System and method for mineralizing co 2 in air

Abstract

Provided in the present invention are a system and method for mineralizing CO2 in air. The system comprises: a carbon sequestrant spreading system and a carbon sequestration space, wherein the carbon sequestrant spreading system uniformly spreads a carbon sequestrant into the carbon sequestration space, and the carbon sequestration space provides a space for full contact between air and the carbon sequestrant; a temperature difference monitoring and control system, which forms convective air in the carbon sequestration space; and a humidity monitoring and control system, which controls the absolute humidity of a convective air outlet. In the present invention, a carbon sequestrant is uniformly spread into a carbon sequestration space by means of a carbon sequestrant spreading system; a certain temperature difference is controlled to be present between an air inlet and an air outlet by means of a temperature difference control system, so as to form convective air between the inlet and the outlet; the humidity of the convective air outlet is controlled by means of a humidity monitoring and control system, so as to realize full contact and reaction between the convective air and the carbon sequestrant in the carbon sequestration space; and after the reaction, the carbon sequestrant is discharged from a carbon sequestrant outlet of the carbon sequestration space or is returned to the spreading system, and decarbonized air is discharged from the air outlet of the carbon sequestration space.

Description

System and method for mineralizing CO2 in air The present application claims priority to the Chinese patent application No. 2024106339709, filed on May 21, 2024, and entitled "System and method for mineralizing CO2 in air", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide mineralization, in particular to a system and method for mineralizing CO2 in air. BACKGROUND

[0002] The concentration of CO2 in air is low, and the average concentration is usually between 300 and 400 ppm, which cannot be used by traditional membrane separation, low-temperature separation and other methods. At present, solution absorption and solid adsorption have become the mainstream scheme of direct air capture (DAC).

[0003] The chemical absorption process based on ethanolamine organic amine solution has been widely used in flue gas capture field, but the high gas treatment capacity and low liquid-gas ratio of direct air capture make the organic amine absorption technology have problems such as large volatilization of amine solution, large gas phase loss, and significant increase in capture cost. Solid adsorption technology can effectively solve the key problems of amine volatilization and water loss. Solid adsorbents mainly include alkali / alkaline earth metal-based adsorbents, metal-organic framework (MOFs) adsorbents, amine-loaded adsorbents, and humidity swing adsorbents, but since DAC was proposed in 1999, researchers have made many achievements in the research of adsorbent materials and adsorption process design optimization. The temperature swing adsorption technology represented by alkali metal-based absorption / adsorbents and organic amine-loaded adsorbents has not yet completely solved the problems of high energy consumption and high cost.

[0004] Moreover, although the traditional DAC technology has completed the capture of CO2 in air, if the stable storage of CO2 is to be realized, the CO2 from DAC must be transported and then injected into geological strata for storage. Such operation has the risk of pipeline leakage, the risk of groundwater pollution during injection, and the risk of triggering seismic activity due to the destruction of geological structure during injection. SUMMARY

[0005] The purpose of the present application is to provide a system and method for mineralizing CO2 in air, so that air and carbon sequestration agent can fully contact and react in the carbon sequestration space, and the CO2 in the air is solidified into stable carbonate by the carbon sequestration agent.

[0006] According to one object of the present application, the present application provides a system for mineralizing CO2 in air, comprising a carbon fixation agent spreading system, a carbon fixation space, a temperature difference monitoring and control system, and a humidity monitoring and control system, wherein the carbon fixation agent spreading system is used to spread the carbon fixation agent into the carbon fixation space uniformly; the carbon fixation space provides sufficient contact space for air and the carbon fixation agent; the temperature difference monitoring and control system is used to form a temperature difference between the air inlet and outlet of the carbon fixation space to form a convection air; and the humidity monitoring and control system is used to control the absolute humidity of the convection air outlet.

[0007] Further, the system further comprises an air monitoring system, which is used to monitor and control the air flow rate, temperature, humidity, and CO2 content of the air inlet and outlet of the carbon fixation space.

[0008] Further, the carbon fixation space comprises an air inlet and a decarburized air outlet arranged oppositely, and further comprises a carbon fixation agent inlet and a carbon fixation agent outlet, wherein the carbon fixation space is connected with the carbon fixation agent spreading system through the carbon fixation agent inlet.

[0009] Further, the flow rate of air in the carbon fixation space is not greater than 2 m / s, and the residence time of air in the carbon fixation space is not less than 5 s.

[0010] Further, the temperature difference monitoring and control system controls the temperature difference in the following ways: using the temperature difference caused by the height difference between the air inlet and outlet, or forming a temperature difference between one end of the carbon fixation space and the other end of the carbon fixation space by means of light radiation, electromagnetic radiation, or heat exchange pipe.

[0011] Further, the temperature difference monitoring and control system controls the temperature difference between the air inlet and outlet to be 0.5-5 ℃.

[0012] Further, the humidity monitoring and control system controls the absolute humidity of the convection air outlet to be not less than 2 g / m 3 .

[0013] Further, the carbon fixation agent is an alkaline calcium / magnesium-based material and derivatives thereof.

[0014] According to another object of the present application, the present application provides a method for mineralizing CO2 in air, comprising the following steps:

[0015] S1, the carbon fixation agent spreading system spreads the carbon fixation agent into the carbon fixation space uniformly;

[0016] S2, the temperature difference monitoring and control system controls the temperature difference between the air inlet and outlet of the carbon fixation space to form a convection air; and the humidity monitoring and control system controls the absolute humidity of the convection air outlet to ensure that CO2 in the air can quickly form carbonate and react with the carbon fixation agent;

[0017] S3, the air is fully contacted and reacted with the carbon fixation agent in the carbon fixation space and is fixed by the carbon fixation agent;

[0018] S4, after the reaction, the carbon fixation agent is discharged from the carbon fixation space or returned to the carbon fixation agent spreading system, and the decarburized air is discharged from the carbon fixation space outlet.

[0019] Further, during the reaction, the air flow rate, temperature, humidity and CO2 content are monitored and controlled by the air monitoring system to ensure that the carbon fixation agent is fully contacted and reacted in the carbon fixation space.

[0020] The technical scheme of the present application spreads a certain amount of carbon fixation agent into the carbon fixation space through the carbon fixation agent spreading system, controls a certain temperature difference between the air inlet and outlet through the temperature difference control system to form a convection air at the inlet and outlet, controls the humidity of the convection air outlet through the humidity monitoring and control system, so that the convection air is fully contacted and reacted with the carbon fixation agent in the carbon fixation space, and after the reaction, the carbon fixation agent is discharged from the carbon fixation space outlet or returned to the spreading system, and the decarburized air is discharged from the carbon fixation space air outlet. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0022] Fig. 1 is a structural schematic diagram of an embodiment of the present application;

[0023] Fig. 2 is a process flow diagram of an embodiment of the present application;

[0024] In the figure: 1, carbon fixation agent spreading system; 2, carbon fixation space; 3, temperature difference monitoring and control system; 4, humidity monitoring and control system; 5, air monitoring system; 6, air inlet; 7, decarburized air outlet. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described below in conjunction with the embodiments, obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0027] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited. In addition, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] Embodiment 1

[0029] As shown in FIG. 1 and FIG. 2, a system for strengthening air mineralization of CO2 includes a carbon sequestration agent spreading system 1, a carbon sequestration space 2, a temperature difference monitoring and control system 3, a humidity monitoring and control system 4, and an air monitoring system 5. Among them:

[0030] The carbon sequestration agent spreading system 1 includes an adsorbent pretreatment system, a metering system, and a dispersion system. The adsorbent pretreatment system is used for pretreatment of the adsorbent, the metering system is used for weighing and metering of the adsorbent, and the dispersion system is used for dispersion and spreading of the adsorbent. The carbon sequestration agent spreading system 1 uniformly spreads a certain amount of carbon sequestration agent into the carbon sequestration space 2. The carbon sequestration space 2 provides sufficient contact space and time for air and carbon sequestration agent. The carbon sequestration space 2 includes an air inlet 6 at one end, a decarbonized air outlet 7 arranged at the other end opposite to the air inlet 6, and a carbon sequestration agent inlet and a carbon sequestration agent outlet.

[0031] The temperature difference monitoring and control system 3 controls the air inlet 6 and the decarburized air outlet 7 of the carbon fixation space 2 to have a certain temperature difference, so that the air forms a convection current between the inlet and the outlet, the flow rate of the air in the carbon fixation space 2 is not greater than 2 m / s, the carbon fixation agent is prevented from separating from the carbon fixation space 2, and the residence time of the air is ensured to be not less than 5 s, so that the CO2 in the air has sufficient contact time and is fixed by the carbon fixation agent.

[0032] The temperature difference monitoring and control system 3 controls the air inlet 6 and the decarburized air outlet 7 of the carbon fixation space 2 to have a certain temperature difference, so that the air forms a convection current between the inlet and the outlet, the flow rate of the air in the carbon fixation space 2 is not greater than 2 m / s, the carbon fixation agent is prevented from separating from the carbon fixation space 2, and the residence time of the air is ensured to be not less than 5 s, so that the CO2 in the air has sufficient contact time and is fixed by the carbon fixation agent.

[0033] The humidity monitoring and control system 4 controls the absolute humidity of the convection air outlet to be not less than 2 g / m 3 , so that the CO2 in the air can quickly form carbonate and react with the carbon fixation agent.

[0034] The carbon fixation agent is a basic calcium / magnesium-based material and its derivative, and the carbon fixation space 2 provides sufficient contact space for air and the carbon fixation agent containing the basic calcium / magnesium-based material and its derivative, so that the CO2 in the air is fixed by the carbon fixation agent as stable carbonate, and after the reaction is completed, the carbon fixation agent is discharged from the carbon fixation agent outlet of the carbon fixation space 2 or part of it returns to the spreading system for continuous reaction, and the decarburized air is discharged from the air outlet of the carbon fixation space 2.

[0035] The air monitoring system 5 is used for monitoring and controlling the air flow rate, temperature, humidity and CO2 content of the air inlet 6 and the decarburized air outlet 7.

[0036] Based on the above technical solution, the principle of the application is as follows:

[0037] The CO2 in the air contacts the carbon fixation agent containing the basic calcium / magnesium-based material and its derivative, and under certain humidity control conditions, the following reaction occurs:

[0038] 2Ca(Mg)X n (OH) m +2CO2=2Ca(Mg)CO3+X 2n O (m+4) +mH2O;

[0039] In the formula, X represents silicon, iron, aluminum, etc.

[0040] The carbon fixation agent spreading system 1 spreads, the air flow rate is controlled, and the humidity monitoring and control system 4 adjusts the humidity of the air outlet, so that the air and the carbon fixation agent fully contact and react in the carbon fixation space 2, and the CO2 in the air is solidified by the carbon fixation agent as stable carbonate.

[0041] The application spreads a certain amount of carbon sequestration agent into the carbon sequestration space 2 through the carbon sequestration agent spreading system 1, controls a certain temperature difference between the air inlet and outlet through the temperature difference control system, thereby forming a convection air at the inlet and outlet, controls the humidity of the convection air outlet through the humidity monitoring and control system 4, makes the convection air fully contact and react with the carbon sequestration agent in the carbon sequestration space 2, and discharges or returns the carbon sequestration agent from the carbon sequestration space 2 outlet after the reaction, and discharges the decarbonized air from the carbon sequestration space 2 air outlet.

[0042] Example 2

[0043] This example is based on the system for strengthening air mineralization of CO2 in example 1, and the carbon sequestration agent is selected as industrial solid waste carbide slag, the main component of which is calcium hydroxide, the content of which is measured to be 90.1%, and the particle size of the carbide slag is controlled to be 100 mesh.

[0044] The carbon sequestration space adopts a tower structure placed vertically, the carbon sequestration tower has a diameter of 2 m and a height of 120 m, the average temperature difference formed by the height difference is 0.6℃, the average flow rate of the air in the carbon sequestration tower is measured to be 0.5 m / s, the concentration of CO2 in the air is 430 ppm, and the average residence time of the air is 240 s, the humidity of the inlet and outlet of the carbon sequestration tower is monitored, and the absolute humidity of the convection air outlet of the carbon sequestration tower is controlled to be 3.3 g / m 3 .

[0045] The carbide slag is spread from the top of the carbon sequestration tower by a spreader, the spreading rate is 89 kg / h, the air and the carbide slag are fully countercurrently contacted in the carbon sequestration tower, so that the CO2 in the air is fixed as stable calcium carbonate by the carbide slag, online CO2 detectors and gas flow meters are arranged at both ends of the carbon sequestration tower, and the absorption and utilization rate η of CO2 of the air after being treated by the carbon sequestration tower is calculated according to the following formula:

[0046] η=(V in ×C in -V out ×C out ) / (V in ×C in )

[0047] Among them:

[0048] V in is the air flow rate, m 3 / h;

[0049] C in is the concentration of carbon dioxide in the air, vol. %;

[0050] V out is the air flow rate, m 3 / h;

[0051] C out The concentration of carbon dioxide in the air discharged from the system, vol%.

[0052] The concentration of carbon dioxide in the purified air discharged from the system was measured to be 62 ppm, and the absorption utilization rate of CO2 after the air was treated by the carbon fixation tower was calculated to be 85.6%.

[0053] Example 3

[0054] This example is based on the system for strengthening air mineralization of CO2 in Example 2, and the operation steps are the same as those in Example 2, except that the carbon fixation space adopts a horizontally placed roller structure, the roller diameter is 2 m, the length is 10 m, a coil heating is arranged at the solid discharge port end of the roller, so that the temperature difference between the two ends of the roller is 2℃, the average flow rate of the air in the roller is measured to be 1.5 m / s, the concentration of CO2 in the air is 430 ppm, and the average residence time of the air is 6.6 s, the humidity at the inlet and outlet of the roller is monitored, and the absolute humidity at the air outlet of the roller is controlled to be 3.5 g / m 3 .

[0055] The carbide slag is spread by a spreader from the solid feeding port of the roller, the spreading rate is 53 kg / h, the air and the carbide slag are fully countercurrently contacted in the roller, so that the CO2 in the air is fixed as stable calcium carbonate, an online CO2 detector and a gas flow meter are arranged at the gas inlet and outlet of the roller, the concentration of carbon dioxide in the purified air discharged from the system is measured to be 62 ppm, and the absorption utilization rate of CO2 after the air is treated by the carbon fixation tower is calculated to be 73.96%.

[0056] Compared with a point source such as flue gas (about 10% CO2), the concentration of CO2 in the air is relatively low, a large amount of air is needed to fix the same amount of CO2, and a large amount of mechanical energy is consumed to blow in the air in the traditional process, and the air convection is realized by using the temperature difference between the air inlet and outlet, so that the mechanical energy consumption can be avoided.

[0057] The temperature difference between the air inlet and outlet and the volume of the carbon fixation space are controlled, so that the air obtains a certain linear speed and residence time, and the carbon fixation agent spread into the carbon fixation space by the carbon fixation agent spreading system is fully contacted and reacted, the CO2 in the air is fixed under certain humidity conditions, the system is simple and easy to operate, and the CO2 in the air can be continuously solidified into stable carbonate.

[0058] The application utilizes the temperature difference between the air inlet and outlet to realize air convection, which can avoid the consumption of mechanical energy such as a fan. Through the spreading of the carbon fixation agent spreading system, the control of air flow rate, the humidity monitoring and control system for the humidity adjustment of the air outlet, the air and the carbon fixation agent are fully contacted and reacted in the carbon fixation space, and the CO2 in the air is solidified into stable carbonate by the carbon fixation agent. The system is simple, the method is simple, the continuous input and output of the carbon fixation agent solid and air can be realized, and the engineering is easy.

[0059] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A system for mineralizing CO2 in air, characterized in that, The carbon fixation device comprises a carbon fixation agent spreading system, a carbon fixation space, a temperature difference monitoring and control system, and a humidity monitoring and control system. The carbon fixation agent spreading system is used to spread the carbon fixation agent evenly into the carbon fixation space. The carbon fixation space provides sufficient contact space for air and the carbon fixation agent. The temperature difference monitoring and control system is used to form a temperature difference between the air inlet and outlet of the carbon fixation space, thereby forming a convection air. The humidity monitoring and control system is used to control the absolute humidity of the convection air outlet.

2. The system for mineralization of CO2 in air according to claim 1, characterized in that, The device further comprises an air monitoring system, which is used to monitor and control the air flow rate, temperature, humidity, and CO2 content of the air inlet and outlet of the carbon fixation space.

3. The system for mineralization of CO2 in air according to claim 1, characterized in that, The carbon fixation space comprises oppositely arranged air inlets and carbon fixation air outlets. The carbon fixation space further comprises a carbon fixation agent inlet and a carbon fixation agent outlet. The carbon fixation space is connected to the carbon fixation agent spreading system through the carbon fixation agent inlet.

4. The system for mineralization of CO2 in air according to claim 3, characterized in that, The air flow rate in the carbon fixation space is not greater than 2 m / s, and the air residence time in the carbon fixation space is not less than 5 s.

5. The system for mineralizing CO2 in air according to claim 1, characterized in that, The temperature difference monitoring and control system controls the temperature difference in the following ways: using the temperature difference caused by the height difference between the air inlets and outlets, or forming a temperature difference between one end of the carbon fixation space and the other end by means of light radiation, electromagnetic radiation, or heat exchange pipes.

6. The system for mineralization of CO2 in air according to claim 5, characterized by, The temperature difference monitoring and control system controls the temperature difference between the air inlets and outlets to be 0.5-5°C.

7. The system for mineralization of CO2 in air according to claim 1, characterized by, The humidity monitoring and control system controls the absolute humidity of the outlet of the convection air to be not less than 2g / m 3 .

8. The system for mineralization of CO2 in air according to claim 1, characterized by, The carbon fixation agent is an alkaline calcium / magnesium-based material and its derivatives.

9. Method for mineralizing CO2 in air using a system for mineralizing CO2 in air according to claim 1, characterized in that, The device comprises the following steps: S1. The carbon fixation agent spreading system spreads the carbon fixation agent evenly into the carbon fixation space. S2. The temperature difference monitoring and control system controls the temperature difference between the air inlets and outlets of the carbon fixation space, thereby forming a convection air. The humidity monitoring and control system controls the absolute humidity of the convection air outlet to ensure that CO2 in the air can quickly form carbonate and react with the carbon fixation agent. S3. The air in the carbon fixation space is in sufficient contact with the carbon fixation agent for reaction. S4. After the reaction is completed, the carbon fixation agent is discharged from the carbon fixation space or returned to the carbon fixation agent spreading system, and the carbon fixation air is discharged from the carbon fixation space outlet.

10. The method of claim 9, wherein, During the reaction, the air flow rate, temperature, humidity, and CO2 content are monitored and controlled by the air monitoring system to ensure that the carbon fixation agent is in sufficient contact with the carbon fixation agent in the carbon fixation space.

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