Synthetic natural gas generating device for capturing carbon dioxide and water from air

Abstract

The invention discloses a device for preparing synthetic natural gas by capturing carbon dioxide and water from air. The device comprises a composite material particle separator, a multi-cavity air capturing device and a low-temperature plasma moving bed reactor, the composite material particle separator is used for gas-solid separation, and composite material particles enter the multi-cavity air trapping device; the multi-chamber air trapping device traps carbon dioxide and water in the air through the composite material particles, and the trapped composite material particles are fed into the low-temperature plasma moving bed reactor to be subjected to methanation reaction with hydrogen to obtain a mixture of methane and water vapor; the reacted high-temperature composite material particles enter the multi-chamber air trapping device again through the composite material particle separator, and circulation is carried out; condensing and compressing the mixture of methane and water vapor to obtain product water and synthetic natural gas; the composite particles can adsorb carbon dioxide and promote a hydromethanation reaction.

Description

Technical Field

[0001] The invention relates to the field of synthetic natural gas, and in particular to a synthetic natural gas generating device for capturing carbon dioxide and water from the air. Background Art

[0002] Human industrial activities have led to a continuous increase in atmospheric CO2 concentration and global warming, and frequent extreme weather and natural disasters. Even through renewable energy substitution, electrification of industrial processes, and conventional carbon capture and storage, it is no longer possible to quickly slow down carbon emissions and achieve the goal of keeping the global average temperature increase below 2°C. Through direct air capture technology, carbon dioxide in the atmosphere is captured and stored or utilized, thereby directly reducing the concentration of carbon dioxide in the atmosphere and forming a true global negative carbon emission path. Direct air capture technology plays an important role in carbon emission reduction technology. According to forecasts (International Energy Agency, 2022), its capture capacity needs to increase from 85 million tons of CO2 / year in 2030 to 1 billion tons of CO2 / year in 2050, accounting for 11% of the global total capture.

[0003] The United States, Canada and other countries have vigorously carried out research on direct air capture technology, including solution absorption technology, solid adsorption technology and electrochemical separation technology, but most of them are only in the concept verification or laboratory verification stage. Although there are more than 30 implementation projects, only 18 are in operation, with a total carbon capture capacity of only 10,000 tons. Technical difficulty, high energy consumption and high cost are the biggest challenges to the development and deployment of direct air capture technology.

[0004] The technical route of "integrated capture and conversion of carbon dioxide in air" has received increasing attention, that is, direct air capture technology is coupled with renewable energy, and green electricity and green hydrogen are used to drive the direct air capture process to produce synthetic fuels or chemicals (such as synthesis gas, methane, methanol, ethylene, etc.), thereby shortening the process flow, significantly reducing energy consumption and costs, and increasing the market's driving force for technology development through product revenue, so as to cope with the development bottleneck of conventional direct air capture technology. The United States has verified the feasibility of preparing synthesis gas by directly reducing carbon dioxide captured from air through electrochemical devices; and verified the feasibility of solid bifunctional materials to implement air capture-in-situ hydrogenation to prepare natural gas and olefins. Nanjing University of Aeronautics and Astronautics in China proposed to use Nix / NaA bifunctional materials to implement air capture and methane reduction to produce synthesis gas; Europe verified the feasibility of the solution capture-conversion integrated route to produce organic compounds. A few domestic units have carried out conceptual research to explore the possibility of air capture and production of hydrocarbon fuels, methanol and formic acid. In short, the "integrated capture and conversion of carbon dioxide in air" technology is in the concept verification stage.

[0005] Therefore, developing a new device and method based on existing adsorbents that can directly capture carbon dioxide and water vapor from the air and realize their integrated conversion has important practical significance and application prospects for improving resource utilization efficiency, reducing energy consumption, and reducing environmental pollution. Summary of the invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and to provide a synthetic natural gas production device that can directly capture carbon dioxide and water from the air.

[0007] To solve the above technical problems, the technical method adopted by the present invention is as follows: the present invention discloses a synthetic natural gas generation device for capturing carbon dioxide and water from air, comprising a composite material particle separator, a multi-chamber air capture device and a low-temperature plasma moving bed reactor; The composite particle separator is used for gas-solid separation, and the composite particles enter the multi-chamber air capture device; The multi-chamber air capture device captures carbon dioxide and water in the air through composite material particles, and the captured composite material particles are sent to a low-temperature plasma moving bed reactor to react with hydrogen to produce a methane and water vapor mixture; the high-temperature composite material particles that have completed the reaction enter the multi-chamber air capture device again through a composite material particle separator, and the cycle is repeated; The methane and water vapor mixture is condensed and compressed to obtain product water and synthetic natural gas; The composite material particles can adsorb carbon dioxide and promote hydromethanation reactions.

[0008] Furthermore, in the low-temperature plasma moving bed reactor, the high-temperature composite material particles that have completed the reaction exchange heat to the particle heat pipe heat exchanger; Before the captured composite material particles are sent into the low-temperature plasma moving bed reactor, the particle heat pipe heat exchanger preheats the captured composite material particles.

[0009] Furthermore, a low-temperature plasma moving bed reactor sealing valve is provided between the low-temperature plasma moving bed reactor and the composite material particle separator, and the low-temperature plasma moving bed reactor sealing valve blows the composite material particles to circulate and prevents gas from backflowing into the low-temperature plasma moving bed reactor.

[0010] Furthermore, the sealing valve of the low-temperature plasma moving bed reactor is connected to the outlet of a delivery gas compressor, and the delivery gas compressor pressurizes the gas and delivers it to the composite material particle separator through a fast riser.

[0011] Furthermore, a synthetic natural gas heat recovery device and a synthetic natural gas condenser are provided at the outlet end of the methane and water vapor mixture of the low-temperature plasma moving bed reactor; The synthetic natural gas heat recovery device preheats the hydrogen based on the heat of the high-temperature methane and water vapor mixture generated after the methanation reaction in the low-temperature plasma moving bed reactor, so that the preheated hydrogen has a certain temperature when entering the low-temperature plasma moving bed reactor; The methane and water vapor mixture after heat exchange passes through a synthetic natural gas condenser and is separated into condensed water and natural gas.

[0012] Furthermore, the natural gas is passed through a synthetic natural gas compressor to generate synthetic natural gas.

[0013] Furthermore, a synthetic natural gas high temperature filter is provided between the low-temperature plasma moving bed reactor and the synthetic natural gas heat recovery device; The high-temperature methane and water vapor mixture enters the synthetic natural gas heat recovery device after the impurities and particulate matter in the synthetic natural gas are removed by a synthetic natural gas high-temperature filter.

[0014] Furthermore, a wind plate is provided at the bottom of the multi-chamber air capture device, and air enters from the bottom of the multi-chamber air capture device through the air capture device blower. Under the action of the vertical partition, the composite material particles are fully contacted with the gas and solid through bubbling and overflow, and the clean air with part of the carbon dioxide and moisture removed is discharged from the bag dust collector at the top of the multi-chamber air capture device.

[0015] Furthermore, a star-shaped sealing valve is provided in the composite material particle conveying pipeline between the multi-chamber air capture device and the low-temperature plasma moving bed reactor.

[0016] Furthermore, the composite material particles are composed of a catalytic component of metal ruthenium, an adsorption component of sodium carbonate and a porous structure of γ-alumina, wherein the catalytic component of metal ruthenium provides a catalytic active center for the hydromethanation reaction; sodium carbonate is used to adsorb carbon dioxide and provide a carbon source for the hydromethanation reaction process; and γ-alumina is used as a supporting material. Beneficial Effects

[0017] 1. Through the adsorption and catalytic properties of composite particles, carbon dioxide and water can be effectively captured and converted under mild conditions without the need for external heat sources or complex equipment, which reduces the difficulty and cost of operation. At the same time, it realizes the resource utilization of greenhouse gases and is fully capable of achieving the goal of negative carbon emissions. Carbon dioxide and water are directly captured from the air and converted by methanation reaction in a low-temperature plasma moving bed reactor through hydrogenation, eliminating the high energy consumption steps of separating and purifying carbon dioxide and water in traditional methods, significantly improving the energy efficiency of the entire system.

[0018] 2. In terms of technology, only local renewable energy and a small amount of water resources are needed to drive the artificial "photosynthetic conversion" of carbon dioxide and water in the air and large-scale production of synthetic natural gas. In the conversion process, cheap and environmentally friendly composite material particles can be recycled, and the converted products (such as synthetic natural gas, water, etc.) have high added value, which further improves the economic and environmental benefits and provides new technical support for green chemistry and sustainable development.

[0019] 3. The integrated device has a modular design and can be expanded in scale according to actual needs. It is easy to integrate with other industrial emission sources or energy systems (thermal power, nuclear power, etc.) and has good adaptability and scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] like Figure 1 As shown, the present invention discloses a synthetic natural gas generation device for capturing carbon dioxide and water from the air, which can directly capture carbon dioxide and water vapor from the atmosphere and convert them into useful chemical raw materials or energy, thereby realizing efficient utilization and conversion of these two major greenhouse gases. The method involves an in-situ hydrogenation methanation reaction, which is a process of directly converting carbon dioxide into methane and water by hydrogenation. During the reaction, the catalyst promotes the reduction reaction of oxygen atoms in carbon dioxide with hydrogen to form water molecules and release methane.

[0023] This reaction is an exothermic reaction, and the heat generated needs to be controlled by a cooling system to prevent the temperature from being too high. Ultimately, the reaction products mainly include synthetic natural gas and water, where synthetic natural gas can be further processed and used as fuel or chemical raw materials.

[0024] Specifically, the device includes a gas delivery compressor 1, a rapid riser 2, a composite material particle separator 3, a multi-chamber air capture device 4, a star-shaped sealing valve 5, a particle heat pipe heat exchanger 6, a low-temperature plasma moving bed reactor 7, a low-temperature plasma moving bed reactor sealing valve 8, a synthetic natural gas heat recovery device 9, a synthetic natural gas condenser 10, a synthetic natural gas compressor 11, a hydrogen compressor 12, an air capture device blower 13, and a synthetic natural gas high-temperature filter 14; each component is connected by a pipeline.

[0025] Among them, the rapid riser 2, the composite material particle separator 3, the air capture device blower 13 and the multi-chamber air capture device 4 constitute a carbon dioxide and water capture unit.

[0026] The low-temperature plasma moving bed reactor 7, the synthetic natural gas heat recovery device 9, the synthetic natural gas condenser 10, and the synthetic natural gas compressor 11 constitute a carbon dioxide and water conversion and collection unit.

[0027] The composite material particles after the reaction pass through the sealing valve 8 of the low-temperature plasma moving bed reactor, the conveying gas compressor 1, the rapid riser 2, the composite material particle separator 3 and then re-enter the capture unit, and the cycle repeats.

[0028] Description of the composite material particle separator 3: The composite material particle separator 3 is connected to the rapid riser 2 and the multi-chamber air capture device 4. The air conveying gas carries the composite material particles 4-1 and is lifted through the rapid riser 2 into the composite material particle separator 3, in which gas-solid separation is carried out. The composite material particles 4-1 enter the multi-chamber air capture device 4 to participate in capture, and the conveying gas is discharged from the bag dust collector 3-1 on the upper part of the composite material particle separator.

[0029] The multi-chamber air capture device 4 is connected to the composite material particle separator 3 and the low-temperature plasma moving bed reactor 7; a wind plate is installed at the bottom of the multi-chamber air capture device 4, and air enters from the bottom through the air capture device blower 13. The composite material particles 4-1 are fully gas-solid contacted by bubbling and overflowing under the action of the vertical partition, and the clean air with part of carbon dioxide and moisture removed is discharged from the bag filter 4-2 at the top of the multi-chamber air capture device, and the captured composite material particles 7-1 enter the pipeline for heat exchange through the star-shaped sealing valve 5. The captured composite material particles 7-1 are preheated by the particle heat pipe heat exchanger 6 in the pipeline, and then flow into the low-temperature plasma moving bed reactor 7. The multi-chamber air capture device 4 adopts a multi-chamber fluidized bed design, and the composite material particles 7-1 are in a bubbling fluidized state. The multi-stage overflow method is used to increase the particle residence time and distribution uniformity, so as to achieve good mixing and contact between gas and solid under the condition of dilute carbon dioxide, and strengthen the transfer process of reactants inside and outside the particles.

[0030] The low-temperature plasma moving bed reactor 7 is a carbon dioxide hydrogenation reaction device, and the methanation reaction temperature range of the device is 120-350°C. For the solid side, its upper inlet is connected to the multi-chamber air capture device 4, and the captured composite material particles 7-1 enter from there, and then the reacted composite material particles 4-1 are output from the lower part; for the gas side, the preheated hydrogen 7-2 enters from the lower right corner of the low-temperature plasma moving bed reactor 7, and the hydrogen and carbon dioxide undergo methanation reaction in the reactor to generate a methane and water vapor mixture 7-3, which is discharged from the upper right corner of the reactor and passes through the synthetic natural gas high-temperature filter 14; the low-temperature plasma moving bed reactor 7 adopts a downward moving bed reactor structure, and the hydrogen contacts the composite material particles 7-1 in countercurrent. The in-situ hydrogenation process of the composite material particles 7-1 is enhanced by low-temperature plasma to improve the hydrogen reaction activity, significantly reduce the in-situ methanation temperature, reduce the consumption of renewable energy, and improve the utilization rate of particles, product selectivity and production efficiency.

[0031] The particle heat pipe heat exchanger 6 is connected to the solid side inlet and outlet of the low-temperature plasma moving bed reactor 7. It absorbs the heat of the high-temperature composite material particles 4-1 flowing out of the outlet and exchanges heat with the composite material particles 7-1 captured at low temperature at the inlet, thereby reducing energy consumption and improving efficiency.

[0032] The low-temperature plasma moving bed reactor sealing valve 8 is connected to the low-temperature plasma moving bed reactor 7 and the outlet of the conveying gas compressor 1. Its main function is to blow the composite material particles 4-1 to make them circulate and prevent the gas from backflowing into the low-temperature plasma moving bed reactor 7, thereby isolating the reactor.

[0033] The synthetic natural gas heat recovery device 9 uses the heat of the high-temperature methane and water vapor mixture 7-3 generated after the methanation reaction of the low-temperature plasma moving bed reactor 7 to preheat the hydrogen, so that the preheated hydrogen 7-2 has a certain temperature when entering the low-temperature plasma moving bed reactor 7, thereby saving energy. Among them, the heat capacity of cold hydrogen is small, and it is easier to absorb heat and heat up. The mixture of hot methane and water vapor has a higher heat capacity and density. Therefore, the cold hydrogen is used as a shell-side fluid to absorb heat, and the methane and water vapor mixture 7-3 is used as a tube-side fluid to have enough residence time to transfer heat, thereby improving the heat exchange effect. The methane and water vapor mixture 7-3 after heat exchange is condensed into water 10-1 through the synthetic natural gas condenser 10 and sent to the water electrolysis device, and the synthetic natural gas 11-1 is obtained through the synthetic natural gas compressor 11 and sent to the natural gas pipeline network.

[0034] The recycling of composite material particles achieved by this device is implemented as follows: the conveying air compressor 1 blows the composite material particles 4-1 into the rapid riser 2 and then enters the composite material particle separator 3 for gas-solid separation. Then the composite material particles 4-1 flow into the multi-chamber air capture device 4 to participate in capture. After the particles have captured carbon dioxide and water, they flow into the low-temperature plasma moving bed reactor 7 for hydrogenation and methanation reaction after heat exchange with the heat pipe. After the reaction, they flow out from the lower part of the low-temperature plasma moving bed reactor 7 for heat exchange with the heat pipe, and then carry the composite material particles 4-1 into the rapid riser 2 through the air to complete the particle circulation flow.

[0035] The synthetic natural gas high temperature filter 14 is connected to the low temperature plasma moving bed reactor 7 at the front end and the synthetic natural gas heat recovery device 9 at the rear end. It is a filtering device used in the synthetic natural gas production process, and is mainly used to remove impurities and particulate matter in the synthetic natural gas to avoid damage to downstream equipment such as the synthetic natural gas heat recovery device 9, which affects production efficiency and synthetic natural gas quality. The synthetic natural gas high temperature filter 14 is usually made of high temperature resistant materials such as stainless steel and ceramics, and can work stably under high temperature conditions, while having efficient filtering performance.

[0036] The specific operation mode of the integrated device is as follows: The composite material particles 4-1 enter the rapid riser 2 under the action of the conveying gas compressor 1, and after being mixed with the conveying gas, pass through the composite material particle separator 3. After gas-solid separation, the composite material particles 4-1 enter the multi-chamber air capture device 4, and the conveying gas is discharged from the bag dust collector 3-1 on the upper part of the composite material particle separator.

[0037] In the multi-chamber air capture device 4, air enters from the bottom through the air capture device blower 13, fully contacts with the composite material particles 4-1, and the clean air with carbon dioxide and moisture removed is discharged from the bag dust collector 4-2 on the upper part of the air capture device blower. The captured composite material particles 7-1 enter the particle heat pipe heat exchanger 6 through the star-shaped sealing valve 5 for preheating, and then flow into the low-temperature plasma moving bed reactor 7, thereby realizing the continuous capture of carbon dioxide and water in the air.

[0038] The low-temperature plasma moving bed reactor 7 is used as a carbon dioxide hydrogenation reaction device. The captured composite material particles 7-1 enter from the upper part, and the reacted composite material particles 7-1 are output from the lower left part, and then the material is circulated through the low-temperature plasma moving bed reactor sealing valve 8, the conveying gas compressor 1, the rapid riser 2, the composite material particle separator 3 and other equipment; The preheated hydrogen 7-2 enters the reactor from the lower right corner, where it undergoes a methanogenic reaction with carbon dioxide. The generated methane and water vapor mixture 7-3 is discharged from the upper right corner and passes through the synthetic natural gas high-temperature filter 14. The high-temperature methane and water vapor mixture then passes through the synthetic natural gas heat recovery device 9 to preheat the hydrogen. The hydrogen then flows into the synthetic natural gas condenser 10 to obtain water 10-1 which is sent to the water electrolysis device. The synthetic natural gas 11-1 compressed by the synthetic natural gas compressor 11 is then sent to the natural gas pipeline network.

[0039] Working principle: This application proposes a new method for capturing carbon dioxide and water from the air and directly converting them into synthetic natural gas. The composite material particles used have adsorption and catalytic effects, and can effectively capture and convert carbon dioxide and water under mild conditions. No external heat source or complex equipment is required, which reduces the difficulty and cost of operation, and realizes the resource utilization of greenhouse gases. The entire system captures and converts carbon dioxide and water in the air through efficient gas-solid contact and heat exchange, generates high-quality methane and water, and realizes the recycling of composite material particles, improving the efficiency and stability of the system. Based on the above principles, a direct air carbon dioxide and water capture and conversion integrated device based on composite material particles is constructed. Through a series of optimized designs and coordinated cooperation of components, the carbon dioxide capture efficiency and methane generation rate are significantly improved, providing important technical support for efficient and economical carbon capture and utilization. Example

[0040] like Figure 1 As shown, a device for capturing carbon dioxide and water from the air and directly converting them into synthetic natural gas in the present application includes a conveying gas compressor 1, a rapid riser 2, a composite material particle separator 3, a multi-chamber air capture device 4, a star-shaped sealing valve 5, a particle heat pipe heat exchanger 6, a low-temperature plasma moving bed reactor 7, a low-temperature plasma moving bed reactor sealing valve 8, a synthetic natural gas heat recovery device 9, a synthetic natural gas condenser 10, a synthetic natural gas compressor 11, a hydrogen compressor 12, an air capture device blower 13, a synthetic natural gas high-temperature filter 14 and auxiliary pipelines.

[0041] The rapid riser 2, the composite material particle separator 3, the air capture device blower 13 and the multi-chamber air capture device 4 constitute a carbon dioxide and water capture unit, which can achieve high-flow and high-efficiency carbon dioxide and water capture and greatly reduce the carbon dioxide concentration in the air.

[0042] The low-temperature plasma moving bed reactor 7, the synthetic natural gas heat recovery device 9, the synthetic natural gas condenser 10, and the synthetic natural gas compressor 11 constitute a carbon dioxide and water conversion and collection unit. The hydrogen prepared by electrolysis is preheated by the synthetic natural gas heat recovery device 9 to facilitate the methanation reaction; and the composite material particles that have completed the reaction pass through the low-temperature plasma moving bed reactor sealing valve 8, the conveying gas compressor 1, the rapid riser 2, and the composite material particle separator 3 and then re-enter the capture unit, and the cycle is repeated.

[0043] The above process of capturing carbon dioxide and water from the air and converting it directly into synthetic natural gas works as follows: Driven by the conveying gas compressor 1, the composite particles 4-1 are mixed with air and flow into the rapid riser 2. Then the mixture passes through the composite particle separator 3 for gas-solid separation. The separated composite particles 4-1 enter the multi-chamber air capture device 4, and the conveying gas is released from the bag dust collector 3-1 on the upper part of the composite particle separator.

[0044] In the multi-chamber air capture device 4, the air sent in by the air capture device blower 13 is fully in contact with the composite material particles 4-1 to remove carbon dioxide and water in the air. The treated clean air is discharged from the bag filter 4-2 on the upper part of the air capture device blower, and the captured composite material particles 7-1 are sent to the particle heat pipe heat exchanger 6 for preheating, and then enter the low-temperature plasma moving bed reactor 7 to achieve continuous capture of carbon dioxide and water in the air.

[0045] The low-temperature plasma moving bed reactor 7 is used as a carbon dioxide hydrogenation reaction device. The captured composite material particles 7-1 enter the low-temperature plasma moving bed reactor 7 from the top, and after the reaction, they are converted into composite material particles 4-1 and discharged from the lower left corner. These composite material particles 4-1 are then circulated through the low-temperature plasma moving bed reactor sealing valve 8, the conveying gas compressor 1, the fast riser 2 and the composite material particle separator 3 and other equipment. At the same time, the preheated hydrogen 7-2 is input from the lower right corner of the low-temperature plasma moving bed reactor 7, and reacts with carbon dioxide in the reactor to form a methanogenic reaction. The generated methane and water vapor mixture 7-2 is discharged from the upper right corner. This high-temperature mixture is then preheated by the synthetic natural gas heat recovery device 9 to treat the hydrogen, and then flows into the synthetic natural gas condenser 10. The water 10-1 obtained in this process is sent to the water electrolysis device, and the compressed synthetic natural gas 11-1 is sent to the natural gas pipeline network.

[0046] The composite material particles used in the present invention are composed of a catalytic component of metal ruthenium, an adsorption component of sodium carbonate, and a porous structure of γ-alumina. The catalytic component of metal ruthenium provides a catalytic active center for the hydromethanation reaction; sodium carbonate is used to adsorb carbon dioxide and provide a carbon source for the hydromethanation reaction process; and γ-alumina is used as a supporting material to significantly improve the dispersion, reaction activity, and cycle stability of the catalytic component of metal ruthenium and the adsorption component of sodium carbonate.

[0047] The technical feature of the device is that the multi-chamber air capture device 4 captures carbon dioxide and water from the air, and then utilizes the low-temperature plasma moving bed reactor 7 to carry out hydrogenation and in-situ methanation reaction of carbon dioxide.

[0048] This combination can effectively convert greenhouse gases in the air into useful synthetic natural gas, realize efficient carbon capture and conversion integration, and simplify the process flow. In the synthetic natural gas production process, the heat generated is recovered by the synthetic natural gas heat recovery device 9 and the synthetic natural gas condenser 10, thereby improving the energy utilization rate of the system. At the same time, a particle heat pipe heat exchanger 6 is also used to further improve the heat exchange efficiency.

[0049] The device uses advanced equipment such as composite material particle separator 3 and fast riser 2, making the entire system compact, small in footprint, and easy to install and maintain. The device can convert carbon dioxide and water vapor in the air into synthetic natural gas, reducing greenhouse gas emissions and having significant environmental benefits.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A synthetic natural gas production device for capturing carbon dioxide and water from air, characterized in that: It comprises a composite material particle separator (3), a multi-chamber air capture device (4) and a low-temperature plasma moving bed reactor (7); The composite material particle separator (3) is used for gas-solid separation, and the composite material particles (7-1) enter the multi-chamber air capture device (4); The multi-chamber air capture device (4) captures carbon dioxide and water in the air through composite material particles (7-1); the captured composite material particles (7-1) are sent to a low-temperature plasma moving bed reactor (7) to undergo a methanogenic reaction with hydrogen (7-2) to obtain a methane and water vapor mixture (7-3); the high-temperature composite material particles (4-1) that have completed the reaction are passed through a composite material particle separator (3) and enter the multi-chamber air capture device (4) again, and the cycle is repeated; The methane and water vapor mixture (7-3) is condensed and compressed to obtain product water (10-1) and synthetic natural gas (11-1); The composite material particles (7-1) can absorb carbon dioxide and promote hydrogenation and methanation reactions.

2. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 1, characterized in that: In the low-temperature plasma moving bed reactor (7), the high-temperature composite material particles (4-1) that have completed the reaction exchange heat to the particle heat pipe heat exchanger (6); Before the captured composite material particles (7-1) are sent into the low-temperature plasma moving bed reactor (7), the particle heat pipe heat exchanger (6) preheats the captured composite material particles (7-1).

3. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 1, characterized in that: A low-temperature plasma moving bed reactor sealing valve (8) is provided between the low-temperature plasma moving bed reactor (7) and the composite material particle separator (3); the low-temperature plasma moving bed reactor sealing valve (8) blows the composite material particles (4-1) to circulate and prevents gas from flowing back into the low-temperature plasma moving bed reactor (7).

4. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 3, characterized in that: The sealing valve (8) of the low-temperature plasma moving bed reactor is connected to the outlet of the delivery gas compressor (1), and the delivery gas compressor (1) pressurizes the gas and delivers it to the composite material particle separator (3) through the fast riser (2).

5. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 1, characterized in that: A synthetic natural gas heat recovery device (9) and a synthetic natural gas condenser (10) are provided at the outlet of the methane and water vapor mixture (7-3) of the low-temperature plasma moving bed reactor (7); The synthetic natural gas heat recovery device (9) preheats the hydrogen based on the heat of the high-temperature methane and water vapor mixture (7-3) generated after the methanation reaction of the low-temperature plasma moving bed reactor (7), so that the preheated hydrogen (7-2) has a certain temperature when entering the low-temperature plasma moving bed reactor (7); The methane and water vapor mixture (7-3) after heat exchange passes through a synthetic natural gas condenser (10) and is separated into condensed water (10-1) and natural gas.

6. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 5, characterized in that: The natural gas is passed through a synthetic natural gas compressor (11) to generate synthetic natural gas (11-1).

7. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 5, characterized in that: A synthetic natural gas high-temperature filter (14) is provided between the low-temperature plasma moving bed reactor (7) and the synthetic natural gas heat recovery device (9); The high-temperature methane and water vapor mixture (7-3) passes through a synthetic natural gas high-temperature filter (14) to remove impurities and particulate matter in the synthetic natural gas and then enters the synthetic natural gas heat recovery device (9).

8. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 1, characterized in that: A wind plate is provided at the bottom of the multi-chamber air capture device (4), and air enters from the bottom of the multi-chamber air capture device (4) through the air capture device blower (13). The composite material particles (4-1) are fully gas-solid contacted by bubbling and overflowing under the action of the vertical partition, and the clean air with part of carbon dioxide and moisture removed is discharged from the bag filter (4-2) at the top of the multi-chamber air capture device.

9. The synthetic natural gas production device for capturing carbon dioxide and water from air according to claim 8, characterized in that: A star-shaped sealing valve (5) is provided in the composite material particle conveying pipeline between the multi-chamber air capture device (4) and the low-temperature plasma moving bed reactor (7).

10. The synthetic natural gas production device for capturing carbon dioxide and water from air according to any one of claims 1 to 9, characterized in that: The composite material particles (7-1) are composed of a catalytic component of metal ruthenium, an adsorption component of sodium carbonate and a porous structure of γ-alumina, wherein the catalytic component of metal ruthenium provides a catalytic active center for the hydrogenation methanation reaction; the sodium carbonate is used to adsorb carbon dioxide and provide a carbon source for the hydrogenation methanation reaction process; and the γ-alumina is used as a supporting material.

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