CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic material

Abstract

The application relates to a CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic materials. 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 connected with a high-voltage power supply; a gas passage for CO2 flow 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 arranged layer by layer along the CO2 gas flow direction; wherein the porous induction layer is opposite to the convex nozzle on the high-voltage electrode, and a hollow corona discharge area is formed between the porous induction layer and the corresponding side high-voltage electrode; the grounding electrode layer is provided with a gas guide hole, and the two sides of the grounding electrode layer are provided with insulating layers. Compared with the prior art, the application can significantly reduce the energy consumption in the reaction process and realize efficient reduction and conversion of CO2.

Description

Technical Field

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

[0002] To control anthropogenic CO2 emissions and mitigate the greenhouse effect, countries worldwide have taken active steps, establishing relevant international conventions and emission reduction targets. Given that CO2 is a cheap and readily available C1 feedstock, CO2 capture and utilization (CCU) technology has been proposed. The CCU approach uses CO2 as a raw material to produce high-value-added chemical feedstocks or fuels, which is not only more economical but also constitutes a complete "carbon cycle," allowing for the recycling of carbon sources.

[0003] In catalysis, plasma can not only activate gas molecules through excitation, ionization, and dissociation, generating active substances such as free radicals, excited-state atoms, and molecules, but it can also modify the catalyst surface, leading to an increase in surface vacancies, defects, active sites, and functional group modification. This surface modification affects the catalyst surface, thereby opening up new reaction pathways, and is one of the main research directions that have attracted attention in recent years. Patent CN109867261A discloses a methane-carbon dioxide plasma catalytic reforming device and method, which utilizes a microwave resonant cavity formed inside a ring waveguide and fills the microwave resonant cavity with a catalyst to achieve efficient CO2 conversion. Patent CN114394574A proposes a method for plasma catalytic preparation of liquid products from a carbon dioxide / methane mixture, utilizing the strong interaction between amino groups and CO2 in the Cu / UiO-66-NH2 catalyst to improve the CO2 conversion rate and liquid C 2+ Product yield. Patent CN109529851A discloses a nickel-based supported catalyst and a method for producing methanol by plasma-catalyzed CO2 hydrogenation using the catalyst. The method employs the synergistic effect of low-temperature plasma and nickel-based supported catalyst to selectively generate methanol from CO2 and hydrogen.

[0004] However, the aforementioned existing technologies still suffer from problems such as insufficient CO2 conversion efficiency and low energy efficiency. Therefore, there is a need to provide a method and apparatus for CO2 reduction catalysis that can effectively couple catalytic action and plasma electrolysis, thereby achieving efficiency enhancement and energy reduction in the CO2 reduction conversion process. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of insufficient CO2 conversion efficiency and low energy efficiency in the existing technology by providing a CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic material.

[0006] The objective of this invention can be achieved through the following technical solutions:

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

[0008] The CO2 activation unit includes a high-voltage electrode connected to a high-voltage power supply; the high-voltage electrode has a gas channel for CO2 flow and a nozzle for injecting CO2.

[0009] Each CO2 conversion unit includes a porous induction layer, a catalyst filling layer, and a grounding electrode layer arranged layer by layer along the CO2 gas flow direction; wherein, the porous induction layer faces the protrusion on the high-voltage electrode, and a hollow corona discharge region is formed between the porous induction layer and the high-voltage electrode on the corresponding side; the grounding electrode layer is provided with gas guiding 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 high-voltage electrode is tubular or sandwich plate in shape.

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

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

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

[0014] Furthermore, the porous induction layer is made of one of the following materials: carrier silicon carbide, molybdenum carbide, tungsten carbide, alumina, silicon oxide, or stainless steel.

[0015] Furthermore, the dielectric constant of the porous induced layer is in the range of 30-500.

[0016] Furthermore, the catalyst support filled in the catalyst filling layer includes one or more of activated alumina and silicon dioxide, 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-like breathable layer and is connected to a grounding device.

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

[0019] Furthermore, the gas guide holes are evenly spaced on the grounding electrode layer, and the diameter of the gas guide holes is 3-5mm.

[0020] Furthermore, the CO2 conversion device can be designed on a large scale according to process requirements, and can be flexibly scaled up by drawing on tubular electrostatic precipitators or interactively arranged plate and frame processing devices.

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

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

[0023] S2: The discharge plasma enters the catalyst-filled layer through the porous induction layer, realizing the primary coupling between the discharge plasma and the catalyst;

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

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

[0026] (1) The CO2 feedstock 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 region. The catalyst is activated by the primary catalytic coupling of the porous induction layer, and the gas flow and electric field are uniformly distributed in the secondary manner. Then, the surface discharge is enhanced by the secondary catalytic coupling of the catalyst particle filling layer, thereby triggering the discharge between particles in this region. This realizes the multi-level coupling between the discharge plasma and the catalyst, and ultimately improves the conversion rate and energy efficiency of CO2.

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

[0028] (3) The present invention can significantly improve CO2 processing 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 transverse airflow layout, and carry the heat out of the reaction system in a timely manner through the gas guide hole, which significantly reduces the energy consumption in 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 heat in the future. It can realize the efficient reduction and conversion of CO2, with good economic and environmental benefits, and has excellent application prospects in the field of energy conservation and emission reduction. Attached Figure Description

[0030] Figure 1 This 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 A magnified view of point C in the middle.

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

[0035] Explanation of markings in the diagram:

[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 guide hole, 7-Hollow corona discharge area, 8-Insulation layer, 9-Grounding device. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0038] In this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] Example 1:

[0041] This embodiment provides a CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material, specifically including a CO2 activation unit and CO2 conversion units disposed 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. The high-voltage electrode 1 has a gas channel 11 for CO2 flow, and a 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 arranged layer by layer along the CO2 gas flow direction. The porous induction layer 4 faces the nozzle 3 on the high-voltage electrode 1, and a hollow corona discharge region 7 is formed between the porous induction layer 4 and the corresponding side of the high-voltage electrode 1. The grounding electrode layer 6 has gas guiding holes 61, and insulating layers 8 are provided on both sides of the grounding electrode layer 6.

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

[0045] S1: Turn on the high-voltage power supply 2 and input the reaction gas containing CO2 into the gas channel 11. The gas enters the hollow corona discharge zone 7 through the jet action of the nozzle 3, which fully activates the CO2 to form discharge plasma.

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

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

[0048] Example 2:

[0049] This embodiment provides a CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material, specifically including a CO2 activation unit and CO2 conversion units disposed 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 tubular or sandwiched plate in shape. The high-voltage electrode 1 is connected to a high-voltage power supply 2, which is a pulsed or high-frequency AC high-voltage power supply with a frequency of 500-10000Hz and a voltage operating range of 0-30kV. A gas channel 11 for CO2 flow is provided inside 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 diameter of the protruding nozzle 3 is in the range of 1-3mm, and the jet velocity of the injected CO2 is 0.2-2m / s.

[0051] like Figure 3-4 As shown, each 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. The porous induction layer 4 faces the nozzle 3 on the high-voltage electrode 1, and a hollow corona discharge region 7 with a spatial distance of 5-20 mm is formed between the porous induction layer 4 and the corresponding high-voltage electrode 1. The porous induction layer 4 is made of one of the following materials: silicon carbide, molybdenum carbide, tungsten carbide, alumina, silicon oxide, or stainless steel, and its dielectric constant ranges from 30 to 500. The catalyst filling layer 5 is filled with one or more catalyst supports, including activated alumina and silicon oxide, and the active catalyst components include one or more of Cu, Ni, Mn, Ag, or Ru. The grounding electrode layer 6 is a mesh-like permeable layer and is connected to a grounding device 9. Gas guide holes 61 are formed on the grounding electrode layer 6, spaced evenly, and have a diameter of 3-5 mm. Both sides of the grounding electrode layer 6 are provided with an insulating layer 8, which includes one or more of enamel or ceramic materials.

[0052] Example 3:

[0053] The purpose of this embodiment is to improve the efficiency and reduce the consumption of CO2 reduction and conversion by means of "wide spacing, stepped stages, high voltage, and low current", and to provide a CO2 conversion device and method with multi-stage coupling of discharge plasma and catalytic material, so as to solve the bottleneck problems existing in the prior art.

[0054] This embodiment of the CO2 conversion device adopts the basic principle of dielectric barrier discharge (DBD). The gap between the high-voltage electrodes 1 is increased to form a hollow corona discharge region 7. Combined with the multi-level coupling effect of plasma and the porous induction layer 4 / catalyst filling layer 5, the space between the electrodes is functionally allocated, achieving a "wide-spacing, tiered" layout. Near the inlet distributed high-voltage electrode 1, a hollow corona discharge region 7 is maintained, followed by a porous induction layer 4 with a certain dielectric barrier effect, which isolates the catalyst filling layer 5 from the hollow corona discharge region 7. Due to the porosity of the porous induction layer 4, airflow and active particles from the hollow corona discharge region 7 can pass through and enter the catalyst filling layer 5. When discharge occurs in the hollow corona discharge region 7, the electric field and current are quickly applied to the catalyst filling layer 5 through the porous induction layer 4, thereby triggering inter-particle discharge in that region. Under the high-voltage discharge of the high-voltage power supply 2, reactants such as CO2 enter the hollow corona discharge region 7 through the jet action of the protruding nozzles 3 arranged on the hollow high-voltage electrode 1 with gas distribution holes. This enhances and extends the discharge current injection, thereby increasing the energy density and fully activating CO2. The CO2 then flows sequentially through the porous induction layer 4 and the catalyst filling layer 5. Due to the large spatial distance of the hollow corona discharge region 7, its CO2 processing capacity can be significantly improved. Through the optimization of the lateral airflow layout, the heat generated by the device can be rationally used for the synchronous thermal activation of the outer catalyst, and the heat can be promptly carried out of the device through the gas guide holes 61 inside the grounding electrode layer 6, achieving efficiency improvement and energy saving in the CO2 reduction and conversion process.

[0055] In this embodiment, the high-voltage electrode 1 is a hollow discharge electrode with gas distribution holes. The electrode material can be 304 or 316L stainless steel, and the electrode shape is tubular or sandwich plate-shaped. The high-voltage power supply 2 is a pulsed or high-frequency AC high-voltage power supply with a frequency of 500-10000Hz and a voltage operating range of 0-30kV. The spatial distance of the hollow corona discharge region 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, alumina, silicon oxide, stainless steel, etc., with a dielectric constant range of 30-500. The catalyst carrier of the catalyst filling layer 5 is commercially available activated alumina, silicon oxide, etc., and the active components are Cu, Ni, Mn, Ag, Ru, etc. The pore size of the nozzle 3 ranges from 1-3mm, and the jet velocity is 0.2-2m / s. The grounding electrode layer 6 is provided with a mesh-like permeable layer to facilitate the uniform distribution of airflow or radial passage through the electrode area. The surface insulating layer 8 of the grounding electrode layer 6 is coated with insulating materials such as enamel or ceramic. Gas guide holes 61 are arranged on the plate surface of the grounding electrode layer 6, with a channel diameter of 3-5 mm, for the outflow of product gas.

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

[0057] The first step involves enhancing and extending the discharge current injection through the cavity of the distributed high-voltage electrode 1 and the jet effect of the nozzle 3, thereby increasing the energy density and fully activating the CO2 molecules when the reactive gases such as CO2 enter the reaction device.

[0058] The second step involves arranging a porous induction layer 4 / catalyst filling layer 5, and combining this with the effect of discharge plasma to achieve 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 involves enhancing surface discharge through the catalyst filling layer 5, improving CO2 conversion efficiency, achieving secondary coupling between plasma and catalytic materials, significantly reducing discharge current, and improving energy efficiency.

[0060] like Figure 5 As shown, the reaction device in this embodiment is designed on a large scale according to process requirements, and flexibly draws on tubular electrostatic precipitators or interactively arranged plate and frame processing devices for engineering superposition and scaling up.

[0061] For the CO2 conversion devices in Examples 4-9 and Comparative Examples 1-3, the performance and effectiveness of the CO2 reduction devices are evaluated using CO2 reduction conversion rate and energy efficiency. The formula for calculating the CO2 reduction conversion rate is as follows:

[0062]

[0063] Where C0 is the concentration of CO2 in the initial gas of the reaction, %; C e The CO2 concentration in the outlet gas after the plasma catalytic reaction conditions stabilized, expressed as a percentage. The CO2 concentration in the gas was detected using an infrared gas analyzer at the reactor outlet.

[0064] The formula for calculating energy efficiency is:

[0065]

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

[0067] Example 4:

[0068] This embodiment provides a specific CO2 conversion device. The difference from Embodiment 3 is that this embodiment uses 304 stainless steel to fabricate the high-voltage electrode 1, which is tubular in shape. The spatial distance of the hollow corona region 7 is set to 10 mm. Gas enters from the hollow high-voltage electrode 1, the orifice diameter of the nozzle 3 is 1 mm, and the jet velocity is 0.2 m / s.

[0069] The porous induction layer 4 is made of alumina. The catalyst filling layer 5 is made of commercially available activated alumina, with Cu as the active component. The grounding electrode layer 6 is a copper mesh coated with an insulating enamel layer. Gas flow guide holes 61 are arranged on the surface of the grounding electrode layer 6, with a diameter of 4 mm. The external high-voltage power supply 2 is a high-frequency AC power supply with a frequency of 3000 Hz and a voltage of 20 kV.

[0070] The feed gas containing 10 vol% CO2 and reducing gas is fed into the CO2 reduction device, and the final CO2 conversion rate is 25%, with an energy efficiency of 1.3 mol / (kW·h).

[0071] Example 5:

[0072] This embodiment provides a specific CO2 conversion device. The difference from Embodiment 3 is that this embodiment uses 304 stainless steel to fabricate the high-voltage electrode 1, which is tubular in shape. The spatial distance of the hollow corona region 7 is set to 10 mm. Gas enters from the hollow high-voltage electrode 1, the orifice diameter of the nozzle 3 is 1 mm, and the jet velocity is 0.2 m / s.

[0073] The porous induction layer 4 is made of silicon carbide. The catalyst filling layer 5 is made of commercially available activated alumina, with Cu as the active component. The grounding electrode layer 6 is a copper mesh coated with an insulating enamel layer. Gas flow guide holes 61 are arranged on the surface of the grounding electrode layer 6, with a diameter of 4 mm. The external high-voltage power supply 2 is a high-frequency AC power supply with a frequency of 5000 Hz and a voltage of 20 kV.

[0074] The feed gas containing 10 vol% CO2 and reducing gas is fed into the CO2 reduction device, and the final CO2 conversion rate is 38%, with an energy efficiency of 1.9 mol / (kW·h).

[0075] Example 6:

[0076] This embodiment provides a specific CO2 conversion device. The difference from Embodiment 3 is that this embodiment uses 304 stainless steel to fabricate the high-voltage electrode 1, which is tubular in shape. The spatial distance of the hollow corona region 7 is set to 10 mm. Gas enters from the hollow high-voltage electrode 1, the orifice diameter of the nozzle 3 is 1 mm, and the jet velocity is 0.2 m / s.

[0077] The porous induction layer 4 is made of silicon carbide. The catalyst filling layer 5 is made of commercially available activated alumina, with Cu as the active component. The grounding electrode layer 6 is a copper mesh coated with an insulating enamel layer. Gas flow guide holes 61 are arranged on the surface of the grounding electrode layer 6, with a diameter of 4 mm. The external high-voltage power supply 2 is a high-frequency AC power supply with a frequency of 5000 Hz and a voltage of 20 kV.

[0078] The feed gas containing 10 vol% CO2 and reducing gas is fed into the above-mentioned CO2 reduction device, and the final CO2 conversion rate is 40%, with an energy efficiency of 2.0 mol / (kW·h).

[0079] Example 7:

[0080] This embodiment provides a specific CO2 conversion device. The difference from Embodiment 3 is that this embodiment uses 304 stainless steel to fabricate the high-voltage electrode 1, which is tubular in shape. The spatial distance of the hollow corona region 7 is set to 10 mm. Gas enters from the hollow high-voltage electrode 1, the orifice diameter of the nozzle 3 is 1 mm, and the jet velocity is 0.2 m / s.

[0081] The porous induction layer 4 is made of tungsten carbide. The catalyst filling layer 5 is made of commercially available activated alumina, with Cu as the active component. The grounding electrode layer 6 is a copper mesh coated with an insulating enamel layer. Gas flow guide holes 61 are arranged on the surface of the grounding electrode layer 6, with a diameter of 4 mm. The external high-voltage power supply 2 is a high-frequency AC power supply with a frequency of 5000 Hz and a voltage of 20 kV.

[0082] The feed gas containing 10 vol% CO2 and reducing gas is fed into the above-mentioned CO2 reduction device, and the final CO2 conversion rate is 48%, with an energy efficiency of 2.6 mol / (kW·h).

[0083] Example 8:

[0084] This embodiment provides a specific CO2 conversion device. The difference from Embodiment 3 is that this embodiment uses 304 stainless steel to fabricate the high-voltage electrode 1, which is tubular in shape. The spatial distance of the hollow corona region 7 is set to 10 mm. Gas enters from the hollow high-voltage electrode 1, the orifice diameter of the nozzle 3 is 1 mm, and the jet velocity is 0.2 m / s.

[0085] The porous induction layer 4 is made of tungsten carbide. The catalyst filling layer 5 is made of commercially available activated alumina, with Cu as the active component. The grounding electrode layer 6 is a copper mesh coated with an insulating enamel layer. Gas flow holes 61 are arranged on the surface of the grounding electrode layer 6, with a diameter of 4 mm. The external high-voltage power supply 2 is a high-frequency AC power supply with a frequency of 5000 Hz and a voltage of 30 kV.

[0086] The feed gas containing 10 vol% CO2 and reducing gas is fed into the CO2 reduction device, and the final CO2 conversion rate is 58%, with an energy efficiency of 2.8 mol / (kW·h).

[0087] Example 9:

[0088] This embodiment provides a specific CO2 conversion device. The difference from Embodiment 3 is that this embodiment uses 304 stainless steel to fabricate the high-voltage electrode 1, which is tubular in shape. The spatial distance of the hollow corona region 7 is set to 15mm. Gas enters from the hollow high-voltage electrode 1, the orifice diameter of the nozzle 3 is 1mm, and the jet velocity is 0.2m / s.

[0089] The porous induction layer 4 is made of tungsten carbide. The catalyst filling layer 5 is made of commercially available activated alumina, with Cu as the active component. The grounding electrode layer 6 is a copper mesh coated with an insulating enamel layer. Gas flow holes 61 are arranged on the surface of the grounding electrode layer 6, with a diameter of 4 mm. The external high-voltage power supply 2 is a high-frequency AC power supply with a frequency of 5000 Hz and a voltage of 30 kV.

[0090] The feed gas containing 10 vol% CO2 and reducing gas is fed into the above-mentioned CO2 reduction device, and the final CO2 conversion rate is 50%, with an energy efficiency of 2.3 mol / (kW·h).

[0091] Comparative Example 1:

[0092] The apparatus of Example 8 and the method of Example 1 are used, wherein the apparatus does not have a hollow corona region:

[0093] When a feed gas containing 10 vol% CO2 and reducing gas is fed into the 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 apparatus of Example 8 and the method of Example 1 are used, wherein the catalyst layer is directly introduced into the apparatus without a porous induction layer:

[0096] The feed gas containing 10 vol% CO2 and reducing gas is fed into the CO2 reduction device, and the final CO2 conversion rate is 30%, with an energy efficiency of 1.8 mol / (kW·h).

[0097] Comparative Example 3:

[0098] The apparatus of Example 8 and the method of Example 1 are used, wherein the apparatus does not contain a catalyst particle packing layer:

[0099] The feed gas containing 10 vol% CO2 and reducing gas is fed into the CO2 reduction device, and the final CO2 conversion rate is 15%, with an energy efficiency of 0.8 mol / (kW·h).

[0100] In summary, the apparatus and method provided by this invention can control the final CO2 conversion rate to nearly 60%, achieving an energy efficiency of 2.8 mol / (kW·h). This represents a significant improvement over existing technologies (with a CO2 conversion rate increase of over 30%).

[0101] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any 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 invention should be within the protection scope 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 CO2 conversion units located on both sides of the CO2 activation unit; The CO2 activation unit includes a high-voltage electrode (1), which is connected to a high-voltage power supply (2); the high-voltage electrode (1) is provided with a gas channel (11) for CO2 to flow through, and the high-voltage electrode (1) is provided with a nozzle (3) for spraying CO2. Each 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; wherein, the porous induction layer (4) is directly opposite the protrusion (3) on the high voltage electrode (1), and a hollow corona discharge region (7) is formed between the porous induction layer (4) and the high voltage electrode (1) on the corresponding side; a gas guiding hole (61) is provided on the grounding electrode layer (6), and an insulating layer (8) is provided on both sides of the grounding electrode layer (6).

2. The 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 high-voltage electrode (1) is tubular or sandwiched plate in shape.

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 500-10000Hz and a voltage operating range of 0-30kV.

4. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that, The orifice diameter of the protruding nozzle (3) is 1-3 mm, and the jet velocity of the injected CO2 is 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 5-20mm.

6. The CO2 conversion device with multi-stage coupling of discharge plasma and catalytic material according to claim 1, characterized in that, The porous induction layer (4) is made of one of the following materials: carrier silicon carbide, molybdenum carbide, tungsten carbide, alumina, silicon oxide or stainless steel. The dielectric constant of the porous induced 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 support filled in the catalyst filling layer (5) includes one or more of active alumina and silicon dioxide, 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-like breathable layer, and the grounding electrode layer (6) is connected to the grounding device (9); The insulating layer (8) includes 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 equally spaced on the ground electrode layer (6), and the diameter of the gas guide holes (61) is 3-5mm.

10. A method for multi-stage coupling conversion of CO2 by discharge plasma and catalytic materials, characterized in that, The CO2 conversion apparatus according to any one of claims 1-9 is used; The method for converting CO2 includes the following steps: S1: Turn on the high voltage power supply (2) and input the reaction gas containing CO2 into the gas channel (11). The gas enters the hollow corona discharge zone (7) through the jet action of the nozzle (3) to fully activate the CO2 to form discharge plasma. S2: The discharge plasma enters the catalyst filling layer (5) through the porous induction layer (4), realizing the primary coupling between the discharge plasma and the catalyst; S3: CO2 achieves secondary coupling between plasma and catalyst under the combined effect of the catalyst filling layer (5) and surface discharge, and is eventually converted into CO.

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