Electrochemical adsorption material and device for capturing carbon dioxide

Abstract

The invention relates to an electrochemical adsorption material and device for capturing carbon dioxide, the adsorption material is composed of an integrated cathode adsorption material, an integrated anode charge balance material and a gel electrolyte, the integrated cathode adsorption material is a polynaphthoquinone-carbon cloth composite material, and the integrated anode charge balance material is a polynaphthoquinone-carbon cloth composite material. The integrated anode charge balance material is a ferrocene-carbon cloth composite material, and the gel electrolyte is a polyion liquid-silicon dioxide gel electrolyte. The method has the advantages that the electrochemical adsorption material has the advantages of high activity (good adsorption performance), high stability (the performance is not reduced after long-term use) and the like, a matched device is modularized, easy to maintain and compact in size, auxiliary equipment is not needed, the capacity is not influenced by the feeding concentration, the purity of released CO2 can be close to 100%, efficient trapping of a wide-concentration CO2 gas source (0.6%-10%) is achieved, and the method is suitable for industrial production. Capturing efficiency and energy consumption control are both considered, and multi-scene application requirements are met.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrochemical adsorption material and device for capturing carbon dioxide, belonging to the technical field of carbon dioxide capture. BACKGROUND

[0002] The greenhouse effect, extreme disaster weather, and global food crisis caused by the gradual increase of CO2 concentration in the earth's atmosphere have attracted more and more attention. The low flexibility and high energy consumption performance bottleneck of CO2 capture technology is one of the important factors limiting the development of carbon capture. Although a series of investments and researches have been made in the industry in recent years to improve the energy consumption of high-efficiency low-cost carbon capture technology, the performance indicators of the existing traditional technology (such as traditional absorption / adsorption method) are still difficult to meet the wide industrial application of carbon capture technology. Therefore, it is urgent to develop a new type of low-energy carbon capture technology.

[0003] The existing carbon capture technology mainly includes temperature swing absorption, temperature swing adsorption, pressure swing adsorption, etc. The temperature swing absorption method uses amines and other chemical solvents to react reversibly with CO2 at low temperature to capture CO2 in flue gas, and then releases high-purity CO2 by heating with steam, while the solvent is regenerated and recycled. The temperature swing adsorption / pressure swing adsorption is similar to the above technology, which uses low temperature / high pressure adsorption and high temperature / low pressure desorption.

[0004] The above-mentioned method in the prior art needs to consume a large amount of heat during the release of CO2 after capture. For example, a 30wt% MEA (ethanolamine) CO2 saturated solution needs to consume nearly 4GJ / t CO2 of energy for heating and regeneration. The high energy consumption (high energy consumption means high operating cost) caused by the regeneration of absorbent / adsorbent seriously hinders the popularization and application of the existing CO2 capture method. In addition, the temperature swing absorption technology usually involves multiple supporting equipment such as absorption tower, desorption tower, and heat exchanger, which has high initial investment and operating cost, and poor flexibility.

[0005] The temperature swing absorption method has the following disadvantages: ① high energy consumption: the heating process of the solvent regeneration link needs to consume a large amount of steam, which is the main source of energy consumption of the whole system, and will cause a significant decrease in power plant efficiency (up to 20-30%); ② solvent degradation and corrosion: impurities such as oxygen, SO x , NO x , etc. in the flue gas will cause solvent degradation and produce corrosive substances, which requires additional pretreatment and regular solvent replenishment; ③ complex system, high investment: involves multiple large equipment such as absorption tower, desorption tower, and heat exchanger, which has high initial investment and operating cost; ④ secondary pollution: some degradation products may cause secondary pollution; ⑤ requires high CO2 concentration in the inlet gas, and the capture efficiency is generally low for low CO2 concentration.

[0006] The temperature swing / pressure swing adsorption method has the following disadvantages: ① high energy consumption: frequent high temperature / low pressure state is required, and energy consumption is large; ② large equipment size: multiple large equipment such as absorption tower, regeneration tower and heat exchanger are involved; ③ complex system and large investment: a large adsorption tower, a large amount of adsorbent and auxiliary equipment such as a powerful vacuum pump are required, resulting in a sharp increase in equipment investment and power consumption; ④ there is a great challenge in the long-term use stability of the adsorption material, which is easy to deactivate and degrade, and cannot be operated for a long time.

[0007] In order to solve the problems of high energy consumption and poor flexibility of the prior art, the electrochemical technology represented by electrochemical adsorption shows a revolutionary direction of low energy consumption and low system complexity. SUMMARY

[0008] The present application provides an electrochemical adsorption material and device for capturing carbon dioxide, which aims to overcome the above-mentioned shortcomings of the prior art and realize effective capture of carbon dioxide with low energy consumption and low system complexity.

[0009] The technical solution of the present application is an electrochemical adsorption material for capturing carbon dioxide, which is composed of an integrated cathode adsorption material, an integrated anode charge balance material and a gel electrolyte. The integrated cathode adsorption material is a polynaphthoquinone-carbon cloth composite material, the integrated anode charge balance material is a ferrocene-carbon cloth composite material, and the gel electrolyte is a polyionic liquid-silica gel electrolyte.

[0010] Preferably, the integrated cathode adsorption material selects a carbon fiber cloth with a surface density of 35 g / m² and a thickness of 150 μm as a substrate and a conductive framework, loads polynaphthoquinone on the surface of the carbon cloth through an impregnation-polymerization process, and the loading amount of polynaphthoquinone is 1.0-1.2 mg / cm². Polynaphthoquinone contains quinone active groups, can specifically bind CO2 through carboxylation reaction in reduced state, and release CO2 in oxidized state; the carbon cloth has the functions of conductive path and mechanical support, the woven porous structure can enhance the wettability of the gel electrolyte and the mass transfer efficiency of CO2, and at the same time, anchor the polynaphthoquinone molecular chain through π-π conjugation effect to prevent loss of active components.

[0011] Preferably, the integrated anode charge balance material selects a carbon fiber cloth with a surface density of 35 g / m² and a thickness of 150 μm as a substrate and a conductive framework, loads ferrocene groups on the surface of the carbon cloth through a covalent grafting process, and the loading amount of ferrocene is 1.2-1.4 mg / cm². The redox potential of ferrocene is-0.04 V, which can be used as an electronic "source / sink" to balance the redox charge of the cathode, ensuring the charge conservation of the device; the carbon cloth substrate realizes the integrated design of the anode, eliminates the additional current cable and the composite process of the substrate, and reduces the interfacial contact resistance.

[0012] Preferably, the gel electrolyte is formed by cross-linking poly-1-vinyl-3-butyl imidazolium bis(trifluoromethylsulfonyl) imide with nano-SiO2 at a mass ratio of 5:1, and the ionic conductivity is 5-8 ms / cm. The gel electrolyte retains the ionic conductivity of the ionic liquid, and the nano-SiO2 forms a three-dimensional cross-linked network, making the electrolyte in a gel state and reducing the risk of leakage; at the same time, the hydrophobic skeleton of the PIL can inhibit the interference of water in the high-humidity gas source on the electroactive material, and adapt to the environment such as humid industrial flue gas. The electrolyte has high mechanical strength, and the absorption device made of the electrolyte has high structural stability.

[0013] A device for capturing carbon dioxide, comprising the adsorption modular unit of the electrochemical adsorption material for capturing carbon dioxide, the adsorption modular unit is a symmetrical layered structure, from one side to the other side, it is in turn a first cathode adsorption component layer, a first gel electrolyte layer and a battery separator, an anode charge balance component, a second gel electrolyte layer and a battery separator, a second cathode adsorption component layer, the symmetrical layered structure is provided with A cathode sealing frame and B cathode sealing frame at both ends, the first cathode adsorption component layer and the second cathode adsorption component layer are composed of the integrated cathode adsorption material, the anode charge balance component is composed of the integrated anode charge balance material, the gel electrolyte layer is composed of the gel electrolyte, the A cathode sealing frame and the B cathode sealing frame are fluororubber sealing frames, and each unit is independently configured with a potential regulation interface.

[0014] Preferably, the array type adsorption module is composed of 11 adsorption modular units arranged in parallel, each adsorption modular unit in the array type adsorption module is fixed and arranged in parallel through a positioning slot plate, the gap between adjacent adsorption modular units is 5 mm, one side of the array type adsorption module in the positioning slot plate is provided with a current collector, the current collector is provided with a plurality of metal protruding contacts connected to the anode and the anode of each adsorption modular unit, the upper protrusion is an anode contact connected to the anode, and the lower protrusion is a cathode contact connected to the cathode, the current collector is slotted in the middle, and the cathode and the anode are connected in parallel through cables at the back of the current collector, respectively, the potential regulation interfaces of the adsorption modular units are uniformly connected by the current collector and then connected to a total control power supply by wires, the other side of the array type adsorption module in the positioning slot plate is provided with a current equalizing plate slotted at the upper end and the lower end, the current equalizing plate is slotted at both ends, and the adsorption module, the positioning slot plate, the current collector and the current equalizing plate constitute an array type adsorption system.

[0015] Preferably, the array adsorption system is installed in a shell assembly, the shell assembly comprises a shell, the inner wall of the shell is coated with ETFE Teflon coating, the collar part of the shell is provided with a U-shaped groove for placing a fluororubber O-ring, the shell is covered and sealed by a cover plate, the middle of the cover plate is connected to a sleeve joint through a threaded internal thread joint, the sleeve joint is connected to a CO2 concentration detection sensor or a pressure detection sensor, the front of the cover plate is provided with two welded quick flanges at both ends, which constitute a CO inlet and outlet, one end of the cover plate is provided with two welded openings of positive and negative electrodes, the positive and negative electrodes are connected to the array adsorption system through wires, and the lower end of the cover plate is also provided with a sealing strip made of PTFE.

[0016] The advantages of the present application are that the electrochemical adsorption material has high activity (good adsorption performance), high stability (long-term use performance does not decrease) and the like, and the supporting device is modular, easy to maintain, compact in size, does not require auxiliary equipment, the capacity is not affected by the concentration of the feed, can realize a CO2 release purity of nearly 100%, can realize efficient capture of a wide concentration CO2 gas source (0.6%~10%), can balance capture efficiency and energy consumption control, and is suitable for multiple scene application requirements. 1) Material performance and process advantages: ① Integrated design simplifies process: both cathode and anode are integrated with carbon cloth as substrate, eliminating the substrate compounding and current collection net pressing process of the prior art electrode, improving the preparation efficiency by 40%, reducing the interface contact resistance by 30%, and improving the electronic transmission efficiency; ② Leak-proof and environmentally resistant: PIL-SiO2 gel electrolyte has no leakage risk, and is suitable for the vibration environment of frequent disassembly and movement of modular units; its hydrophobic skeleton can withstand a relative humidity of 90% or more, expanding the application scenarios of ocean, humid industrial flue gas, etc.; ③ Cost and stability: the cost of carbon cloth raw material is lower than that of carbon nanotube and other materials, and the synthesis process of polynaphthoquinone is simple, reducing the overall material cost by 25%; the anchoring effect of carbon cloth on the electroactive component enables the material to realize more than 8000 cycles, with a capacity loss of ≤25% after cycling, achieving a significant reduction in material production cost while maintaining excellent capture performance.

[0017] 2) Device adaptability and scene compatibility: ① Flexible expansion and convenient maintenance: standardized modular units can be flexibly stacked according to the processing gas volume, and only the faulty local unit needs to be replaced, with a maintenance time of ≤20 minutes, greatly reducing the downtime loss of industrial operation; ② Multi-scene adaptation: can efficiently process CO2 gas sources with a concentration of 0.6%~10%, with a single-mole CO2 capture-release energy consumption controlled at 45~95kJ, suitable for both high-humidity industrial flue gas treatment and low-concentration CO2 regulation requirements of submarine and other marine closed cabins. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a composition schematic diagram of the electrochemical adsorption material for capturing carbon dioxide according to the present application.

[0019] Figure 2 is Figure 1 Scanning electron microscope image of the cathode adsorption material.

[0020] Figure 3 is a structural schematic diagram of the device for capturing carbon dioxide of the present application.

[0021] Figure 4 is an exploded structural schematic diagram of the housing assembly of the device for capturing carbon dioxide of the present application.

[0022] Figure 5 is an exploded structural schematic diagram of the array adsorption system of the device for capturing carbon dioxide of the present application.

[0023] Figure 6 is a structural schematic diagram of the adsorption modular unit of the device for capturing carbon dioxide of the present application.

[0024] Figure 7 is an exploded structural schematic diagram of the device for capturing carbon dioxide of the present application.

[0025] Figure 8 is a result diagram of the high humidity source adaptability test of the device for capturing carbon dioxide of the present application.

[0026] Figure 9 is an adsorption performance cycle test result diagram of the cycle stability test of the device for capturing carbon dioxide of the present application.

[0027] Figure 10 is a charge density change trend diagram in the adsorption cycle process of the cycle stability test of the device for capturing carbon dioxide of the present application.

[0028] Figure 11 is an adsorption capacity and Faraday efficiency diagram corresponding to different inlet gas concentrations in the multi-concentration gas source adaptability test of the device for capturing carbon dioxide of the present application.

[0029] Figure 12 is a technical advantage comparison diagram of the electrochemical adsorption material and device for capturing carbon dioxide of the present application compared with the prior art.

[0030] 11 is an A cathode sealing frame, 12 is a first cathode adsorption assembly layer, 13 is a first gel electrolyte layer and battery separator, 14 is an anode charge balance assembly, 15 is a second gel electrolyte layer and battery separator, 16 is a second cathode adsorption assembly layer, 17 is a B cathode sealing frame, 21 is a positioning card slot plate, 22 is a current equalization plate, 23 is an array adsorption module, 24 is a current collector, 31 is a card sleeve connector, 32 is a ball head screw nut, 33 is a positive and negative electrode, 34 is a cover plate, 35 is a quick mounting flange, 36 is a sealing strip, 37 is a fluorine rubber O ring, 38 is a shell, 39 is a wire. DETAILED DESCRIPTION

[0031] The application will be further described in detail below in combination with examples and specific embodiments.

[0032] As shown in Figure 1 , 2 , an electrochemical adsorption material for capturing carbon dioxide is composed of three parts: an integrated cathode adsorption material, an integrated anode charge balance material, and a gel electrolyte. The formula, structure, and function of each part are as follows: The integrated cathode adsorption material is a poly-naphthoquinone-carbon cloth (PNQ-CC) composite material. A carbon fiber cloth with a surface density of 35 g / m² and a thickness of 150 μm is selected as the substrate and conductive framework. Poly-naphthoquinone is loaded on the surface of the carbon cloth through an immersion-polymerization process, and the poly-naphthoquinone loading amount is 1.0-1.2 mg / cm². Poly-naphthoquinone contains quinone active groups, which can specifically bind CO₂ through carboxylation reaction in the reduced state, and release CO₂ in the oxidized state; the carbon cloth has both conductive paths and mechanical support functions, and its woven porous structure can enhance the gel electrolyte wettability and CO₂ mass transfer efficiency, and anchor the poly-naphthoquinone molecular chain through π-π conjugation effect to prevent the loss of active components.

[0033] The integrated anode charge balance material is a ferrocene-carbon cloth (Fc-CC) composite material. The same size carbon fiber cloth as the cathode is selected, and ferrocene groups are loaded on the surface of the carbon cloth through covalent grafting process, and the ferrocene loading amount is 1.2-1.4 mg / cm². The redox potential of ferrocene is -0.04 V, which can balance the redox charge of the cathode as an electron "source / sink", ensuring the charge conservation of the device; the carbon cloth substrate realizes the integrated design of the anode, eliminating the need for additional current cable and substrate composite process, and reducing the interface contact resistance.

[0034] The gel electrolyte is a polyionic liquid-silica gel electrolyte (PIL-SiO2) formed by cross-linking poly-1-vinyl-3-butylimidazolium bis(trifluoromethanesulfonyl) imide (PIL) and nano-SiO2 at a mass ratio of 5:1, with an ionic conductivity of 5-8 ms / cm. The gel electrolyte retains the ionic conductivity of the ionic liquid, and the nano-SiO2 forms a three-dimensional cross-linked network, making the electrolyte in a gel state, reducing the risk of leakage; at the same time, the hydrophobic skeleton of PIL can inhibit the interference of water in high humidity gas source on the electroactive material, and adapt to humid industrial flue gas and other environments. The electrolyte has high mechanical strength, and the absorption device made of it has strong structural stability.

[0035] As a specific example, the preparation of an electrochemical adsorption material for capturing carbon dioxide includes: Preparation of PNQ-CC integrated cathode adsorption material: 50 mg of 1,4-naphthoquinone was dissolved in 40 mL of N-methyl-2-pyrrolidone (NMP) and ultrasonicated at 5°C for 20 min to form a uniform naphthoquinone monomer dispersion; then 150 μm thick, 35 g / m² carbon fiber cloth was immersed in the above dispersion for 30 min, and then taken out and heated at 65°C under nitrogen atmosphere for 72 h to allow the naphthoquinone monomer to polymerize in situ on the surface of the carbon cloth; the polymerized carbon cloth was washed with 1 mol / L hydrochloric acid, deionized water and methanol, and dried at 120°C for 12 h to obtain a PNQ-CC cathode adsorption assembly with a poly-naphthoquinone loading of 1.1 mg / cm².

[0036] Preparation of Fc-CC integrated anode charge balance material: carbon fiber cloth of the same size as the cathode was placed in concentrated nitric acid and refluxed at 60°C for 2 h to introduce carboxyl active sites and activate the surface, and then washed and dried for standby; the activated carbon cloth was immersed in a N,N-dimethylformamide (DMF) solution containing 0.1 mol / L ferrocene methylamine and 0.1 mol / L N,N'-dicyclohexyl carbodiimide (DCC), and reacted at room temperature for 24 h to graft ferrocene onto the surface of the carbon cloth through an amide bond; the grafting process was repeated twice, and the resulting Fc-CC anode charge balance assembly had a ferrocene loading of 1.3 mg / cm² after washing and drying.

[0037] Preparation of PIL-SiO2 gel electrolyte: 1-vinyl-3-butylimidazole bromide and lithium bis(trifluoromethanesulfonyl)imide were ion exchanged at a molar ratio of 1:1, and then free radical polymerization was performed to obtain poly-1-vinyl-3-butylimidazole bis(trifluoromethanesulfonyl)imide (PIL); PIL and nano-SiO2 (particle size 20 nm) were mixed at a mass ratio of 5:1, 0.5% azobis isobutyronitrile (AIBN) initiator was added, and crosslinking was performed at 60°C for 3 h to form a PIL-SiO2 gel electrolyte, and the ionic conductivity of the prepared electrolyte was about 6.5 mS / cm.

[0038] As shown in Figures 3-6 , a capture device is constructed based on the above electrochemical adsorption material for capturing carbon dioxide, and a modular unit + array type stacking structure design is adopted, specifically: Single adsorption modular unit: symmetrical layered structure, from one side to the other side in turn: first cathode adsorption assembly layer 12, first gel electrolyte layer and battery separator 13, anode charge balance assembly 14, second gel electrolyte layer and battery separator 15, second cathode adsorption assembly layer 16, symmetrical layered structure as a whole both ends are respectively provided with A cathode sealing frame 11 and B cathode sealing frame 17, the first cathode adsorption assembly layer 12 and the second cathode adsorption assembly layer 16 are composed of the integrated cathode adsorption material, the anode charge balance assembly 14 is composed of the integrated anode charge balance material, the gel electrolyte layer is composed of the gel electrolyte, and the A cathode sealing frame 11 and the B cathode sealing frame 17 are fluorine rubber sealing frames.

[0039] The thickness of the A cathode sealing frame 11 and the B cathode sealing frame 17 is 500 μm, which realizes the sealing and shaping of the gel electrolyte and forms a 500 μm wide gas flow gap; each unit is independently configured with a potential regulating interface, and can be independently applied with a 1.2-1.8 V charging potential and a 0.4-0.6 V discharging potential.

[0040] As a specific example, during assembly, the 500 μm thick fluorine rubber sealing frame is fixed in the mold, and the PNQ-CC cathode adsorption assembly, the PIL-SiO2 gel electrolyte layer, the battery separator, the Fc-CC anode charge balance assembly, another layer of battery separator, the PIL-SiO2 gel electrolyte layer, another PNQ-CC cathode adsorption assembly are laid in turn, another side sealing frame is covered, hot pressing sealing (0.3 MPa, 100℃, 5 min), the potential regulating interface is welded, and an adsorption modular basic unit with a size of 18 cm×27 cm×1 cm is obtained.

[0041] Arrayed adsorption system: the arrayed adsorption module 23 is composed of 11 adsorption modular units arranged in parallel, the adsorption modular units in the arrayed adsorption module 23 are fixed by the positioning slot plate 21 to be arranged in parallel, the gap between adjacent adsorption modular units is 5 mm, which is used for sufficient contact between the gas to be treated and the CO2 active adsorption electrode, and a plurality of fluid gaps realize uniform distribution of the gas to be treated. The current collector 24 is arranged on one side of the arrayed adsorption module 23 in the positioning slot plate 21, the current collector 24 is provided with a plurality of metal protruding contacts for connecting the anode and the cathode of each adsorption modular unit, wherein the upper protrusion is an anode contact for connecting the anode, and the lower protrusion is a cathode contact for connecting the cathode directly reacting with CO2, the current collector 24 is slotted in the middle to enable the gas flow to pass through, and the cathode and the anode are connected in parallel through the cables at the back of the current collector 24. The potential regulation interface of each adsorption modular unit is connected uniformly by the current collector 24, and then connected to the total control power supply by wires, so that independent regulation or cooperative operation of multiple units can be realized, and the capture requirements of different concentration gas sources can be adapted. Corresponding to the geometric position of the current collector 24, that is, the other side of the arrayed adsorption module 23 in the positioning slot plate 21 is provided with a flow equalizing plate 22 which is slotted at the upper and lower ends, the raw material gas enters through the slot in the middle of the current collector 24, the raw material gas is discharged from the both ends of the flow equalizing plate 22, so that the gas flow fully contacts each corner of the arrayed adsorption module 23, improves the capture efficiency, and also makes the flow field more uniform.

[0042] Flow field sealing and concentration monitoring system: the arrayed adsorption system is installed in the shell assembly, the shell assembly is composed of a shell 38 to form a basic sealing assembly, the inner wall of the shell 38 is coated with an ETFE Teflon coating at the contact boundary with the electrode to prevent the stainless steel of the shell from being corroded by the active substances in the electrode; the shell 38 has a U-shaped groove at the neck part to place a fluororubber O-ring 37; the shell 38 has eight bolt holes outside the neck to place fixing screws. The shell 38 is completely covered and sealed by a cover plate 34, the shell 38 and the cover plate 34 are both made of stainless steel, the cover plate 34 has a threaded inner joint in the middle to connect a sleeve joint 31, the sleeve joint 31 can connect a CO2 concentration detection sensor or a pressure detection sensor to realize real-time monitoring of the operation process of the device. The cover plate 34 has two large openings at the two ends of the front surface for welding quick flanges 35 (KF25 quick flanges), the quick flanges 35 are used for CO2 gas inlet and outlet. One end of the cover plate 34 has two small openings for welding positive and negative electrodes 33, the positive and negative electrodes 33 are connected to the arrayed adsorption system by wires. The outer circle of the cover plate 34 also has eight bolt holes for cooperation with the stainless steel shell 38, and then the entire device is sealed by retracting a ball head screw nut 32. There is also a sealing strip 36 made of PTFE at the lower end of the cover plate 34 to prevent CO2 leakage (i.e. not passing through the adsorption array and directly discharging to the outlet from the gap above).

[0043] As a specific example, when the device is assembled, the assembled plurality of adsorption modular units are inserted into the clamping grooves in the positioning clamping groove plate 21 in sequence, the metal protruding contacts of the current collector 24 are one-to-one corresponding and fully attached to the notches of the positioning clamping groove plate 21, and the attached current collector 24 is fastened by screw connection through the positioning screw holes at the bottom and the screw holes on the positioning clamping groove plate 21; similarly, the uniform flow plate 22 is also fixed in the same way. The assembled array type adsorption system is placed in the shell 38. The quick mounting flange 35 and the electrode 33 are welded to the corresponding hole positions on the cover plate 34, and the clamping sleeve joint 31 is connected to the internal thread at the center of the cover plate 34. The electrode 33 welded on the cover plate 34 is connected by a wire. The fluorine rubber O-ring 37 and the sealing strip 36 are placed in the corresponding positions of the stainless steel shell 38, and finally the cover plate 34 is covered, the corresponding hole positions of the cover plate 34 and the shell 38 are connected by the ball head screw nut 32, and the device is sealed.

[0044] The working principle of the device is as follows: the gas to be treated enters the array type system through the main gas inlet pipe and is evenly distributed to the gas flow channels of each adsorption modular unit through the gaps of the positioning clamping groove plate 21; when a charging potential of 1.3 V is applied to the adsorption unit, the polynaphthoquinone in the PNQ-CC cathode is reduced to a semiquinone radical anion, which reacts with CO2 diffused to the active layer to form a carbonate complex to capture CO2, and at the same time, the ferrocene in the Fc-CC anode is oxidized to ferrocenium ion to balance the charge; when the cathode is saturated, a discharging potential of 0.5 V is applied, the carbonate complex in the cathode is oxidized and decomposed to release high-purity CO2, and the ferrocenium ion in the anode is reduced to ferrocene, completing the charge compensation and regeneration of the adsorption material, and realizing the cycle of CO2 capture and release.

[0045] The performance of the device is tested as follows: 1. High humidity source adaptability test: CO2-N2 mixed gas with a relative humidity of 85% and a CO2 concentration of 5% is introduced at a flow rate of 20 mL / min and a temperature of 25°C, a charging potential of 1.3 V and a discharging potential of 0.5 V are applied. The CO2 concentration at the outlet of the device is stable at 0.1%~0.8%, the Faraday efficiency is 89.2%, and the capture capacity is 46.5 μmol (only 3.1% lower than that in a dry environment); after continuous operation for 200 h, the capture capacity remains 42.8 μmol, the capacity loss rate is 7.1%, the electrolyte has no leakage, and the electrode has no obvious aging. The test results are shown in Figure 8 .

[0046] 2. Cycle stability test: pure CO2 gas source (1 atm, 25℃), charging potential 1.3V, discharging potential 0.5V, single cycle duration 30min. The test results show that the device has a capture capacity of 44.6μmol after 2000 cycles (loss of 7.1%), 40.8μmol after 3000 cycles (loss of 14.8%), 36.0μmol after 4000 cycles (loss of 24.3%), and 33.6μmol after 5000 cycles (loss of 29.6%). During the 20000-second cycle adsorption process, the charge density did not decrease significantly, and the Faraday efficiency remained at 88%~90% without significant decay. The test results are shown in Figure 9 、 10

[0047] 3. Multi-concentration gas source adaptability test: CO2-N2 mixed gas with CO2 concentration of 0.5%, 2.5%, 5%, and 10% was introduced, respectively, at a flow rate of 50mL / min and a temperature of 25℃, and a charging potential of 1.3V was applied. The test results are as follows: the capture capacity at different concentrations is stable at 45~48μmol, and the Faraday efficiency is 88.5%, 89.3%, 89.7%, and 90.2%, respectively; at a low concentration of 0.6%, the adsorption breakthrough occurs after processing 15 bed volumes (1050mL) of gas, and at a high concentration of 10%, the adsorption breakthrough occurs after processing 10 bed volumes (700mL) of gas, and the capacity does not fluctuate significantly, which is suitable for wide-concentration gas sources. The test results are shown in Figure 11

[0048] 4. Typical application scenario simulation test: CO2 adsorption test was performed by introducing simulated automobile exhaust gas (6% CO2, 12% O2 , 78% N2, 75% RH, 40℃), and the exhaust gas flow rate was 80mL / min, and the device was subjected to 10Hz vibration at the same time. The test results show that the outlet CO2 concentration is ≤0.8%, the Faraday efficiency is 88%, the capture capacity does not decay after 100h of operation in a vibration environment, and the stability is significantly improved.

[0049] As shown in Figure 12 , according to the above tests, the present technical solution has significant advantages in core principle, gas source concentration adaptation range, energy consumption per mole of CO2 capture, cycle stability performance, high-humidity environment tolerance (85% RH), maintenance cost and portability, environmental friendliness, device volume and integration, product CO2 purity, and typical scenario adaptability compared with the prior art chemical absorption method and temperature swing / pressure swing adsorption method.

[0050] The above-described is only a preferred embodiment of the present application, and it should be noted that for those skilled in the art, without departing from the inventive concept, a number of modifications and improvements can be made, which are within the scope of protection of the present application.​​

Claims

1. An electrochemical adsorbent material for capturing carbon dioxide, characterized by, The integrated cathode adsorption material is a polynaphthoquinone-carbon cloth composite material, the integrated anode charge balance material is a ferrocene-carbon cloth composite material, and the gel electrolyte is a polyionic liquid-silica gel electrolyte.

2. An electrochemical adsorbent material for capturing carbon dioxide as claimed in claim 1, wherein, The integrated cathode adsorption material selects a carbon fiber cloth with an area density of 35 g / m2 and a thickness of 150 μm as a substrate and a conductive framework, and loads polynaphthoquinone on the surface of the carbon cloth through an immersion-polymerization process, and the polynaphthoquinone loading amount is 1.0-1.2 mg / cm2.

3. An electrochemical adsorbent material for capturing carbon dioxide as claimed in claim 1, wherein, The integrated anode charge balance material selects a carbon fiber cloth with an area density of 35 g / m2 and a thickness of 150 μm as a substrate and a conductive framework, and loads a ferrocene group on the surface of the carbon cloth through a covalent grafting process, and the ferrocene loading amount is 1.2-1.4 mg / cm2.

4. An electrochemical adsorbent material for capturing carbon dioxide as defined in claim 1, wherein, The gel electrolyte is formed by cross-linking poly-1-vinyl-3-butylimidazolium bis(trifluoromethanesulfonyl) imide and nano-SiO2 at a mass ratio of 5:1, and the ionic conductivity is 5-8 ms / cm.

5. An apparatus for capturing carbon dioxide, characterized by, The application relates to an adsorption modular unit for capturing carbon dioxide, which is composed of an electrochemical adsorption material as claimed in any one of claims 1-4, and is a symmetrical layered structure, which comprises, from one side to the other, a first cathode adsorption component layer (12), a first gel electrolyte layer and a battery separator (13), an anode charge balance component (14), a second gel electrolyte layer and a battery separator (15), and a second cathode adsorption component layer (16). The symmetrical layered structure is provided with an A cathode sealing frame (11) and a B cathode sealing frame (17) at both ends, respectively. The first cathode adsorption component layer (12) and the second cathode adsorption component layer (16) are composed of the integrated cathode adsorption material, the anode charge balance component (14) is composed of the integrated anode charge balance material, the gel electrolyte layer is composed of the gel electrolyte, the A cathode sealing frame (11) and the B cathode sealing frame (17) are fluororubber sealing frames, and each unit is independently provided with a potential control interface.

6. A device for capturing carbon dioxide as claimed in claim 5 wherein, Arrayed adsorption module (23) is composed of 11 parallel arranged adsorption modular units, each adsorption modular unit in arrayed adsorption module (23) is fixed and arranged in parallel through positioning slot plate (21), the gap between adjacent adsorption modular units is 5mm, one side of arrayed adsorption module (23) in positioning slot plate (21) is provided with current collector (24), current collector (24) is provided with a plurality of metal protruding contact points connected with anode and cathode of each adsorption modular unit, wherein the upper protrusion is anode contact point connected with anode, and the lower protrusion is cathode contact point connected with cathode, the middle of current collector (24) is slotted, the cathode and the anode are respectively connected in parallel through the cable at the back of current collector (24), the potential regulation interface of each adsorption modular unit is uniformly connected by current collector (24) and then connected to the total control power supply by wire, the other side of arrayed adsorption module (23) in positioning slot plate (21) is provided with flow equalizing plate (22) with slots at the upper and lower ends, the flow equalizing plate (22) is provided with slots at the two ends, and arrayed adsorption system is composed of adsorption module (23), positioning slot plate (21), current collector (24) and flow equalizing plate (22).

7. A device for capturing carbon dioxide as claimed in claim 6 wherein, The array adsorption system is installed in a shell assembly, which includes a shell (38) with an ETFE Teflon coating on the inner wall, a U-shaped groove with a fluorine rubber O-ring (37) at the neck part of the shell (38), and a cover plate (34) covering and sealing the shell (38), with a threaded inner joint connecting a sleeve joint (31) in the middle of the cover plate (34), and a CO （2） A concentration detection sensor or a pressure detection sensor, with two welded quick flanges (35) at the two ends of the front surface of the cover plate (34) to form a CO2 gas inlet and outlet, two openings with welded positive and negative electrodes (33) at one end of the cover plate (34), the positive and negative electrodes (33) connected to the array adsorption system through wires, and a PTFE sealing strip (36) at the lower end of the cover plate (34).

Images