows Figure 5 As shown, it includes an outer frame 43, a plasma discharge unit 41 and a catalyst unit 42 fixed in the outer frame 43, and the plasma discharge unit 41 and the catalyst unit 42 are arranged in sequence along the gas flow direction.

[0056] The structure of the plasma discharge unit 41 is as follows: Figure 8 As shown, it includes electrode units arranged in sequence perpendicular to the airflow direction, each electrode unit ( Figure 7 ) includes a high-voltage electrode 411 and a grounding electrode 412. In this embodiment, the high-voltage electrode and the grounding electrode are both plate-shaped metal electrodes. The two metal plates are parallel to each other and are both arranged horizontally. Both sides of the high-voltage electrode and the grounding electrode are respectively covered with a blocking dielectric layer 414, and the dielectric barrier layer is made of quartz. There is a discharge gap 413 between the dielectric barriers in each electrode unit and between the dielectric barriers of adjacent electrode units, and the gas passes through the discharge gap. Among all the metal electrode plates, the grounding electrode plates and the high-voltage electrode plates are arranged alternately, and the electrode plates at the bottom and top layers are both grounding electrodes. All the grounding electrodes are connected in parallel and then grounded, and all the high-voltage electrodes are connected in parallel and then connected to a high-frequency high-voltage power supply. The high-frequency high-voltage power supply uses a 15000V, 10kHz or higher frequency high-voltage power supply, which can be set to adjustable frequency and power.

[0057] Application Example 1 VOCs waste gas treatment process

[0058] The process of treating VOCs waste gas using the device and method of the above-mentioned embodiment 1 or embodiment 2 is as follows: Fig. 9 As shown, when treating malodorous gas from a sewage station regulating tank, the distance l between the catalyst and the discharge assembly is adjusted within 5 to 10 cm, for example, it can be adjusted to 5 cm, 6 cm, 8 cm or 10 cm.

[0059] as follows Fig.10 The power density is shown as 7.2J / L (2W / m 3 / h exhaust gas), the toluene degradation efficiency changes with the toluene inlet concentration at different distances between the catalyst TiO2 and the discharge disk. As can be seen from the figure, the degradation effect of the 5cm spacing is better than that of the 10cm spacing, which means that the closer the catalyst is to the discharge area, the better the degradation effect will be. The reason is that the closer the distance is, the shorter the time it takes for the active intermediates generated by the discharge to reach the catalyst, the smaller the energy decay of the active intermediates, and the higher the electron temperature on the catalyst surface. Once the electron temperature of the catalyst is increased, more free electron-hole pairs are generated, and its catalytic activity will also increase, thereby further catalyzing the degradation of toluene and improving the degradation efficiency.

[0060] as follows Fig.11 The power density is shown as 10.8J / L (3W / m 3 / h exhaust gas), the degradation efficiency of ethyl acetate changes with the inlet concentration at different distances between the catalyst TiO2 and the discharge disk. As can be seen from the figure, the degradation effect of the 5cm spacing is better than that of the 10cm spacing, which means that the closer the catalyst is to the discharge area, the better the degradation effect will be. The reason is that the closer the distance is, the shorter the time it takes for the active intermediates generated by the discharge to reach the catalyst, the smaller the energy decay of the active intermediates, and the higher the electron temperature on the catalyst surface. Once the electron temperature of the catalyst is increased, more free electron-hole pairs are generated, and its catalytic activity is also increased, thereby further catalyzing the degradation of ethyl acetate and improving the degradation efficiency.

[0061] From the test, it is found that for toluene, when the power density is 7.2J / L, the unit waste gas treatment power consumption is 2W / (m 3 / h), using TiO2 catalyst, and the catalyst is placed 5cm away from the discharge area. For a concentration of 100mg / m 3 The degradation efficiency of low-concentration toluene waste gas can reach more than 85%, especially when the inlet toluene concentration is >120mg / m 3 When the power density is 10.8J / L, the unit waste gas treatment power consumption is 3W / (m 3 / h), using TiO2 catalyst and placing the catalyst 5cm away from the discharge area (exhaust gas residence time 0.05s), it is expected to achieve a degradation efficiency of more than 90%.

[0062] The above is only a specific implementation case of the patent of the present invention, but the technical features of the patent of the present invention are not limited thereto. Any changes or modifications made by any technician in the relevant field within the field of the present invention are covered by the patent scope of the present invention.

Claims

1. A method for treating organic waste gas by double dielectric barrier discharge plasma excitation catalytic gas phase reaction, characterized in that: The invention adopts a device for treating organic waste gas by using double dielectric barrier discharge plasma to excite catalytic gas phase reaction; the device comprises a reactor cylinder, one end of the reactor cylinder is provided with a gas inlet, and the other end is provided with a gas outlet; the device also comprises at least one reaction unit arranged on the gas path in the reactor cylinder, the reaction unit comprises a plasma discharge unit and a catalyst unit arranged in sequence along the gas path; the plasma discharge unit adopts a high-frequency high-voltage power supply, the discharge voltage is 15000V and above, and the frequency is 10kHz and above; The method comprises the following steps: in a reactor device, the organic waste gas to be treated is sequentially treated by a plasma discharge unit and a catalyst unit or alternately treated by a plasma discharge unit and a catalyst unit, and the purified waste gas is discharged; the distance between the plasma discharge unit and the catalyst unit is 5 to 10 cm; The flow rate of the organic waste gas to be treated through the plasma discharge unit and the catalyst unit is 0.5-1.0 m / s; the residence time of the waste gas before reaching the catalyst after discharge is less than 0.1 s; The organic pollutants in the organic waste gas to be treated are ethyl acetate or toluene.

2. The method according to claim 1, characterized in that: The gas in the reactor cylinder flows along the axial direction of the cylinder; the reaction unit is arranged on a cross section perpendicular to the gas flow direction, and a plurality of reaction units are stacked in sequence along a direction perpendicular to the gas flow direction.

3. The method according to claim 2, characterized in that: Sequentially stacked reaction units are arranged on at least two radial cross sections along the gas flow direction.

4. The method according to claim 1, characterized in that: The plasma discharge unit is a plurality of tubular electrode assemblies stacked in sequence along a direction perpendicular to the gas flow direction or a plurality of plate electrode assemblies stacked in sequence along a direction perpendicular to the gas flow direction.

5. The method according to claim 4, characterized in that: The tubular electrode assembly comprises a grounding electrode core rod and a high-voltage electrode core rod arranged in parallel in the same vertical plane, and a blocking dielectric tube respectively wrapped around the grounding electrode core rod and the high-voltage electrode core rod; the areas between the blocking dielectric tubes in a single tubular electrode assembly and the areas between the blocking dielectric tubes of adjacent tubular electrode assemblies are both discharge areas, and the discharge areas are for gas to pass through; all the grounding electrode core rods are connected in parallel and then grounded, and all the high-voltage electrode core rods are connected in parallel and then externally connected to a high-frequency high-voltage power supply.

6. The method according to claim 4, characterized in that: The plate-type electrode assembly of the plasma discharge unit includes a high-voltage electrode plate and a grounding electrode plate that are arranged in parallel and horizontally, and a blocking dielectric layer that is respectively arranged on both sides of the high-voltage electrode plate and the grounding electrode plate; the blocking dielectric layers of a single plate-type electrode assembly and the blocking dielectric layers of adjacent plate-type electrode assemblies are the discharge areas, and the discharge areas are for gas to pass through; all the grounding electrode plates are connected in parallel and then grounded; all the high-voltage electrode plates are connected in parallel and then externally connected to a high-frequency high-voltage power supply.

7. The method according to claim 1, characterized in that: The catalyst unit adopts a supported catalyst and is distributed on a cross section parallel to the plasma discharge unit; the catalyst unit is slidably mounted on the inner wall of the reactor cylinder.

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