Carbon dioxide trapping agent and method for trapping, storing and utilizing carbon dioxide

Abstract

The invention belongs to the field of carbon dioxide trapping, and particularly relates to a carbon dioxide trapping agent and a carbon dioxide trapping, storage and utilization method, a carbon dioxide trapping agent composition comprises carboxylic acid, a solvent and alkali, the solvent is a good solvent of the carboxylic acid and the alkali, the chemical formula of the carboxylic acid is R-COOH, R is substituted or unsubstituted C4-C21 alkyl, and the alkali is a non-substituted or unsubstituted C4-C21 alkyl. The substitution refers to that one or more H on the alkyl is substituted by alkyl,-OH,-COOH, aryl, amino or-X, and X refers to a halogen atom F, Cl, Br or I. The carboxylate aqueous solution CO2 absorbent is prepared by taking carboxylic acid and alkali as raw materials, the prepared CO2 absorbent has excellent CO2 trapping performance, after the CO2 absorbent traps CO2, the property is stable, storage is facilitated, regeneration of the CO2 absorbent can reversely release CO2 without or only needing a small amount of external energy consumption, and therefore recycling of the absorbent is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of carbon dioxide capture, and particularly relates to a carbon dioxide capture agent and a method for carbon dioxide capture, storage and utilization, such as a carbon dioxide capture agent in flue gas and a method for carbon dioxide capture, storage and utilization. Background Art

[0002] The combustion of fossil fuels produces a large amount of CO 2 gas. The environmental pollution and climate change problems caused by the large-scale emission of CO 2 gas have become one of the major threats faced by human society. To address climate change issues such as global warming, countries around the world have put forward carbon neutrality visions. Among the six greenhouse gases, the contribution of carbon dioxide emissions is about 75%, having the greatest impact.

[0003] Generally speaking, there are mainly four ways to achieve a substantial reduction in carbon dioxide. By saving energy and improving energy efficiency, using non-fossil energy to replace fossil energy, using new technologies to capture, store and utilize carbon dioxide, and increasing carbon sinks through afforestation. The first three are related to the energy system. Although afforestation has a lower cost, its high demand for land will lead to land competition with the goal of increasing productivity.

[0004] Compared with other technologies, carbon capture, storage and utilization technology is the only negative emission technology that can reduce the content of carbon dioxide in the atmosphere. This technology is mainly divided into three parts: capture, storage and utilization. Capture is the first step of carbon capture and storage. Carbon dioxide needs to exist in a relatively high purity during transportation, storage and utilization. In most cases, the concentration of carbon dioxide in industrial tail gas is low, so carbon dioxide must be separated from the tail gas, and this process is called carbon dioxide capture. The report "Carbon Dioxide Emissions in 2022" released by the International Energy Agency pointed out that from 2019 to 2022, global CO 2Emissions by industry show that the industry with the largest absolute increase is power generation and heating. Therefore, the power industry is the main field of application for CCS technology (Carbon Capture and Storage, the technology of capturing and storing carbon dioxide). To achieve the goal of capturing carbon dioxide in flue gas, it is necessary to technically transform carbon dioxide emission sources and install carbon dioxide capture systems. Generally speaking, according to the different positions of capturing carbon dioxide in each process of the fossil energy life cycle, the capture technologies applicable to power plants are divided into three types: "post-combustion capture", "pre-combustion capture", and "oxy-fuel combustion". Among them, the "post-combustion capture" technology is applicable to the retrofit of existing power plant flues and is thus the most widely used. The main methods for carbon capture from flue gas containing carbon dioxide in power plant flues mainly include chemical absorption using alkaline solutions and physical absorption using non-corrosive solvents such as methanol or polyethylene glycol dimethyl ether. It also includes adsorption using porous solid adsorbents, membrane separation methods, etc. However, due to the low separation efficiency of adsorption and membrane separation methods for CO 2 , they have not been widely applied. Among these main capture technologies, chemical absorption and physical absorption are relatively the most mature and have been widely used in the chemical industry.

[0005] Amine scrubbing is a method for removing acidic gases. Since R.R. Bottoms obtained a patent for using ethanolamine solution to remove acidic gases in 1930, the decarbonization method using alkyl alkanolamine has become a widely used method in the gas purification process. When this method is used, it has the following defects: a. When used in systems containing a large amount of nitrogen oxides and / or sulfur-containing gases, it is necessary to purify nitrogen oxides and / or sulfur-containing gases in advance; b. Liquid amines have some serious drawbacks, including problems such as amine evaporation, corrosion of equipment, and high energy costs for regeneration. A feasible method to reduce corrosion and regeneration energy is to use supported amine adsorbents. However, currently, due to the high cost of raw materials for synthesizing supported amine adsorbents, they cannot be widely applied in industrial environments.

[0006] The Radu Custelcean group reported a method for direct air capture at the laboratory scale using mostly off-the-shelf materials and equipment: using a household humidifier, achieving CO 2 absorption through an aqueous solution of easily obtainable and environmentally friendly amino acids (glycine and sarcosine), and then reacting the solution that has absorbed CO 2 with a simple guanidine compound (guanidine adsorbent) to obtain guanidine compound crystals. These guanidine compound crystals are insoluble carbonates. Finally, by relatively gently heating the carbonate crystals using concentrated solar energy, nearly quantitative regeneration of the guanidine compound and effective CO 2 release can be achieved. However, the regeneration temperature of the guanidine adsorbent is relatively high (80 - 120 °C), thus requiring more energy consumption.

[0007] On the other hand, there are problems with CCS in terms of the transportation and storage of CO 2 , such as immature technology, high cost, energy consumption, and risks. Therefore, developing a CO 2 capturing agent with excellent capture performance, low regeneration energy consumption, and environmental friendliness is the key to carbon dioxide capture, storage, and utilization. Summary of the Invention

[0008] To improve the deficiencies of the existing technology, the present invention provides a carbon dioxide capturing agent and a method for carbon dioxide capture, storage, and utilization. Specifically, it is a method for capturing carbon dioxide in flue gas, storing it, and using it. The carbon dioxide capturing agent is an aqueous carboxylate solution prepared from a carboxylic acid and a base, and can be used as a CO 2 absorbent. This CO 2 absorbent has excellent CO 2 capture performance.

[0009] A composition for a carbon dioxide capturing agent, the composition comprising a carboxylic acid, a solvent, and a base. The solvent is a good solvent for the carboxylic acid and the base. The chemical formula of the carboxylic acid is R-COOH, wherein R is a substituted or unsubstituted C 4 ~C 21 hydrocarbyl group.

[0010] According to an embodiment of the present invention, the substitution means that one or more H on the alkyl group are substituted by a hydrocarbyl group, -OH, -COOH, an aryl group, an amino group, or -X, where X refers to a halogen atom F, Cl, Br, or I.

[0011] According to an embodiment of the present invention, R contains one or more olefinic groups and / or acetylenic groups.

[0012] According to an embodiment of the present invention, the carboxylic acid is a saturated monocarboxylic acid of C 8 ~C 18 , such as octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, or dodecanoic acid.

[0013] According to an embodiment of the present invention, the carboxylic acid is a polycarboxylic acid of C 8 ~C 14 , such as suberic acid, undecanedioic acid, dodecanedioic acid, or tridecanedioic acid.

[0014] According to an embodiment of the present invention, the carboxylic acid is a mono- or poly-unsaturated carboxylic acid of C 8 ~C 22 , such as 2-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 10-undecenoic acid, oleic acid, linoleic acid, ricinoleic acid, eicosapentaenoic acid, or docosatetraenoic acid.

[0015] According to an embodiment of the present invention, the carboxylic acid is a C 5 ~C 12 carboxylic acid containing one phenyl group, such as at least one of phenylvaleric acid, phenylnonanoic acid, phenylnonanedioic acid, phenylnonenoic acid, and phenylnonadienoic acid.

[0016] According to an embodiment of the present invention, the base is selected from at least one of inorganic bases and organic bases.

[0017] According to an embodiment of the present invention, the inorganic base may be NaOH, KOH, Ca(OH) 2 , LiOH, NH 3 H 2 O, NaHCO 3 , Na 2 CO 3 , KHCO 3 , K 2 CO 3 , Ca(HCO 3 ) 2 , CaCO 3 or at least one of them.

[0018] According to an embodiment of the present invention, the organic base may be at least one of methylamine, ethylamine, propylamine, butylamine, ethylenediamine, ethanolamine, and triethanolamine, such as ethanolamine.

[0019] According to an embodiment of the present invention, the solvent may be water or a composite solvent; specifically, the composite solvent is a composite solvent of water and an organic solvent. For example, the composite solvent is selected from at least one of water / methanol, water / ethanol, water / propyl alcohol, and water / acetonitrile, such as water / acetonitrile.

[0020] According to an embodiment of the present invention, the molar amount of the carboxylic acid and the base is equal or the base is in excess. For example, the molar ratio can be selected as 1:1, 1:1.1, 1:1.5, or 1:2.

[0021] According to an embodiment of the present invention, the molar amount of the carboxylic acid and the base being equal or the base being in excess means that the molar ratio of H + in the carboxylic acid to OH - in the base is less than or equal to 1. When the carboxylic acid is in excess, it cannot be completely salted, and the absorption effect is poor; when the base is in excess, the absorption performance is improved, including the common absorption performance of carboxylate and base. After regeneration, the absorption performance is the absorption performance of carboxylate, but the carboxylate absorbed by the base cannot be regenerated.

[0022] According to an embodiment of the present invention, the composition further includes a carboxylate formed by a carboxylic acid and a base. Specifically, in the composition, the mass fraction of the carboxylate formed by the carboxylic acid and the base is greater than 0 and less than or equal to 30%, for example, greater than 3 and less than or equal to 20%, and exemplary values are 1%, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 25%.

[0023] A carbon dioxide capture agent, the capture agent includes a solvent and a carboxylate dissolved in the solvent, and the mass fraction of the carboxylate is greater than 0 and less than or equal to 30%, for example, greater than 3 and less than or equal to 20%, and exemplary values are 1%, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 25%.

[0024] According to an embodiment of the present invention, the solvent and the carboxylate have the definitions as described above.

[0025] According to an embodiment of the present invention, the pH value of the carbon dioxide capture agent is 7 - 14, preferably the pH value of the carbon dioxide capture agent is 7 - 12, for example, it is 7, 8, 9, 10, 11 or 12.

[0026] According to an embodiment of the present invention, the carbon dioxide capture agent is a micellar solution of a carboxylate. Specifically, when the capture agent captures carbon dioxide, a micellar solution system, an emulsion system, a solid - liquid two - phase system, a liquid - liquid two - phase system or a solid - phase system is formed.

[0027] A carbon dioxide capture method, the method uses the above - mentioned carbon dioxide capture agent or a composition for the carbon dioxide capture agent to capture CO 2 , and includes the following steps:

[0028] Contact a gas containing CO 2 with the above - mentioned composition for the carbon dioxide capture agent or the above - mentioned carbon dioxide capture agent to capture CO 2 capture.

[0029] According to an embodiment of the present invention, the contact means introducing a gas containing CO 2 into the composition for the carbon dioxide capture agent or the carbon dioxide capture agent.

[0030] According to an embodiment of the present invention, the contact is carried out under airtight conditions.

[0031] According to an embodiment of the present invention, the contact includes first storing the composition for the carbon dioxide capture agent or the carbon dioxide capture agent in a sealed container, and introducing a gas containing CO 2 into the sealed container to contact with the composition for the carbon dioxide capture agent or the carbon dioxide capture agent.

[0032] According to an embodiment of the present invention, a gas inlet channel and a gas outlet channel are provided on the closed container, and the gas inlet channel is used to introduce a gas containing CO 2 into the composition for carbon dioxide capturant or the carbon dioxide capturant, and the gas outlet channel is used to export the gas after CO 2 is adsorbed from the closed container.

[0033] According to an embodiment of the present invention, the contact time of the gas containing CO 2 with the composition for carbon dioxide capturant or the carbon dioxide capturant is 0.5 to 4 h, and preferably the contact time for capture is 1 h, 2 h or 3 h.

[0034] According to an embodiment of the present invention, in the gas containing CO 2 , the partial pressure of the CO 2 gas is 2 to 100%, preferably the partial pressure of the CO 2 gas is 4 to 100%, and further preferably, the partial pressure of the CO 2 gas is 10 to 100%.

[0035] According to an embodiment of the present invention, the gas containing CO 2 is flue gas, and the partial pressure of CO 2 in the flue gas is 13% to 20%, so capture can be achieved.

[0036] According to an embodiment of the present invention, the capture temperature is 0 to 90°C, preferably the capture temperature is 0 to 60°C, and further preferably, the capture temperature is 0 to 50°C. For example, the capture temperature is 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C.

[0037] According to an embodiment of the present invention, the capture amount of CO 2 gas by the composition for carbon dioxide capturant or the carbon dioxide capturant is 5 mg / g to 50 mg / g.

[0038] According to an embodiment of the present invention, after CO 2 contacts with the composition for carbon dioxide capturant, carboxylate and CO 2 form carboxylic acid and bicarbonate, thereby forming a micelle solution system, an emulsion system, a solid-liquid two-phase system, a liquid-liquid two-phase system or a solid-phase system, and these systems have good stability under closed conditions and are convenient for transportation and storage.

[0039] According to an embodiment of the present invention, after capturing CO 2 , the following steps are further included: storing the gas containing CO 2The capture agent.

[0040] According to an embodiment of the present invention, the storage is to store the capture agent containing CO 2 in a closed environment.

[0041] According to an embodiment of the present invention, the temperature of the closed environment is 0 to 50 °C, for example, room temperature.

[0042] According to an embodiment of the present invention, the capture agent containing CO 2 does not separate after being stored in a closed environment for at least 20 days.

[0043] According to an embodiment of the present invention, after capturing CO 2 or storing the capture agent containing CO 2 , the following steps are further included: regenerating the capture agent.

[0044] According to an embodiment of the present invention, regenerating the capture agent includes the following steps: placing the capture agent after capturing CO 2 or storing the capture agent containing CO 2 in an environment with a CO 2 partial pressure less than 2% to release CO 2 to obtain a regenerated capture agent.

[0045] According to an embodiment of the present invention, releasing the CO 2 is carried out in an environment with a CO 2 partial pressure less than 1%, preferably in an environment with a CO 2 partial pressure less than 0.5%, for example, in the atmosphere.

[0046] According to an embodiment of the present invention, releasing the CO 2 is carried out under the condition of a temperature of 0 to 90 °C, preferably under the condition of a temperature of 20 to 60 °C, for example, under normal temperature and pressure.

[0047] According to an embodiment of the present invention, the CO 2 absorbed in the capture agent can be reversibly released under normal temperature and pressure. This reaction is a reversible reaction, and the cyclic regeneration of the absorbent and the quantitative release of CO 2 can be achieved by placing it open at room temperature, introducing an inert gas, or providing a temperature above 35 °C.

[0048] A composition for the above carbon dioxide capture agent, the above carbon dioxide capture agent, or the above carbon dioxide capture method in the waste stream of power plants, cement manufacturing, steel manufacturing, glass manufacturing, brewing, syngas production, natural gas and biogas purification, synthetic ammonia, or any other industrial process that produces acidic gases for CO 2Applications in processing, preferably for enhanced oil and gas recovery in geological utilization; chemical utilization for preparing liquid fuels and biodegradable polymers; biological utilization for conversion into food, feed, chemicals, and biological CO 2 Gas fertilizer; or for geological sequestration, such as for enhanced oil, gas, geothermal, shale gas, coalbed methane, and in-situ leaching of uranium ore mining, preparing liquid fuels, synthesizing polyols, methanol, carbonates, biodegradable polymers, converting into food and feed, converting into chemicals, and used as a CO 2 Gas fertilizer for plants.

[0049] According to an embodiment of the present invention, the storage of CO in flue gas 2 is due to carbon dioxide being an acidic gas. When carbon dioxide is introduced, it reacts with the hydroxide ions generated by the hydrolysis of carboxylate sodium to form hydrophobic carboxylic acid and NaHCO 3 ; both are transformed from a transparent carboxylate solution into a micelle solution system, an emulsion system, a solid-liquid two-phase system, a liquid-liquid two-phase system, or a solid phase system, mainly existing in a liquid-liquid two-phase system or a solid phase system, with good stability under normal temperature and airtight environment, facilitating transportation and storage.

[0050] According to an embodiment of the present invention, for the utilization of carbon dioxide in flue gas, at normal temperature and pressure, the partial pressure of CO 2 is relatively low. Therefore, the carboxylic acid in the solution continuously reacts with sodium bicarbonate, gradually releasing CO 2 to increase its concentration in the space, while the liquid-liquid two-phase system or solid phase system that absorbs CO 2 returns to the initial carboxylate micelle solution state.

[0051] Advantages

[0052] The present invention provides a capture system, which is a composition for a carbon dioxide capture agent or a carbon dioxide capture agent, having the following advantages:

[0053] 1. The capture system has a high capture capacity, ranging from 5 mg / g to 50 mg / g, with excellent performance, being green, environmentally friendly, and different from currently commercial amine absorbents.

[0054] 2. The capture system always exists in a liquid or solid form, enabling the transportation and storage of CO in flue gas 2 . Under airtight environmental room temperature conditions, CO can be stably stored for a long time 2 .

[0055] 3. The capture system provided by the present invention is a new type of flue gas carbon dioxide capture agent. This carboxylate-based capture agent has a wide natural source and a low price, making it a potential alternative to amine absorbents. At the same time, it expands the utilization pathways of CO in flue gas 2 .

[0056] The present invention also provides a method for capturing, storing and utilizing carbon dioxide in flue gas, which has the following characteristics:

[0057] 1. Starting from the major national demand for energy conservation and emission reduction, the present invention proposes a method for capturing, storing and utilizing CO in flue gas. 2 This method helps to alleviate the climate change problem caused by anthropogenic emissions from industrial point sources and solve the environmental pollution problem caused by greenhouse gases. 2 in flue gas, which helps to mitigate the climate change problem caused by anthropogenic emissions from industrial point sources and solve the environmental pollution problem caused by greenhouse gases. 2

[0058] 2. After capturing CO by the present invention, the system can reversibly release CO at normal temperature and pressure. 2 This enables efficient conversion of CO to generate economic benefits. The release process is a reversible reaction and does not require external energy supply or only requires a small amount of energy. 2 2 BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Digital photos of the aqueous solution of saturated carboxylate salt for capturing CO before and after in the present invention: where a, b, c, d, e, f are the structural formulas of sodium heptanoate, sodium octanoate, sodium nonanoate, sodium decanoate, sodium undecanoate, and sodium laurate respectively; g, h, I, j, k, l respectively represent the forms of the carboxylate salt solution before capturing CO. 2 2 m, n, o, p, q, r respectively represent the forms of the capturer after capturing CO. 2

[0060] Figure 2 For the capture performance data of the capturer: where, Figure 2 (a) The middle line represents the capture performance of the aqueous carboxylate salt system with a mass fraction of 5 wt% C 1 -C 12 . The top line represents the capture performance of the aqueous carboxylate salt solution with 10 wt% C 8 -C 11 . The bottom black line represents the systematic error; Figure 2 (b) Represents the capture performance of the aqueous sodium octanoate solution with a mass fraction of 5 wt% at different temperatures and partial pressures. The horizontal line represents the systematic error; Figure 2 (c) Represents the critical partial pressure test for the capture of CO by the aqueous sodium octanoate solution; 2 Figure 2 (d) Represents the three-cycle regeneration performance test of the aqueous sodium octanoate solution in bubbling CO 2 / N 2 .

[0061] Figure 3In (a), (b), (c), and (d), they respectively represent the CO capture critical partial pressure performance tests of aqueous solutions of sodium nonanoate, sodium decanoate, sodium undecanoate, and sodium laurate. 2

[0062] Figure 4 In (a), (c), (d), and (e), they respectively represent the 3-cycle regeneration performance tests of aqueous solutions of sodium nonanoate, sodium decanoate, sodium undecanoate, and sodium laurate in bubbling pure CO 2 / N 2 ; Figure 4 (b) represents the 3-cycle regeneration performance test of sodium nonanoate aqueous solution in bubbling simulated flue gas CO 2 / N 2 ; Figure 4 (f) is the capture and release performance of aqueous solutions of sodium octanoate, sodium nonanoate, sodium decanoate, sodium undecanoate, and sodium laurate for simulated flue gas.

[0063] Figure 5 These are digital photos before and after the capture of CO by the aqueous carboxylate solution in the present invention: where a, b, c, d, e, f are respectively the structural formulas of sodium decanoate, sodium 2-decenoate, 10-hydroxy-2-decenoate, sodium 9-decenoate, sodium 4-decenoate, 10-hydroxy-sodium decanoate; g, h, I, j, k, l respectively represent the morphology of the carboxylate salt solution before capturing CO 2 ; m, n, o, p, q, r respectively represent the morphology of the capture agent after capturing CO 2 2 .

[0064] Figure 6 These are the performance data of the capture agent: among them, Figure 6 (a) The upper broken line represents the capture performance of the carboxylate salt system with a mass fraction of 5 wt% of C 10 , and the bottom black line represents the systematic error; Figure 6 (b) represents the critical partial pressure test of the capture of CO by the aqueous solution of sodium 4-decenoate with a mass fraction of 5 wt%. 2

[0065] Figure 7 These are digital photos before and after the capture of CO by the aqueous carboxylate solution in the present invention: where a, b, c, d, e, f are respectively the structural formulas of sodium octadecanoate, sodium oleate (9-octadecenoic acid), sodium linoleate (9,12-octadecadienoic acid), sodium ricinoleate, 12-hydroxy-sodium octadecanoate, 18-hydroxy-sodium octadecanoate; g, h, I, j, k, l respectively represent the morphology of the carboxylate salt solution before capturing CO 2 ; m, n, o, p, q, r respectively represent the morphology of the carboxylate salt solution after capturing CO 2 2 . ​​​​

[0066] Figure 8 Performance data of the capture agent: Among them, Figure 8 (a) The upper broken line represents the capture performance of the carboxylate aqueous system with a mass fraction of 5 wt% of C 18 , and the black line at the bottom represents the systematic error; Figure 8 (b) represents the capture performance of the aqueous solution of sodium oleate with a mass fraction of 5 wt% at different temperatures, and the horizontal line represents the systematic error; Figure 8 (c), (e), and (f) respectively represent the critical partial pressure performance tests of the aqueous solutions of sodium linoleate, sodium oleate, and sodium ricinoleate for capturing CO 2 ; Figure 8 (d) is the 3-cycle regeneration performance test of the aqueous solution of sodium linoleate in a bubbling simulated flue gas of CO 2 / N 2 ;

[0067] Figure 9 Digital photos before and after the capture of CO by the carboxylate aqueous solution in the present invention: Among them, a, b, c, d, e, f are the structural formulas of sodium benzoate, sodium phenylpropionate, 4-phenylbutyrate, 5-phenylvalerate, 6-phenylhexanoate, and 8-phenyloctanoate respectively; g, h, I, j, k, l respectively represent the morphologies of the carboxylate salt solutions before capturing CO 2 ; m, n, o, p, q, r respectively represent the morphologies of the carboxylate salt solutions after capturing CO 2 ; 2 ;

[0068] Figure 10 Performance data of the capture agent: Among them, Figure 10 (a) The upper broken line represents the capture performance of the carboxylate aqueous system with a mass fraction of 5 wt% of C 1 -C 8 , and the black line at the bottom represents the systematic error; Figure 10 (b) represents the conductivity test of the aqueous solution of sodium 5-phenylvalerate with a mass fraction of 5 wt% for capturing CO 2 gases with different partial pressures; Specific implementation mode

[0069] The following will further elaborate on the capture agent of the present invention, its preparation method, and application in combination with specific embodiments. It should be understood that the following embodiments are only for illustrative explanation of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0070] Example 1: Preparation of an aqueous solution of sodium heptanoate with a mass fraction of 5 wt% (C7:0)

[0071] Weigh 0.5 g of sodium heptanoate and 9.5 g of deionized water, and successively add them into a 20-ml vial. Sonicate for 10 min to obtain a homogeneous aqueous solution of sodium heptanoate with a mass fraction of 5 wt%.

[0072] Example 2: Preparation of sodium octanoate solutions with mass fractions of 5 wt% and 10 wt% respectively.

[0073] Weigh 0.5 g / 1 g of sodium octanoate and 9.5 g / 9 g of deionized water, and successively add them into a 50-ml colorimetric tube. Sonicate for 10 min to obtain homogeneous aqueous solutions of sodium octanoate (C8:0) with mass fractions of 5 wt% and 10 wt% respectively.

[0074] Example 3: Preparation of sodium nonanoate solutions with mass fractions of 5 wt% and 10 wt% respectively

[0075] Weigh 0.5 g / 1 g of sodium nonanoate and 9.5 g / 9 g of deionized water, and successively add them into a 50-ml colorimetric tube. Sonicate for 10 min to obtain homogeneous aqueous solutions of sodium nonanoate (C9:0) with mass fractions of 5 wt% and 10 wt% respectively.

[0076] Example 4: Preparation of sodium decanoate solutions with mass fractions of 5 wt% and 10 wt% respectively

[0077] Weigh 0.5 g / 1 g of sodium decanoate and 9.5 g / 9 g of deionized water, and successively add them into a 50-ml colorimetric tube. Sonicate for 10 min to obtain homogeneous aqueous solutions of sodium decanoate (C10:0) with mass fractions of 5 wt% and 10 wt% respectively.

[0078] Example 5: Preparation of sodium undecanoate solutions with mass fractions of 5 wt% and 10 wt% respectively

[0079] Weigh 0.447 g / 0.894 g of undecanoic acid, 0.096 g / 0.192 g of NaOH, and 9.46 g / 8.91 g of deionized water, and successively add them into a 50-ml colorimetric tube. Sonicate for 10 min to obtain homogeneous aqueous solutions of sodium undecanoate (C11:0) with mass fractions of 5 wt% and 10 wt% respectively.

[0080] Example 6: Preparation of sodium laurate solutions with mass fractions of 5 wt% and 10 wt% respectively

[0081] Weigh 0.5 g / 1 g of sodium laurate and 9.5 g / 9 g of deionized water, and successively add them into a 50-ml colorimetric tube. Sonicate for 10 min to obtain homogeneous aqueous solutions of sodium laurate with mass fractions of 5 wt% and 10 wt% respectively.

[0082] Example 7: Preparation of an aqueous solution of sodium 2-decenoate (C10:1, ω-8) with a mass fraction of 5 wt%

[0083] Weigh 0.5 g of sodium 2-decenoate and 9.5 g of deionized water, and add them successively to a 50-ml small glass bottle. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 2-decenoate with a mass fraction of 5 wt%.

[0084] Example 8: Preparation of an aqueous solution of sodium 10-hydroxy-2-decenoate (10-OH, C10:1, ω-8) with a mass fraction of 5 wt%.

[0085] Weigh 0.5 g of sodium 10-hydroxy-2-decenoate and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 10-hydroxy-2-decenoate with mass fractions of 5 wt% and 10 wt%.

[0086] Example 9: Preparation of a solution of sodium 9-decenoate (C10:0, ω-1) with a mass fraction of 5 wt%

[0087] Weigh 0.5 g of sodium 9-decenoate and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 9-decenoate with a mass fraction of 5 wt%.

[0088] Example 10: Preparation of a solution of 4-decenoic acid (C10:0, ω-6) with a mass fraction of 5 wt%

[0089] Weigh 0.5 g of 4-decenoic acid and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium decanoate with a mass fraction of 5 wt%.

[0090] Example 11: Preparation of a solution of sodium 10-hydroxy-decanoate (10-OH, C10:0) with a mass fraction of 5 wt%

[0091] Weigh 0.5 g of sodium 10-hydroxy-decanoate and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 10-hydroxy-decanoate with a mass fraction of 5 wt%.

[0092] Example 12: Preparation of an aqueous solution of sodium oleate (C18:1, ω-9) with a mass fraction of 5 wt%

[0093] Weigh 0.5 g of sodium oleate and 9.5 g of deionized water, and add them successively to a 50-ml small glass bottle. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium oleate with a mass fraction of 5 wt%.

[0094] Example 13: Preparation of an aqueous solution of sodium linoleate (C18:2, ω-6) with a mass fraction of 5 wt%.

[0095] Weigh 0.5 g of sodium 10-hydroxy-2-decenoate and 9.5 g of deionized water, and sequentially add them to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 10-hydroxy-2-decenoate with a mass fraction of 5 wt%.

[0096] Example 14: Preparation of a solution of sodium ricinoleate (12-OH, C18:1, ω-9) with a mass fraction of 5 wt%

[0097] Weigh 0.5 g of sodium ricinoleate and 9.5 g of deionized water, and sequentially add them to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium ricinoleate with a mass fraction of 5 wt%.

[0098] Example 15: Preparation of a solution of sodium 12-hydroxyoctadecanoate (12-OH, C18:0) with a mass fraction of 5 wt%

[0099] Weigh 0.5 g of sodium 12-hydroxyoctadecanoate and 9.5 g of deionized water, and sequentially add them to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 12-hydroxyoctadecanoate with a mass fraction of 5 wt%.

[0100] Example 16: Preparation of a solution of sodium 18-hydroxyoctadecanoate (18-OH, C18:0) with a mass fraction of 5 wt%

[0101] Weigh 0.5 g of sodium 18-hydroxyoctadecanoate and 9.5 g of deionized water, and sequentially add them to a 50-ml colorimetric tube. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium 18-hydroxyoctadecanoate with a mass fraction of 5 wt% saline solution.

[0102] Example 17: Preparation of an aqueous solution of sodium benzoate with a mass fraction of 5 wt%

[0103] Weigh 0.5 g of sodium benzoate and 9.5 g of deionized water, and sequentially add them to a 50-ml vial. Ultrasonic for 10 min to obtain a homogeneous aqueous solution of sodium benzoate with a mass fraction of 5 wt%.

[0104] Example 18: Preparation of an aqueous solution of sodium phenylpropionate with a mass fraction of 5 wt%.

[0105] Weigh 0.5 g of sodium phenylpropionate and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Sonicate for 10 min to obtain a homogeneous aqueous solution of sodium phenylpropionate with a mass fraction of 5 wt%.

[0106] Example 19: Preparation of an aqueous solution of sodium phenylbutyrate with a mass fraction of 5 wt%

[0107] Weigh 0.5 g of sodium phenylbutyrate and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Sonicate for 10 min to obtain a homogeneous aqueous solution of sodium phenylbutyrate with a mass fraction of 5 wt%.

[0108] Example 20: Preparation of a solution of 5-phenyl-valeric acid sodium salt with a mass fraction of 5 wt%

[0109] Weigh 0.5 g of 5-phenyl-valeric acid sodium salt and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Sonicate for 10 min to obtain a homogeneous aqueous solution of 5-phenyl-valeric acid sodium salt with a mass fraction of 5 wt%.

[0110] Example 21: Preparation of a solution of 6-phenyl-hexanoic acid sodium salt with a mass fraction of 5 wt%

[0111] Weigh 0.5 g of 6-phenyl-hexanoic acid sodium salt and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Sonicate for 10 min to obtain a homogeneous aqueous solution of 6-phenyl-hexanoic acid sodium salt with a mass fraction of 5 wt%.

[0112] Example 22: Preparation of a solution of 8-phenyl-octanoic acid sodium salt with a mass fraction of 5 wt%

[0113] Weigh 0.5 g of 8-phenyl-octanoic acid sodium salt and 9.5 g of deionized water, and add them successively to a 50-ml colorimetric tube. Sonicate for 10 min to obtain a homogeneous aqueous solution of 8-phenyl-octanoic acid sodium salt with a mass fraction of 5 wt%.

[0114] As Figure 1 shown in the digital photos (g), (h), (I), (j), (k), (l), they are the physical pictures of aqueous solutions of sodium heptanoate, sodium octanoate, sodium nonanoate, sodium decanoate, sodium undecanoate, and sodium laurate respectively. The above aqueous solutions are all homogeneous and transparent micellar solutions.

[0115] Test Example 1: CO 2 Capture performance test

[0116] Sample 1: 5 wt% aqueous solution of sodium heptanoate prepared in Example 1;

[0117] Sample 2: 5 wt% and 10 wt% aqueous sodium octanoate solutions prepared in Example 2;

[0118] Sample 3: 5 wt% and 10 wt% aqueous sodium nonanoate solutions prepared in Example 3;

[0119] Sample 4: 5 wt% and 10 wt% aqueous sodium decanoate solutions prepared in Example 4;

[0120] Sample 5: 5 wt% and 10 wt% aqueous sodium undecanoate solutions prepared in Example 5;

[0121] Sample 6: 5 wt% and 10 wt% aqueous sodium laurate solutions prepared in Example 6.

[0122] Sample 7: 5 wt% aqueous sodium 2-decenoate solution prepared in Example 7;

[0123] Sample 8: 5 wt% aqueous sodium 10-hydroxy-2-decenoate solution prepared in Example 8;

[0124] Sample 9: 5 wt% aqueous sodium 9-decenoate solution prepared in Example 9;

[0125] Sample 10: 5 wt% aqueous sodium 4-decenoate solution prepared in Example 10;

[0126] Sample 11: 5 wt% aqueous sodium 10-hydroxy-decanoate solution prepared in Example 11;

[0127] Sample 12: 5 wt% aqueous sodium oleate solution prepared in Example 12;

[0128] Sample 13: 5 wt% aqueous sodium linoleate solution prepared in Example 13;

[0129] Sample 14: 5 wt% aqueous sodium ricinoleate solution prepared in Example 14;

[0130] Sample 17: 5 wt% aqueous sodium benzoate solution prepared in Example 17;

[0131] Sample 18: 5 wt% aqueous sodium phenylacetate solution prepared in Example 18;

[0132] Sample 19: 5 wt% aqueous sodium phenylbutyrate solution prepared in Example 19;

[0133] Sample 20: 5 wt% aqueous sodium 5-phenyl-pentanoate solution prepared in Example 20;

[0134] Sample 21: 5 wt% aqueous sodium 6-phenyl-hexanoate solution prepared in Example 21;

[0135] Sample 22: 5 wt% aqueous solution of sodium 8-phenyloctanoate prepared in Example 22.

[0136] The capture performance of CO was tested using the above 22 samples respectively. 2 For the performance test method of Sample 1: Weigh 10 g of a 5 wt% aqueous solution of sodium heptanoate and place it in a sealed vial. Seal the vial mouth with a rubber stopper and two needles. One needle is inserted into the solution, and the other needle is placed above the liquid surface and connected to the surrounding environment. Additionally, install a syringe tube stuffed with cotton to prevent liquid loss. Continuously bubble pure CO 2 or simulated flue gas (where the composition of the simulated flue gas is N 2 (74.89%), CO 2 (20%), O 2 (5%), CO (20 ppm), SO 2 (600 ppm), and NO 2 (500 ppm)) for 60 min to allow the solution to absorb CO 2 until saturation, achieving the capture of CO 2 . Record the mass change of the bottle during the CO 2 capture process by the weighing method to obtain the CO 2 capture performance.

[0137] Meanwhile, the CO 2 capture performance tests were carried out on Samples 2 - 22 and pure water using the same method.

[0138] The CO 2 capture performance of the above Samples 2 - 6 is as Figure 2 shown. As can be seen from Figure 2 (a), for the 6 samples (aqueous solutions of C 8 -C 12 sodium salts), the CO 2 capture amounts are all higher than that of pure water, and they all have the performance of capturing CO 2 . Among them, for Samples 2 - 6 (C 8 -C 11 ), the CO 2 capture amount per unit mass is higher. When the corresponding concentration is 10 wt%, the capture amount is higher than 10 mg / g, and the highest can reach 12.2 mg / g; for C 1 -C 7 monocarboxylic acid sodium salts, the CO 2 capture amount per unit mass is lower.

[0139] The capture performance of CO in the flue gas for Samples 2 - 6 is as 2 shown. As can be seen from Figure 4 ​Figure 4 (f) It can be seen that the mass of CO captured by Samples 2-6 from flue gas is lower than that of pure CO captured 2 , which are 1.18 mg / g, 1.94 mg / g, 3.72 mg / g, 2.02 mg / g and 2.87 mg / g respectively, accounting for 15.6%, 22.8%, 38.9%, 21.5% and 28.8% of the pure CO captured 2 . 2

[0140] See Figure 2 (b) As shown, for the effects of different temperatures and CO partial pressures on the CO capture performance of Test Sample 2, it is found that the reaction occurring in this capture process is an exothermic reaction. The higher the temperature, the lower the capture performance. When the temperature reaches about 80 °C, the CO capture performance is close to that of pure water; at the same time, according to Henry's law, with the increase of CO partial pressure, the capture performance improves 2 . 2 2 2

[0141] The CO capture performance of the above Samples 7-11 is as shown in 2 Figure 6 Figure 6 (a). It can be seen that the CO capture amounts of the 5 samples are all higher than that of pure water, and they all have the performance of capturing CO 2 . Among them, the CO capture amounts per unit mass of Samples 7-9 are higher. The performance of sodium undecylenate is close to that of sodium caprate. When the corresponding concentration is 5 wt%, the capture amounts are all higher than 9 mg / g, and the highest can reach 10.49 mg / g. The CO capture amounts per unit mass of Samples 10-11 are lower and slightly higher than that of pure water 2 . 2 2

[0142] The CO capture performance of the above Samples 12-14 is as shown in 2 Figure 8 Figure 8 (a). It can be seen that the CO capture amounts of the aqueous solutions of sodium oleate, sodium linoleate and sodium ricinoleate in the 3 samples are close. When the corresponding concentration is 5 wt%, the capture amounts are all higher than 9 mg / g, and the highest can reach 10.11 mg / g. While sodium octadecanoate, 12-hydroxy-octadecanoate and 18-hydroxy-octadecanoate are insoluble in water, so they do not have the performance of capturing CO 2 . 2

[0143] Based on this, it is inferred that when the concentrations of the aqueous solutions of sodium oleate, sodium linoleate and sodium ricinoleate are 30 wt%, their corresponding CO capture amounts are greater than 50 mg / g 2 .​​​​​​​​​​​

[0144] See Figure 8 (b), the effect of different temperatures on the CO capture performance of test sample 13 was investigated. It was found that the reaction occurring during the capture process was an exothermic reaction, and the higher the temperature, the lower the capture performance. When the temperature reached about 80 °C, the CO capture performance was close to that of pure water. 2 2

[0145] The CO capture performance of the above samples 17 - 22 was as follows 2 Figure 10 Figure 10 (a) It can be seen that the CO capture amount performance of samples 17 - 22 gradually increased. Among them, the CO capture amount performance of samples 20 - 22 was relatively high. When the corresponding concentration was 5 wt%, the capture amount was higher than 9 mg / g for all, and the highest could reach 10.11 mg / g. Since sodium octadecanoate, 12 - hydroxy - octadecanoate, and 18 - hydroxy - octadecanoate were insoluble in water, their CO capture performance was similar to that of pure water. 2 2 2

[0146] Test Example 2: Stability test of the capture agent for CO 2

[0147] Sample 1: After the capture of CO by sample 2 in Test Example 1. 2

[0148] Sample 2: After the capture of CO by sample 3 in Test Example 1. 2

[0149] Sample 3: After the capture of CO by sample 4 in Test Example 1. 2

[0150] Sample 4: After the capture of CO by sample 5 in Test Example 1. 2

[0151] Sample 5: After the capture of CO by sample 6 in Test Example 1. 2

[0152] Sample 6: After the capture of CO by sample 7 in Test Example 1. 2

[0153] Sample 7: After the capture of CO by sample 9 in Test Example 1. 2

[0154] Sample 8: After the capture of CO by sample 10 in Test Example 1. 2

[0155] Sample 9: After the capture of CO by sample 12 in Test Example 1. 2

[0156] Sample 10: CO captured by Sample 13 in Test Example 1 2 After that.

[0157] Sample 11: CO captured by Sample 14 in Test Example 1 2 After that.

[0158] Sample 12: CO captured by Sample 20 in Test Example 1 2 After that.

[0159] Sample 13: CO captured by Sample 21 in Test Example 1 2 After that.

[0160] Sample 14: CO captured by Sample 22 in Test Example 1 2 After that.

[0161] The above samples after refer to the solutions that reach saturation by using the CO capture performance method in Test Example 1 2 The capture agent for CO in the present invention is convenient for storage and has stable properties.

[0162] Test the stability of CO sequestration for the above 14 samples respectively. Among them, the method for testing the stability of CO sequestration in the samples is as follows: Place the sample to be tested in an environment at room temperature of 20 - 30 °C for 30 days. If there is no stratification and its morphology still remains in the emulsion form, solid state or oil - water two - phase, it indicates that the capture agent for CO in the present invention 2 is convenient for storage and has stable properties. 2 in the present invention 2 is convenient for storage and has stable properties.

[0163] Test Example 3: Critical partial pressure performance test of CO capture 2

[0164] Sample 1: 5wt% sodium octanoate aqueous solution prepared in Example 2.

[0165] Sample 2: 5wt% sodium nonanoate aqueous solution prepared in Example 3.

[0166] Sample 3: 5wt% sodium decanoate aqueous solution prepared in Example 4.

[0167] Sample 4: 5wt% sodium undecanoate aqueous solution prepared in Example 5.

[0168] Sample 5: 5wt% sodium laurate aqueous solution prepared in Example 6.

[0169] Sample 6: 5wt% sodium 4 - decenoate aqueous solution prepared in Example 10.

[0170] Sample 7: 5wt% sodium oleate aqueous solution prepared in Example 12.

[0171] ​Sample 8: 5 wt% aqueous solution of sodium linoleate prepared in Example 13.

[0172] Sample 9: 5 wt% aqueous solution of sodium ricinoleate prepared in Example 14.

[0173] Sample 10: 5 wt% aqueous solution of 5-phenylvaleric acid sodium salt prepared in Example 20.

[0174] Configure CO 2 gas with different partial pressures. Two airbags are filled with carbon dioxide and nitrogen respectively. Use a CO 2 flowmeter and an N 2 flowmeter to control the flow rate and prepare CO 2 gas with different partial pressures. For example: Configure 20% CO 2 gas. Connect the airbag to the flowmeter and introduce carbon dioxide into the oxygen bag at a gas flow rate of 300 mL / min for 5 min, then introduce nitrogen into the oxygen bag at a flow rate of 300 mL / min for 20 min to fully mix the gas in the oxygen bag and prepare simulated gas with a CO 2 content of 20% for standby; successively prepare CO 2 gas with partial pressures of 0, 4%, 5%, 30%, 50, and 100%.

[0175] Test the CO 2 critical partial pressure performance of the above 10 samples. The critical partial pressure performance test method is as follows: Measure 20 ml of the sample and place it in a 50 ml beaker. Seal the bottle mouth with plastic wrap. Insert the detection probe and temperature probe of the conductivity meter into the liquid surface through small holes. Pass the prepared CO 2 gas with different partial pressures into the sample through a needle tip for bubbling. The gas flow rate is 30 ml / min. Conduct magnetic stirring in the sample and test and record the change process of the conductivity of the sample over time.

[0176] The conductivity of the above 10 samples changes with CO 2 gas with different partial pressures as shown in Figure 2 , Figure 3 , Figure 6 , Figure 8 , Figure 10 . It can be seen from Figure 2 (c) that the critical partial pressure for Sample 1 to capture CO 2 is 5%. It can be known from Figure 3 (a), (b), (c), (d) that the critical partial pressures for Samples 2 - 5 to capture CO 2 are 5%, 6%, 6%, and 5% respectively. It can be seen from Figure 6 (b) that the critical partial pressure for Sample 10 is 10%. It can be seen from Figure 8As can be seen from (c), (e), and (f), Samples 12 - 14 can all capture CO 2 , and the critical partial pressures of Samples 12 - 13 are 2% and 4% respectively. As can be seen from Figure 10 (b), Sample 20 can capture CO in simulated flue gas 2 . Usually, the partial pressure of CO in flue gas 2 is generally 13% - 20%. Thus, it can be known that the capture agent in the present invention can be used to capture CO in flue gas 2 .

[0177] Test Example 4: Recycling performance of the capture agent

[0178] Sample 1: 5 wt% aqueous solution of sodium octanoate prepared in Example 2

[0179] Sample 2: 5 wt% aqueous solution of sodium nonanoate prepared in Example 3

[0180] Sample 3: 5 wt% aqueous solution of sodium decanoate prepared in Example 4

[0181] Sample 4: 5 wt% aqueous solution of sodium undecanoate prepared in Example 5

[0182] Sample 5: 5 wt% aqueous solution of sodium laurate prepared in Example 6

[0183] Sample 6: 5 wt% aqueous solution of sodium linoleate prepared in Example 13

[0184] The recycling performance of the above 6 samples was tested respectively. Among them, the test method for recycling performance is as follows: Measure 20 ml of the sample and place it in a 50 ml beaker. Seal the bottle mouth with plastic wrap. Place the detection probe and temperature probe of the conductivity meter through the small hole below the liquid level. Pass pure CO 2 or simulated flue gas into the sample through a needle tip for bubbling, with a gas flow rate of 30 ml / min, and stir magnetically. Test and record the change process of the conductivity of the sample over time. After the reaction is complete and the conductivity no longer changes, remove the airbag filled with CO 2 and replace it with an airbag filled with N 2 . Pass N 2 into the sample through a needle tip for bubbling, test and record the change process of the conductivity of the sample over time. After the reaction is complete and the conductivity no longer changes, complete 1 cycle. Test the change process of the conductivity of the sample over time for 3 cycle processes in this way

[0185] The test results of the recycling performance of the above 6 samples are as shown in Figure 2 (d), Figure 4 , Figure 8 as shown. As can be seen from Figure 2(d) It can be seen that after 3 cycles of alternately introducing pure CO 2 / N 2 into the sample 1, the conductivity of the material can still recover to the initial state, indicating good stability and that the release process does not require external energy supply.

[0186] From Figure 4 (a) and (b), it can be seen that after 3 cycles of alternately introducing pure CO 2 / N 2 and simulated flue gas / N 2 into the sample 2, the conductivity of the material can still recover to the initial state. From Figure 4 (c), (d) and (e), it can be seen that after 3 cycles of alternately introducing pure CO 2 / N 2 into the samples 3 - 5, the conductivity of the material can still recover to the initial state. From Figure 8 (d), it can be seen that after 3 cycles of alternately introducing simulated flue gas / N 2 into the sample 6, the conductivity of the material can still recover to the initial state, indicating good stability and that the release process does not require external energy supply.

[0187] Test Example 5: Release performance of CO 2 in flue gas by the capture agent.

[0188] Sample 1: Sample 2 in Test Example 1.

[0189] Sample 2: Sample 3 in Test Example 1.

[0190] Sample 3: Sample 4 in Test Example 1.

[0191] Sample 4: Sample 5 in Test Example 1.

[0192] Sample 5: Sample 6 in Test Example 1.

[0193] The release performance of CO 2 in flue gas captured by the above 5 samples was tested respectively. Among them, the test method for the release performance of CO 2 in flue gas captured is as follows: Weigh 0.1 g of the sample and place it in the lid of a 10 mL centrifuge tube with a lid diameter of 0.6 cm and a height of 0.4 cm. Place the lid in the transparent leaf chamber of a fully sealed portable photosynthesis instrument Li - 6800. Set the concentration of CO 2 in the reference chamber to 400 μmol*mol -1 , set the cooling fan to low speed, set the gas flow rate to 200 μmol*s -1 . After the instrument is successfully matched, record the concentration of CO 2 in the current sample chamber every 5 s. Wait until CO 2When the concentration reaches the same as that set in the reference chamber and no longer changes with time, stop the test and conduct 3 - 5 parallel tests. In the data exported by the instrument, the unit of carbon dioxide concentration is μmol*mol -1 , that is, the amount of substance of carbon dioxide contained in each mole of gas. After unit conversion and integration over time, the total amount of carbon dioxide released can be obtained. Through data processing, the total amount of CO 2 released is obtained.

[0194] The formula for the amount of carbon dioxide released is as follows: Where: ΔCO 2 : The difference in concentration between the sample chamber and the reference chamber (unit: μmol*mol -1 ), v: gas flow rate (unit: μmol*s -1 ), m: sample mass (unit: g).

[0195] The release performance quality of CO 2 in the flue gas captured by the above 5 samples is as Figure 4 (f) shown. As can be seen from Figure 4 (f), the release amount of samples 1 - 5 is equivalent to the capture amount, and the release efficiency can reach over 90%. The proportion of the release mass of sample 1 in the CO 2 in the flue gas of the capture amount is close to 96.6%, almost completely released; the proportion of the release mass of sample 2 in the CO 2 in the flue gas of the capture amount is 94.2%. The difference may be attributed to the release of CO 2 by the sample during the sample placement process, resulting in a smaller test result.

[0196] The specific implementation modes of the present invention have been exemplarily described above through embodiments. However, the protection scope of the present invention is not limited to the above - mentioned exemplary implementation modes. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A composition for a carbon dioxide capture agent, characterized in that: The composition comprises carboxylic acid, solvent and base, wherein the solvent is a good solvent for the carboxylic acid and the base, the chemical formula of the carboxylic acid is R-COOH, wherein R is a substituted or unsubstituted C4-C 21 Hydrocarbon; The substitution means that one or more H on the alkyl group is replaced by a hydrocarbon group, -OH, -COOH, an aryl group, an amino group or -X, wherein X is a halogen atom F, Cl, Br or I.

2. The composition according to claim 1, characterized in that The carboxylic acid is C8~C 18 Saturated monocarboxylic acid, C8~C 14 Polycarboxylic acid, C8~C 22 Mono- or poly-unsaturated carboxylic acids or C5-C 12 At least one of the carboxylic acids; Preferably, the base is selected from at least one of an inorganic base and an organic base; Preferably, the solvent is selected from water or a complex solvent.

3. The composition according to claim 1 or 2, characterized in that The composition also contains a carboxylate formed by carboxylic acid and a base; the mass fraction of the carboxylate is greater than 0 and less than or equal to 30%.

4. A carbon dioxide capture agent, which is specially prepared in that it comprises a solvent and a carboxylate dissolved in the solvent, wherein the mass fraction of the carboxylate is greater than 0 and less than or equal to 30%, and the carboxylate is a carboxylate formed by carboxylic acid and a base, and the solvent, carboxylic acid and base have the definitions described in any one of claims 1 to 3.

5. The collector according to claim 4, characterized in that The pH value of the carbon dioxide capture agent is 7-14; Preferably, the carbon dioxide capture agent is a transparent solution or a micellar solution.

6. A method for capturing carbon dioxide, characterized in that: The method comprises the following steps: The gas containing CO2 is contacted with the capture composition according to any one of claims 1 to 3 or the carbon dioxide capture agent according to any one of claims 4 to 5 to capture CO2.

7. The method according to claim 6, characterized in that The contact is carried out under closed conditions; After capturing CO2, the method further includes the following step: storing the capture agent containing CO2.

8. The method according to claim 6 or 7, characterized in that: After capturing CO2 or storing the capture agent containing CO2, the method further includes the following step: regenerating the capture agent. Preferably, regenerating the capture agent comprises the following steps: placing the capture agent after capturing CO2 or storing the capture agent containing CO2 in an environment with a CO2 partial pressure of less than 2% to release CO2 to obtain a regenerated capture agent.

9. The method according to claim 8, characterized in that The CO2 is released in an environment where the CO2 partial pressure is less than 1%; Preferably, the CO2 is released at a temperature of 0 to 90°C.

10. Use of a composition according to any one of claims 1 to 3, a capture agent according to any one of claims 4 to 5, or a method for capturing CO2 according to any one of claims 6 to 9 in the treatment of CO2 in waste streams in power plants, cement manufacturing, steel manufacturing, glass manufacturing, brewing, synthesis gas production, natural gas and biogas purification, ammonia synthesis or any other industrial process producing acidic gas; It is preferably used for geological utilization to enhance oil recovery and gas production; chemical utilization to prepare liquid fuels and degradable polymers; or biological utilization to convert into food, feed, chemicals and bio-CO2 gas fertilizer; or for geological storage, for example, for enhancing the mining of oil, natural gas, geothermal energy, shale gas, coalbed methane, and uranium mines, preparing liquid fuels, synthesizing polyols, methanol, carbonates, and degradable polymers, converting them into food and feed, converting them into chemicals, and using them as CO2 gas fertilizer for plants.

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