CN117138550A - Wet-method-desorbed air carbon capturing microalgae carbon fixing system and method - Google Patents

Abstract

This application proposes a wet desorption air carbon capture microalgae carbon fixation system and method. The system includes a carbon capture component, which includes a carbon adsorption component and a carbon desorption component; the carbon adsorption component includes a carbon capturer equipped with a carbon adsorption material. It is used to capture CO ₂ in the passing air; the carbon desorption component includes a desorption liquid tank containing desorption alkali liquid; the outlet of the desorption liquid tank is connected to the carbon capturer, and the CO ₂ is captured by spraying the desorption alkali liquid. carbon adsorption material; the liquid outlet of the carbon catcher is connected to the inlet of the desorption liquid tank, which is used to recover the desorption alkali liquid with dissolved CO ₂ until the pH of the desorption alkali liquid in the desorption liquid tank is not greater than 9; microalgae carbon fixation Component, which includes a photobioreactor for cultivating photobioreactors. When the pH of the desorption alkali solution in the desorption liquid tank is not greater than 9, it is input into the photobioreactor as a culture solution for photobioreactors. When the pH of the culture solution is greater than 9, it is transferred to the desorption solution tank.

Description

Wet desorption air carbon capture microalgae carbon fixation system and method

Technical field

This application relates to the technical field of carbon dioxide reuse, and in particular to wet desorption air carbon capture microalgae carbon fixation systems and methods.

Background technique

Carbon dioxide capture, utilization and storage (CCUS) technology is an important technological approach to address climate change. Direct Air Capture (DAC) technology can capture carbon dioxide emissions from distributed sources (such as small combustion devices, vehicles, etc.) that account for nearly 50% of total emissions. It has flexible layout locations, can capture cars, and can Advantages such as directly reducing the carbon dioxide content in the air have attracted more and more attention at home and abroad.

The solid adsorption method is the most commonly used direct air carbon capture technology. The solid adsorbent adsorbs carbon dioxide in the air under normal temperature and pressure conditions, and then uses the characteristics of the adsorption rate of carbon dioxide on the adsorbent to change under different temperatures or humidity. , the separation of carbon dioxide is achieved through heating or humidification. Among related technologies, the temperature swing adsorption method has been used to carry out tests and demonstrations of air carbon dioxide capture technology. The carbon dioxide is captured and purified into high-concentration carbon dioxide and then injected underground for geological storage. However, the concentration of carbon dioxide in the air is very low, only about 400 ppm, which is about 1/300 of the concentration of carbon dioxide in coal flue gas. Concentrating low-concentration carbon dioxide in the air into high-concentration carbon dioxide is very energy-intensive.

The prior art CN105032113A discloses a wet desorption mixed gas carbon capture technology, which desorbs carbon dioxide through the method characteristics of increasing the partial pressure of ambient water vapor, realizes desorption of carbon dioxide and circulation of adsorbents, and reduces air carbon dioxide to a certain extent. Energy consumption required for capture. But processes such as purging and drying are required, often resulting in new energy consumption. In addition, the enriched carbon dioxide also requires energy for further conversion and utilization or geological storage, which requires additional energy consumption. The prior art CN111151119A discloses a method for efficiently capturing and utilizing CO ₂ from the air based on microalgae biotechnology. High-concentration bicarbonate is added to the initial culture medium to form an artificial "carbon pool" to provide the necessary conditions for the growth of microalgae. While increasing the carbon source required, the pH value of the culture medium is increased to increase the mass transfer rate of carbon dioxide in the air flowing into the culture medium. The pH range of the culture medium is 10.0-12.5, and the algae species are haloalkali algae species suitable for high pH. However, the medium with high pH value in this technical method has limited algae species that can adapt to the growth, and is not suitable for the cultivation of freshwater algae; and there are no measures to strengthen the absorption of air carbon dioxide. The medium naturally dissolves less carbon dioxide in the air, and cannot fix large quantities. of carbon dioxide.

Contents of the invention

The present application aims to solve, at least to a certain extent, one of the technical problems in the related art.

To this end, the purpose of this application is to propose a wet desorption air carbon capture and microalgae carbon fixation system and method. The adsorption and desorption processes of CO ₂ gas in the air are alternately carried out, and the carbon capture component and the microalgae carbon fixation component are connected. The system is simple and realizes the integration of carbon dioxide capture and fixation. By arranging the humidifying regeneration adsorbent in the carbon capturer 1, it can achieve efficient adsorption of carbon dioxide in the air. After the adsorption is completed, the carbonate solution is directly used to desorb the adsorbed carbon dioxide and convert it into Bicarbonate is required for the growth of microalgae, and the system process is simple. In addition, the wet desorption air carbon capture microalgae carbon fixation system of this embodiment has low energy consumption. It adopts wet desorption of carbon dioxide and does not require heating processes. The system avoids processes such as residual gas purging and carbon dioxide purification and compression, and has low energy consumption.

According to the first aspect of this application, a wet desorption air carbon capture microalgae carbon fixation system is proposed, including:

A carbon capture assembly, which includes a carbon adsorption assembly and a carbon desorption assembly; the carbon adsorption assembly includes a carbon capturer provided with a carbon adsorption material for capturing CO ₂ in the passing air; the carbon desorption assembly It includes a desorption liquid tank containing desorption alkali liquid; the outlet of the desorption liquid tank is connected to the carbon capturer, and the carbon adsorption material after CO ₂ capture is sprayed by the desorption alkali liquid; the carbon capture material is The liquid outlet of the carbonizer is connected to the inlet of the desorption liquid tank, and is used to recover the desorption alkali liquid with dissolved CO ₂ until the pH of the desorption alkali liquid in the desorption liquid tank is not greater than 9;

Microalgae carbon fixation component, which includes a photobioreactor for cultivating photobioreactors. When the pH of the desorption alkali solution in the desorption liquid tank is not greater than 9, it is input into the photobioreactor as a culture solution for photobioreactors. within, and when the pH of the culture fluid in the photobioreactor is greater than 9, it is transported to the desorption liquid tank.

In some embodiments, a diverter assembly is provided at the outlet of the desorption liquid tank; the diverter assembly includes a first pipeline and a second pipeline respectively connected to the outlet of the desorption liquid tank; and a diverter assembly is provided on the first pipeline. The first valve is connected to the carbon capturer; a second valve is provided on the second pipeline and connected to the photobioreactor.

In some embodiments, the microalgae carbon fixation component further includes a culture liquid tank; the culture liquid tank contains culture liquid, and its inlet is connected to the desorption liquid tank through the second pipeline. When the pH of the desorption alkali solution in the box is not greater than 9, it is input into the culture solution tank for replenishing liquid to the photoenergy organisms in the photobioreactor.

In some embodiments, the carbon adsorption component further includes a pH meter disposed in the desorption liquid tank for measuring the pH value of the desorption alkali solution.

In some embodiments, an air supply component is also included, which is connected to the carbon adsorption component, and dries and purifies the air before transporting it to the carbon adsorption component.

In some embodiments, the air supply assembly includes an air dryer, an air filter and a pump connected in sequence according to the direction of gas flow.

In some embodiments, the carbon adsorbent material is a resin-based adsorbent.

According to the second aspect of the present application, a method of wet desorption of air carbon capture and microalgae carbon fixation is proposed. The method uses the system described in any of the above embodiments for carbon fixation, including the following processes:

The CO ₂ gas in the air passes through the carbon adsorption material in the carbon catcher and is adsorbed. After the carbon adsorption material is saturated, the carbon adsorption material is sprayed with the desorption alkali in the desorption liquid tank until the desorption liquid tank is reached. The pH of the desorption alkali solution within is not greater than 9;

When the pH of the desorption alkali solution is not greater than 9, it is transported into the photobioreactor as a culture solution for the photobioreactor. After the photobioreactor absorbs and utilizes the desorption alkali solution, the When the pH value of the desorption alkali solution rises to greater than 9, it flows back to the desorption liquid tank.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of the drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

Figure 1 is a schematic structural diagram of a wet desorption air carbon capture microalgae carbon fixation system proposed in an embodiment of the present application;

Figure 2 is a schematic structural diagram of a wet desorption air carbon capture microalgae carbon fixation system proposed in an embodiment of the present application;

Figure 3 is a schematic structural diagram of a wet desorption air carbon capture microalgae carbon fixation system proposed in another embodiment of the present application;

In the picture; 1. Carbon trap; 2. Desorption liquid tank; 3. Photobioreactor; 4. First pipeline; 5. Second pipeline; 6. First valve; 7. Second valve; 8. Circulating water pump; 9. Culture solution tank; 10. Feed pump; 11. Return pump; 12. Fan.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

Examples of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The examples described below with reference to the accompanying drawings are illustrative and are intended to explain the application and are not to be construed as limitations of the application.

As shown in Figures 1-3, according to the first aspect of the present application, a wet desorption air carbon capture and microalgae carbon fixation system is proposed, including: a carbon capture component and a microalgae carbon fixation component; wherein the carbon capture component It includes a carbon adsorption component and a carbon desorption component; the carbon adsorption component includes a carbon capturer 1 provided with carbon adsorption material for capturing CO ₂ in the passing air; the carbon desorption component includes a desorption device containing a desorption alkali solution. Liquid tank 2; the outlet of the desorption liquid tank 2 is connected to the carbon catcher 1, and the carbon adsorption material after CO ₂ capture is sprayed with desorption alkali solution; the liquid outlet of the carbon catcher 1 is connected to the inlet of the desorption liquid tank 2, and The desorption alkali liquid with dissolved CO ₂ is recovered until the pH of the desorption alkali liquid in the desorption liquid tank 2 is not greater than 9.

Among them, the carbon capture component includes a carbon adsorption component and a carbon desorption component that are connected in sequence. The carbon adsorption component includes a carbon capturer 1. The carbon capturer 1 is filled with a carbon adsorption material for adsorbing _CO2 gas in the air. During the carbon capture When air is introduced into the device 1, the air passes through the carbon adsorbent material in the carbon capture device 1 and fully contacts the carbon adsorbent material, which is conducive to the rapid adsorption of CO ₂ gas in the air by the carbon adsorbent material. The example carbon trap 1 is provided with an air inlet for introducing air, an air outlet for discharging air, a liquid inlet for spraying the desorption alkali liquid, and an outlet for discharging the desorption alkali liquid. Liquid port, the carbon adsorbent material 10 is a resin-type adsorbent. In addition, in order to further enhance the carbon capture performance of the carbon adsorbent material 10 and improve the carbon capture efficiency; the pore size structure of the resin-type molded adsorbent can be changed through a foaming porous granulation process. , increasing its specific surface area to obtain a modified porous adsorbent. After the air enters the carbon catcher 1 through the air inlet, the carbon adsorption material in the carbon catcher 1 adsorbs the CO ₂ gas in the air. The adsorbed air is discharged from the air outlet. At the same time, the desorption alkali solution is pH 9-12. The alkali liquid is passed into the carbon trap 1, and the desorption alkali liquid in this embodiment is a solution such as sodium hydroxide, potassium hydroxide, etc., which can undergo a chemical neutralization reaction with CO ₂ gas to generate bicarbonate. That is, after the carbon adsorption material is saturated, the carbon adsorption material in the alkali solution spray trap is desorbed, and the adsorbed CO ₂ gas is desorbed. The carbonate radicals in the desorbed alkali solution will react with carbon dioxide. Resulting in a decrease in the pH value of the desorption alkali solution.

In this embodiment, the carbon desorption assembly includes a desorption liquid tank 2 containing desorption alkali liquid. The outlet of the desorption liquid tank 2 is connected to the liquid inlet of the carbon capturer 1, and the desorption alkali liquid is used to spray the CO ₂ captured carbon. Adsorption material; the liquid outlet of the carbon catcher 1 is connected to the inlet of the desorption liquid tank 2, which is used to recover the desorption alkali liquid with dissolved CO ₂ until the pH of the desorption alkali liquid in the desorption liquid tank 2 is not greater than 9 to achieve carbon removal. Carbon dioxide desorption from adsorbent materials. During this process, the pH value of the desorption alkali solution at the bottom of the desorption solution tank 2 is monitored in real time. When the pH value of the desorption alkali liquid at the bottom of the desorption liquid tank 2 is greater than 9, the desorption alkali liquid at the bottom of the desorption liquid tank 2 is used for carbon dioxide desorption in the carbon trap.

Microalgae carbon fixation component, which includes a photobioreactor 3 for cultivating photobioreactors. When the pH of the desorption alkali solution in the desorption liquid tank 2 is not greater than 9, it is input into the photobioreactor 3 as a culture solution for photobioreactors, and When the pH of the culture solution in the photobioreactor 3 is greater than 9, it is transported to the desorption solution tank 2 .

The photobioreactor grows in the photobioreactor 3 through the culture medium as a microalgae carbon fixation component. The photobioreactor 3 is connected to the desorption liquid tank 2. When the pH of the desorption alkali in the desorption liquid tank 2 is not greater than 9 , the desorbed alkali solution can be input into the photobioreactor 3 as a culture solution for photoenergy organisms. After the photoenergy organisms such as microalgae absorb the bicarbonate in the desorbed alkali solution, they convert carbon dioxide into organic matter, and the pH value of the culture solution increases to 9-12, filter the culture solution in the photobioreactor 3 and then transport it to the desorption solution tank 2 through the reflux pump 11 to complete the circulation of the desorption alkali solution and the microalgae fixation of carbon dioxide.

Therefore, in this embodiment, the adsorption and desorption processes of CO ₂ gas in the air are carried out alternately. The carbon capture component and the microalgae carbon fixation component are connected. The system is simple and realizes the integration of carbon dioxide capture and fixation. By installing the carbon capture device 1 The humidified regeneration adsorbent is arranged inside, which can achieve efficient adsorption of carbon dioxide in the air. After the adsorption is completed, the carbonate solution is directly used to desorb the adsorbed carbon dioxide and convert it into bicarbonate required for the growth of microalgae. The system process is simple. In addition, the wet desorption air carbon capture microalgae carbon fixation system of this embodiment has low energy consumption. It adopts wet desorption of carbon dioxide and does not require heating processes. The system avoids processes such as residual gas purging and carbon dioxide purification and compression, and has low energy consumption.

In some embodiments, the outlet of the desorption liquid tank 2 is provided with a diverter assembly; the diverter assembly includes a first pipeline 4 and a second pipeline 5 respectively connected to the outlet of the desorption liquid tank 2; the first pipeline 4 is provided with a first Valve 6 is connected to the carbon capturer 1; a second valve 7 is provided on the second pipeline 5 and connected to the photobioreactor 3.

Among them, in this embodiment, the outlet of the desorption liquid tank 2 is provided with a diverting component for diverting the desorption alkali liquid in the desorption liquid tank 2 . The splitting assembly includes a first pipeline 4 and a second pipeline 5; the first pipeline 4 connects the outlet of the desorption liquid tank 2 and the liquid inlet of the carbon catcher 1, and is used to transfer the desorption alkali solution in the desorption liquid tank 2 When the pH is greater than 9, it is input into the carbon catcher 1 to spray and elute the carbon adsorbent material in the carbon catcher 1. The first pipeline 4 is provided with a first valve 6; the second pipeline 5 is connected to the desorption liquid tank. The outlet of 2 and the liquid inlet of the photobioreactor 3 are used to input the desorption alkali solution in the desorption liquid tank 2 into the photobioreactor 3 when the pH is not greater than 9, and are used to replenish the photobioreactor 3 with light energy. , wherein the second pipeline 5 is provided with a second valve 7, and in this embodiment, a circulating water pump 8 is provided at the outlet of the desorption liquid tank 2.

In some solutions, the carbon adsorption component also includes a pH meter disposed in the desorption liquid tank 2 for measuring the pH value of the desorbed alkali liquid. Therefore, in this embodiment, the pH value of the desorbed alkali liquid in the desorption liquid tank 2 can be measured. The value is determined by passing the first pipeline 4 or the second pipeline 5 through the first pipeline 4 or the second pipeline 5 to conduct a qualitative analysis of the desorbed alkaline fluid. Compared with the related technology that uses desorption alkali solution to directly soak the carbon adsorption material for a period of time, which reduces the CO ₂ elution efficiency, and the related technology has always used the desorption alkali solution with a pH of 9-12 to continuously spray the carbon adsorption material, causing Desorption alkali liquid is used in large quantities, which wastes resources. This application can circulate the desorption alkali liquid when its pH value is 9-12, reuse the spray carbon adsorption material, and directly transport it to the light when its pH value is not greater than 9. Bioreactor 3 ensures CO ₂ elution efficiency while rationally utilizing the desorption alkali solution to achieve resource conservation and reduce system consumption costs.

In some embodiments, the microalgae carbon fixation assembly also includes a culture liquid tank 9; the culture liquid tank 9 contains culture liquid, and its inlet is connected to the desorption liquid tank 2 through the second pipeline 5. When the pH of the desorption alkali solution is not greater than 9, it is input into the culture solution tank 9 for replenishing liquid to the photoenergy organisms in the photobioreactor 3 .

The microalgae carbon fixation component also includes a culture liquid tank 9 containing culture liquid. The inlet of the culture liquid tank 9 is connected to the second pipeline 5, and its outlet is connected to the photobioreactor 3. The desorption alkali in the desorption liquid tank 2 is When the liquid pH is not greater than 9, the desorbed alkali liquid is input into the culture liquid tank 9 for storage. A liquid feeding pump 10 is provided between the culture liquid tank 9 and the photobioreactor 3. When the photobioreactor 3 needs to replenish liquid, the culture liquid tank 9 The culture fluid can be pumped in quantitatively for photobiotic rehydration. In addition, the quality of the culture solution in the culture solution tank 9 can be monitored at all times to keep the quality of the culture solution and the ion level therein basically consistent.

In some embodiments, an air supply component is also included, which is connected to the carbon adsorption component, and dries and purifies the air before transporting it to the carbon adsorption component.

The wet desorption air carbon capture microalgae carbon fixation system of this embodiment also includes an air supply component. The air supply component is connected to the carbon adsorption component to dry and purify the air and then transport it to the carbon adsorption component. The example air supply component includes an air dryer, an air filter and a pump that are connected in sequence according to the direction of gas flow. After the air passes through the air dryer and the air filter to remove moisture and impurities, it passes through the carbon capturer 1 through the pump. The air behind the carbon collector 1 is driven and discharged by the fan 12.

According to the second aspect of the present application, a method of wet desorption of air carbon capture and microalgae carbon fixation is proposed. The method uses the system in any of the above embodiments to fix carbon, including the following processes:

S1: The air passes through the carbon adsorption material in the carbon catcher 1 and the CO ₂ gas is adsorbed. After the carbon adsorption material is saturated, the carbon adsorption material is sprayed with the desorption alkali solution in the desorption liquid tank 2 until the desorption liquid tank The pH of the desorption alkali solution within 2 shall not be greater than 9;

S2: When the pH of the desorbed alkali solution is not greater than 9, it is transported into the photobioreactor 3 as the culture solution of the photobioreactor 3. After the photobioreactor absorbs and utilizes the desorbed alkali solution, the pH value of the desorbed alkali solution rises. When the value is greater than 9, it flows back to the desorption liquid tank 2.

Among them, when air is introduced into the carbon catcher 1, the air passes through the carbon adsorbent material in the carbon catcher 1 and fully contacts the carbon adsorbent material. The carbon adsorbent material quickly absorbs CO ₂ gas in the air, and the adsorbed air is captured by the carbon capture material. discharge from the air outlet of device 1. The desorption alkali liquid with a pH of 9-12 is passed into the carbon capture device 1, and the carbon adsorbent material that has adsorbed CO ₂ gas is sprayed, and the desorption alkali solution at the bottom of the carbon capture device 1 is collected by the desorption liquid tank 2, and at the same time, the collected The pH value of the desorbed alkali liquid is monitored in real time. When the pH value of the desorbed alkali liquid is greater than 9, it continues to enter the carbon trap 1 for carbon adsorption material spraying. When the pH value of the desorbed alkali liquid is not greater than 9, it is used as The culture solution of the photobioreactor 3 is transferred to the culture solution tank 9 to replenish the photobioreactor 3 .

It should be noted that in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Furthermore, in the description of the present application, unless otherwise stated, the meaning of “plurality” is two or more.

Any process or method descriptions in flowcharts or otherwise described herein may be understood to represent modules, segments, or portions of code that include one or more executable instructions for implementing the specified logical functions or steps of the process. , and the scope of the preferred embodiments of the present application includes additional implementations in which functions may be performed out of the order shown or discussed, including in a substantially simultaneous manner or in the reverse order, depending on the functionality involved, which shall It should be understood by those skilled in the technical field to which the embodiments of this application belong.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "an example," "specific examples," or "some examples" or the like means that specific features are described in connection with the embodiment or example. , structures, materials or features are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present application have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and cannot be understood as limitations of the present application. Those of ordinary skill in the art can make modifications to the above-mentioned embodiments within the scope of the present application. The embodiments are subject to changes, modifications, substitutions and variations.

Claims (8)

1. The air carbon capturing microalgae carbon fixing system by wet desorption is characterized by comprising the following components:

a carbon capture assembly comprising a carbon adsorption assembly and a carbon desorption assembly; the carbon adsorption component comprises a carbon catcher provided with a carbon adsorption material for absorbing CO in the passing air ₂ Capturing; the carbon desorption assembly comprises a desorption solution box containing desorption alkali solution; the outlet of the desorption liquid box is connected with the carbon catcher, and CO is sprayed by using the desorption alkali liquid ₂ The carbon adsorbing material after trapping; the liquid outlet of the carbon catcher is connected with the inlet of the desorption liquid box and is used for dissolving CO ₂ Recovering the desorption alkali liquor until the pH value of the desorption alkali liquor in the desorption liquor box is not more than 9;

the microalgae carbon fixing component comprises a photobioreactor for culturing light energy organisms, wherein the microalgae carbon fixing component is used as a culture solution of the light energy organisms to be input into the photobioreactor when the pH value of the desorption alkali solution in the desorption solution tank is not more than 9, and is used as the culture solution of the light energy organisms to be input into the desorption solution tank when the pH value of the culture solution in the photobioreactor is more than 9.

2. The system of claim 1, wherein the outlet of the desorber tank is provided with a diverter assembly; the flow dividing assembly comprises a first pipeline and a second pipeline which are respectively connected with the outlet of the desorption liquid tank; a first valve is arranged on the first pipeline and is connected with the carbon catcher; and a second valve is arranged on the second pipeline and is connected with the photobioreactor.

3. The system of claim 2, wherein the microalgae carbon fixing component further comprises a culture solution tank; the culture solution tank is filled with culture solution, an inlet of the culture solution tank is connected with the desorption solution tank through the second pipeline, and the culture solution tank is input when the pH value of the desorption alkali solution in the desorption solution tank is not more than 9 and is used for supplementing the light energy biological fluid into the photobioreactor.

4. A system according to any one of claims 1-3, characterized in that the carbon adsorption module further comprises a pH meter arranged in the desorption tank for measuring the pH value of the desorption alkaline solution therein.

5. The system of claim 4, further comprising an air supply assembly coupled to the carbon adsorption assembly for drying and purifying air for delivery to the carbon adsorption assembly.

6. The system of claim 5, wherein the air supply assembly comprises an air dryer, an air filter, and a pump member connected in sequence according to a direction of air flow.

7. The system of claim 1, wherein the carbon adsorbent material is a resin type adsorbent.

8. A method for carbon sequestration by wet desorption of air carbon capture microalgae, characterized in that the method adopts the system of any one of claims 1-7 for carbon sequestration, comprising the following steps:

the air passes through CO in the carbon adsorption material in the carbon catcher ₂ After the carbon adsorption material is adsorbed and saturated, spraying and washing the carbon adsorption material by using desorption alkali liquor in a desorption liquid box until the pH value of the desorption alkali liquor in the desorption liquid box is not more than 9;

and when the pH value of the desorption alkali liquor is not more than 9, the culture solution serving as the light energy organism in the photobioreactor is conveyed into the photobioreactor, and after the light energy organism absorbs and utilizes the desorption alkali liquor, the desorption alkali liquor is refluxed to the desorption liquid tank when the pH value is increased to be more than 9.