An integrated electrolytic cell carbon dioxide capture and conversion system

Abstract

This invention discloses an integrated electrolytic cell system for carbon dioxide capture and conversion, belonging to the field of direct air carbon capture technology. The system includes a fan, dual capture and conversion electrolytic cells, an electrolyte storage tank, a pump, a condenser heat exchanger, a gas-liquid separation device, a power supply, and valve groups. The capture and conversion electrolytic cells are cylindrically wound with an outer shell, an anode flow channel, a porous anode electrode, a medium-temperature resistant ion exchange membrane, and a porous cathode electrode, combining adsorption and electrocatalytic functions. The two capture and conversion electrolytic cells alternately operate in capture and electrocatalytic conversion states. During capture, the temperature is maintained at 25°C to adsorb carbon dioxide and water from the air. During conversion, the temperature is raised to 60°C~120°C using ohmic internal resistance to achieve in-situ desorption of carbon dioxide and electrocatalytic reduction to generate syngas. This invention integrates the capture and conversion process, eliminating desorption and storage / transport stages, reducing energy consumption and costs, and enabling continuous and stable operation. It is suitable for the on-site resource utilization of atmospheric carbon dioxide.

Description

Technical Field

[0001] This invention belongs to the field of direct air carbon capture technology, specifically relating to an integrated electrolytic cell carbon dioxide capture and conversion system. Background Technology

[0002] The continuous rise in the concentration of greenhouse gases in the atmosphere has exacerbated the global greenhouse effect and related climate change issues. As the main greenhouse gas, carbon dioxide capture and resource utilization have become key means to address climate change.

[0003] Currently, significant progress has been made in chemical carbon capture (CCC) technology targeting large point sources, but research on carbon capture from sparse emission sources such as the atmosphere remains insufficient. Direct air capture (DAC), compared to traditional flue gas capture methods, offers advantages such as high deployment flexibility and is not limited by the location of emission sources, making it a crucial pathway for achieving large-scale carbon dioxide emission reduction. However, existing carbon capture, utilization, and storage (CVS) technologies generally face challenges such as high costs and difficulties in carbon dioxide utilization. Coupled with CVS technology, carbon dioxide resource utilization can not only help reduce capture and storage costs but also effectively avoid the geographical mismatch between carbon sources and storage sites, providing a feasible path for on-site carbon dioxide utilization.

[0004] Current air carbon capture technologies generally employ a "capture-desorption, then conversion and utilization" process. This involves first capturing carbon dioxide from the air using an adsorbent, then releasing the carbon dioxide through desorption, before subsequent resource utilization and high-value-added product production. This process inevitably involves carbon dioxide desorption, compression storage, and long-distance transportation, increasing the complexity of the process, causing significant energy losses, and raising the overall economic cost of the carbon capture and conversion process, thus limiting the large-scale application of direct air carbon capture technology. Therefore, developing an integrated device capable of realizing air carbon capture and in-situ conversion and utilization has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] (a) Purpose of the invention To address the shortcomings of existing technologies where air carbon capture requires desorption, storage, and transportation before conversion and utilization, resulting in complex processes, high energy consumption, and high costs, this invention provides an integrated electrolytic cell carbon dioxide capture and conversion system. This system integrates carbon dioxide capture and electrocatalytic conversion processes in situ, enabling carbon dioxide capture and conversion to be completed within the same system. This eliminates the need for separate desorption, storage, and transportation steps, simplifying the process and reducing adsorbent regeneration energy consumption and carbon dioxide storage and transportation costs.

[0006] (II) Technical Solution An integrated electrolytic cell carbon dioxide capture and conversion system includes a blower, a capture and conversion electrolytic cell, an electrolyte storage tank, a pump, a gas-liquid separator, a condenser heat exchanger, a power supply, and several valve groups. The fan is connected to the No. 1 and No. 2 trapping and conversion electrolytic cells via a gas flow meter, an air inlet ball valve, a No. 1 gas inlet solenoid valve, and a No. 2 gas inlet solenoid valve, respectively, to supply air; Two electrolyte storage tanks and two pumps are provided for each of the capture and conversion electrolytic cells, namely Electrolyte Storage Tank No. 1 and Electrolyte Storage Tank No. 2, and Pump No. 1 and Pump No. 2, respectively. Electrolyte Storage Tank No. 1 and Electrolyte Storage Tank No. 2 are connected to Capture and Conversion Electrolytic Cell No. 1 and Capture and Conversion Electrolytic Cell No. 2, respectively, through Pump No. 1 and Pump No. 2, to provide circulating anolyte. The condensing heat exchanger is connected to the electrolyte bypass via a first condensing solenoid valve and a second condensing solenoid valve, respectively, for cooling the electrolyte and simultaneously regulating the temperature of the anode electrolyte. The gas-liquid separation device is connected to the cathode outlet of the trapping-conversion electrolytic cell and is used to separate the gas and liquid products at the cathode outlet of the trapping-conversion electrolytic cell; the power supply is electrically connected to the trapping-conversion electrolytic cell and is used to provide electrical energy for the electrocatalytic reduction reaction of the trapping-conversion electrolytic cell. The trapping and conversion electrolytic cell is the core component, consisting of a shell, an anode channel, a porous anode electrode, a medium-temperature resistant ion exchange membrane, and a porous cathode electrode stacked and wound into a cylindrical shape. The porous cathode electrode has both adsorption sites for carbon dioxide and water and electrocatalytic active sites, and by doping with carbon fibers, it has suitable conductivity, enabling in-situ electric heating and providing electrons for the electrocatalytic reaction. The trapping and conversion electrolyzer is provided in two forms, namely the No. 1 trapping and conversion electrolyzer and the No. 2 trapping and conversion electrolyzer. The two trapping and conversion electrolyzers are in the "trapping" and "electrocatalytic conversion" states respectively at the same time, and can switch alternately over time to achieve the continuity of carbon dioxide trapping and in-situ conversion. The valve group includes an air inlet ball valve, a first gas inlet solenoid valve, a second gas inlet solenoid valve, an electrolyte solenoid valve, a first condensation solenoid valve, a second condensation solenoid valve, a first back pressure valve, a second back pressure valve, an air outlet solenoid valve, a gas-liquid separation solenoid valve, a product outlet solenoid valve, and a leakage solenoid valve. The air outlet solenoid valve includes a first air outlet solenoid valve and a second air outlet solenoid valve. The gas-liquid separation solenoid valve includes a first gas-liquid separation solenoid valve and a second gas-liquid separation solenoid valve. The first back pressure valve and the second back pressure valve regulate the pressure of the first and second trapping and conversion electrolytic cells, respectively, to ensure that the system traps and converts at the optimal pressure. Each valve group is set up for the two trapping and conversion electrolytic cells to achieve independent on / off and state control of the two trapping and conversion electrolytic cells.

[0007] Furthermore, the cathode outlet of the trapping and conversion electrolytic cell is connected to the atmospheric environment and the gas-liquid separation device respectively through a three-way pipe, so as to realize the switching between tail gas emission in the trapping state and product transportation in the conversion state.

[0008] Furthermore, the gas-liquid separation device is equipped with a leakage solenoid valve. When the liquid stored in the gas-liquid separation device reaches a set threshold, the leakage solenoid valve automatically opens and discharges the liquid.

[0009] Furthermore, when the capture-conversion electrolyzer changes from the electrocatalytic conversion state to the capture state, the electrolyte pumped out of the electrolyte storage tank by the pump needs to pass through the condenser heat exchanger before entering the capture-conversion electrolyzer; the anode electrolyte is cooled to 25°C by the condenser heat exchanger, which indirectly maintains the capture-conversion electrolyzer at 25°C to ensure that the porous cathode electrode can normally capture carbon dioxide and water in the air.

[0010] Furthermore, under the influence of the power supply, there is a potential difference between the membrane electrode assembly consisting of the porous cathode electrode, the intermediate-temperature ion exchange membrane, and the porous anode electrode. Under the influence of this potential difference, due to the ohmic internal resistance, the membrane electrode assembly is intentionally heated to 60℃~120℃. Under this intermediate-temperature environment, some carbon dioxide and water are desorbed from the porous cathode electrode, forming a local high-concentration carbon dioxide region at the cathode. At the same time, under the intermediate-temperature environment, the activity of the active sites on the porous cathode electrode is enhanced, promoting the electrocatalytic reduction of carbon dioxide and water.

[0011] Furthermore, both the No. 1 and No. 2 collecting and converting electrolytic cells are equipped with pressure gauges and thermometers to enable real-time monitoring of the internal pressure and temperature of the collecting and converting electrolytic cells, ensuring the safe operation of the system. Both the No. 1 and No. 2 electrolyte storage tanks are equipped with level gauges to enable real-time monitoring of the electrolyte balance, facilitating timely replenishment of electrolyte. The gas-liquid separation device is equipped with a level gauge, which, in conjunction with a leakage solenoid valve, enables timely discharge of liquid.

[0012] Furthermore, a movable base is provided below the capture-conversion electrolytic cell to facilitate movement and deployment.

[0013] Furthermore, the cathode porous electrode is made of carbon fiber skeleton with attached metal-organic framework material (MOF-CF); the anode electrolyte is potassium bicarbonate solution.

[0014] Furthermore, the system also includes a monitoring and control terminal, which is electrically connected to the fan, gas flow meter, two capture-conversion electrolytic cells, two electrolyte storage tanks, two pumps, condenser heat exchanger, gas-liquid separation device, power supply and all valve groups, to realize the automated control of the entire system and real-time monitoring of operating parameters.

[0015] The system of this invention has two core operating states during operation, and the two capture-conversion electrolytic cells alternately implement the two states: 1. Capture state: The porous cathode electrode acts as an adsorbent, selectively capturing carbon dioxide and water in the air. At this time, the condenser heat exchanger cools and keeps the anode electrolyte at 25°C, indirectly maintaining the capture conversion electrolytic cell at the optimal capture temperature of 25°C. The outlet gas of the capture conversion electrolytic cell is directly discharged to the atmosphere through the air outlet solenoid valve without passing through the gas-liquid separation device. 2. Electrocatalytic conversion state: The air supply to the cathode is stopped, and the power source is the capture and conversion electrolyzer. Due to the ohmic internal resistance, the porous cathode electrode heats up to 60~120℃. This medium-temperature environment promotes the desorption of some carbon dioxide and water in the porous cathode electrode, forming a local high-concentration carbon dioxide region on the cathode. At the same time, it enhances the catalytic activity of the active sites on the porous cathode electrode. The adsorbed carbon dioxide and water undergo an electrocatalytic reduction reaction on the porous cathode electrode as reactants to generate syngas. An oxygen evolution reaction occurs on the porous anode electrode. The reaction products are transported to the gas-liquid separation device for gas-liquid separation through a gas-liquid separation solenoid valve. The separated syngas is output through the product outlet solenoid valve.

[0016] (III) Beneficial Effects In-situ integration of capture and conversion simplifies the process: Carbon dioxide capture and electrocatalytic conversion are integrated into the same porous electrode cathode of the electrolyzer, eliminating the need for desorption, compression storage and long-distance transportation, resulting in a simpler process and higher operating efficiency.

[0017] Reduced energy consumption and costs: In-situ heating is achieved by utilizing the ohmic resistance of electrocatalysis, eliminating the need for additional heating equipment and reducing adsorbent regeneration energy consumption; storage and transportation are eliminated, reducing equipment, transportation and energy costs and solving the industry's high cost pain point.

[0018] Dual-cell alternating continuous operation: Two capture-conversion electrolyzers are set up, with one capturing and one converting alternately without interruption, realizing continuous capture and conversion of carbon dioxide and stable output of syngas, making it more suitable for industrial applications.

[0019] Medium-temperature environment improves conversion efficiency: During conversion, the temperature is raised to 60℃~120℃ in situ to form a local high-concentration carbon dioxide zone, which at the same time enhances the activity of catalytic active sites, significantly improving carbon dioxide conversion efficiency and syngas yield.

[0020] Flexible and controllable: Equipped with a mobile base for easy mobile deployment and adaptable to multiple scenarios; with matching monitoring and control terminals and instruments, it can achieve automated regulation and safe operation, with better stability and reliability.

[0021] On-site carbon source utilization: Realizing on-site capture of carbon dioxide and in-situ conversion into high-value-added syngas effectively avoids the problem of geographical mismatch between carbon sources and storage sites, and provides a feasible path for carbon resource utilization. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the electrolytic cell-type integrated carbon dioxide capture and conversion system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the trapping and conversion electrolytic cell according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1. Fan; 2. Gas flow meter; 3. No. 1 trapping and conversion electrolytic cell; 4. No. 2 trapping and conversion electrolytic cell; 5. No. 1 electrolyte storage tank; 6. No. 2 electrolyte storage tank; 7. No. 1 pump; 8. No. 2 pump; 9. Condenser heat exchanger; 10. Gas-liquid separator; 11. Air inlet ball valve; 12. No. 1 air inlet solenoid valve; 13. No. 2 air inlet solenoid valve; 14. No. 1 electrolyte solenoid valve; 15. No. 2 electrolyte solenoid valve; 16. No. 1 condenser 17. Solenoid valve; 18. No. 1 back pressure valve; 19. No. 2 back pressure valve; 20. No. 1 air outlet solenoid valve; 21. No. 2 air outlet solenoid valve; 22. No. 1 gas-liquid separation solenoid valve; 23. No. 2 gas-liquid separation solenoid valve; 24. Product outlet solenoid valve; 25. Leakage solenoid valve; 26. Power supply; 27. Housing; 28. Anode flow channel; 29. ​​Anode porous electrode; 30. Medium-temperature resistant ion exchange membrane; 31. Cathode porous electrode. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the specific embodiments. All equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection of the present invention.

[0025] The electrolytic cell-type integrated carbon dioxide capture and conversion system provided by this invention has the following overall structure: Figure 1 As shown, the system includes a fan 1, a gas flow meter 2, a first-stage collection and conversion electrolytic cell 3, a second-stage collection and conversion electrolytic cell 4, a first-stage electrolyte storage tank 5, a second-stage electrolyte storage tank 6, a first-stage pump 7, a second-stage pump 8, a condenser heat exchanger 9, a gas-liquid separation device 10, a power supply 26, a monitoring and control terminal, and several valve groups. The valve groups include an air inlet ball valve 11, a first-stage gas inlet solenoid valve 12, a second-stage gas inlet solenoid valve 13, a first-stage electrolyte solenoid valve 14, a second-stage electrolyte solenoid valve 15, a first-stage condenser solenoid valve 16, a second-stage condenser solenoid valve 17, a first-stage back pressure valve 18, a second-stage back pressure valve 19, a first-stage air outlet solenoid valve 20, a second-stage air outlet solenoid valve 21, a first-stage gas-liquid separation solenoid valve 22, a second-stage gas-liquid separation solenoid valve 23, a product outlet solenoid valve 24, and a leakage solenoid valve 25. The blower 1 is connected to the first collection and conversion electrolytic cell 3 and the second collection and conversion electrolytic cell 4 respectively through the gas flow meter 2, the air inlet ball valve 11, the first gas inlet solenoid valve 12 and the second gas inlet solenoid valve 13, and is used to supply air; The No. 1 electrolyte storage tank 5 and the No. 2 electrolyte storage tank 6 are respectively connected to the No. 1 collection and conversion electrolytic cell 3 and the No. 2 collection and conversion electrolytic cell 4 via the No. 1 pump 7 and the No. 2 pump 8, respectively, to provide circulating anolyte; The condenser heat exchanger 9 is connected to the electrolyte bypass via a first condenser solenoid valve 16 and a second condenser solenoid valve 17, respectively, for cooling the electrolyte. The No. 1 back pressure valve 18 and the No. 2 back pressure valve 19 respectively regulate the pressure of the No. 1 collection and conversion electrolytic cell 3 and the No. 2 collection and conversion electrolytic cell 4 to ensure that the system collects and converts under the optimal pressure.

[0026] The capture-conversion electrolyzer is the core of the system, and its internal structure is as follows: Figure 2 As shown, the No. 1 trap-conversion electrolytic cell 3 and the No. 2 trap-conversion electrolytic cell 4 have completely identical structures. They are both composed of a shell 27, an anode flow channel 28, an anode porous electrode 29, a medium-temperature resistant ion exchange membrane 30, and a cathode porous electrode 31 stacked and wound into a cylindrical shape. The cathode porous electrode 31 adopts a carbon fiber skeleton with attached metal-organic framework material (MOF-CF), which has both adsorption sites for carbon dioxide and water and electrocatalytic active sites, and has suitable conductivity. It can realize in-situ electric heating and provide electrons for electrocatalytic reaction. The anode electrolyte is potassium bicarbonate solution, which is stored in the No. 1 electrolyte storage tank 5 and the No. 2 electrolyte storage tank 6, respectively.

[0027] Under the influence of power supply 26, there is a potential difference between the membrane electrode assembly consisting of cathode porous electrode 31, intermediate-temperature ion exchange membrane 30, and anode porous electrode 29. Under this potential difference, due to the ohmic internal resistance, the membrane electrode assembly is intentionally heated to 60℃~120℃. Under this intermediate-temperature environment, some carbon dioxide and water are desorbed from the cathode porous electrode 31, forming a local high-concentration carbon dioxide region at the cathode. At the same time, under the intermediate-temperature environment, the activity of the active sites on the cathode porous electrode 31 is enhanced, promoting the electrocatalytic reduction of carbon dioxide and water.

[0028] It is understandable that when the capture-conversion electrolytic cell 3 (or 4) changes from the electrocatalytic conversion state to the capture state, the electrolyte pumped out by the electrolyte storage tank 5 (or 6) via the pump 7 (or 8) needs to pass through the condenser heat exchanger 9 before entering the capture-conversion electrolytic cell 3 (or 4); the anode electrolyte is cooled to 25°C by the condenser heat exchanger, which indirectly maintains the capture-conversion electrolytic cell 3 (or 4) at 25°C to ensure that the cathode porous electrode 31 can normally capture carbon dioxide and water in the air.

[0029] In this embodiment, the preferred electrocatalytic reduction reaction temperature of the cathode porous electrode 31 is 100°C, and the reaction pressure is atmospheric pressure. The electrocatalytic reduction reaction of carbon dioxide and water occurs on the cathode porous electrode 31 to generate syngas, and the oxygen evolution reaction occurs on the anode porous electrode 29. Its reaction is as follows: , , .

[0030] All operating parameters of the system of this invention are automatically regulated by the monitoring and control terminal. Pressure gauges and temperature gauges are installed on the No. 1 collection and conversion electrolytic cell 3 and the No. 2 collection and conversion electrolytic cell 4. Liquid level gauges are installed on the No. 1 electrolyte storage tank 5, the No. 2 electrolyte storage tank 6 and the gas-liquid separation device 10 to realize real-time monitoring of the system's operating status.

[0031] The specific working steps of the system in this embodiment are as follows: S1. Turn on the main power supply of the system, and start the No. 1 pump 7, No. 2 pump 8 and condenser heat exchanger 9 through the monitoring and control terminal. Keep the No. 1 electrolyte solenoid valve 14 and No. 2 electrolyte solenoid valve 15 closed, and open the No. 1 condenser solenoid valve 16 and No. 2 condenser solenoid valve 17. The condenser heat exchanger 9 cools the bypass electrolyte through the No. 1 condenser solenoid valve 16 and No. 2 condenser solenoid valve 17, which indirectly maintains the internal temperature of the No. 1 capture and conversion electrolytic cell 3 and the No. 2 capture and conversion electrolytic cell 4 at 25°C to prepare for carbon dioxide capture. S2. The monitoring and control terminal controls the gas flow meter 2, air inlet ball valve 11, gas inlet solenoid valve 12, gas inlet solenoid valve 13, air outlet solenoid valve 20, and air outlet solenoid valve 21 to open, while keeping gas-liquid separation solenoid valve 22 and gas-liquid separation solenoid valve 23 closed, thus completing the on / off control of the gas path. S3. Start the fan 1. The fan 1 delivers air to the cathode side of the No. 1 trapping and conversion electrolytic cell 3 and the No. 2 trapping and conversion electrolytic cell 4 through the gas flow meter 2, the air inlet ball valve 11, the No. 1 gas inlet solenoid valve 12 and the No. 2 gas inlet solenoid valve 13, respectively. At the same time, adjust the No. 1 back pressure valve 18 and the No. 2 back pressure valve 19 to regulate the pressure of the No. 1 trapping and conversion electrolytic cell 3 and the No. 2 trapping and conversion electrolytic cell 4, respectively, to ensure that the system performs the trapping operation under the optimal pressure. At this time, the No. 1 trapping and conversion electrolytic cell 3 and the No. 2 trapping and conversion electrolytic cell 4 both enter the "trapping" state. Carbon dioxide and water in the air are selectively adsorbed by the cathode porous electrode 31. The trapped exhaust gas is directly discharged into the atmosphere through the air outlet solenoid valve / solenoid valve. S4. When the collection reaches the set time and the cathode porous electrode 31 is saturated with adsorption, the monitoring and control terminal switches the valve group and equipment status: closing the No. 1 gas inlet solenoid valve 12, the No. 1 air outlet solenoid valve 20, and the No. 1 condenser solenoid valve 16; opening the No. 1 electrolyte solenoid valve 14, the No. 1 gas-liquid separation solenoid valve 22, and the product outlet solenoid valve 24. At the same time, the power supply 26 applies electrical energy to the No. 1 collection and conversion electrolytic cell 3. Under the action of the power supply 26, a potential difference is generated between the membrane electrode assembly consisting of the cathode porous electrode 31, the medium-temperature resistant ion exchange membrane 30, and the anode porous electrode 29. Due to the ohmic internal resistance, the membrane electrode assembly heats up to 100°C. At this time, the No. 1 collection and conversion electrolytic cell 3 changes from the "collection" state. In the "electrocatalytic conversion" state, the No. 2 trapping conversion electrolyzer 4 continues to work in the "trapping" state; the No. 1 back pressure valve 18 is adjusted to maintain the No. 1 trapping conversion electrolyzer 3 at the optimal pressure for the conversion reaction. This medium-temperature environment causes some carbon dioxide and water to desorb from the cathode porous electrode 31, forming a local high-concentration carbon dioxide area, while enhancing the activity of the catalytic active sites. Carbon dioxide and water undergo an electrocatalytic reduction reaction to generate syngas. The reaction products are transported to the gas-liquid separation device 10 through the No. 1 gas-liquid separation solenoid valve 22 for gas-liquid separation. The separated syngas is stably output through the product outlet solenoid valve 24. When the liquid in the gas-liquid separation device 10 reaches the liquid level threshold, the leakage solenoid valve 25 automatically opens to drain the liquid. S5. After the No. 1 trapping and conversion electrolytic cell 3 completes the electrocatalytic conversion for the set time, the monitoring and control terminal switches states again: It opens the No. 1 gas inlet solenoid valve 12, the No. 1 air outlet solenoid valve 20, and the No. 1 condenser solenoid valve 16; it closes the No. 1 electrolyte solenoid valve 14 and the No. 1 gas-liquid separation solenoid valve 22. The electrolyte is cooled to 25°C by the condenser heat exchanger 9 before entering the No. 1 trapping and conversion electrolytic cell 3, indirectly maintaining its temperature at 25°C and restoring its trapping capacity; simultaneously, it closes the No. 2 gas inlet solenoid valve 13, the No. 2 air outlet solenoid valve 21, and the No. 2 condenser solenoid valve 22. The solenoid valve 17 opens the second electrolyte solenoid valve 15 and the second gas-liquid separation solenoid valve 23. The power supply 26 applies electrical energy to the second trapping and conversion electrolytic cell 4. The second back pressure valve 19 is adjusted to maintain the second trapping and conversion electrolytic cell 4 under the optimal pressure for conversion reaction. At this time, the first trapping and conversion electrolytic cell 3 returns to the "trapping" state, and the second trapping and conversion electrolytic cell 4 changes to the "electrocatalytic conversion" state. The reaction products of the second trapping and conversion electrolytic cell 4 are transported to the gas-liquid separation device 10 through the second gas-liquid separation solenoid valve 23. The synthesis gas is continuously output through the product outlet solenoid valve 24. S6. Following the switching logic of steps S4 and S5, the system continuously and alternately controls the "capture" and "electrocatalytic conversion" states of the No. 1 capture-conversion electrolyzer 3 and the No. 2 capture-conversion electrolyzer 4 to achieve continuous capture and in-situ conversion of carbon dioxide, ensuring stable output of syngas products.

[0032] Furthermore, in this embodiment, filters can be added to the outlet ends of the No. 1 air outlet solenoid valve 20 and the No. 2 air outlet solenoid valve 21 to prevent the catalyst material on the cathode porous electrode 31 from falling off and causing air pollution; a movable base is set below the capture and conversion electrolytic cell to facilitate the on-site movement and deployment of the system and adapt to different application scenarios.

Claims

1. An integrated electrolytic cell-type carbon dioxide capture and conversion system, characterized in that, The system includes a blower (1), a first-stage trapping and conversion electrolytic cell (3), a second-stage trapping and conversion electrolytic cell (4), an electrolyte storage tank, a pump, a condenser heat exchanger (9), a gas-liquid separation device (10), a power supply (26), and a valve group. The first-stage trapping and conversion electrolytic cell (3) and the second-stage trapping and conversion electrolytic cell (4) are in the "trapping" state and the "electrocatalytic conversion" state at the same time, respectively, and can switch alternately over time. When in the "trapping" state, the temperature of the trapping and conversion electrolytic cell is maintained at 25°C to adsorb carbon dioxide and water in the air. When in the "electrocatalytic conversion" state, the power supply (26) works and uses the ohmic internal resistance to heat the trapping and conversion electrolytic cell to 60°C to 120°C, so that the adsorbed carbon dioxide and water are desorbed and undergo an electrocatalytic reduction reaction to generate syngas.

2. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, The blower (1) is connected to the No. 1 trapping and conversion electrolytic cell (3) and the No. 2 trapping and conversion electrolytic cell (4) respectively through a gas flow meter (2) and a valve group, and is used to provide air; two electrolyte storage tanks and two pumps are provided respectively, namely No. 1 electrolyte storage tank (5), No. 2 electrolyte storage tank (6), No. 1 pump (7) and No. 2 pump (8), which are used to provide circulating anolyte to the corresponding trapping and conversion electrolytic cells; the valve group includes an air inlet ball valve (11) and a No. 1 gas inlet solenoid valve. Valve (12), No. 2 gas inlet solenoid valve (13), No. 1 electrolyte solenoid valve (14), No. 2 electrolyte solenoid valve (15), No. 1 condensation solenoid valve (16), No. 2 condensation solenoid valve (17), No. 1 back pressure valve (18), No. 2 back pressure valve (19), air outlet solenoid valve, gas-liquid separation solenoid valve, product outlet solenoid valve (24), and leakage solenoid valve (25); each valve group is set for two collection and conversion electrolytic cells to realize independent on / off and state control of the two collection and conversion electrolytic cells.

3. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, The cathode outlet of the trapping and conversion electrolytic cell is connected to the atmospheric environment and the gas-liquid separation device (10) respectively through a three-way pipe, so as to realize the switching between tail gas emission in the trapping state and product transportation in the conversion state.

4. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, The condenser heat exchanger (9) is connected to the electrolyte pipeline through a valve group for cooling the electrolyte. When the trapping and conversion electrolytic cell switches from the electrocatalytic conversion state to the trapping state, the electrolyte pumped out flows through the condenser heat exchanger (9) and is cooled to 25°C before entering the trapping and conversion electrolytic cell. When in the trapping state, the electrolyte bypasses the condenser heat exchanger (9).

5. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, The gas-liquid separation device (10) is connected to the cathode outlet of the collection and conversion electrolytic cell through a valve group for gas-liquid separation of the product; the gas-liquid separation device (10) is equipped with a liquid level gauge and a leakage solenoid valve (25). When the liquid reaches the set threshold, the leakage solenoid valve (25) automatically opens to drain the liquid.

6. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, The trapping and conversion electrolytic cell is composed of a shell (27), an anode channel (28), an anode porous electrode (29), a medium-temperature resistant ion exchange membrane (30), and a cathode porous electrode (31) stacked and wound into a cylindrical shape.

7. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 6, characterized in that, The cathode porous electrode (31) is made of carbon fiber skeleton with attached organic metal framework material, i.e. MOF-CF material; a movable base is provided below the capture and conversion electrolytic cell.

8. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, It also includes a monitoring and control terminal, which is electrically connected to the fan (1), gas flow meter (2), collection and conversion electrolytic cell, electrolyte storage tank, pump, condenser heat exchanger (9), gas-liquid separation device (10), power supply (26) and all valve groups to realize automated control and monitoring of operating parameters.

9. The electrolytic cell-type integrated carbon dioxide capture and conversion system according to claim 1, characterized in that, The power source (26) is electrically connected to the trapping and conversion electrolytic cell to supply power for the electrocatalytic reduction reaction.

10. A method of operating the system as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Start the system so that both the No. 1 trapping conversion electrolytic cell (3) and the No. 2 trapping conversion electrolytic cell (4) are in the trapping state, and carbon dioxide and water in the air are adsorbed by the cathode porous electrode (31). S2: When the No. 1 trapping and conversion electrolytic cell (3) is saturated with adsorption, it is switched to the electrocatalytic conversion state, while the No. 2 trapping and conversion electrolytic cell (4) remains in the trapping state; the No. 1 trapping and conversion electrolytic cell (3) is heated under the action of the power supply (26) to desorb carbon dioxide and water and electrocatalytically reduce them to syngas, and the product enters the gas-liquid separation device (10). S3: When the No. 1 trapping and conversion electrolyzer (3) has completed the conversion, switch it back to the trapping state, and at the same time switch the No. 2 trapping and conversion electrolyzer (4) to the electrocatalytic conversion state. S4: Repeat steps S2 and S3 to achieve alternating collection and conversion in the two collection-conversion electrolyzers, continuously outputting syngas.

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