A CO2 direct air capture system and method for increasing CO2 partial pressure

Abstract

This invention discloses a CO2 direct air capture system and method for increasing CO2 partial pressure. The system includes a first air pump, a second air pump, a microbial fuel cell device, a CO2 capture device, a rich liquid desorption unit, and a CO2 storage unit. The microbial fuel cell device includes a reactor housing, a proton exchange membrane, wires, and external circuitry. The first air pump is located outside the microbial fuel cell device and pumps ambient air into the cathode chamber. A jacket is provided outside the reactor housing to enclose the reactor housing. The CO2 capture device is a sealed housing with a liquid inlet, a liquid outlet, an air inlet, and an air outlet. The air outlet of the cathode chamber of the microbial fuel cell device is connected to the air inlet of the CO2 capture device via a pipe, and a second air pump is installed on the pipe. The rich liquid desorption unit includes a battery waste heat heating device and an electrically heated desorber. The CO2 storage unit includes a CO2 compressor and a CO2 storage container.

Description

Technical Field

[0001] This invention relates to the field of direct air capture of carbon dioxide, and more specifically to a CO2 direct air capture system and method for increasing CO2 partial pressure. Background Technology

[0002] Carbon dioxide capture, utilization, and storage (CCUS) technology is crucial for achieving carbon neutrality and is considered the most economical and feasible method for large-scale reduction of greenhouse gas emissions and mitigation of global warming. Large-scale application of this technology will help significantly reduce carbon dioxide emissions in the short term, effectively mitigating the greenhouse effect. CCUS is divided into capture, transport, utilization, and storage stages according to its technological process. CO2 capture refers to the process of separating CO2 from industrial, energy activities, or the atmosphere.

[0003] Currently, the main carbon dioxide capture technologies include chemical absorption, physical absorption, membrane separation, and adsorption.

[0004] (1) Chemical absorption method: This method utilizes chemical reagents to react with carbon dioxide to form salts (such as carbonates or bicarbonates), which are then released and collected by heating or reducing pressure. Commonly used chemical absorbents include amines, such as ethylenediamine and methylamine. It is suitable for low-concentration carbon dioxide environments, such as flue gas treatment in coal-fired power plants, cement plants, and steel plants. However, the chemical absorption method suffers from problems such as high energy consumption in the capture process, low absorbent recycling efficiency, high CO2 recovery costs, large CO2 capture equipment, and limited operational flexibility.

[0005] (2) Physical absorption method: Acidic components are separated and removed by absorbing acidic gases with organic solvents under pressure. The regeneration of the solvent is achieved by depressurization, and the required regeneration energy is relatively small. The physical absorption method is suitable for CO2 separation when the CO2 concentration in the gas is high, such as CO2 separation in IGCC. It is carried out at a high operating pressure and is not suitable for CO2 separation in tail gas.

[0006] (3) Membrane separation method: The membrane separation method uses the different permeability of thin films made of specific materials to separate gases. Membrane materials are divided into two types: organic polymer membranes and inorganic membranes; it is suitable for occasions that require high-purity carbon dioxide; its disadvantage is that the CO2 separation rate of existing membrane materials is relatively low, making it difficult to obtain high-purity CO2. To achieve a certain emission reduction, a multi-stage separation process is often required.

[0007] (4) Adsorption method: This method involves selectively adsorbing CO2 onto an adsorbent under certain conditions, and then desorbing the CO2 by restoring the conditions, thereby achieving CO2 separation. Commonly used adsorbents include: natural zeolite, molecular sieves, activated alumina, silica gel, "molecular basket" adsorbents, lithium compound adsorbents, and carbon-based adsorbents. The main disadvantages of adsorption method for CO2 separation are: low separation rate; a limited number of adsorbents with high CO2 selectivity; and high cost when used in the power industry.

[0008] Direct air capture (DAC) is a technology that captures carbon dioxide from the atmosphere. It is an important CCUS (Carbon Dioxide-Sensitive Air) technology and an indispensable negative emission technology. Currently reported CO2 direct air capture technologies include solid-state adsorption and solution adsorption. Solid-state adsorption is a method that can effectively adsorb carbon dioxide from the air under normal temperature and pressure conditions, with advantages such as high adsorption efficiency, good material stability, and low operating costs. However, solid-state adsorption has disadvantages such as limited adsorption capacity, complex regeneration processes, and high equipment costs. Solution adsorption mainly uses alkaline hydroxide solutions (such as NaOH, KOH, and Ca(OH)2) for air decarbonization. These solutions have strong carbon dioxide binding capacity, low volatility, and relatively mature processes, making them the main choice for air capture absorbents. However, alkaline absorption methods have the disadvantage of strong corrosiveness to equipment materials, especially during long-term operation, where corrosion significantly increases the cost of equipment maintenance and replacement. Currently, the most commonly used method for CO2 capture in flue gas is amine solution absorption, due to its advantages of high absorption efficiency, high reaction rate, and strong regeneration capability. However, because the partial pressure of CO2 in the air is low, the application of amine solution absorption in direct air capture results in the loss of chemical solvents due to the need to process large amounts of air. In existing technologies, when using amine solutions for direct air capture, the proportion of CO2 in the air is only 0.04%, resulting in low absorption efficiency and utilization of the amine solution during the capture process. Furthermore, in traditional rich-liquid desorption methods, a large amount of energy needs to be input into the system for desorption, which increases the overall economic cost of the system.

[0009] A microbial fuel cell (MFC) is a device that uses microorganisms to directly convert the chemical energy of organic matter into electrical energy. Its basic working principle is as follows: In the anaerobic environment of the anode chamber, organic matter decomposes under the action of microorganisms, releasing electrons and protons. Electrons are effectively transferred between the biological components and the anode via a suitable electron transport medium, and then transferred to the cathode through an external circuit to form an electric current. Protons are transferred to the cathode through a proton exchange membrane. The oxidant (usually oxygen) gains electrons at the cathode, is reduced, and combines with protons to form water. Based on the electron transfer method, microbial fuel cells can be classified into direct and indirect microbial fuel cells. Direct microbial fuel cells refer to those where electrons are directly transferred from fuel molecules to the electrodes during fuel oxidation, and then the reaction on the electrode surface is directly catalyzed by a biocatalyst; this reaction is called a redox reaction in chemistry. If the fuel reacts in the electrolyte or elsewhere, and electrons are transferred to the electrodes via a redox medium, the cell is called an indirect microbial fuel cell. Based on whether an electron transport medium is required, microbial fuel cells can also be classified as having a medium or not. Microbial fuel cells typically include a proton exchange membrane, anode, cathode, anode chamber, cathode chamber, wires, and external circuitry. External circuitry refers to the current path outside the power source; that is, the path from the positive terminal of the power source, through wires, loads, and other components, and finally back to the negative terminal. External circuitry usually consists of wires, switches, and loads; it is the site where electrical energy is converted into other forms of energy.

[0010] There are currently no reports of combining microbial fuel cells with direct carbon dioxide air capture. Summary of the Invention

[0011] The purpose of this invention is to address the above-mentioned problems by providing a CO2 direct air capture system and method that increases CO2 partial pressure.

[0012] To achieve its objective, the present invention employs the following technical solution:

[0013] A first aspect of the present invention provides a CO2 direct air capture system for increasing CO2 partial pressure, comprising a first air pump, a second air pump, a microbial fuel cell device, a CO2 capture device, a liquid-rich desorption unit, and a CO2 storage unit.

[0014] The microbial fuel cell device includes a reactor housing, a proton exchange membrane, wires, and an external circuit. The proton exchange membrane is vertically installed inside the reactor housing, dividing the interior of the reactor housing into an anode chamber and a cathode chamber. An anode is installed in the anode chamber, and a cathode is installed in the cathode chamber. The two ends of the wires are connected to the anode and cathode, respectively. The external circuit is located outside the reactor housing and connected to the wires. A first air pump is located outside the microbial fuel cell device and is connected to the cathode chamber through an air inlet pipe to pump ambient air into the cathode chamber. A jacket is installed outside the reactor housing to enclose the reactor housing. An air outlet is provided on the anode chamber. An air inlet and an air outlet are provided on the cathode chamber.

[0015] The CO2 capture device is a sealed box, and the CO2 capture device is equipped with a liquid inlet, a liquid outlet, an air inlet, and an air outlet; the air outlet of the cathode chamber of the microbial fuel cell device is connected to the air inlet of the CO2 capture device through a pipe, and a second air pump is installed on the pipe.

[0016] The rich liquid desorption unit includes a battery waste heat heating device and an electrically heated desorber. The battery waste heat heating device is a jacket installed outside the reactor box, with an inlet and an outlet. The inlet of the jacket is connected to the outlet of the CO2 capture device via a pipe, and the jacket is used to circulate the rich liquid after CO2 absorption. The main body of the electrically heated desorber is an electric heater. The outlet of the jacket is connected to the inlet of the electric heater via a pipe, allowing the rich liquid in the jacket to be input into the electric heater. The electric heater is electrically connected to the external circuit of the microbial fuel cell device to obtain electrical energy for heating. An air outlet is provided on the main body of the electrically heated desorber. The outlet of the electric heater is connected to the inlet of the CO2 capture device via a pipe.

[0017] The CO2 storage unit includes a CO2 compressor and a CO2 storage device; the outlet of the electric heating desorber and the outlet of the anode chamber are both connected to the CO2 compressor through pipes, and the CO2 compressor and the CO2 storage device are connected through pipes.

[0018] Preferably, the inlet of the CO2 capture device 3 is also connected to a replenishment pipe for replenishing new absorbent from the outside.

[0019] Preferably, the CO2 capture device contains an absorbent liquid, which is selected from single amine absorbent liquid, mixed amine absorbent liquid, and ionic solution.

[0020] Preferably, the single amine absorbent is selected from monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA).

[0021] Preferably, all of the pipes are equipped with on / off valves.

[0022] Preferably, a water pump is installed on the pipeline used for circulating liquids to regulate the flow rate and velocity.

[0023] Preferably, the cathode material is selected from graphite, carbon cloth, carbon paper, and carbon-supported platinum material, and the anode material is selected from carbon paper, carbon cloth, graphite rod, graphite fiber brush, activated carbon, and carbon nanotubes.

[0024] Preferably, an oxygen sensor is provided in the cathode chamber to monitor the oxygen concentration in the cathode chamber.

[0025] A second aspect of the present invention provides a method for direct CO2 air capture that increases CO2 partial pressure, employing the system capture described in any of the above claims, comprising the following steps:

[0026] Step 1: Increase CO2 partial pressure

[0027] Water containing organic matter is introduced into the anode chamber of the microbial fuel cell device, CO2 absorbent is injected into the CO2 capture device, the first air pump is turned on, and air is pumped into the cathode chamber of the microbial fuel cell device. Oxygen in the air participates in the reaction and is consumed in the cathode chamber. The partial pressure of CO2 in the deoxygenated air is increased and then pumped into the CO2 capture device by the second air pump.

[0028] Step 2: CO2 capture and adsorption

[0029] Air with increased CO2 partial pressure enters the CO2 capture device and is adsorbed by the CO2 absorbent liquid therein, making the CO2 absorbent liquid rich in liquid.

[0030] Step 3: Thermal desorption of CO2

[0031] The rich liquid enters the jacket outside the reactor box of the microbial fuel cell device from the CO2 capture device. The heat generated by the reaction inside the reactor box heats the rich liquid in the jacket. The heated rich liquid enters the electrically heated desorber and is further heated to cause thermal desorption of CO2. CO2 gas is desorbed from the rich liquid.

[0032] Step 4, CO2 storage

[0033] The CO2 gas produced by the reaction in the anode chamber of the microbial fuel cell device enters the CO2 compressor through a pipeline. The CO2 gas desorbed from the rich liquid in the electrically heated desorber also enters the CO2 compressor through a pipeline. The CO2 compressor compresses the CO2 gas and then sends it to the CO2 storage tank for storage.

[0034] The water containing organic matter mentioned in step 1 is organic wastewater containing sugars, fats, and proteins.

[0035] The beneficial effects of this invention are:

[0036] (1) When the absorbent absorbs CO2, the proportion of CO2 increases from 0.04% in the ambient air to 0.0506% after deoxygenation, which is nearly 1.3 times higher, thus improving the absorption efficiency and utilization rate of the absorbent.

[0037] (2) The anode feed of the microbial fuel cell is wastewater and the cathode feed is air, which realizes the treatment of wastewater and captures CO2 in the air at the same time, reducing the economic cost of wastewater treatment.

[0038] (3) In the rich liquid desorption device, the heat generated by the internal reaction of the microbial fuel cell device is used to preheat the rich liquid. The temperature of the reactor box of the microbial fuel cell device is 30℃~40℃, while the optimal operating temperature of the microbial fuel cell is 20℃~35℃. Using the heat generated in the reactor box to heat the rich liquid reduces the temperature of the reactor box and keeps the internal reaction temperature at the optimal temperature. On the other hand, it increases the temperature of the rich liquid and reduces energy consumption for further heating and desorption of the rich liquid.

[0039] (4) The electricity generated by the microbial fuel cell device is used to heat the rich liquid through an electric heater, so that the rich liquid reaches the target desorption temperature. No external energy input is required, which greatly reduces the energy consumption of rich liquid desorption.

[0040] The system of this invention can simultaneously achieve wastewater treatment and direct CO2 air capture. The wastewater treatment performed by the microbial fuel cell device provides heat to the CO2 direct air capture unit, which greatly reduces the energy consumption required for CO2 direct air capture. At the same time, the rich liquid during the CO2 direct air capture process cools the reactor box of the microbial fuel cell device and promotes the reaction therein. The two promote each other, reducing energy consumption and economic costs. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the CO2 direct air capture system of the present invention.

[0042] Figure 2 This is a schematic diagram of the CO2 direct air capture method of the present invention.

[0043] in, Figure 1 The elements or structures indicated by the reference numerals in the attached figures are:

[0044] First air pump 1, second air pump 6;

[0045] Reactor housing 21, proton exchange membrane 22, wires 23, external circuit 24, anode 25, cathode 26;

[0046] CO2 capture device 3;

[0047] Jacket 41, electrically heated desorber 42;

[0048] CO2 compressor 51, CO2 storage device 52. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, but this does not limit the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0050] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0051] like Figure 1 The CO2 direct air capture system of the present invention, which improves CO2 partial pressure, mainly consists of a first air pump 1, a second air pump 6, a microbial fuel cell device, a CO2 capture device 3, a rich liquid desorption unit, and a CO2 storage unit.

[0052] The microbial fuel cell device includes a reactor housing 21, a proton exchange membrane 22, wires 23, and an external circuit 24. The proton exchange membrane 22 is vertically installed inside the reactor housing 21, dividing the interior of the reactor housing 21 into an anode chamber and a cathode chamber. An anode 25 is installed in the anode chamber, and a cathode 26 is installed in the cathode chamber. The two ends of the wires 23 are connected to the anode 25 and the cathode 26, respectively. The external circuit 24 is located outside the reactor housing 21 and connected to the wires 23. A first air pump 1 is located outside the microbial fuel cell device and is connected to the cathode chamber through an air inlet pipe to pump ambient air into the cathode chamber. A jacket 41 is installed outside the reactor housing 21 to enclose the reactor housing. An air outlet is provided on the anode chamber. An air inlet and an air outlet are provided on the cathode chamber.

[0053] The CO2 capture device 3 is a sealed box, equipped with a liquid inlet, a liquid outlet, an air inlet, and an air outlet. The air outlet of the cathode chamber of the microbial fuel cell device is connected to the air inlet of the CO2 capture device 3 via a pipe, and a second air pump 6 is installed on this pipe. The CO2 capture device 3 contains an absorbent liquid.

[0054] The rich liquid desorption unit includes a battery waste heat heating device and an electric heating desorber 42. The battery waste heat heating device is a jacket 41 installed outside the reactor housing 21. The jacket 41 is provided with an inlet and an outlet. The inlet of the jacket 41 is connected to the outlet of the CO2 capture device 3 through a pipe. The jacket 41 is used to circulate the rich liquid after CO2 absorption. The main body of the electric heating desorber 42 is an electric heater (for example, an electric water heater can be used directly). The outlet of the jacket 41 is connected to the inlet of the electric heater through a pipe, and the rich liquid in the jacket 41 is input into the electric heater. The electric heater is electrically connected to the external circuit 24 of the microbial fuel cell device to obtain electrical energy for heating. An air outlet is provided on the main body of the electric heating desorber 42. The outlet of the electric heater is connected to the inlet of the CO2 capture device 3 through a pipe.

[0055] The CO2 storage unit includes a CO2 compressor 51 and a CO2 storage unit 52; the outlet of the electric heating desorber 42 and the outlet of the anode chamber are both connected to the CO2 compressor 51 through pipes, and the CO2 compressor 51 and the CO2 storage unit 52 are connected through pipes.

[0056] In some implementations, a replenishment pipe is also connected to the inlet of the CO2 capture device 3 for replenishing the absorbent from the outside. As the number of system cycles increases, the absorption efficiency of the absorbent decreases, and there is also some loss. Therefore, new absorbent is added periodically to ensure the system's operating efficiency.

[0057] In some embodiments, the absorbent in the CO2 capture device 3 is selected from a single amine absorbent, a mixed amine absorbent, and an ionic solution.

[0058] In some implementations, the single amine absorbent is selected from monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA).

[0059] In some implementations, all pipelines are equipped with on / off valves to control the flow of gas or liquid.

[0060] In some implementation schemes, water pumps are installed on the pipes used to circulate liquids to regulate flow rate and velocity.

[0061] In some implementation schemes, the cathode 26 is made of materials such as graphite, carbon cloth, carbon paper, and platinum-containing materials (carbon-loaded platinum), while the anode 25 is made of materials such as carbon paper, carbon cloth, graphite rod, graphite fiber brush, activated carbon, and carbon nanotubes.

[0062] In some implementations, an oxygen sensor is provided in the cathode chamber to monitor the oxygen concentration in the cathode chamber.

[0063] The working principle of the system of this invention (its working principle and process are as follows) Figure 2 (As shown) is:

[0064] In a microbial fuel cell device, organic wastewater is introduced into the anode chamber, which is filled with electroactive microorganisms attached to the anode surface. These microorganisms metabolize the organic matter in the wastewater (which contains abundant organic matter such as sugars, fats, proteins, and other pollutants), breaking it down into simpler substances while releasing electrons (electrons). - ) and proton (H + The released electrons are transferred to the anode surface through the electron transport chain outside the microorganism and flow to the cathode through the external circuit. This process generates an electric current. The reaction at the anode is as follows: Organic matter → CO2 + H2 + +e - Simultaneously, protons migrate from the anode chamber to the cathode chamber through the proton exchange membrane. In the cathode chamber, electrons undergo a reduction reaction with protons from the anode chamber and oxygen from the air (containing 78.08% N2, 20.95% O2, and 0.04% CO2) pumped into the cathode chamber by the first gas pump. The cathode reaction is as follows: O2 + 4H+ + +4e - →2H₂O. Through the above reaction in the microbial fuel cell device, the organic matter in the wastewater is gradually decomposed into harmless CO₂ and water, thus purifying the wastewater. Simultaneously, it consumes oxygen from air 1, increasing the partial pressure of CO₂ in the air. Furthermore, the metabolic activity of the microorganisms provides a stable electron flow for the microbial fuel cell, thereby generating electricity.

[0065] In the CO2 capture device, the absorbent enters through the inlet. Air 2 (98.77% N2, 0% O2, 0.0506% CO2) from the cathode chamber, after oxygen consumption, is pumped into the CO2 capture device by a second pump. The absorbent adsorbs and captures the CO2 in the air 2. Air 3 (98.82% N2, 0% O2, 0% CO2) and the CO2-rich liquid are discharged through the outlet and outlet, respectively. Through the above reactions in the CO2 capture device, the capture of CO2 from the air is completed.

[0066] In the rich liquid desorption unit, the reactor chamber of the microbial fuel cell device generates heat due to the internal reactions, causing the reactor chamber shell itself to heat up. Rich liquid flows through a jacket located outside the reactor chamber, acting as a heat exchange medium to exchange heat with the reactor chamber. The rich liquid absorbs heat from the reactor chamber shell, thus receiving initial heating, while the reactor chamber itself cools down (the waste heat temperature of the microbial fuel cell is 30℃~40℃, while the optimal operating temperature of the microbial fuel cell is 20℃~35℃), which is beneficial for the reaction within the reactor chamber. After initial heating, the rich liquid enters an electrically heated desorber. The electrical energy for the electrically heated desorber comes from the electricity generated by the microbial fuel cell device. The electrically heated desorber further heats the rich liquid to the CO2 desorption temperature, causing CO2 to desorb from the rich liquid. The absorbent is then desorbed, becoming a lean liquid. The lean liquid re-enters the CO2 capture device through pipelines to continue the adsorption-desorption cycle, continuously capturing CO2 from the air.

[0067] In the CO2 storage unit, the CO2 generated from the anode chamber of the microbial fuel cell device and the CO2 from the rich liquid desorption unit are first pressurized by the CO2 compressor and then stored in the CO2 storage tank.

[0068] Example 2

[0069] The present invention provides a method for direct CO2 air capture to increase CO2 partial pressure, using any one of the CO2 direct air capture systems of the present invention in Example 1, comprising the following steps:

[0070] Step 1: Increase CO2 partial pressure

[0071] Wastewater containing organic matter (including sugars, fats, proteins, etc.) is introduced into the anode chamber of the microbial fuel cell device. CO2 absorbent is injected into the CO2 capture device. The first air pump is turned on to pump air into the cathode chamber of the microbial fuel cell device. Oxygen in the air participates in the reaction and is consumed in the cathode chamber. The CO2 partial pressure in the deoxygenated air is increased and then pumped into the CO2 capture device by the second air pump. The oxygen concentration in the cathode chamber can be monitored by an oxygen sensor. When the oxygen concentration in the cathode chamber is lower than 1%, the first air pump is turned off and the second air pump is turned on to pump the deoxygenated air in the cathode chamber into the CO2 capture device.

[0072] Step 2: CO2 capture and adsorption

[0073] Air with increased CO2 partial pressure enters the CO2 capture device and is adsorbed by the CO2 absorbent liquid therein, which then becomes a rich liquid.

[0074] Step 3: Thermal desorption of CO2

[0075] The rich liquid enters the jacket outside the reactor box of the microbial fuel cell device from the CO2 capture device. The heat generated by the reaction inside the reactor box heats the rich liquid in the jacket. The heated rich liquid enters the electrically heated desorber and is further heated to cause thermal desorption of CO2, and CO2 gas is desorbed from the rich liquid.

[0076] Step 4, CO2 storage

[0077] The CO2 gas produced by the reaction in the anode chamber of the microbial fuel cell device enters the CO2 compressor through a pipeline. The CO2 gas desorbed from the rich liquid in the electrically heated desorber also enters the CO2 compressor through a pipeline. The CO2 compressor compresses the CO2 gas and then sends it to the CO2 storage tank for storage.

Claims

1. A CO2 direct air capture system for increasing CO2 partial pressure, characterized in that: It includes a first air pump, a second air pump, a microbial fuel cell device, a CO2 capture device, a rich liquid desorption unit, and a CO2 storage unit; The microbial fuel cell device includes a reactor housing, a proton exchange membrane, wires, and an external circuit. The proton exchange membrane is vertically installed inside the reactor housing, dividing the interior of the reactor housing into an anode chamber and a cathode chamber. An anode is installed in the anode chamber, and a cathode is installed in the cathode chamber. The two ends of the wires are connected to the anode and cathode, respectively. The external circuit is located outside the reactor housing and connected to the wires. A first air pump is located outside the microbial fuel cell device and is connected to the cathode chamber through an air inlet pipe to pump ambient air into the cathode chamber. A jacket is installed outside the reactor housing to enclose the reactor housing. An air outlet is provided on the anode chamber. An air inlet and an air outlet are provided on the cathode chamber. The CO2 capture device is a sealed box, and the CO2 capture device is provided with a liquid inlet, a liquid outlet, an air inlet, and an air outlet; the air outlet of the cathode chamber of the microbial fuel cell device is connected to the air inlet of the CO2 capture device through a pipe, and a second air pump is installed on the pipe. The rich liquid desorption unit includes a battery waste heat heating device and an electric heating desorber. The battery waste heat heating device is a jacket installed outside the reactor box, with an inlet and an outlet. The inlet of the jacket is connected to the outlet of the CO2 capture device via a pipe, and the jacket is used to circulate the rich liquid after CO2 absorption. The main body of the electric heating desorber is an electric heater. The outlet of the jacket is connected to the inlet of the electric heater via a pipe, allowing the rich liquid in the jacket to be input into the electric heater. The electric heater is electrically connected to the external circuit of the microbial fuel cell device to obtain electrical energy for heating. An outlet is provided on the main body of the electric heating desorber. The outlet of the electric heater is connected to the inlet of the CO2 capture device via a pipe. The CO2 storage unit includes a CO2 compressor and a CO2 storage tank. The outlet of the electric heating desorber and the outlet of the anode chamber are both connected to the CO2 compressor via pipes, and the CO2 compressor and the CO2 storage tank are connected via pipes.

2. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 1, characterized in that: The CO2 capture device is also connected to a replenishment pipe at the inlet for replenishing new absorbent from the outside.

3. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 1, characterized in that: The CO2 capture device contains an absorbent liquid, which is selected from single amine absorbent liquid, mixed amine absorbent liquid, and ionic solution.

4. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 3, characterized in that: The single amine absorbent is selected from monoethanolamine (MEA), diethanolamine (DEA), or methyldiethanolamine (MDEA).

5. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 1, characterized in that: All of the aforementioned pipelines are equipped with on / off valves.

6. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 1, characterized in that: Pipelines used for circulating liquids are equipped with water pumps to regulate flow rate and velocity.

7. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 1, characterized in that: The cathode material is selected from graphite, carbon cloth, carbon paper, or carbon-supported platinum material, and the anode material is selected from carbon paper, carbon cloth, graphite rod, graphite fiber brush, activated carbon, or carbon nanotubes.

8. The CO2 direct air capture system for increasing CO2 partial pressure according to claim 1, characterized in that: An oxygen sensor is installed in the cathode chamber to monitor the oxygen concentration in the cathode chamber.

9. A method for direct CO2 air capture that increases CO2 partial pressure, characterized in that, The system capture method according to any one of claims 1 to 8 includes the following steps: Step 1: Increase CO2 partial pressure Water containing organic matter is introduced into the anode chamber of the microbial fuel cell device, CO2 absorbent is injected into the CO2 capture device, the first air pump is turned on, and air is pumped into the cathode chamber of the microbial fuel cell device. Oxygen in the air participates in the reaction and is consumed in the cathode chamber. The partial pressure of CO2 in the deoxygenated air is increased and then pumped into the CO2 capture device by the second air pump. Step 2: CO2 capture and adsorption. Air with increased CO2 partial pressure enters the CO2 capture device and is adsorbed by the CO2 absorption liquid therein, making the CO2 absorption liquid a rich liquid. Step 3: The CO2 thermal desorption rich liquid enters the jacket outside the reactor box of the microbial fuel cell device from the CO2 capture device. The heat generated by the reaction inside the reactor box heats the rich liquid in the jacket. The heated rich liquid enters the electrically heated desorber and is further heated to cause CO2 thermal desorption. CO2 gas is desorbed from the rich liquid. Step 4: The CO2 gas generated in the anode chamber of the CO2 storage microbial fuel cell device enters the CO2 compressor through a pipeline. The CO2 gas desorbed from the rich liquid in the electrically heated desorber also enters the CO2 compressor through a pipeline. The CO2 compressor compresses the CO2 gas and then delivers it to the CO2 storage container for storage.

10. The method according to claim 9, characterized in that: The water containing organic matter mentioned in step 1 is organic wastewater containing sugars, fats, and proteins.

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