Discharge plasma and catalytic material multi-stage coupled CO2 conversion device and method

Abstract

The invention relates to a discharge plasma and catalytic material multi-stage coupled CO2 conversion device and method. The CO2 conversion device comprises a CO2 activation unit and CO2 conversion units arranged on the two sides of the CO2 activation unit; the CO2 activation unit comprises a high-voltage electrode, and the high-voltage electrode is connected with a high-voltage power supply; a gas channel for CO2 to circulate is arranged in the high-voltage electrode, and a convex nozzle for spraying CO2 is arranged on the high-voltage electrode; the CO2 conversion unit comprises a porous induction layer, a catalyst filling layer and a grounding electrode layer which are arranged layer by layer in the CO2 gas circulation direction; wherein the porous induction layer directly faces the convex nozzle on the high-voltage electrode, and a hollow corona discharge area is formed between the porous induction layer and the high-voltage electrode on the corresponding side; the grounding electrode layer is provided with a gas diversion hole, and the two sides of the grounding electrode layer are respectively provided with an insulating layer. Compared with the prior art, energy consumption in the reaction process can be remarkably reduced, and efficient reduction conversion of CO2 is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO2 conversion, and in particular relates to a CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic material. Background Art

[0002] Energy is vital to a country's economic and social development, and even directly affects national security. Since the Industrial Revolution, the concentration of CO2 in the atmosphere has increased by more than 45%, which is obviously related to the utilization of fossil resources. In order to control the anthropogenic emission of CO2 and slow down the greenhouse effect, countries around the world have taken active actions and formulated relevant international conventions and emission reduction targets. Considering that CO2 is a cheap and readily available C1 raw material, the technology of CO2 capture and utilization (CCU) was proposed. The idea of ​​CCU is to use CO2 as a raw material to produce chemical raw materials or fuels with high added value, which is not only more economical, but also can constitute a complete "carbon cycle" so that the carbon source can be recycled.

[0003] During the catalytic process, plasma can not only activate gas molecules through excitation, ionization and dissociation to produce active substances such as free radicals, excited atoms and molecules, but also modify the catalyst surface, resulting in surface vacancies, defects, increased active sites and functional group modifications. This surface modification will affect the catalyst surface, thereby opening up new reaction pathways, and is one of the main research directions of concern in recent years. Patent CN109867261A discloses a methane-carbon dioxide plasma catalytic reforming device and a catalytic reforming method, which utilizes a microwave resonant cavity formed inside a ring waveguide and fills a catalyst in the microwave resonant cavity to achieve efficient conversion of CO2. Patent CN114394574A proposes a method for preparing a liquid product from a carbon dioxide / methane mixture by plasma catalysis, which utilizes the strong interaction between amino groups and CO2 in the Cu / UiO-66-NH2 catalyst to improve the conversion rate of CO2 and the efficiency of liquid C 2+ Patent CN109529851A discloses a nickel-based supported catalyst and a method for producing methanol by hydrogenating CO2 using plasma catalysis thereof, which uses low-temperature plasma and a nickel-based supported catalyst to synergistically activate CO2 and hydrogen to selectively produce methanol.

[0004] However, the above-mentioned prior art still has problems such as insufficient CO2 conversion efficiency and low energy efficiency. Therefore, it is necessary to provide a method and device for CO2 reduction catalysis that can well couple catalysis and plasma discharge, so as to achieve efficiency improvement and consumption reduction in the CO2 reduction conversion process. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art in terms of insufficient CO2 conversion efficiency and low energy efficiency and to provide a CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic material.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention provides a CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material, which comprises a CO2 activation unit and CO2 conversion units arranged on both sides of the CO2 activation unit;

[0008] The CO2 activation unit comprises a high-voltage electrode connected to a high-voltage power supply; a gas channel for CO2 circulation is provided in the high-voltage electrode, and a protruding nozzle for injecting CO2 is provided on the high-voltage electrode;

[0009] The CO2 conversion units all include a porous induction layer, a catalyst filling layer and a grounding electrode layer which are arranged layer by layer along the CO2 gas flow direction; wherein the porous induction layer is directly opposite to the protrusion on the high-voltage electrode, and a hollow corona discharge zone is formed between the porous induction layer and the high-voltage electrode on the corresponding side; the grounding electrode layer is provided with gas conduction holes, and insulating layers are provided on both sides of the grounding electrode layer.

[0010] Furthermore, the high-voltage electrode is a hollow discharge electrode with gas distribution holes, and the shape of the high-voltage electrode is tubular or sandwich plate.

[0011] Furthermore, the high voltage power supply is a pulse or high frequency AC high voltage power supply with a frequency of 500-10000 Hz and a voltage operating range of 0-30 kV.

[0012] Furthermore, the aperture range of the protruding nozzle is 1-3 mm, and the jet velocity of the CO2 is 0.2-2 m / s.

[0013] Furthermore, the spatial distance of the hollow corona discharge zone is 5-20 mm.

[0014] Furthermore, the material of the porous inducing layer includes one of carrier silicon carbide, molybdenum carbide, tungsten carbide, aluminum oxide, silicon oxide or stainless steel.

[0015] Furthermore, the dielectric constant of the porous induction layer ranges from 30 to 500.

[0016] Furthermore, the catalyst carrier filled in the catalyst filling layer includes one or more of activated alumina and silicon oxide, and the catalyst active component includes one or more of Cu, Ni, Mn, Ag or Ru.

[0017] Furthermore, the grounding electrode layer is a mesh-shaped air-permeable layer and is connected to a grounding device.

[0018] Furthermore, the insulating layer includes one or more of enamel or ceramic materials.

[0019] Furthermore, the gas guide holes are arranged at equal intervals on the ground electrode layer, and the aperture of the gas guide holes is 3-5 mm.

[0020] Furthermore, the CO2 conversion device can be designed on a large scale according to process requirements, and can flexibly draw on tubular electrostatic precipitators or interactively arranged plate-and-frame processing devices for engineering superposition and amplification.

[0021] The present invention also provides a method for converting CO2 by multi-stage coupling of discharge plasma and catalytic material using the above-mentioned CO2 conversion device, comprising the following steps:

[0022] S1: Turn on the high voltage power supply, input the reaction gas containing CO2 into the gas channel, and the gas enters the hollow corona discharge area through the jet action of the convex nozzle, fully activating CO2 to form discharge plasma;

[0023] S2: The discharge plasma enters the catalyst filling layer through the porous induction layer, achieving a primary coupling between the discharge plasma and the catalyst;

[0024] S3: CO2 achieves secondary coupling between plasma and catalyst under the combined action of the catalyst filling layer and surface discharge, and is finally converted into CO.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The CO2 raw material reaction gas of the present invention enters the hollow corona discharge zone through the high-voltage electrode, so that CO2 is fully activated in this area, and the catalyst is activated through the first catalytic coupling of the porous induction layer, and the airflow and electric field are distributed twice; then the surface discharge is strengthened through the second catalytic coupling of the catalyst particle filling layer, thereby initiating discharge between particles in this area, realizing multi-level coupling of the discharge plasma and the catalyst, and finally improving the CO2 conversion rate and energy efficiency.

[0027] (2) The present invention enhances and extends the discharge current injection through the jet design of the hollow high-voltage electrode and the protruding nozzle, thereby improving the energy density, fully activating CO2, and avoiding the catalyst short-circuit effect.

[0028] (3) The present invention can significantly improve the CO2 treatment capacity by setting up a hollow corona discharge zone, and rationally use the heat generated by the reaction device for the synchronous thermal activation of the outer catalyst by optimizing the lateral layout of the airflow, and timely bring the heat out of the reaction system through the gas guide holes, thereby significantly reducing the energy consumption during the reaction process.

[0029] (4) The CO2 conversion device of the present invention has a simple and compact overall structure and is easy to scale up and utilize for subsequent heat. It can achieve efficient reduction and conversion of CO2, has good economic and environmental benefits, and has excellent application prospects in the field of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the CO2 conversion device of the present invention.

[0031] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0032] Figure 3 for Figure 1 Enlarged view of point B in the middle.

[0033] Figure 4 for Figure 1 Enlarged view of point C in the middle.

[0034] Figure 5 It is a schematic diagram of the superposition engineering enlargement design of the CO2 conversion device of the present invention.

[0035] Description of the markings in the figure:

[0036] 1-high voltage electrode, 11-gas channel, 2-high voltage power supply, 3-protruding nozzle, 4-porous induction layer, 5-catalyst filling layer, 6-grounding electrode layer, 61-gas flow guide hole, 7-hollow corona discharge area, 8-insulating layer, 9-grounding device. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0038] In the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] Embodiment 1:

[0041] This embodiment provides a CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material, which specifically includes a CO2 activation unit and CO2 conversion units arranged on both sides of the CO2 activation unit.

[0042] like Figure 1 As shown, the CO2 activation unit includes a high-voltage electrode 1, which is connected to a high-voltage power supply 2. A gas channel 11 for CO2 to flow is provided in the high-voltage electrode 1, and a protruding nozzle 3 for injecting CO2 is also provided on the high-voltage electrode 1.

[0043] The CO2 conversion unit includes a porous induction layer 4, a catalyst filling layer 5 and a grounding electrode layer 6 which are arranged layer by layer along the CO2 gas flow direction. The porous induction layer 4 faces the protrusion 3 on the high-voltage electrode 1, and a hollow corona discharge area 7 is formed between the porous induction layer 4 and the high-voltage electrode 1 on the corresponding side. The grounding electrode layer 6 is provided with gas guide holes 61, and both sides of the grounding electrode layer 6 are provided with insulating layers 8.

[0044] This embodiment also provides a method for converting CO2 by multi-stage coupling of discharge plasma and catalytic material using the above device, which specifically includes the following steps:

[0045] S1: Turn on the high voltage power supply 2, input the reaction gas containing CO2 into the gas channel 11, and the gas enters the hollow corona discharge area 7 through the jet action of the protruding nozzle 3, fully activating the CO2 to form a discharge plasma;

[0046] S2: the discharge plasma enters the catalyst filling layer 5 through the porous induction layer 4, achieving a primary coupling between the discharge plasma and the catalyst;

[0047] S3: CO2 realizes secondary coupling between plasma and catalyst under the combined action of the catalyst filling layer 5 and the surface discharge, and is finally converted into CO.

[0048] Embodiment 2:

[0049] This embodiment provides a CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material, which specifically includes a CO2 activation unit and CO2 conversion units arranged on both sides of the CO2 activation unit.

[0050] The CO2 activation unit includes a high-voltage electrode 1, which is a hollow discharge electrode with gas distribution holes. The high-voltage electrode 1 is in the shape of a tube or a sandwich plate. The high-voltage electrode 1 is connected to a high-voltage power supply 2, which is a pulse or high-frequency AC high-voltage power supply with a frequency of 500-10000Hz and a voltage working range of 0-30kV. A gas channel 11 for CO2 circulation is provided in the high-voltage electrode 1. Figure 2 As shown, the high voltage electrode 1 is provided with a protruding nozzle 3 for injecting CO2, the aperture range of the protruding nozzle 3 is 1-3 mm, and the jet velocity of the injected CO2 is 0.2-2 m / s.

[0051] like Figure 3-4 As shown, the CO2 conversion unit includes a porous induction layer 4, a catalyst filling layer 5 and a grounding electrode layer 6 arranged layer by layer along the CO2 gas flow direction. Among them, the porous induction layer 4 is directly opposite to the protrusion 3 on the high-voltage electrode 1, and a hollow corona discharge zone 7 with a space distance of 5-20mm is formed between the porous induction layer 4 and the high-voltage electrode 1 on the corresponding side. The material of the porous induction layer 4 includes one of the carrier silicon carbide, molybdenum carbide, tungsten carbide, aluminum oxide, silicon oxide or stainless steel, and the dielectric constant of the porous induction layer 4 is in the range of 30-500. The catalyst carrier filled in the catalyst filling layer 5 includes one or more of activated aluminum oxide and silicon oxide, and the catalyst active component includes one or more of Cu, Ni, Mn, Ag or Ru. The grounding electrode layer 6 is a mesh air-permeable layer, and the grounding electrode layer 6 is connected to the grounding device 9. The grounding electrode layer 6 is provided with gas guide holes 61, and the gas guide holes 61 are arranged at equal intervals on the grounding electrode layer 6, and the aperture of the gas guide holes 61 is 3-5mm. Insulating layers 8 are provided on both sides of the ground electrode layer 6. The insulating layers 8 include one or more materials such as enamel or ceramic.

[0052] Embodiment 3:

[0053] The purpose of this embodiment is to achieve efficiency improvement and consumption reduction of CO2 reduction conversion through the "wide spacing, stepped, high voltage, and low current" approach, and then provide a CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic materials to solve the bottleneck problems existing in the prior art.

[0054] The CO2 conversion device of this embodiment follows the basic principle of dielectric barrier discharge (DBD), enlarges the gap of the high-voltage electrode 1 to form a hollow corona discharge zone 7, and combines the multi-stage coupling effect of plasma and porous induction layer 4 / catalyst filling layer 5 to adjust the functional area of ​​the space between the electrodes, that is, to achieve a "wide spacing, stepped" layout. A hollow corona discharge zone 7 is retained near the air-inlet distributed high-voltage electrode 1, followed by a porous induction layer 4 with a certain dielectric barrier effect, which is used to isolate the catalyst filling layer 5 from the hollow corona discharge zone 7. Due to the porosity of the porous induction layer 4, the airflow and active particles in the hollow corona discharge zone 7 can be allowed to pass through and enter the catalyst filling layer 5. When the hollow corona discharge zone 7 discharges, the electric field and current are quickly applied to the catalyst filling layer 5 through the porous induction layer 4, thereby inducing discharge between the particles in this area. Under the high-voltage discharge of the high-voltage power supply 2, reactants such as CO2 enter the hollow corona discharge area 7 through the jet action of the protruding nozzle 3 arranged on the hollow high-voltage electrode 1 with gas distribution holes, which can enhance and extend the discharge current injection, thereby improving the energy density, and fully activating CO2, and then sequentially flowing through the porous induction layer 4 and the catalyst filling layer 5. Due to the large spatial distance of the hollow corona discharge area 7, the unit's ability to process CO2 can be significantly improved. Through the optimization of the lateral layout of the airflow, the heat generated by the device can be reasonably used for the synchronous thermal activation of the outer catalyst, and the heat can be promptly taken out of the device through the gas guide hole 61 on the inner side of the ground electrode layer 6, so as to achieve efficiency improvement and consumption reduction in the CO2 reduction and conversion process.

[0055] The high-voltage electrode 1 of this embodiment is a hollow discharge electrode with gas distribution holes. The electrode material can be selected from 304, 316L stainless steel, etc., and the electrode shape is tubular or sandwich plate. The high-voltage power supply 2 is a high-voltage power supply such as pulse or high-frequency AC, with a frequency of 500-10000Hz and a voltage working range of 0-30kV. The spatial distance of the hollow corona discharge zone 7 is 5-20mm. The porous induction layer 4 is a porous medium, and the material carrier of the induction layer is silicon carbide, molybdenum carbide, tungsten carbide, aluminum oxide, silicon oxide, stainless steel, etc., and its dielectric constant range is 30-500. The catalyst carrier of the catalyst filling layer 5 is made of commercial activated alumina, silicon oxide and other materials, and the active components are Cu, Ni, Mn, Ag, Ru, etc. The aperture range of the protruding nozzle 3 is 1-3mm, and the jet velocity is 0.2-2m / s. The ground electrode layer 6 is provided with a mesh air permeable layer to facilitate the uniform distribution of the airflow or radial penetration of the electrode area. The surface insulating layer 8 of the ground electrode layer 6 is coated with insulating materials such as enamel and ceramic. The gas guide hole 61 is arranged on the plate surface of the ground electrode layer 6, and its hole diameter is 3-5mm, which is used for the outflow of the product gas.

[0056] The method for CO2 reduction conversion using the above device in this embodiment is specifically as follows:

[0057] In the first step, when the reaction gas such as CO2 enters the reaction device, the discharge injection is enhanced and extended through the jet effect of the cavity + protruding nozzle 3 of the distributed high-voltage electrode 1, the energy density is increased, and the CO2 molecules are fully activated.

[0058] In the second step, the porous induction layer 4 / catalyst filling layer 5 is arranged, and the discharge plasma is combined with the effect of the discharge plasma to achieve a primary coupling between the discharge plasma and the catalytic material, thereby further effectively activating the catalyst in the porous induction layer 4 / catalyst filling layer 5.

[0059] The third step is to strengthen the surface discharge by setting the catalyst filling layer 5, improve the CO2 conversion efficiency, realize the secondary coupling effect between plasma and catalytic materials, greatly reduce the discharge current, and improve the energy efficiency.

[0060] like Figure 5 As shown, the reaction device of this embodiment is designed on a large scale according to the process requirements, and flexibly draws on the tubular electrostatic precipitator or the interactively arranged plate-and-frame treatment device for engineering superposition and amplification.

[0061] For the CO2 conversion devices in the following Examples 4-9 and Comparative Examples 1-3, the performance and effect of the CO2 reduction devices were evaluated using CO2 reduction conversion rate and energy efficiency. The CO2 reduction conversion rate calculation formula is:

[0062]

[0063] Where C0 is the concentration of CO2 in the initial reaction gas, %; C e It is the CO2 concentration in the outlet gas after the plasma catalytic reaction conditions are stabilized, %. The CO2 concentration in the gas is detected by an infrared gas analyzer to detect the concentration at the reactor outlet.

[0064] The energy efficiency calculation formula is:

[0065]

[0066] Among them, Q CO2 is the gas flow rate of CO2, mL / min; P d is the discharge power, W.

[0067] Embodiment 4:

[0068] This embodiment provides a specific CO2 conversion device. The difference from Example 3 is that this embodiment uses 304 stainless steel to make the high-voltage electrode 1, and the high-voltage electrode 1 is tubular. The space distance of the hollow corona zone 7 is set to 10mm, the gas enters from the hollow high-voltage electrode 1, the aperture of the protruding nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0069] The material carrier of the porous induction layer 4 is selected as alumina. The carrier of the catalyst filling layer 5 is commercial activated alumina, and the active component is Cu. The grounding electrode layer 6 is a copper metal mesh, and an insulating enamel layer is coated on the surface. The gas guide hole 61 is arranged on the plate surface of the grounding electrode layer 6, and the hole diameter is set to 4mm. The external high-voltage power supply 2 is a high-frequency AC power supply, the frequency is set to 3000Hz, and the voltage is set to 20kV.

[0070] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 25% and the energy efficiency was 1.3 mol / (kW·h).

[0071] Embodiment 5:

[0072] This embodiment provides a specific CO2 conversion device. The difference from Example 3 is that this embodiment uses 304 stainless steel to make the high-voltage electrode 1, and the high-voltage electrode 1 is tubular. The space distance of the hollow corona zone 7 is set to 10mm, the gas enters from the hollow high-voltage electrode 1, the aperture of the protruding nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0073] The material carrier of the porous induction layer 4 is selected as silicon carbide. The carrier of the catalyst filling layer 5 is commercial activated alumina, and the active component is Cu. The grounding electrode layer 6 is a copper metal mesh, and an insulating enamel layer is coated on the surface. The gas guide hole 61 is arranged on the plate surface of the grounding electrode layer 6, and the hole diameter is set to 4mm. The external high-voltage power supply 2 is a high-frequency AC power supply, the frequency is set to 5000Hz, and the voltage is set to 20kV.

[0074] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 38% and the energy efficiency was 1.9 mol / (kW·h).

[0075] Embodiment 6:

[0076] This embodiment provides a specific CO2 conversion device. The difference from Example 3 is that this embodiment uses 304 stainless steel to make the high-voltage electrode 1, and the high-voltage electrode 1 is tubular. The space distance of the hollow corona zone 7 is set to 10mm, the gas enters from the hollow high-voltage electrode 1, the aperture of the protruding nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0077] The material carrier of the porous induction layer 4 is selected as silicon carbide. The carrier of the catalyst filling layer 5 is commercial activated alumina, and the active component is Cu. The grounding electrode layer 6 is a copper metal mesh, and an insulating enamel layer is coated on the surface. The gas guide hole 61 is arranged on the plate surface of the grounding electrode layer 6, and the hole diameter is set to 4mm. The external high-voltage power supply 2 is a high-frequency AC power supply, the frequency is set to 5000Hz, and the voltage is set to 20kV.

[0078] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 40% and the energy efficiency was 2.0 mol / (kW·h).

[0079] Embodiment 7:

[0080] This embodiment provides a specific CO2 conversion device. The difference from Example 3 is that this embodiment uses 304 stainless steel to make the high-voltage electrode 1, and the high-voltage electrode 1 is tubular. The space distance of the hollow corona zone 7 is set to 10mm, the gas enters from the hollow high-voltage electrode 1, the aperture of the protruding nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0081] The material carrier of the porous induction layer 4 is selected to be tungsten carbide. The carrier of the catalyst filling layer 5 is commercial activated alumina, and the active component is Cu. The grounding electrode layer 6 is a copper metal mesh, and an insulating enamel layer is coated on the surface. The gas guide hole 61 is arranged on the plate surface of the grounding electrode layer 6, and the hole diameter is set to 4mm. The external high-voltage power supply 2 is a high-frequency AC power supply, the frequency is set to 5000Hz, and the voltage is set to 20kV.

[0082] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 48% and the energy efficiency was 2.6 mol / (kW·h).

[0083] Embodiment 8:

[0084] This embodiment provides a specific CO2 conversion device. The difference from Example 3 is that this embodiment uses 304 stainless steel to make the high-voltage electrode 1, and the high-voltage electrode 1 is tubular. The space distance of the hollow corona zone 7 is set to 10mm, the gas enters from the hollow high-voltage electrode 1, the aperture of the protruding nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0085] The material carrier of the porous induction layer 4 is selected to be tungsten carbide. The carrier of the catalyst filling layer 5 is commercial activated alumina, and the active component is Cu. The grounding electrode layer 6 is a copper metal mesh, and an insulating enamel layer is coated on the surface. The gas guide hole 61 is arranged on the plate surface of the grounding electrode layer 6, and the hole diameter is set to 4mm. The external high-voltage power supply 2 is a high-frequency AC power supply, the frequency is set to 5000Hz, and the voltage is set to 30kV.

[0086] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 58% and the energy efficiency was 2.8 mol / (kW·h).

[0087] Embodiment 9:

[0088] This embodiment provides a specific CO2 conversion device. The difference from Example 3 is that this embodiment uses 304 stainless steel to make the high-voltage electrode 1, and the high-voltage electrode 1 is tubular. The space distance of the hollow corona zone 7 is set to 15mm, the gas enters from the hollow high-voltage electrode 1, the aperture of the protruding nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0089] The material carrier of the porous induction layer 4 is selected to be tungsten carbide. The carrier of the catalyst filling layer 5 is commercial activated alumina, and the active component is Cu. The grounding electrode layer 6 is a copper metal mesh, and an insulating enamel layer is coated on the surface. The gas guide hole 61 is arranged on the plate surface of the grounding electrode layer 6, and the hole diameter is set to 4mm. The external high-voltage power supply 2 is a high-frequency AC power supply, the frequency is set to 5000Hz, and the voltage is set to 30kV.

[0090] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 50% and the energy efficiency was 2.3 mol / (kW·h).

[0091] Comparative Example 1:

[0092] The device of Example 8 is used and the method of Example 1 is applied, wherein no hollow corona zone is provided in the device:

[0093] When the raw gas containing 10 vol% CO2 and reducing gas is transported to the above-mentioned CO2 reduction device, the final CO2 conversion rate is only 20%, and the energy efficiency is only 1.3 mol / (kW·h).

[0094] Comparative Example 2:

[0095] The device of Example 8 is used and the method of Example 1 is applied, wherein the porous induction layer is not provided in the device and the catalyst layer is directly entered:

[0096] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 30% and the energy efficiency was 1.8 mol / (kW·h).

[0097] Comparative Example 3:

[0098] The device of Example 8 is used and the method of Example 1 is applied, wherein no catalytic particle filling layer is provided in the device:

[0099] The raw gas containing 10 vol% CO2 and reducing gas was transported to the above-mentioned CO2 reduction device, and the final CO2 conversion rate was 15% and the energy efficiency was 0.8 mol / (kW·h).

[0100] In summary, the device and the corresponding method provided by the present invention can control the final CO2 conversion rate to be close to 60%, and the energy efficiency can reach 2.8 mol / (kW·h), which is a significant improvement compared to the results of the prior art (the CO2 conversion rate is increased by more than 30%).

[0101] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material, characterized in that: It includes a CO2 activation unit and a CO2 conversion unit arranged on both sides of the CO2 activation unit; The CO2 activation unit comprises a high-voltage electrode (1), the high-voltage electrode (1) being connected to a high-voltage power supply (2); a gas channel (11) for CO2 to flow is provided in the high-voltage electrode (1), and a protruding nozzle (3) for injecting CO2 is provided on the high-voltage electrode (1); The CO2 conversion unit comprises a porous induction layer (4), a catalyst filling layer (5) and a grounding electrode layer (6) which are arranged layer by layer along the CO2 gas flow direction; wherein the porous induction layer (4) is directly opposite to the protrusion (3) on the high-voltage electrode (1), and a hollow corona discharge zone (7) is formed between the porous induction layer (4) and the high-voltage electrode (1) on the corresponding side; the grounding electrode layer (6) is provided with a gas conduction hole (61), and both sides of the grounding electrode layer (6) are provided with an insulating layer (8).

2. A CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The high-voltage electrode (1) is a hollow discharge electrode with gas distribution holes, and the shape of the high-voltage electrode (1) is a tube or a sandwich plate.

3. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The high voltage power supply (2) is a pulse or high frequency AC high voltage power supply with a frequency of 500-10000 Hz and a voltage operating range of 0-30 kV.

4. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The aperture of the protruding nozzle (3) is in the range of 1-3 mm, and the jet velocity of the CO2 is in the range of 0.2-2 m / s.

5. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The spatial distance of the hollow corona discharge zone (7) is 5-20 mm.

6. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The material of the porous induction layer (4) includes one of carrier silicon carbide, molybdenum carbide, tungsten carbide, aluminum oxide, silicon oxide or stainless steel; The dielectric constant of the porous induction layer (4) is in the range of 30-500.

7. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The catalyst carrier filled in the catalyst filling layer (5) includes one or more of activated alumina and silicon oxide, and the catalyst active component includes one or more of Cu, Ni, Mn, Ag or Ru.

8. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The grounding electrode layer (6) is a mesh-shaped air-permeable layer, and the grounding electrode layer (6) is connected to a grounding device (9); The insulating layer (8) comprises one or more of enamel or ceramic materials.

9. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that: The gas guide holes (61) are arranged at equal intervals on the ground electrode layer (6), and the diameter of the gas guide holes (61) is 3-5 mm.

10. A method for converting CO2 by multi-stage coupling of discharge plasma and catalytic material, characterized in that: A CO2 conversion device according to any one of claims 1 to 9; The method for converting CO2 comprises the following steps: S1: Turn on the high voltage power supply (2), input the reaction gas containing CO2 into the gas channel (11), and the gas enters the hollow corona discharge area (7) through the jet action of the protruding nozzle (3), fully activating the CO2 to form a discharge plasma; S2: the discharge plasma enters the catalyst filling layer (5) through the porous induction layer (4), thereby achieving a primary coupling between the discharge plasma and the catalyst; S3: CO2 realizes secondary coupling between plasma and catalyst under the combined action of discharge inside the catalyst filling layer (5) and along the surface, and is finally converted into CO.

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