A direct air carbon capture in-situ utilization system and method

Abstract

The present application belongs to the technical field of air carbon capture and utilization, and discloses a direct air carbon capture in-situ utilization system and method.In the present application, carbon dioxide in the air reacts with alcohol amine absorbent in an in-situ electrically driven reduction device cathode chamber to generate carbamate, so as to achieve the purpose of carbon dioxide absorption and enrichment.After carbon dioxide is enriched, it is subjected to electrocatalytic reduction, and carbamate is reduced to carbon monoxide and alcohol amine by electrons.After carbon dioxide in the air is absorbed and enriched and then electrocatalytically reduced to carbon monoxide, on the one hand, the problems of high cost of low-concentration carbon dioxide capture and difficulty in utilization after capture are solved, and on the other hand, the process of absorption and conversion can be controlled by detecting the PH value of the cathode chamber solution to realize continuous reaction, improve the carbon capture efficiency, and realize high efficiency and low energy consumption of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field related to carbon capture and utilization, and more specifically, relates to a direct air carbon capture in-situ utilization system and method. Background Art

[0002] Direct air capture (DAC) is a promising technology for addressing climate change and reducing atmospheric carbon dioxide concentrations. Compared to traditional carbon capture, utilization, and storage (CCUS) technologies, DAC offers advantages such as flexibility, wide applicability, and geographic independence. It can capture CO2 emissions directly from distributed sources, not just large point sources. By capturing CO2 from the air, DAC can directly reduce atmospheric CO2 levels, which is crucial for achieving carbon neutrality.

[0003] Existing DAC technologies primarily include solution absorption, solid adsorption, and electrodialysis. Liquid absorbents or solid adsorbent materials are used to enrich low-concentration CO2 in the air to high concentrations for geological storage or utilization. DAC technology generally consists of an air capture module, an absorbent or adsorbent regeneration module, and a CO2 storage module. In the air capture module, CO2 is captured from the air using equipment such as induced draft fans, then absorbed or concentrated using an absorbent or adsorbent. The regeneration module regenerates the absorbent or adsorbent through methods such as high-temperature desorption, and finally transfers the collected CO2 to a storage tank for storage. From a thermodynamic perspective, this requires two energy barriers: absorption, desorption, and electrolytic reduction. The main drawback of current DAC technology is its high energy consumption, generally ranging from 5 to 10 GJ / t CO2. This high technical cost results in poor overall technical and economic performance. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the existing technology, the present invention provides a direct air carbon capture in-situ utilization system and method, which is used to solve the problems of high energy consumption and high cost in the carbon dioxide capture and utilization process in the current DAC technology, so as to achieve the technical effect of low-cost enrichment of low-concentration carbon dioxide in the air and in-situ utilization to generate high-value-added fuel.

[0005] To achieve the above objectives, according to one aspect of the present invention, a direct air carbon capture in-situ utilization system is provided, comprising: an air input device, a carbon capture electrocatalytic device, a carbon monoxide storage tank, and a blower;

[0006] The carbon capture electro-catalytic device comprises a direct current power supply and sequentially connected inlet water-blocking gas permeable membrane, in-situ electrically driven reduction device, outlet water-blocking gas permeable membrane, cathode induced draft fan and fourth pipeline; the direct current power supply is used for controlling start and stop of electro-catalytic reduction reaction in the in-situ electrically driven reduction device; the air input device is a gas source of the carbon capture electro-catalytic device;

[0007] The in-situ electrically driven reduction device is sequentially provided with cathode end plate, cathode electrode, cathode chamber, ion exchange membrane, anode chamber, anode electrode and anode end plate from left to right; the anode chamber sensor is installed in the anode chamber and has the functions of detecting pH value, temperature, pressure and liquid level of the anode chamber; the cathode chamber sensor is installed in the cathode chamber and has the functions of detecting pH value, temperature, pressure and liquid level of the cathode chamber; the cathode chamber contains alcohol amine absorbent and the anode chamber contains pure water.

[0008] The carbon monoxide storage tank is connected to one end of the sixth pipeline, the air blower is connected to one end of the fifth pipeline, the other end of the fifth pipeline and the other end of the sixth pipeline are connected to one end of the fourth pipeline through a three-way pipe, the other end of the fourth pipeline is connected to the outlet water-blocking gas permeable membrane; the fourth valve is arranged on the sixth pipeline between the carbon monoxide storage tank and the three-way pipe, and the third valve is arranged on the fifth pipeline between the air blower and the three-way pipe.

[0009] Preferably, the air input device comprises a fan, a first pipeline, an air compressor, a second pipeline, a first valve, a dust removal tower, a third pipeline and a second valve which are sequentially connected; the second valve is connected to the inlet water-blocking gas permeable membrane along the third pipeline.

[0010] Preferably, the cathode liquid supplementing device comprises a sixth valve, an eighth pipeline, a cathode liquid storage tank, a seventh pipeline and a fifth valve which are sequentially connected; the fifth valve is connected to the cathode liquid inlet of the cathode chamber, and the sixth valve is connected to the cathode liquid outlet of the cathode chamber; further comprising a seventh valve and a ninth pipeline connected to the cathode liquid storage tank, when the seventh valve is opened, fresh cathode liquid can be supplemented through the ninth pipeline.

[0011] Preferably, the anode liquid supplementing device and the oxygen storage device are further included, the anode liquid supplementing device comprises a ninth valve, an eleventh pipeline, an anode liquid storage tank, a tenth pipeline and an eighth valve which are sequentially connected; the eighth valve is connected to the anode liquid inlet of the anode chamber, and the ninth valve is connected to the anode liquid outlet of the anode chamber; further comprising a tenth valve and a twelfth pipeline connected to the anode liquid storage tank, when the tenth valve is opened, fresh anode liquid can be supplemented through the twelfth pipeline; the oxygen storage device comprises an anode induced draft fan and an oxygen storage tank which are sequentially connected along the eleventh pipeline; one end of the eleventh pipeline is connected to the anode liquid storage tank, and the other end is connected to the oxygen storage tank.

[0012] Preferably, the alcohol amine absorbent is 3-aminopropanol or 1,3-propanediamine, and the molar concentration is 0.5-5 mol / L.

[0013] Preferably, the cathode electrode is silver foam or nano-silver, and the anode electrode is nickel foam or iridium oxide.

[0014] Preferably, the ion exchange membrane is a proton exchange membrane or an anion exchange membrane.

[0015] The present application relates to the method of the above-mentioned direct air carbon capture in-situ utilization system, comprising the following steps:

[0016] Step S1: air enters the in-situ electrically-driven reduction device through an air input device;

[0017] Step S2: carbon dioxide in the air reacts with the alcohol amine absorbent in the cathode chamber of the in-situ electrically-driven reduction device to generate carbamate, and other components in the air are discharged through the fifth pipeline under the action of the air blower;

[0018] Step S3: the real-time pH value of the alcohol amine absorbent in the cathode chamber is detected by a cathode chamber sensor to determine the degree of enrichment of carbon dioxide in the alcohol amine absorbent, when the real-time pH value is within the range of the first preset pH value and the second preset pH value, the air input device stops air input, and the direct current power supply is turned on;

[0019] Step S4: after the direct current power supply is turned on, an electrocatalytic reduction reaction is carried out, the carbamate is reduced to carbon monoxide and alcohol amine by receiving electrons, the generated carbon monoxide is transported to a carbon monoxide storage tank, and the pure water in the anode chamber is reduced to oxygen which is transported to an oxygen storage tank by an anode induced air blower;

[0020] Step S5: as the electrocatalytic reduction proceeds, the real-time pH value of the alcohol amine absorbent in the cathode chamber gradually increases, when the real-time pH value is within the range of the third preset pH value and the fourth preset pH value, the direct current power supply is turned off, and steps S1-S4 are repeated.

[0021] Preferably, the first preset pH value is less than the second preset pH value, the second preset pH value is less than the third preset pH value, and the third preset pH value is less than the fourth preset pH value.

[0022] Preferably, the first preset pH value in step S3 is 7, and the second preset pH value is 8.

[0023] Preferably, the third preset pH value in step S5 is 11, and the fourth preset pH value is 12.5.

[0024] Overall, compared with the prior art, the direct air carbon capture in-situ utilization system and method provided by the present application mainly has the following beneficial effects:

[0025] 1. The present application can solve the problems of high cost of low concentration carbon dioxide capture and difficulty of utilization after capture by absorbing and enriching carbon dioxide in the air and electrocatalytically reducing it to carbon monoxide by the in-situ electrically driven reduction device. On the other hand, the process of absorption and conversion can be controlled by detecting the pH value of the cathode chamber solution to realize continuous reaction, improve the carbon capture efficiency, and realize high efficiency of the system.

[0026] 2. The system of the present application combines the two key steps of carbon capture and electrocatalytic reduction of carbon dioxide in the air, realizes the effective conversion and utilization of carbon dioxide, and reduces the cost of carbon sequestration. The present application absorbs low concentration carbon dioxide by using alcohol amine absorption solvent, and omits the absorption process. From the thermodynamic point of view, the absorption and electrolytic reduction processes are experienced, only one energy barrier needs to be crossed, and the energy consumption is reduced. In addition, due to the integration of the reaction process, the number of reactors is reduced, and the system cost and total energy consumption are reduced.

[0027] 3. The in-situ electrically driven reduction device for carbon dioxide capture has a compact structure, can be modularized, is conducive to equipment installation and transfer and application, has the potential for large-scale application, and can adapt to different scales and needs of carbon dioxide capture and reduction scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a process flow diagram of a direct air carbon capture in-situ utilization system;

[0029] Figure 2 It is a schematic diagram of an in-situ electrocatalytic reduction device in a direct air carbon capture in-situ utilization system;

[0030] Figure 3 It is a reaction principle schematic diagram of a direct air carbon capture in-situ utilization system.

[0031] In all the drawings, the same reference signs are used to indicate the same elements or structures, wherein: 1, fan; 2, air compressor; 3, dust removal tower; 4, inlet water-blocking air permeable membrane; 5, in-situ electrically driven reduction device; 6, outlet water-blocking air permeable membrane; 7, direct current power supply; 8, cathode induced draft fan; 9, air blower; 10, carbon monoxide storage tank; 11, cathode liquid storage tank; 12, cathode liquid water pump; 13, anode liquid storage tank; 14, anode liquid water pump; 15, anode induced draft fan; 16, oxygen storage tank; 201, first pipeline; 202, second pipeline; 203, third pipeline; 204, fourth pipeline; 205, fifth pipeline; 206, sixth pipeline; 207, seventh pipeline; 208, eighth pipeline; 209, ninth pipeline; 210, tenth pipeline; 211, eleventh pipeline; 212, twelfth pipeline; 213, tee; 301, first valve; 302, second valve; 303, third valve; 304, fourth valve; 305, fifth valve; 306, sixth valve; 307, seventh valve; 308, eighth valve; 309, ninth valve; 310, tenth valve; 501, cathode end plate; 502, anode end plate; 503, cathode electrode; 504, anode electrode; 505, cathode chamber; 506, anode chamber; 507, ion exchange membrane; 508, anode chamber sensor; 509, cathode chamber sensor; 701, cathode power supply line; 702, anode power supply line. DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0033] The present application provides a direct air carbon capture in-situ utilization system, comprising: an air input device, a carbon capture electro-catalytic device, a carbon monoxide storage tank 10, an air blower 9, as shown in Figure 1 .

[0034] The carbon capture electro-catalytic device comprises a direct current power supply 7 and an inlet water-blocking air permeable membrane 4, an in-situ electrically driven reduction device 5, an outlet water-blocking air permeable membrane 6, a cathode induced draft fan 8 and a fourth pipeline 204 connected in sequence, the direct current power supply 7 is used to control the start and stop of the electro-catalytic reduction reaction in the in-situ electrically driven reduction device;

[0035] The in-situ electrically driven reduction device 5 is sequentially provided with a cathode end plate 501, a cathode electrode 503, a cathode chamber 505, an ion exchange membrane 507, an anode chamber 506, an anode electrode 504 and an anode end plate 502 from left to right; an anode chamber sensor 508 is installed in the anode chamber 506 and has the functions of detecting the pH value, temperature, pressure and liquid level of the anode chamber; a cathode chamber sensor 509 is installed in the cathode chamber 505 and has the functions of detecting the pH value, temperature, pressure and liquid level of the cathode chamber; the cathode chamber 505 contains an alcohol amine absorbent, and the anode chamber 506 contains pure water;

[0036] The carbon monoxide storage tank 10 is connected to one end of the sixth pipeline 206, the air blower 9 is connected to one end of the fifth pipeline 205, the other end of the fifth pipeline 205 and the other end of the sixth pipeline 206 are connected to one end of the fourth pipeline 204 through the three-way pipe 213, and the other end of the fourth pipeline 204 is connected to the outlet water-blocking air-permeable membrane 6; the fourth valve 304 is arranged on the sixth pipeline 206 between the carbon monoxide storage tank 10 and the three-way pipe 213, and the third valve 303 is arranged on the fifth pipeline 205 between the air blower 9 and the three-way pipe 213.

[0037] In a further preferred scheme, the air input device comprises a fan 1, a first pipeline 201, an air compressor 2, a second pipeline 202, a first valve 301, a dust removal tower 3, a third pipeline 203 and a second valve 302 connected in sequence; the second valve 302 is connected to the inlet water-blocking air-permeable membrane 4 along the third pipeline 203.

[0038] In a further preferred scheme, a cathode liquid supplementing device is further included, the cathode liquid supplementing device comprises a sixth valve 306, an eighth pipeline 208, a cathode liquid storage tank 11, a seventh pipeline 207, a water pump 12 and a fifth valve 305 connected in sequence; the fifth valve 305 is connected to the cathode liquid inlet of the cathode chamber 505, and the sixth valve 306 is connected to the cathode liquid outlet of the cathode chamber 505; a seventh valve 307 and a ninth pipeline 209 connected to the cathode liquid storage tank 11 are further included, and when the seventh valve 307 is opened, fresh cathode liquid can be supplemented through the ninth pipeline 209.

[0039] In a further preferred scheme, the anolyte replenishing device and the oxygen storage device are further included, the anolyte replenishing device comprises a ninth valve 309, an eleventh pipeline 211, an anolyte storage tank 13, a tenth pipeline 210 and an eighth valve 308 connected in sequence; the eighth valve 308 is connected to the anolyte inlet of the anode chamber 506, and the ninth valve 309 is connected to the anolyte outlet of the anode chamber 506; the tenth valve 310 and a twelfth pipeline connected to the anolyte storage tank 13 are further included, and when the tenth valve 310 is opened, fresh anolyte can be replenished through the twelfth pipeline 212; the oxygen storage device comprises an anode blower 15 and an oxygen storage tank 16 connected in sequence along the eleventh pipeline 211; one end of the eleventh pipeline 211 is connected to the anolyte storage tank 13, and the other end is connected to the oxygen storage tank 16.

[0040] In a further preferred scheme, the alcohol amine absorbent is set as 3-aminopropanol or 1,3-propanediamine, and the molar concentration is 0.5-5 mol / L.

[0041] In a further preferred scheme, the cathode electrode 503 is foamed silver or nano-silver, and the anode electrode 504 is foamed nickel or iridium oxide.

[0042] In a further preferred scheme, the ion exchange membrane 507 is set as a proton exchange membrane or an anion exchange membrane.

[0043] In a further preferred scheme, the method of the direct air carbon capture in-situ utilization system comprises the following steps:

[0044] Step S1: air enters the in-situ electrically driven reduction device 5 through an air input device;

[0045] Step S2: carbon dioxide in the air reacts with the alcohol amine absorbent in the cathode chamber 505 of the in-situ electrically driven reduction device 5 to generate carbamate, and other components in the air are discharged through the fifth pipeline under the action of the blower;

[0046] Step S3: the real-time pH value of the alcohol amine absorbent in the cathode chamber is detected by the cathode chamber sensor 509 to determine the degree of carbon dioxide enrichment of the alcohol amine absorbent, when the real-time pH value is within the range of the first preset pH value and the second preset pH value, the air input device stops air input, and the direct current power supply 7 is turned on;

[0047] Step S4: after the direct current power supply 7 is turned on, an electrocatalytic reduction reaction is carried out, the carbamate is reduced to carbon monoxide and alcohol amine by receiving electrons, the generated carbon monoxide is transported to the carbon monoxide storage tank 10, and the pure water in the anode chamber 506 is reduced to oxygen which is transported to the oxygen storage tank 16 by the anode blower 15;

[0048] Step S5: As the electrocatalytic reduction proceeds, the real-time pH value of the alcoholamine absorbent in the cathode chamber gradually increases. When the real-time pH value is within the range of the third preset pH value and the fourth preset pH value, the DC power supply is turned off and steps S1-S4 are repeated.

[0049] Among them, the first preset pH value is less than the second preset pH value, the second preset pH value is less than the third preset pH value; the third preset pH value is less than the fourth preset pH value, and the determination of the above preset pH values ​​can be adaptively adjusted according to the type of cathode liquid and its concentration.

[0050] In a further preferred embodiment, in step S3, the first preset pH value is 7, and the second preset pH value is 8.

[0051] In a further preferred embodiment, the third preset pH value in step S5 is 11, and the fourth preset pH value is 12.5.

[0052] As Figure 2 Taking the embodiment shown as an example, when carbon capture of carbon dioxide in the air is performed, the specific working process of the system of the present invention is as follows:

[0053] Fan 1 is turned on to introduce air, which is then delivered to air compressor 2 via first pipe 201. After compression, first valve 301 is opened, and the air is delivered to dust removal tower 3 via second pipe 202 to remove particulate matter. Second valve 302 is then opened, and the air is delivered to inlet water-blocking and breathable membrane 4 via third pipe 203. The air then enters in-situ electrically driven reduction device 5. Carbon dioxide in the air reacts with the alcoholamine absorbent in cathode chamber 505 to form carbamate, absorbing and enriching the carbon dioxide. Other components in the air pass through outlet water-blocking and breathable membrane 6, through fourth pipe 204, and are accelerated by induced draft fan 8. Third valve 303 is opened, fourth valve 304 is closed, and the air is discharged through fifth pipe 205 by blower 9. Furthermore, sixth valve 306 and fifth valve 305 connecting to cathode chamber 505 are closed, and ninth valve 309 and eighth valve 308 connecting to anode chamber 506 are closed.

[0054] When performing in-situ utilization of carbon dioxide in the air, the specific working process of the system of the present invention is as follows:

[0055] Close fan 1, air compressor 2, second valve 302 and third valve 303, open fourth valve 304 to connect direct current power supply 7, carbamate in cathode chamber 505 is reduced to carbon monoxide and alcohol amine by electron on the surface of cathode electrode 503, the generated carbon monoxide is transported to carbon monoxide storage tank 10 by outlet water-blocking gas-permeable membrane 6, fan 8, fourth pipeline 204 and sixth pipeline 206. At the same time, water molecules in anode chamber 506 are oxidized to oxygen by losing electrons on the surface of anode electrode 504, open ninth valve 309, anode liquid flows into anode liquid storage tank 13 through eleventh pipeline 211, close tenth valve 310, oxygen enters oxygen storage tank 16 through eleventh pipeline 211 under the action of anode fan 15. Anode liquid in anode liquid storage tank 13 returns to anode chamber 506 under the action of anode liquid pump 14 through tenth pipeline 210. At the same time, sixth valve 306 and fifth valve 305 connected to cathode chamber 505 remain closed. When the tenth valve 310 is opened, fresh anode liquid can be supplemented through the twelfth pipeline 212.

[0056] When the cathode liquid in the cathode chamber 505 is updated, the specific working process of the system of the application is: close the second valve 302, the third valve 303 and the fourth valve 304, open the sixth valve 306 and the fifth valve 305 connected to the cathode chamber 505, the cathode liquid flows to the cathode liquid storage tank 11 through the eighth pipeline 208, and flows to the cathode chamber 505 through the seventh pipeline 207 under the action of the cathode liquid pump 12. When the seventh valve 307 is opened, fresh cathode liquid can be supplemented through the ninth pipeline 209.

[0057] The application provides a direct air carbon capture in-situ utilization system and method, which comprises chemical reactions as shown in the figure, mainly including: Figure 3

[0058] When carbon dioxide in the air is captured, the cathode chamber:

[0059] CO2(g) + 2RNH2 (aq) → RNH3 + (aq) + RNHCOO - (aq)

[0060] When the carbon dioxide is in-situ utilized, the cathode chamber:

[0061] RNHCOO - (aq) +2H2O (aq) +2e - → RNH2 (aq) +CO (g) + 3OH - (aq)

[0062] When the carbon dioxide is in-situ utilized, the anode chamber:

[0063] ​2H2O (aq) - 2e - → O2 (g) + 2OH - (aq)

[0064] where RNH2represents the alcohol amine molecule, RNHCOO"represents the carbamate, RNH3 + represents the protonated amine.

[0065] Those skilled in the art will readily understand that the above description is only preferred embodiments of the present application and is not intended to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A direct air carbon capture in-situ utilization system, characterized in that: include: Carbon capture electrocatalytic device, carbon monoxide storage tank (10), blower (9); The carbon capture electrocatalytic device comprises a DC power supply (7), and an inlet water-blocking and breathable membrane (4), an in-situ electric drive reduction device (5), an outlet water-blocking and breathable membrane (6), a cathode induced draft fan (8), and a fourth pipeline (204) connected in sequence. The DC power supply (7) is used to control the start and stop of the electrocatalytic reduction reaction in the in-situ electric drive reduction device; The in-situ electric driven reduction device (5) is provided with the following components from left to right: a cathode terminal plate (501), a cathode electrode (503), a cathode chamber (505), an ion exchange membrane (507), an anode chamber (506), an anode electrode (504), and an anode terminal plate (502); an anode chamber sensor (508) is installed in the anode chamber (506), and a cathode chamber sensor (509) is installed in the cathode chamber (505); an alcohol amine absorbent is contained in the cathode chamber (505), and pure water is contained in the anode chamber (506); The carbon monoxide storage tank (10) is connected to one end of the sixth pipeline (206), the blower (9) is connected to one end of the fifth pipeline (205), the other end of the fifth pipeline (205) and the other end of the sixth pipeline (206) are connected to one end of the fourth pipeline (204) through a three-way pipe (213), and the other end of the fourth pipeline (204) is connected to the outlet water-blocking and breathable membrane (6); a fourth valve (304) is provided on the sixth pipeline (206) between the carbon monoxide storage tank (10) and the three-way pipe (213), and a third valve (303) is provided on the fifth pipeline (205) between the blower (9) and the three-way pipe (213); The invention also includes an air input device, which includes a fan (1), a first pipe (201), an air compressor (2), a second pipe (202), a first valve (301), a dust removal tower (3), a third pipe (203), and a second valve (302) connected in sequence; one end of the second valve (302) is connected to the third pipe (203), and the other end is connected to the inlet water-blocking and breathable membrane (4).

2. The direct air carbon capture in-situ utilization system according to claim 1, characterized in that: The invention also includes a cathode liquid replenishing device, which includes a sixth valve (306), an eighth pipeline (208), a cathode liquid storage tank (11), a seventh pipeline (207), a water pump (12), and a fifth valve (305) connected in sequence; the fifth valve (305) is connected to the cathode liquid inlet of the cathode chamber (505), and the sixth valve (306) is connected to the cathode liquid outlet of the cathode chamber (505); and the invention also includes a seventh valve (307) and a ninth pipeline (209) connected to the cathode liquid storage tank (11). When the seventh valve (307) is opened, fresh cathode liquid is replenished through the ninth pipeline (209).

3. The direct air carbon capture in-situ utilization system according to claim 1, characterized in that: The invention also includes an anolyte replenishing device and an oxygen storage device, wherein the anolyte replenishing device includes a ninth valve (309), an eleventh pipeline (211), an anolyte storage tank (13), a tenth pipeline (210), and an eighth valve (308) connected in sequence; the eighth valve (308) is connected to the anolyte inlet of the anode chamber (506), and the ninth valve (309) is connected to the anolyte outlet of the anode chamber (506); the invention also includes a tenth valve (310) and a twelfth pipeline connected to the anolyte storage tank (13); when the tenth valve (310) is opened, fresh anolyte is replenished through the twelfth pipeline (212); the oxygen storage device includes an anode draft fan (15) and an oxygen storage tank (16) connected in sequence along the eleventh pipeline (211); one end of the eleventh pipeline (211) is connected to the anolyte storage tank (13), and the other end is connected to the oxygen storage tank (16).

4. The direct air carbon capture in-situ utilization system according to claim 1, characterized in that: The alcoholamine absorbent is set to 3-aminopropanol, and its molar concentration is 0.5-5 mol / L.

5. The direct air carbon capture in-situ utilization system according to claim 1, characterized in that: The cathode electrode (503) is foamed silver or nano-silver, and the anode electrode (504) is foamed nickel or iridium oxide.

6. The direct air carbon capture in-situ utilization system according to claim 1, characterized in that: The ion exchange membrane (507) is configured as a proton exchange membrane or an anion exchange membrane.

7. A method for direct air carbon capture in-situ utilization system according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1: air enters the in-situ electric driven reduction device (5) through the air input device; Step S2: Carbon dioxide in the air reacts with an alcoholamine absorbent in the cathode chamber (505) of the in-situ electrically driven reduction device (5) to generate carbamate, and other components in the air are discharged through the fifth pipe (205) by the action of the blower (9); Step S3: The cathode chamber sensor (509) detects the real-time pH value of the alcoholamine absorbent in the cathode chamber to determine the degree of carbon dioxide enrichment of the alcoholamine absorbent. When the real-time pH value is within the range of the first preset pH value and the second preset pH value, the air input device stops inputting air and the DC power supply (7) is turned on. Step S4: After the DC power supply (7) is turned on, an electrocatalytic reduction reaction is carried out, and the carbamate group obtains electrons and is reduced to carbon monoxide and alcohol amine. The generated carbon monoxide is transported to the carbon monoxide storage tank (10), and at the same time, the pure water in the anode chamber (506) is reduced to oxygen and transported to the oxygen storage tank (16) through the anode induced draft fan (15); Step S5: As the electrocatalytic reduction proceeds, the real-time pH value of the alcoholamine absorbent in the cathode chamber gradually increases. When the real-time pH value is within the range between the third preset pH value and the fourth preset pH value, the DC power supply (7) is turned off, and steps S1-S4 are repeated. Among them, the first preset pH value is less than the second preset pH value, the second preset pH value is less than the third preset pH value; and the third preset pH value is less than the fourth preset pH value.

8. The method of the direct air carbon capture in-situ utilization system according to claim 7, characterized in that: In step S3, the first preset pH value is 7, and the second preset pH value is 8.

9. The method of direct air carbon capture in-situ utilization system according to claim 8, characterized in that: In step S5, the third preset pH value is 11, and the fourth preset pH value is 12.5.

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