Process method and system for directly capturing carbon dioxide from air and converting and utilizing carbon dioxide

Abstract

The invention provides a process method and system for directly capturing carbon dioxide from air and converting and utilizing the carbon dioxide. The process method comprises the following steps: adsorbing raw material gas through a carbon dioxide trapping device, and heating and desorbing to obtain purified carbon dioxide gas; the purified carbon dioxide gas and the electrolyte are subjected to electrocatalytic conversion to obtain synthesis gas, oxygen and condensate water, and the condensate water is recycled through water treatment operation to be used for supplementing the electrolyte; the method comprises the following steps: carrying out Fischer-Tropsch synthesis reaction, hydrocracking and isomerization reaction on synthesis gas to obtain an isomerized oil-gas mixture, wherein heat energy generated by the reaction provides heating desorption heat; and carrying out gas-liquid separation on the heterogeneous oil-gas mixture to obtain combustible gas and an upgraded oil product, carrying out rectification operation on the upgraded oil product to obtain an SAF component and a heavy oil product, and carrying out oxygen-enriched combustion reaction on the combustible gas and oxygen to provide heating desorption heat or supply required heat energy. An integrated and flexible industrial technology platform is developed, carbon capture and conversion processes are seamlessly connected, full-chain optimization from CO2 removal to high-added-value product generation is realized, and self heat energy requirements and wastewater utilization can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon dioxide capture and utilization, and particularly relates to a process method and system for directly capturing carbon dioxide from the air and converting and utilizing it. Background Art

[0002] Direct Air Capture (DAC) is a technology aimed at removing carbon dioxide (CO2) from the atmosphere to address climate change and reduce greenhouse gas emissions. Its background stems from the continuous increase in global carbon emissions, and traditional emission reduction measures (such as afforestation) may not be sufficient to achieve the goal of the Paris Agreement, which is to limit the global temperature increase within 2°C. The DAC technology extracts CO2 directly from the air through chemical reactions or physical adsorption, and then sequesters it (such as underground storage) or re-uses it (such as producing fuels or materials). Currently, DAC faces challenges of high energy consumption, high cost, and technology scaling, but its potential is gradually emerging and is regarded as an important supplementary means to achieve net-zero emissions.

[0003] The captured carbon dioxide can be utilized through various channels, which can not only reduce greenhouse gas emissions but also create economic value. First, permanent storage is the most common method, such as injecting it into underground geological formations (such as abandoned oil fields or saline aquifers) or converting it into stable salts through mineralization for use in building materials such as concrete. Second, industrial uses include using carbon dioxide in carbonated beverage production, solution filling, or refrigerants. Although it cannot be permanently sequestered, it can recycle resources. Third, Enhanced Oil Recovery (EOR): Injecting CO2 into oil fields to increase oil production while partially sequestering CO2, but it is controversial due to the increased use of fossil fuels. Finally, converting it into value-added products has the greatest potential. Using renewable energy (such as wind energy, solar energy) to drive water-based technologies to combine CO2 with hydrogen in water and generate methanol, gasoline, diesel, or aviation fuel through catalytic reactions. For example, producing aviation fuel through the Fischer-Tropsch process or developing zero-carbon gasoline. This closed-loop model incorporates it into the energy and industrial systems to achieve carbon recycling. The advantage of fuel substitution is that it can directly replace traditional fossil fuels and is compatible with existing infrastructure, but it faces high consumption and costs. In the future, with the decline in the production cost of green hydrogen and technological optimization, the economic viability and scaling potential of carbon dioxide conversion will be significantly enhanced, becoming a key driver for carbon reduction goals.

[0004] Converting carbon dioxide into fuel is the core path to achieve a closed-loop of carbon elements. By converting the captured CO2 into recyclable substances, it reduces the dependence on fossil resources and lowers net emissions. Among them, the high demand and wide application of synthetic fuels become an important starting point. Using water-based technologies driven by renewable energy (such as wind energy, solar energy) to combine CO2 with hydrogen in water and generate methanol, gasoline, diesel, or aviation fuel through catalytic reactions. For example, producing aviation fuel through the Fischer-Tropsch process or developing zero-carbon gasoline. This closed-loop model incorporates it into the energy and industrial systems to achieve carbon recycling. The advantage of fuel substitution is that it can directly replace traditional fossil fuels and is compatible with existing infrastructure, but it faces high consumption and costs. In the future, with the decline in the production cost of green hydrogen and technological optimization, the economic viability and scaling potential of carbon dioxide conversion will be significantly enhanced, becoming a key driver for carbon reduction goals.

[0005] Currently, direct air carbon capture and carbon conversion and utilization belong to different industries and operate independently, without forming a full-chain industry with a synergistic and organically linked upstream and downstream. The world's leading DAC companies are engaged in environmental protection or climate improvement work, and their core task is to reduce the concentration of greenhouse gases. For example, Climeworks is operating its flagship "Mammoth" in Norway, which is currently the world's largest DAC plant with a designed annual carbon capture capacity of 36,000 tons of carbon dioxide. Through cooperation with Carbfix, it mineralizes carbon dioxide into permanent underground basalt storage projects; Carbon Engineering is cooperating with 1PointFive to build the "Stratos" project in the Permian Basin of Texas, USA, aiming to start production in 2025 with an annual carbon capture volume of 500,000 tons of carbon dioxide, with part used for enhanced oil recovery (EOR) and part for geological storage; Heirloom is operating a limestone-based DAC project in California with an annual carbon capture volume of about 1,000 tons of carbon dioxide, and cooperating with CarbonCure to embed carbon dioxide into concrete for permanent storage. Carbon dioxide utilization belongs to the chemical energy industry, emphasizing resource reuse and economic value creation. Due to differences in direction technology, mode, and market demand for economic value creation between these two fields, natural barriers have formed. DAC companies are good at carbon capture and storage but lack professional capabilities in chemical conversion; while chemical energy companies focus on raw material processing and have limited interest in promoting large-scale carbon capture supply and technology docking. In addition, policy support and market incentives often target a single industry or technological innovation respectively, lacking a mechanism to integrate upstream and downstream. Although both have potential good effects in the carbon cycle, it is currently difficult to synthesize a complete chain industry, and there is an urgent need to break through the barriers through cross-industry cooperation and technology integration. Summary of the Invention

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a process method and system for directly capturing carbon dioxide from the air and converting and utilizing it. This process method seamlessly connects the carbon capture and conversion processes to achieve full-chain optimization from carbon dioxide removal to the generation of high-value-added products.

[0007] To achieve the above purpose and other related purposes, the first aspect of the present invention provides a process method for directly capturing carbon dioxide and converting and utilizing it, including:

[0008] a) Adsorbing air through a carbon dioxide capture device and heating and desorbing to obtain purified carbon dioxide gas;

[0009] b) Obtaining syngas, oxygen, and product gas condensate water by electrocatalytic oxidation of the purified carbon dioxide gas and electrolyte, and recycling the product gas condensate water for preparing the electrolyte;

[0010] c) The syngas is used to obtain Fischer-Tropsch oil through the Fischer-Tropsch synthesis reaction. The Fischer-Tropsch oil and hydrogen are used to obtain an isomerized oil and gas mixture through hydrocracking and isomerization. The heat energy of the Fischer-Tropsch synthesis reaction and hydrocracking and isomerization provides the heat for desorption.

[0011] d) The isomerized oil and gas mixture is subjected to gas-liquid separation to obtain combustible gas and upgraded oil products. The upgraded oil products are subjected to distillation operation to obtain sustainable aviation fuel and heavy oil products. The combustible gas undergoes an oxy-fuel combustion reaction with the oxygen in step b) to provide the heat for desorption.

[0012] Preferably, steam is introduced to provide heat for desorbing carbon dioxide. The temperature of the steam is 100 - 120 °C, preferably 110 °C.

[0013] Preferably, the molar ratio of hydrogen to carbon monoxide in the syngas is 1 - 3:1, which can be 1:1, 2:1, or 3:1.

[0014] In the second aspect of the present invention, a system for directly capturing carbon dioxide from the air and its conversion and utilization is provided. Along the gas inflow direction, a carbon dioxide capture module, an electrolysis module, and a Fischer-Tropsch synthesis and upgrading module are successively fluidly connected. The carbon dioxide capture module is successively provided with a carbon dioxide capture device and a carbon dioxide storage tank along the gas inflow direction. The electrolysis module is successively provided with an electrolytic cell and a syngas storage tank along the gas inflow direction. The Fischer-Tropsch synthesis and upgrading module is successively provided with a Fischer-Tropsch synthesis device, a product separation unit, and an upgrading unit along the gas inflow direction. The carbon dioxide capture module, the electrolysis cell module, and the Fischer-Tropsch synthesis and upgrading module are externally connected to a common engineering module, and the common engineering module includes a heat exchange device and a water treatment device.

[0015] Preferably, the carbon dioxide capture device is provided with a steam inlet and a steam outlet. The steam inlet is connected to the heat exchange device through a second pipeline, and the heat of the steam is provided by the heat exchange device for desorbing carbon dioxide.

[0016] Preferably, the carbon dioxide capture device is further provided with a cooling water channel for introducing cooling water into the carbon dioxide capture device.

[0017] Preferably, the carbon dioxide capture module further includes a vacuum device and a first cooling device provided between the carbon dioxide capture device and the carbon dioxide storage tank.

[0018] Preferably, the electrolysis module further includes a compression device provided between the carbon dioxide storage tank of the carbon dioxide capture module and the electrolytic cell, for providing pressure for the high-purity carbon dioxide gas introduced into the electrolytic cell.

[0019] Preferably, the electrolytic cell comprises an anode chamber, a cathode chamber and an ion exchange membrane, wherein the ion exchange membrane is arranged between the anode chamber and the cathode chamber. Specifically, the anode catalyst used in the anode chamber is nickel foam, platinum mesh or titanium mesh, and the cathode catalyst used in the cathode chamber is a nanocatalyst, a molecular catalyst or a metal single atom catalyst.

[0020] Preferably, the anode chamber and cathode chamber of the electrolytic cell are both provided with a feed port and a discharge port, and the feed ports of the anode chamber and cathode chamber of the electrolytic cell are connected to an electrolyte storage tank, and the electrolyte storage tank is used to provide an electrolyte. Specifically, the electrolyte is one or more of a sulfuric acid solution, a potassium sulfate solution, a potassium nitrate solution and a potassium hydroxide solution, preferably a sulfuric acid / potassium sulfate solution with a mass ratio of 5‰. The electrolyte is cooled by a second cooling device and passed into the anode chamber and cathode chamber of the electrolytic cell. Preferably, the feed port of the cathode chamber of the electrolytic cell is connected to a compression device, and carbon dioxide flows from the carbon dioxide storage tank into the cathode chamber of the electrolytic cell after being compressed by a compression device, and then a reduction reaction occurs in the cathode chamber, and synthesis gas is produced at the same time. An oxidation reaction occurs on the surface of the anode chamber of the electrolytic cell to produce oxygen.

[0021] Preferably, the electrolysis module further comprises an oxygen storage tank, and the oxygen storage tank is connected to the discharge port of the anode chamber of the electrolytic cell.

[0022] Preferably, the electrolysis module further comprises a first post-processing device, which is connected to the discharge port of the cathode chamber of the electrolytic cell, and comprises a first gas-liquid separation device and a third cooling device. After the water vapor contained in the synthesis gas is separated by the first gas-liquid separation device, the synthesis gas enters the cooling device, and enters the synthesis gas storage tank for temporary storage after cooling. A second post-processing device is connected between the discharge port of the anode chamber of the electrolytic cell and the oxygen storage tank, and comprises a second gas-liquid separation device and a fourth cooling device. After the water vapor contained in the oxygen generated by the anode chamber is separated by the second gas-liquid separation device, the oxygen enters the cooling device, and enters the oxygen storage tank for temporary storage after cooling.

[0023] Preferably, the Fischer-Tropsch synthesis and upgrading module also includes a second compression device, which is arranged between the synthesis gas storage tank and the Fischer-Tropsch synthesis device and is used to compress the synthesis gas to the pressure required for Fischer-Tropsch synthesis and then pass it into the Fischer-Tropsch synthesis device.

[0024] Preferably, the Fischer-Tropsch synthesis device further comprises a first cooling hot water inlet and a first cooling steam outlet. Fischer-Tropsch synthesis is an exothermic reaction, and cooling water is introduced from the first cooling water inlet to take away a large amount of reaction heat and flows out from the first cooling water outlet. Preferably, the first cooling water outlet is connected to a heat exchange device through a first pipeline, which is used to absorb heat and take away the heat released by the Fischer-Tropsch synthesis reaction when water is converted into water vapor.

[0025] Preferably, the outlet of the Fischer-Tropsch synthesis device is further connected to a product separation unit, which includes a third gas-liquid separation tank and an oil-water separator. The third gas-liquid separation tank includes a gas outlet and a liquid outlet. The gas outlet is connected to the second compression device to recycle the unreacted syngas as recycle gas; the liquid outlet is connected to the oil-water separator.

[0026] Preferably, the oil-water separator further includes a product oil outlet and a water outlet to separate the product oil component and water in the liquid product. The oil outlet is further sequentially connected to a heating device and a pressurizing device to heat and pressurize the oil component, thereby upgrading the Fischer-Tropsch synthesis product.

[0027] Preferably, the upgrading unit further includes a combustion device and a rectification device. The combustion device is connected to the gas outlet of the fourth gas-liquid separation tank to provide combustible gas for the combustion device, and the rectification device is connected to the upgraded oil product outlet of the fourth gas-liquid separation tank.

[0028] The third aspect of the present invention provides the use of the above process method and system in the conversion and utilization of carbon dioxide.

[0029] The system and process method for directly capturing carbon dioxide from the air and converting and utilizing it according to the present invention have the following beneficial effects:

[0030] 1. Develop an integrated and flexible industrial technology platform to seamlessly connect the carbon capture and conversion processes, achieve full-chain optimization from CO2 removal to the production of high-value-added products, break through the technical and market barriers, improve energy efficiency and economy, and make up for the deficiencies of traditional industries acting independently and lacking coordination;

[0031] 2. Through modular design and cross-field compatibility, this patent not only reduces the operating cost, but also promotes the deep integration of the environmental protection and chemical energy industries, providing innovative and replicable solutions for carbon neutrality;

[0032] 3. Energy integration: Meet the cooling demand and partially meet the heat energy demand for carbon dioxide desorption;

[0033] 4. Oxygen-enriched combustion speeds up the combustion reaction rate, improves the heat utilization rate, and reduces the flue gas volume;

[0034] 5. The wastewater is purified and then utilized, reducing the water consumption of the entire industrial chain. Description of the Drawings

[0035] Figure 1 It shows a system diagram for directly capturing carbon dioxide and converting and utilizing it;

[0036] Figure 2 It shows a schematic diagram of the electrolytic cell structure in the electrolysis module.

[0037] Reference Numerals:

[0038] 1 Carbon Dioxide Capture Module

[0039] 11 Induced Draft Fan

[0040] 12 Carbon Dioxide Capture Device

[0041] 121 Steam Inlet

[0042] 122 Steam Outlet

[0043] 13 Vacuum Device

[0044] 14 First Cooling Device

[0045] 15 Carbon Dioxide Storage Tank

[0046] 2 Electrolysis Module

[0047] 21 Electrolyte Storage Tank

[0048] 22 Second Cooling Device

[0049] 23 Electrolyzer

[0050] 231 Anode Chamber

[0051] 232 Cathode Chamber

[0052] 233 Anode Chamber Feed Inlet

[0053] 234 Cathode Chamber Feed Inlet

[0054] 235 Anode Chamber Discharge Outlet

[0055] 236 Cathode Chamber Discharge Outlet

[0056] 24 First Gas-Liquid Separation Tank

[0057] 25 Third Cooling Device

[0058] 26 Syngas Storage Tank

[0059] 27 Second Gas-Liquid Separation Tank

[0060] 28 Fourth Cooling Device

[0061] 29 Oxygen Storage Tank

[0062] 210 First Compression Device

[0063] 3 Fischer-Tropsch Synthesis and Upgrading Module

[0064] 31 Second Compression Device

[0065] 32 Fifth Cooling Device

[0066] 33 Fischer-Tropsch synthesis unit

[0067] 331 First cooling hot water inlet

[0068] 332 First cooling steam outlet

[0069] 34 Third gas-liquid separation tank

[0070] 341 Second cooling water inlet

[0071] 342 Second cooling water outlet

[0072] 35 Oil-water separation tank

[0073] 36 Heating device

[0074] 37 Pressurizing device

[0075] 38 Upgrading unit

[0076] 381 Hydrocracking reactor

[0077] 382 Fourth gas-liquid separation tank

[0078] 383 Combustion device

[0079] 3831 Third cooling water inlet

[0080] 3832 Fourth cooling water inlet

[0081] 384 Fifth gas-liquid separation tank

[0082] 385 Distillation device

[0083] 386 Seventh cooling device

[0084] 387 Eighth cooling device

[0085] 388 Sixth cooling device

[0086] 4 Utility module

[0087] 41 Heat exchange device

[0088] 42 Water treatment device

[0089] 100 First pipeline

[0090] 200 Second pipeline

[0091] 300 Third pipeline

[0092] 400 Fourth pipeline

[0093] 500 Fifth pipeline

[0094] 600 Sixth pipeline Detailed implementation manners

[0095] The present invention provides a process for directly capturing carbon dioxide from air and converting and utilizing it, which comprises the following steps:

[0096] a) Adsorbing the raw material gas by a carbon dioxide capture device, and heating and desorbing to obtain purified carbon dioxide gas;

[0097] b) Obtaining syngas, oxygen and product gas condensate water by electrocatalytic conversion of the purified carbon dioxide gas and electrolyte, and recycling the product gas condensate water for preparing the electrolyte;

[0098] c) Obtaining Fischer-Tropsch oil by Fischer-Tropsch synthesis of the syngas, and obtaining an isomerized oil and gas mixture by hydrocracking and isomerization of the Fischer-Tropsch oil and hydrogen, wherein the heat energy of the Fischer-Tropsch synthesis and hydrocracking and isomerization provides the heat for heating and desorbing;

[0099] d) Separating the isomerized oil and gas mixture into combustible gas and upgraded oil products, obtaining sustainable aviation fuel and heavy oil products by rectifying the upgraded oil products, and performing an oxy-fuel combustion reaction of the combustible gas and the oxygen in step b) to provide the heat for heating and desorbing.

[0100] According to the process requirements, the feeding temperature of the above-mentioned air is 10-40°C, preferably 20°C; the humidity of the above-mentioned air is 5%RH-95%RH.

[0101] The carbon dioxide capture device adopts solid adsorption, liquid desorption, variable humidity adsorption or electrochemical solution to capture carbon dioxide in the air. Preferably, the above-mentioned carbon dioxide capture device adopts solid adsorption, preferably a resin-based carbon dioxide adsorbent. More preferably, the active functional groups of the aforementioned adsorbent are one or two of amine groups and quaternary ammonium groups, preferably amine groups. By chemically modifying and introducing amine groups, the adsorption capacity of the resin for carbon dioxide can be significantly enhanced, the capture rate can be accelerated, the capture time can be saved, and the capture efficiency can be improved.

[0102] Taking primary amine as an example, the chemical equation (1) for adsorbing and desorbing carbon dioxide is as follows:

[0103]

[0104] Preferably, the adsorption efficiency of the above-mentioned adsorbent is 0.20-0.30 kgCO2 / kgS / day, preferably 0.30 kgCO2 / kgS / day. In the above unit, S represents solid adsorbent, and kgCO2 / kgS / day represents the amount of carbon dioxide absorbed by each kilogram of solid adsorbent per day.

[0105] In a preferred embodiment, the temperature of the above-mentioned heating and desorption is 80-120 °C, preferably 110 °C.

[0106] In step S2, the pressure for the electrocatalytic oxidation of the high-purity carbon dioxide gas is 5-8 bar, preferably 7 bar; the temperature is 30-50 °C, preferably 40 °C.

[0107] Preferably, the above-mentioned electrolyte is one or more of sulfuric acid solution, potassium sulfate solution, potassium nitrate solution and potassium hydroxide solution, preferably a sulfuric acid / potassium sulfate solution with a mass ratio of 5‰.

[0108] In a preferred embodiment, by controlling the electrolysis potential and selecting a specific electrolyte for regulation, synthesis gas with different ratios of carbon monoxide to hydrogen is obtained, providing the possibility of obtaining a variety of different products downstream.

[0109] Taking the sulfuric acid / potassium sulfate solution as an example, the chemical equation (2) for the electrocatalytic conversion of carbon dioxide is as follows:

[0110]

[0111] Among them, the chemical equation (3) for the reduction reaction occurring at the cathode is as follows:

[0112] CO2 + 4e - +4H + → CO + H2 + H2O (3)

[0113] The chemical equation (4) for the oxidation reaction occurring at the anode is as follows:

[0114] 2H2O→O2+ 4e - +4H + (4)

[0115] Furthermore, the adjustable molar ratio of hydrogen to carbon monoxide in the above-mentioned synthesis gas is 1-3:1, and can be 1:1, 2:1, 3:1.

[0116] In a preferred embodiment, the electrolytic water generated by the electrocatalytic conversion is recycled through water treatment operations and used to prepare the electrolyte, reducing the water consumption in the process.

[0117] In step S3, the pressure for the Fischer-Tropsch synthesis reaction of the synthesis gas is 20-40 bar, preferably 30 bar; the temperature is 200-400 °C, preferably 300 °C.

[0118] In a preferred embodiment, the pressure for introducing hydrogen is 70-90 bar, preferably 80 bar; the temperature is 20-30 °C, preferably 25 °C.

[0119] In a preferred embodiment, the mass ratio of the aforementioned hydrogen to the Fischer-Tropsch oil is 30 to 50:1. Sufficient hydrogen supply provides sufficient hydrogen atoms for hydrocracking and isomerization, promoting the cracking reaction of large hydrocarbon molecules. Additionally, the hydrogenation process can saturate unsaturated hydrocarbons, making the product have better stability and improving the low-temperature fluidity of the product.

[0120] The pressure of the above-mentioned hydrocracking and isomerization is 70 to 90 bar, preferably 80 bar; the temperature is 300 to 400 °C, preferably 350 °C.

[0121] In a specific embodiment, both the above-mentioned Fischer-Tropsch synthesis reaction and hydrocracking and isomerization are exothermic reactions, and the heat energy generated by the reactions can be used as the heat source for the carbon dioxide desorption process.

[0122] In step S4, the mass ratio of the above-mentioned oxygen to the combustible gas is 4 to 6:1. Oxygen acts as an oxidizer to improve the combustion efficiency and reduce pollutant emissions. Due to the increase in the oxygen content, the required amount of combustion-supporting air is reduced, thereby reducing the flue gas volume and the flue gas loss.

[0123] In a preferred embodiment, the temperature of the above-mentioned oxy-fuel combustion is 200 to 300 °C, preferably 250 °C. Heat is obtained through oxy-fuel combustion for use in desorbing carbon dioxide.

[0124] Furthermore, the above-mentioned rectification operation uses a rectification column, and the rectification column includes a condenser at the top of the column and a reboiler at the bottom of the column. Through the rectification operation, the upgraded oil products are separated according to the volatility differences of each component, enabling the light components (low-boiling components) in the mixture to be enriched at the top of the column and the heavy components (high-boiling components) to be enriched at the bottom of the column, thereby achieving separation.

[0125] Among them, the temperature of the reboiler at the bottom of the column is 300 to 400 °C, preferably 350 °C; the temperature of the condenser at the top of the column is 150 to 200 °C, preferably 200 °C. Further preferably, sustainable aviation fuel is enriched at the top of the column and obtained by flowing out through the condenser at the top of the column, and the heavy oil product is enriched at the bottom of the column and obtained by flowing out through the reboiler at the bottom of the column. Furthermore, the top of the column is composed of light hydrocarbon components, including C4-C16 hydrocarbon components, among which the C8-C16 hydrocarbon components account for 88% to 95%, including straight-chain alkanes, branched-chain alkanes, cycloalkanes, and aromatic hydrocarbons, the C4-C8 hydrocarbon components account for 5% to 10%, and other light hydrocarbons or un-cracked long-chain alkanes account for 2% to 5%. The bottom of the column mainly consists of heavy oil products, including 98% to 100% of alkanes with more than C17 and other light hydrocarbon components.

[0126] The present invention also provides a system for directly capturing carbon dioxide from the air and converting and utilizing it, as Figure 1As shown in the figure, a carbon dioxide capture module 1, an electrolysis module 2, and a Fischer-Tropsch synthesis and upgrading module 3 are arranged in sequence along the gas inflow direction and are in fluid communication with each other. The carbon dioxide capture module 1 is provided with a carbon dioxide capture device 12 and a carbon dioxide storage tank 15 in sequence along the gas inflow direction and they are in fluid communication with each other. The electrolysis module 2 is provided with an electrolytic cell 23 and a syngas storage tank 26 in sequence along the gas inflow direction and they are in fluid communication with each other. The Fischer-Tropsch synthesis and upgrading module 3 is provided with a Fischer-Tropsch synthesis device 33 and an upgrading unit 38 in sequence along the gas inflow direction and they are in fluid communication with each other. A common engineering module 4 is externally connected to the carbon dioxide capture module 1, the electrolysis module 2, and the Fischer-Tropsch synthesis and upgrading module 3. The common engineering module 4 includes a heat exchange device 41 and a water treatment device 42.

[0127] Further, the above heat exchange device recovers and reuses the heat generated by the system, meeting the cooling demand while meeting the heat demand of the system. The above water treatment device treats wastewater through steps of pretreatment, primary treatment, secondary treatment, and tertiary treatment. The pretreatment includes separating oil and water, neutralizing and adjusting, and coagulating and precipitating the wastewater, and preliminarily pretreating the recycled water. The primary treatment includes anaerobic and aerobic treatments to degrade organic substances into inorganic substances to achieve the purpose of purifying water quality. The secondary treatment includes steps of activated carbon adsorption and multi-effect evaporation, further removing fine suspended solids and colloidal substances in water through high-efficiency filtration to ensure that the effluent water quality meets the reuse standard. The tertiary treatment includes steps of ultrafiltration, reverse osmosis, and electro-desealing to further treat and ensure that the water quality can be recycled.

[0128] In a preferred embodiment, the above heat exchange device is selected from heat exchangers, and the above water treatment device is selected from reclaimed water reuse equipment.

[0129] As Figure 1 shown in the figure, an induced draft fan 11 is further connected to the gas inlet end of the carbon dioxide capture device 12 for introducing air or other gases containing carbon dioxide.

[0130] The above carbon dioxide capture device 12 captures carbon dioxide in the air by solid adsorption, liquid absorption, variable humidity adsorption, or electrochemical solution. Preferably, the above carbon dioxide capture device 12 uses solid adsorption, preferably a resin-based carbon dioxide adsorbent. More preferably, the active functional groups of the aforementioned adsorbent are one or both of amine groups and quaternary ammonium groups, preferably amine groups. By chemically modifying and introducing amine groups, the adsorption capacity of the resin for carbon dioxide can be significantly enhanced, the capture rate can be accelerated, the capture time can be saved, and the capture efficiency can be improved.

[0131] When a large amount of air enters the carbon dioxide capture device 12 during adsorption, the weakly basic groups on the surface of the solid amine come into full contact with carbon dioxide in the air and undergo a chemical reaction, thereby fixing a large amount of carbon dioxide on the surface of the solid amine adsorbent until saturation; when adsorption saturation occurs, high-concentration carbon dioxide is released by heating, thus completing a complete adsorption-desorption cycle.

[0132] More preferably, the above carbon dioxide capture device is selected from carbon dioxide capturers.

[0133] In a preferred embodiment, the carbon dioxide capture device 12 is further provided with a steam inlet 121 and a steam outlet 122. The steam inlet 121 is connected to the outlet of the heat exchange device 41 through the second pipeline 200, and the heat of the steam required for desorbing carbon dioxide is provided by the heat exchange device 41 for desorbing carbon dioxide.

[0134] In a preferred embodiment, the above carbon dioxide capture device 12 is further provided with a cooling water channel for introducing cooling water into the carbon dioxide capture device.

[0135] Preferably, the above carbon dioxide capture module 1 further includes a vacuum device 13 and a first cooling device 14 provided between the carbon dioxide capture device 12 and the carbon dioxide storage tank 15. The aforementioned vacuum device 13 is used to discharge the air in the carbon dioxide gas, prevent it from mixing into the carbon dioxide and causing a decrease in the carbon dioxide concentration, and prevent the aging of the adsorption material by the oxygen in the air under high-temperature and high-humidity conditions; the aforementioned first cooling device 14 is used to cool the high-temperature carbon dioxide. Preferably, the above first cooling device 14 is connected to the inlet of the water treatment device 42 through the fifth pipeline 500 for recovering cooling water. More preferably, the above first cooling device 14 is selected from the first condensation tower.

[0136] In the above system, as Figure 1 shown, the electrolysis module 2 further includes a first compression device 210, and the first compression device 210 is arranged between the carbon dioxide storage tank 15 of the carbon dioxide capture module 2 and the electrolytic cell 23 for compressing the carbon dioxide gas and introducing it into the electrolytic cell 23.

[0137] In a preferred embodiment, the main function of the electrolysis module 2 is to electrochemically reduce the high-purity carbon dioxide obtained by the carbon dioxide capture module 1 to carbon monoxide. At the same time, hydrogen and oxygen will also be obtained during the electrolysis of water, and synthesis gas of different specifications can be obtained by mixing carbon monoxide and hydrogen in different proportions.

[0138] Specifically, as Figure 2As shown, the electrolytic cell 23 includes an anode chamber 231, a cathode chamber 232, and a diaphragm disposed between the anode chamber 231 and the cathode chamber 232. Specifically, the anode catalyst used in the anode chamber 231 is nickel foam, platinum mesh, or titanium mesh, and the cathode catalyst used in the cathode chamber 232 is a nano-catalyst, a molecular catalyst, or a metal single-atom catalyst.

[0139] In a specific embodiment, both the anode chamber 231 and the cathode chamber 232 of the electrolytic cell are provided with a feed port and a discharge port. The feed ports 233 and 234 of the anode chamber 231 and the cathode chamber 232 of the electrolytic cell are both connected to an electrolyte storage tank 21. The feed ports of the anode chamber and the cathode chamber communicate with the discharge port of the electrolyte storage tank 21 for supplying electrolyte to the electrolytic cell. Specifically, the electrolyte is one or more of sulfuric acid solution, potassium sulfate solution, potassium nitrate solution, and potassium hydroxide solution, preferably a sulfuric acid / potassium sulfate solution with a mass ratio of 5‰. The electrolyte is cooled by a second cooling device 22 and then introduced into the anode chamber 231 and the cathode chamber 232 of the electrolytic cell. Preferably, the feed port of the cathode chamber 234 of the electrolytic cell is connected to a first compression device 210. Carbon dioxide flows from a carbon dioxide storage tank 15 into the cathode chamber 232 of the electrolytic cell after being compressed by the first compression device 210, and then a reduction reaction occurs in the cathode chamber 232, generating syngas simultaneously. An oxidation reaction occurs on the surface of the anode chamber 231 of the electrolytic cell, producing oxygen. More preferably, the above-mentioned second cooling device 22 is selected from a second condensing tower, and the above-mentioned first compression device 210 is selected from a first air compressor.

[0140] Further preferably, as Figure 1 shown, the feed port of the above-mentioned electrolyte storage tank 21 is connected to the outlet of a water treatment device 42 of a public works module 4 through a sixth pipeline 600 for reusing the water recovered in the system and reducing water resource waste.

[0141] In a further embodiment, the above-mentioned electrolysis module further includes a post-treatment unit, and the post-treatment unit includes a first post-treatment unit and a second post-treatment unit. Preferably, the above-mentioned electrolysis module further includes an oxygen storage tank (29), and the oxygen storage tank (29) communicates with the discharge port of the anode chamber of the electrolytic cell for storing the oxygen generated at the anode.

[0142] In another embodiment, as Figure 1 and Figure 2As shown, the first post-processing unit is arranged at the discharge port 236 of the cathode chamber of the electrolytic cell, and the post-processing unit includes a first gas-liquid separation tank 24 and a third cooling device 25. After the water vapor contained in the synthesis gas is separated by the first gas-liquid separation tank 24, the synthesis gas enters the third cooling device 25, and enters the synthesis gas storage tank 26 for temporary storage after being cooled. More preferably, the third cooling device 25 is connected to the inlet of the water treatment device 42 through the fourth pipeline 400, so as to recover the condensed water. Specifically, the third cooling device 25 is selected from the third condensation tower

[0143] Preferably, the discharge port 235 of the anode chamber of the electrolytic cell is connected to a second post-processing unit, which includes a second gas-liquid separation tank 27 and a fourth cooling device 28. The oxygen generated by the anode chamber 232 passes through the second gas-liquid separation tank 27 to separate the contained water vapor, enters the fourth cooling device 28, and enters the oxygen storage tank 29 for temporary storage after being cooled. More preferably, the fourth cooling device 28 is connected to the inlet of the water treatment device 42 through the fourth pipeline 400, which is used to recycle the condensed water for reuse. Specifically, the fourth cooling device 28 is selected from the fourth condensation tower.

[0144] In the above system, if Figure 1 As shown, the Fischer-Tropsch synthesis and upgrading module 3 also includes a second compression device 31, which is arranged between the synthesis gas storage tank 26 and the Fischer-Tropsch synthesis device 33, and is used to compress the synthesis gas to the pressure required for Fischer-Tropsch synthesis and then pass it into the Fischer-Tropsch synthesis device 33. The synthesis gas flowing into the second compression device 33 will first be compressed to the pressure required for Fischer-Tropsch synthesis, and then input into the Fischer-Tropsch synthesis device 33. Preferably, the compressed synthesis gas also needs to be cooled by the protective cooling water of the fifth cooling device 32 before passing into the Fischer-Tropsch synthesis device 33, and the fifth cooling device 33 is arranged between the second compression device 31 and the Fischer-Tropsch synthesis device 33. Specifically, the above-mentioned Fischer-Tropsch synthesis device 33 is selected from the Fischer-Tropsch synthesizer, the above-mentioned second compression device 31 is selected from the second air compressor, and the fifth cooling device 33 is selected from the fifth condensation tower.

[0145] In a preferred embodiment, the Fischer-Tropsch synthesis device 33 further includes a first cooling water inlet 331 and a first cooling water outlet 332. Fischer-Tropsch synthesis is an exothermic reaction, and cooling water is introduced from the first cooling water inlet 331 to take away a large amount of reaction heat, and flows out from the first cooling outlet 332. Preferably, the first cooling water outlet 332 is connected to the inlet of the heat exchange device 41 through the first pipeline 100, and is used to absorb heat when the heat released by the Fischer-Tropsch synthesis reaction is converted from water to water vapor. The excess steam from the Fischer-Tropsch synthesis device 33 is preferably used to heat other equipment units without the need to input steam from the outside.

[0146] In a preferred embodiment, the outlet of the Fischer-Tropsch synthesis unit 33 is further connected to a product separation unit, and the product separation unit includes a third gas-liquid separation tank 34 and an oil-water separator 35. The third gas-liquid separation tank 34 includes a gas outlet and a liquid outlet. The gas outlet is connected to the second compression device 31 to recycle the unreacted syngas as recycle gas; the liquid outlet is connected to the oil-water separator 35. Preferably, the third gas-liquid separation tank 34 further includes a second cooling hot water inlet 341 and a second cooling steam outlet 342, which use hot water to take away the heat of the Fischer-Tropsch reaction and further cool the crude Fischer-Tropsch syngas for gas-liquid separation. The second cooling steam outlet 342 is connected to the inlet of the heat exchange device 41 through a first pipeline 100 to recover and reuse the heat of the crude Fischer-Tropsch syngas.

[0147] In a preferred embodiment, the oil-water separator 35 further includes a product oil outlet and a water outlet to separate the product oil component and water in the crude Fischer-Tropsch syngas. The oil outlet is further sequentially connected to a heating device 36 and a pressurizing device 37 to heat and pressurize the oil component, thereby upgrading the Fischer-Tropsch synthesis product. The water outlet is connected to the inlet of the water treatment device 42 through a third pipeline 300 for recycling the water component. Specifically, the heating device 36 is selected from heaters, and the pressurizing device 37 is selected from pressurizing pumps.

[0148] In a specific embodiment, the heating device 36 and the pressurizing device 37 are connected between the oil-water separator 35 and the upgrading unit 38, and the upgrading unit 38 includes a hydrocracking and isomerization reactor 381 and a fourth gas-liquid separation tank 382 connected in sequence. The Fischer-Tropsch synthesis product is refined into synthetic fuels, especially aviation turbine fuels, diesel oils, paraffin oils, and / or crude gas oils, such as kerosene (SAF - Sustainable Aviation Fuel), crude gasoline or light gasoline, through the upgrading unit 38. To manufacture industrial kerosene, diesel oil, and crude gasoline, it is necessary to convert the paraffin products produced by Fischer-Tropsch synthesis through hydroisomerization and hydrocracking to generate an isomerized oil-gas mixture to manufacture high-value aviation turbine fuels that meet the cold property requirements.

[0149] Further preferably, the hydrocracking and isomerization reactor 381 further includes a hydrogen inlet to provide the hydrogen required for the hydroisomerization and hydrocracking reactions. Further, the hydrogen is provided by the electrolytic cell of the electrolysis module, or the hydrogen is provided by an external hydrogen tanker or hydrogen gas cylinder.

[0150] More specifically, the isomerized oil-gas mixture after the hydrocracking and isomerization reaction enters the fourth gas-liquid separation tank 382 after being cooled by a sixth cooling device 388 to separate combustible gas and upgraded oil products. Specifically, the sixth cooling device is selected from a sixth condensing tower.

[0151] In a specific embodiment, the above-mentioned upgrading unit further includes a combustion device 383 and a rectification device 385. The combustion device 383 is connected to the gas outlet of the fourth gas-liquid separation tank 382 to provide combustible gas for the combustion device 383. The rectification device 385 is connected to the upgraded oil product outlet of the fourth gas-liquid separation tank 382. Preferably, the combustion device 383 further includes an oxygen input port, which is connected to the oxygen storage tank 29 and is used for oxy-fuel combustion of the combustible gas and oxygen. The combustion device 383 further includes a third cooling water inlet 3831 and a third cooling water outlet 3832. The third cooling water outlet 3832 is connected to the inlet of the heat exchange device 41 through a first pipeline 100 and serves as a heat source for the carbon dioxide capture module 1. Specifically, the above-mentioned combustion device 383 is selected from a burner.

[0152] Specifically, the discharge port of the above-mentioned combustion device 383 is further connected to a fifth gas-liquid separation tank 384. The fifth gas-liquid separation tank 384 includes a gas outlet and a liquid outlet. The gas outlet is connected to the heat exchange device 41 through a first pipeline 100 to provide heat for the carbon dioxide capture module 1. The liquid outlet is connected to the inlet of the water treatment device 42 through a third pipeline 300 to provide electrolyte for the electrolyte storage tank 21.

[0153] Preferably, the rectification device 382 is selected from a rectification tower, and the rectification tower includes a condenser at the top of the tower and a reboiler at the bottom of the tower. Through rectification operation, the upgraded oil product is separated according to the volatility differences of each component, so that the light components (low-boiling components) in the mixture are enriched at the top of the tower, and the heavy components (high-boiling components) are enriched at the bottom of the tower, thereby achieving separation. The rectification tower includes 8-12 theoretical plates and uses Pall rings as packing. The upgraded oil product is disassembled into different distillates and obtained products after being cooled by a seventh cooling device 386 and an eighth cooling device 387, such as flood control turbine fuel and diesel, aviation turbine fuel and crude gas oil, aviation turbine fuel, crude gasoline and diesel, or similar heavy oil products.

[0154] In a preferred embodiment, the cooling water outlets of the above-mentioned seventh cooling device 386 and eighth cooling device 387 are connected to the inlet of the heat exchange device to further provide heat for desorbing carbon dioxide.

[0155] To better understand the present invention, the following refers to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0156] Example 1 - Module 1 - Carbon Dioxide Capture Module

[0157] Resin-based carbon dioxide adsorbents are selected, with a carbon dioxide capture efficiency of 40%, carbon dioxide in the air at 420 ppm, and an air circulation volume of 1 million cubic meters per day. The production efficiency of the adsorbent is 0.25 kgCO2 / kgS / day, so the required amount of adsorbent is 1200 kgS. Each carbon dioxide capturer is loaded with 400 kg of adsorbent, so 3 carbon dioxide capturers need to be set up. Since the adsorbent itself contains hydrophilic groups and has certain water absorption characteristics, moisture needs to be removed synchronously during carbon dioxide desorption. The molar ratio of carbon dioxide to moisture is between 0.70 and 0.90, and calculated at 0.80, the heat for desorbing moisture is 1.225 MJ / kgCO2, and the heat for carbon dioxide desorption remains unchanged at 1.70 MJ / kgCO2. According to the bulk density of the required 1200 kg of adsorbent and the air contactor with supporting dimensions, the total heat required for heating the adsorbent and the air contactor, and the heat of the purge gas (110°C water vapor, sensible heat and latent heat) is 8.625 MJ / kgCO2 (2.555 + 4.070 + 2.0). In addition, the electrical energy consumption required for the air circulation fan and vacuum device (0.080 bar) configured for the air contactor is 3 MJ / kgCO2 (1.0 + 2.0).

[0158] Therefore, the required thermal energy is 12.5 kgCO2 / h × (1.225 + 1.70 + 8.625) MJ / kgCO2 = 144.375 MJ / h = 40.10 kW; the required electrical energy is 12.5 kgCO2 / h × 3 MJ / kgCO2 = 37.5 MJ / h = 10.4 kW.

[0159] Among them, the theoretically recoverable heat is 12.5 kgCO2 / h × 8.625 MJ / kgCO2 = 107.8 MJ / h = 29.9 kW. In fact, for 12.5 kg / h of carbon dioxide and 20.1 kg / h of water cooling from 100°C to 25°C (generally, the inlet temperature of the cooling water is 20°C and the outlet is 30°C), the recoverable heat is 15.29 kW, and the cooling water demand is 3.25 tons per day. The sensible heat and latent heat released by the purge steam (from 110°C gas to 100°C liquid) is 7.67 kW, and the remaining 40.10 - 7.67 = 32.43 kW is provided by hot water at 110°C. The hot water cools from 110°C to 80°C, and the calculated hot water flow rate is 21 tons per day. Assuming that 1 / 5 - 1 / 3 of the high-temperature (80 - 100°C) heat of the solid adsorbent material and the carbon dioxide capturer after carbon dioxide desorption is taken away by the cooling water, that is, 1 / 4 of the theoretically recoverable heat of 29.9 kW = 7.475 kW is taken away by the cooling water, then the cooling water (20 - 30°C) demand is 1.58 tons per day. In this way, the total recoverable heat is 15.29 + 7.475 = 22.765 kW.

[0160] Example 2 Module 2 - Electrolysis Module

[0161] Carbon dioxide from the carbon dioxide storage tank is boosted to 5 - 8 bar by the first air compressor (including condenser). Here, the gas is heated up after compression. Assuming the gas pressure rises to 7 bar, the heat released by the gas cooling is approximately 0.59 kW, and this part of energy recovery is ignored. The carbon dioxide gas enters the cathode chamber of the 2.1 electrolyzer. A reduction reaction occurs at the cathode to generate syngas (carbon monoxide and hydrogen), and the ratio of hydrogen to carbon monoxide can be adjusted from 1 - 3:1; an oxidation reaction occurs at the anode to generate oxygen. Both the syngas and oxygen gas streams contain a large amount of water vapor and need to be treated by preliminary condensation (separation tanks AB) and deep cold drying (cold drying equipment AB). After treatment, the two gas streams enter their respective storage tanks (oxygen storage tank, carbon dioxide storage tank). The electrolyte is pumped out from the electrolyte storage tank and enters the electrolyzer. The flow rate of the electrolyte (5‰ sulfuric acid / potassium sulfate solution) is 4.5 tons per day. The temperature of the electrolyte rises to 85 °C after passing through the electrolyzer and then returns to the electrolyzer after being cooled by the heat exchanger. The heat exchanger is cooled by cooling water (temperature 20 - 30 °C, flow rate 9.8 tons per day), and the heat exchange amount is 4.71 kW.

[0162] Example 3 Fischer - Tropsch Synthesis and Upgrading Module

[0163] The syngas obtained in Example 2 and the recycle gas flashed out after Fischer - Tropsch synthesis are compressed together and then enter the Fischer - Tropsch synthesizer for Fischer - Tropsch reaction. The heat released in the Fischer - Tropsch synthesizer is carried away by the heat absorption when hot water turns into water vapor. The synthesis products are complex in composition, including unreacted gas, light hydrocarbon components, jet fuel components, paraffin oil, and water, etc. The syngas passes through the third gas - liquid separation tank to remove the unreacted gas therein and enters the compressor inlet for recycle use. The separated liquid components enter the oil - water separator for chromatography. The separated water is discharged from the lower part, and after membrane purification and desalination treatment, it serves as one of the supplementary water sources for the electrolyte; the upper components are synthetic oil products, which are heated to 350 °C by a heater, and after the pressure is increased by a high - pressure pump, they enter the dewaxing hydrocracking and isomerization reactor. The purchased high - pressure hydrogen is depressurized to 80 bar and then enters the dewaxing hydrocracking and isomerization reactor. The resulting oil - gas mixture is cooled from 350 °C to 200 °C by the sixth cooling device. The cooled oil - gas mixture is separated into combustible gas and upgraded oil products with a higher SAF content after passing through the fourth gas - liquid separation tank. The combustible gas enters the burner and undergoes oxy - fuel combustion with a part of the oxygen from the oxygen storage tank, and the heat released is used as a heat source for the front - end carbon dioxide capture module. The oil products from the oil - water separator are heated to 200 °C by a heating device and then enter the distillation column (8 - 12 theoretical plates, Pall ring packing). The jet fuel components are produced at the top of the distillation column, and the heavy oil part is produced at the bottom. After cooling, they enter the product storage tanks respectively, waiting for detection and sales.

[0164] Example 4 - Public Works Module

[0165] The public works system includes two parts: heat recovery and water recovery. It is required that both energy and water reach a balanced state, and the insufficient heat is supplemented by electric heating or gas filtration.

[0166] Heat demand side: Steam inlet of the carbon dioxide capture device, 110°C, 280 kg / day, 7.67 kW;

[0167] Hot water for carbon dioxide desorption, 110°C, 21000 kg / day, 32.43 kW.

[0168] Heat supply side: Cooling steam of the Fischer-Tropsch synthesis device, 120°C, 530 kg / day, 13.79 kW;

[0169] Cooling water of the third gas-liquid separation tank, 25°C, 1380 kg / day, 6.63 kW;

[0170] Desorbed hot water, 25°C, 120 kg / day, 0.59 kW;

[0171] The seventh and eighth cooling devices of the distillation column, 25°C, 310 kg / day, 1.50 kW;

[0172] Cooling water of the combustion device, 80°C, 8400 kg / day, 13.2 kW;

[0173] Gas outlet of the fifth gas-liquid separation tank, 25°C, 380 kg / day, 1.89 kW.

[0174] Matching process: The 120°C steam heats 625 kg / day of desorbed hot water from 30°C to 110°C, and the 2.5 kW of heat is supplemented by an external heat source or electric heating. The remaining cooling water 9800 + 3250 + 1580 - 625 ≈ 14 tons of circulating water is cooled by the air cooler of the public works module.

[0175] Table 1 Heat Matching Table

[0176] Demand side / kW Supply side / kW Difference 7.67 13.79 +6.12 / 120℃ 32.43 10.61+13.2 -8.62 2.5

[0177] 8.62 - 6.12 = 2.5, and this part of the difference is supplemented by electric heating or a gas boiler. For example, an electric heating rod is installed at the steam inlet of the carbon dioxide capture device to provide 2.5 kW, or the natural gas supply volume in the combustion device is increased (0.25 Nm 3 ) to provide 2.5 kW of heat.

[0178] The electrolysis module replenishes 366 kg / day of demineralized water for electrolysis. The existing available water = 524 + 31 + 85 + 114 + 62 = 816 kg / day. After complete treatment, except for replenishing fresh demineralized water, the remaining amount is 816 - 366 = 450 kg / day.

[0179] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A process for directly capturing carbon dioxide from air and its conversion and utilization, comprising the following steps: a) Adsorbing the raw material gas through a carbon dioxide capture device, and heating and desorbing to obtain purified carbon dioxide gas; b) Obtaining syngas, oxygen and product gas condensate by electrocatalytic conversion of the purified carbon dioxide gas and electrolyte, and recycling the product gas condensate to supplement the electrolyte; c) Obtaining Fischer-Tropsch oil through Fischer-Tropsch synthesis reaction of the syngas, and obtaining an isomerized oil and gas mixture by hydrocracking and isomerization of the Fischer-Tropsch oil and hydrogen, and providing heat for heating and desorption by the heat energy of the Fischer-Tropsch synthesis reaction and hydrocracking and isomerization; d) Separating the isomerized oil and gas mixture into combustible gas and upgraded oil products, obtaining sustainable aviation fuel and heavy oil products after rectification operation of the upgraded oil products, and providing heat for heating and desorption by oxy-fuel combustion reaction of the combustible gas and the oxygen in step b).

2. The process method according to claim 1, characterized in that, In step a), any one or more of the following conditions are included: a1) The feeding temperature of the air is 10-40 °C; a2) The carbon dioxide capture device uses solid adsorption, liquid absorption, variable humidity adsorption or electrochemical solution to capture carbon dioxide in the air, preferably resin-based carbon dioxide adsorbent in solid adsorption, and the active functional groups of the resin-based carbon dioxide adsorbent are one or two of amine groups and quaternary ammonium groups; a3) The temperature of the heating and desorption is 80-120 °C.

3. The process method according to claim 1, characterized in that, In step b), any one or more of the following conditions are included: b1) The electrolyte is one or more of sulfuric acid solution, potassium sulfate solution, potassium nitrate solution and potassium hydroxide solution, preferably sulfuric acid / potassium sulfate solution with a mass ratio of 5‰; b2) The pressure of the high-purity carbon dioxide gas is 5-8 bar, and the temperature is 30-50 °C; b3) The molar ratio of hydrogen to carbon monoxide in the syngas is 1-3:

1.

4. The process method according to claim 1, characterized in that, In step c), any one or more of the following conditions are included: c1) The pressure of the syngas for Fischer-Tropsch synthesis reaction is 20-40 bar; the temperature is 200-400 °C; c2) The mass ratio of hydrogen to Fischer-Tropsch oil is 30-50:1; c3) The pressure of the hydrogen is 70-90 bar, and the temperature is 20-30 °C; c4) The pressure of the hydrocracking and isomerization is 70-90 bar; the temperature is 300-400 °C.

5. The process method according to claim 1, characterized in that, In step d), any one or more of the following conditions are included: d1) The mass ratio of oxygen to combustible gas is 4-6:1; d2) The temperature of the oxy-fuel combustion is 200-300 °C, preferably 250 °C; d3) The rectification operation uses a rectification column, and the rectification column includes a top condenser and a bottom reboiler. The temperature of the top condenser is 150-200 °C, and the temperature of the bottom reboiler is 300-400 °C.

6. A system for implementing the process method according to any one of claims 1 to 5, characterized in that, A carbon dioxide capture module (1), an electrolysis module (2), and a Fischer-Tropsch synthesis and upgrading module (3) are arranged in sequence along the gas inflow direction and are in fluid communication with each other. The carbon dioxide capture module (1) is provided with a carbon dioxide capture device (12) and a carbon dioxide storage tank in sequence along the gas inflow direction. The electrolysis module (2) is provided with an electrolytic cell (23) and a syngas storage tank (26) in sequence along the gas inflow direction. The Fischer-Tropsch synthesis and upgrading module (3) is provided with a Fischer-Tropsch synthesis device (33) and an upgrading unit (38) in sequence along the gas inflow direction. A common engineering module (4) is externally connected to the carbon dioxide capture module (1), the electrolysis module (2), and the Fischer-Tropsch synthesis and upgrading module (3). The common engineering module (4) includes a heat exchange device (41) and a water treatment device (42).

7. The system for direct carbon dioxide capture and conversion and utilization according to claim 6, wherein Including any one or more of the following conditions: 1) The carbon dioxide capture device (12) uses solid adsorption, liquid desorption, variable humidity adsorption, or electrochemical solution to capture carbon dioxide in the air; 2) The carbon dioxide capture device (12) is provided with a steam inlet (121) and a steam outlet (122). The steam inlet (121) of the carbon dioxide capture device (12) is connected to the outlet of the heat exchange device (41) through a second pipeline; 3) The electrolytic cell (23) includes an anode chamber (231), a cathode chamber (232), and a diaphragm. The diaphragm is arranged between the anode chamber (231) and the cathode chamber (232). The anode chamber (231) is provided with a feed inlet (233) and a discharge outlet (231). The cathode chamber (232) is provided with a feed inlet (234) and a discharge outlet (232). The feed inlet (234) of the cathode chamber is connected to the outlet of the carbon dioxide storage tank, and the discharge outlet (232) of the cathode chamber is connected to the syngas storage tank (26); 4) The Fischer-Tropsch synthesis device (33) includes a first cooling water inlet (331) and a first cooling hot water outlet (332). The first cooling steam outlet (332) of the Fischer-Tropsch synthesis device (33) is connected to the inlet of the heat exchange device (41) through a first pipeline (100); 5) The upgrading unit (38) includes a hydrocracking and isomerization reactor (381) and a fourth gas-liquid separation tank (382) connected in sequence; 8. The system for directly capturing carbon dioxide and converting and utilizing the same according to claim 7, wherein Including any one or more of the following conditions: 31) An electrolyte storage tank (21) is connected to both the feed inlet (233) of the anode chamber of the electrolytic cell and the feed inlet (234) of the cathode chamber. The feed inlets (233) of the anode chamber and (234) of the cathode chamber are connected to the discharge outlet of the electrolyte storage tank (21); 32) The electrolysis module (2) further includes an oxygen storage tank (29). The oxygen storage tank (29) is connected to the discharge outlet (231) of the anode chamber (231) of the electrolytic cell; 51) The hydrocracking and isomerization reactor (381) is provided with a hydrogen inlet for providing hydrogen for hydrocracking and isomerization; 52) The upgrading unit further includes a combustion device (383) and a rectification device (385). The gas inlet of the combustion device (383) is communicated with the gas outlet of the fourth gas-liquid separation tank (382), and the gas inlet of the rectification device (385) is communicated with the upgraded oil product outlet of the fourth gas-liquid separation tank (382).

9. The system for directly capturing carbon dioxide and converting and utilizing the same according to claim 8, wherein including any one or more of the following conditions: 32) The feed port of the electrolyte storage tank (21) is connected to the outlet of the water treatment device (42) of the utility module (4) through the sixth pipeline (600); 521) The combustion device (383) further includes an oxygen input port, and the oxygen input port is communicated with the oxygen storage tank (29); 522) The combustion device (383) further includes a third cooling water inlet (3831) and a third cooling water (3832) outlet. The third cooling water outlet (3832) is communicated with the inlet of the heat exchange device (41) through the first pipeline (100); 523) The discharge port of the combustion device (383) is further communicated with the inlet of the fifth gas-liquid separation tank (384). The fifth gas-liquid separation tank (384) further includes a gas outlet and a liquid outlet. The gas outlet is communicated with the heat exchange device (41) through the first pipeline (100), and the liquid outlet is communicated with the inlet of the water treatment device (42) through the third pipeline (300); 524) The rectification device (382) is selected from a rectification column.

10. Use of the process method according to any one of claims 1 to 5 and the system according to any one of claims 6 to 9 in the conversion and utilization of carbon dioxide.

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