Compositions for co2 capture, methods of co2 absorption and desorption

Abstract

The present application relates to the technical field of CO2 capture, and discloses a composition for CO2 capture, and a method for CO2 absorption and desorption, wherein the composition comprises an organic amine and a thermal degradation inhibitor; the thermal degradation inhibitor is a non-ionic organic compound, and the non-ionic organic compound comprises at least one five-membered aromatic nitrogen heterocycle containing a pyrrole nitrogen. When the composition is used in CO2 absorption and desorption, the thermal degradation rate of the organic amine is greatly reduced, and the stability is good.

Description

Technical Field

[0001] This invention relates to the field of CO2 capture technology, and more specifically to a composition for CO2 capture and a method for CO2 absorption and desorption. Background Technology

[0002] CCUS technology is the fundamental technology for achieving carbon neutrality. Carbon capture is the first and most expensive part of the entire process. Among all carbon capture technologies, post-combustion carbon capture technology can be integrated into existing CO2 emission sources without modifying existing equipment, and has the potential for large-scale application. The chemical absorption method based on organic amines is currently the most mature post-combustion carbon capture technology route.

[0003] Organic amines are characterized by their rapid CO2 absorption rate and high absorption capacity, making the development of high-performance and highly stable organic amines a key research direction. After absorbing CO2 in an absorption tower (40-60℃), organic amines need to be sent to a desorption tower for heating to release CO2, thus enabling the recycling of organic amines. Current research on organic amine absorbents mainly focuses on improving their absorption performance. For example, WO2023066400A1 discloses a method of compounding amino acids, organic amines, activators, and promoters to increase carbon dioxide adsorption capacity and reduce regeneration energy consumption. CN115138178A discloses the use of a low-volatility, low-regeneration-temperature ionic liquid, polyamine organic amine, and solvent as a composite absorbent to reduce the water content of the absorbent, thereby reducing regeneration energy consumption.

[0004] However, under the high temperature and high CO2 load conditions of the desorption tower, organic amines are prone to thermal degradation, generating other substances. Degradation products include various anions, such as formate, acetate, and oxalate, which can form thermally stable salts with amines. Furthermore, the degradation products also contain organic matter formed by urethane polymerization or the breaking of their own carbon chains, leading to a decrease in the overall alkalinity of the solution and thus hindering effective CO2 absorption. Thermal degradation reduces the concentration of the main component, deviates from the optimal operating point, and results in unstable operation and increased operating costs. CN117244384A discloses an enhanced anti-degradation capability by adding sulfur-containing antioxidants and / or chelating agents to a low-water absorbent; however, this formulation has poor oxidation inhibition effects, providing only a weak inhibitory effect.

[0005] Long-chain organic amines have the potential to be the main absorbent in carbon capture and absorption agents, with higher absorption rates and cycle capacity. However, due to their longer molecular chains and more complex spatial configurations, they are more prone to thermal degradation under high temperature and high load conditions, making it difficult to maintain long-term stable operation during large-scale commercial operation. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of organic amine absorbents being easily degraded during desorption and having poor stability in CO2 absorption and desorption operations in the prior art. This invention provides a composition for CO2 capture and a method for CO2 absorption and desorption. When this composition is used in CO2 absorption and desorption, the thermal degradation rate of organic amines is significantly reduced, and the stability is good.

[0007] To achieve the above objectives, the present invention provides a composition for CO2 capture, the composition comprising an organic amine and a thermal degradation inhibitor; the thermal degradation inhibitor is a nonionic organic compound, and the nonionic organic compound comprises at least one five-membered aromatic nitrogen heterocycle containing pyrrole nitrogen.

[0008] Preferably, the nonionic organic compound is a compound represented by formula (1) and / or formula (2);

[0009] Equation (1), Equation (2),

[0010] R1 and R6 are respectively selected from hydrogen atoms or substituents of at least one of alkyl and aryl groups containing C1-C3, preferably any one of hydrogen atoms, methyl, ethyl, n-propyl, isopropyl, phenyl and benzyl;

[0011] R2, R3, R4, R5, R7, R8, and R9 are either hydrogen atoms or C1-C3 alkyl groups, preferably at least one of hydrogen atoms, methyl, ethyl, n-propyl, and isopropyl.

[0012] A second aspect of the present invention provides a method for CO2 absorption and desorption, the method comprising:

[0013] S1. Contact the CO2-containing raw gas with the composition for CO2 capture described in the first aspect to perform CO2 absorption and obtain a CO2-rich absorbent liquid.

[0014] S2. Desorb the CO2-rich absorbent to obtain CO2 and the desorbent.

[0015] The composition provided by this invention, through the synergistic effect of thermal degradation inhibitors and organic amines, can significantly reduce the thermal degradation rate of organic amines under high temperature and high CO2 loading conditions, thereby improving system stability. In particular, it can greatly enhance the stability of long-chain organic amine solutions under high temperature (100-150℃) and high CO2 loading conditions. It is especially suitable for the absorption and desorption stages of CO2 capture systems in industrial flue gas from coal-fired power plants, chemical plants, and other industrial applications. Attached Figure Description

[0016] Figure 1These are the thermal stability change curves of the organic amine components in the compositions of Examples 1-3 and Comparative Example 1 of this invention;

[0017] Figure 2 These are the thermal stability change curves of the thermal degradation inhibitors in the compositions of Examples 1-3 of this invention;

[0018] Figure 3 This is a comparison chart of the CO2 absorption rates of the compositions in Example 1 and Comparative Example 1 of the present invention;

[0019] Figure 4 This is a comparison chart of the CO2 absorption capacity of the compositions in Example 1 and Comparative Example 1 of the present invention;

[0020] Figure 5 This is a comparison chart of the CO2 desorption rates of the compositions in Example 1 and Comparative Example 1 of the present invention;

[0021] Figure 6 This is a comparison chart of the CO2 desorption capacity of the compositions in Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] Long-chain organic amines have higher absorption rates and cycling capacities, but accelerated thermal degradation tests have shown that the thermal degradation of long-chain amines is very severe, and it is further aggravated with the increase of CO2 loading and temperature. The inventors of this invention conducted gas chromatography and gas chromatography-mass spectrometry analysis on the thermally degraded solution and found that its degradation products are mainly chain-like small molecules, and the thermal degradation of long-chain amines is mainly due to the breaking of CN bonds in the amine structure.

[0024] Based on the findings of the above problems, the present invention proposes a composition for CO2 capture, the composition comprising an organic amine and a thermal degradation inhibitor; the thermal degradation inhibitor is a nonionic organic compound, and the thermal degradation inhibitor comprises at least one five-membered aromatic nitrogen heterocycle containing pyrrole nitrogen.

[0025] In the above composition, the introduction of a pyrrole nitrogen-containing five-membered aromatic nitrogen heterocycle thermal degradation inhibitor significantly suppresses the thermal degradation of organic amines, especially long-chain organic amines, during desorption. This is likely because the pyrrole nitrogen-containing five-membered aromatic nitrogen heterocycle thermal degradation inhibitor possesses a high highest occupied molecular orbital (HOMO) energy level. Its synergistic effect with the organic amine optimizes the electronic structure characteristics of the organic amine, increasing the electron cloud density of specific chemical bonds in the molecule, thereby improving the thermodynamic stability of the covalent bonds and inhibiting the thermal degradation of the organic amine. Furthermore, the thermal degradation inhibitor is essentially not involved in the absorption and desorption processes and does not affect the CO2 capture performance of the absorbent.

[0026] In this invention, the thermal degradation inhibitor is a nonionic organic compound, and the thermal degradation inhibitor includes at least one five-membered aromatic nitrogen heterocycle containing pyrrole nitrogen. In this invention, the range of structural options for the thermal degradation inhibitor is relatively wide; the hydrogen or carbon atoms on the five-membered aromatic nitrogen heterocycle can also be replaced by other substituents, preferably electron-donating groups, all of which can improve the stability of the composition during the desorption process.

[0027] According to some preferred embodiments of the present invention, the thermal degradation inhibitor is a compound represented by formula (1) and / or formula (2);

[0028] Equation (1), Equation (2),

[0029] R1 and R6 may be the same or different, and are respectively selected from hydrogen atoms or substituents of at least one of alkyl and aryl groups containing C1-C3, preferably any one of hydrogen atoms, methyl, ethyl, n-propyl, isopropyl, phenyl and benzyl;

[0030] R2, R3, R4, R5, R7, R8, and R9 may be the same or different, and are at least one of hydrogen atom, C1-C3 alkyl group, and nitro group, preferably at least one of hydrogen atom, methyl group, ethyl group, n-propyl group, and isopropyl group.

[0031] According to some preferred embodiments of the present invention, the thermal degradation inhibitor is selected from at least one of 2-ethyl-4-methylimidazole, pyrrole, N-methylpyrrole, N-ethylpyrrole, 1-(1-methylethyl)-1H-pyrrole, and N-benzylpyrrole. Using the above-mentioned preferred thermal degradation inhibitors is beneficial for further improving stability, possibly because fewer alkyl groups provide better solubility, while achieving a higher molar concentration at the same mass ratio.

[0032] In this invention, the selection range for the content of each component in the composition is relatively wide. Preferably, based on the total mass of the composition, the content of the organic amine is 15-45 wt%, preferably 20-40 wt%; the content of the thermal degradation inhibitor is 5-20 wt%, preferably 10-18 wt%, for example, it can be a specific content value of 10, 11, 12, 13, 14, 15, 16, 17, 18 wt%, or any range between the two. The above-mentioned preferred composition of organic amine and thermal degradation inhibitor is beneficial to further exert the synergistic effect of thermal degradation inhibitor and organic amine, and further improve the stability of the absorbent. Excessive content of thermal degradation inhibitor may affect the viscosity of the composition and thus impair CO2 absorption performance.

[0033] In this invention, the organic amine can be any organic amine in the art that can be used for CO2 capture, and can be a short-chain amine or a long-chain amine; the invention does not have any particular limitation in this regard. Preferably, the organic amine is a long-chain organic amine containing at least two amino groups and having 3 or more carbon atoms, and more preferably a long-chain organic amine with 3-15 carbon atoms. In the above preferred cases, the composition can achieve a balance between high amino utilization, absorption rate, cycling loading, and excellent pyrolysis stability.

[0034] According to some preferred embodiments of the present invention, the organic amine is at least one of the compounds represented by formula (3).

[0035] Equation (3),

[0036] Each R can be the same or different, and is selected from at least one of hydrogen atom, methyl and ethyl. x and y are integers of 3 or more, preferably integers of 3-5, for example, 3, 4, and 5; n is an integer of 1-5, preferably an integer of 2-3.

[0037] According to some particularly preferred embodiments of the present invention, the organic amine is selected from at least one of N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 3,3'-iminobis(N,N-dimethylpropylamine), N,N-bis(3-aminopropyl)methylamine, N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, N,N',N”,N’”-tetramethyltripropylenetetramine, N,N-bis(3-aminopropyl)methylamine, and N,N-bis[3(methylamino)propyl]methylamine, more preferably, the organic amine is N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine.

[0038] Using the above-mentioned preferred organic amines helps to ensure the amino concentration at the same mass concentration, thereby ensuring absorption performance.

[0039] According to the present invention, preferably, the composition further contains a solvent, which may be water. For example, the solvent water may be deionized water.

[0040] Preferably, the solvent content is 35-85 wt%, more preferably 40-60 wt%, based on the total mass of the composition. For example, it can be a specific content such as 40, 45, 50, 55, 60 wt%, or any range between the two.

[0041] A second aspect of the present invention provides a method for CO2 absorption and desorption, the method comprising:

[0042] S1. Contact the CO2-containing raw gas with the composition for CO2 capture described in the first aspect to perform CO2 absorption and obtain a CO2-rich absorbent liquid.

[0043] S2. Desorb the CO2-rich absorbent to obtain CO2 and the desorbent.

[0044] In this invention, there is no particular limitation on the source of the CO2-containing feed gas, and the method can be applied to industrial flue gas containing CO2 from power generation, steel, chemical, and refining plants. Preferably, the volume content of CO2 in the CO2-containing feed gas is 5-20%, more preferably 10-15%, for example, it can be a specific volume content of 10%, 11%, 12%, 13%, 14%, 15%, or any range between two.

[0045] The present invention has a wide range of options for the conditions of CO2 absorption, and conventional absorption methods and conditions in the art can be adopted. For example, in industrial operation, the CO2 absorption can be carried out in an absorption tower.

[0046] According to some preferred embodiments of the present invention, in step S1, the conditions for CO2 absorption include: a temperature of 20-60°C, for example, a specific temperature such as 20°C, 30°C, 40°C, 50°C, 60°C, or any range between two; preferably, a pressure of 0.01-0.2 MPa. Using the above-mentioned preferred absorption conditions is beneficial for meeting the conditions of conventional industrial waste such as power plant flue gas.

[0047] According to the present invention, preferably, the flow rate ratio of the CO2-containing feed gas to the composition is 1 Nm³. 3 / h: 20-50L / h, preferably 1Nm 3 / h: 30-40L / h, for example, 30, 35, 40 L / h.

[0048] Preferably, in step S2, the desorption conditions include: a temperature of 100-150°C, for example, specific temperatures such as 100°C, 110°C, 120°C, 130°C, 140°C, and 150°C, or any range between the two; and a desorption pressure of 0-400 kPa. At the above desorption temperatures, conventional organic amines, especially long-chain organic amine absorbents, are prone to thermal degradation, generating degradation products. This results in the desorbed liquid being unusable and exhibiting poor operational stability. Using the composition of the present invention, the organic amines can maintain a high amine retention rate and good stability under the above-mentioned high-temperature conditions.

[0049] According to some preferred embodiments of the present invention, the method further includes: returning the desorbent obtained in step S2 to step S1 to provide the composition. In the present invention, during the desorption process, the organic amine exhibits a low thermal degradation rate and a high amine retention rate, allowing it to be directly reused as an absorbent in step S1 without purification and separation, resulting in good stability during continuous operation. Compared with the prior art, it has the advantage of high thermal stability.

[0050] The present invention will be described in detail below through embodiments.

[0051] Unless otherwise specified, the raw materials used in the following examples and comparative examples are all commercially available.

[0052] The following examples illustrate the preparation of the compositions of the present invention.

[0053] Example 1

[0054] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 2-ethyl-4-methylimidazole, and deionized water according to the specified proportions, and add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition S1.

[0055] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 10% 2-ethyl-4-methylimidazole, and 60% deionized water.

[0056] Example 2

[0057] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, pyrrole, and deionized water according to the specified proportions, and add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition S2.

[0058] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 10% pyrrole, and 60% deionized water.

[0059] Example 3

[0060] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, N-methylpyrrole, and deionized water according to the specified proportions, and add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition S3.

[0061] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 10% N-methylpyrrole, and 60% deionized water.

[0062] Example 4

[0063] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 2-ethyl-4-methylimidazole, and deionized water according to the specified proportions, and add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition S4.

[0064] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 30% 2-ethyl-4-methylimidazole, and 40% deionized water.

[0065] Example 5

[0066] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 2-ethyl-4-methylimidazole, and deionized water according to the specified proportions, and add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition S5.

[0067] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 3% 2-ethyl-4-methylimidazole, and 67% deionized water.

[0068] Example 6

[0069] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 3-nitropyrrole, and deionized water according to the specified proportions, and add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition S6.

[0070] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 10% 3-nitropyrrole, and 60% deionized water.

[0071] Comparative Example 1

[0072] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine and deionized water according to the specified ratio, add them to a three-nozzle round-bottom flask equipped with a mechanical stirrer, raise the temperature to 40°C, stir at 500 r / min for 10-30 min, and obtain composition DS1.

[0073] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine and 70% deionized water.

[0074] Comparative Example 2

[0075] Weigh N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 1-ethyl-3-methylimidazoline bis(trifluoromethylsulfonyl)imine, and deionized water according to the specified proportions. Add them to a three-necked round-bottom flask equipped with a mechanical stirrer. Raise the temperature to 40°C and stir at 500 r / min for 10-30 min to ensure that the inhibitor is fully dissolved and dispersed, thus obtaining composition DS2.

[0076] The composition comprises, by a total mass of 100%, 30% N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 10% 1-ethyl-3-methylimidazoline bis(trifluoromethylsulfonyl)imine, and 65% deionized water.

[0077] Test Example 1

[0078] This test example tested the thermal stability of the two-phase absorbents provided in the above embodiments and comparative examples, and the results are shown in Table 1.

[0079] The test method included: the absorbent pre-absorbing a mixed gas with a CO2 volume concentration of 12% and an N2 volume concentration of 88%; after CO2 saturation, the absorbent was transferred to a thermal degradation reactor and placed in an oven at 150°C; samples were taken every 48 hours, and the samples were analyzed by gas chromatography to obtain the retention rates of amines and thermal degradation inhibitors in the solution. The amine retention rate change curves of Examples 1-3 and Comparative Example 1 are shown below. Figure 1 As shown, the retention rate curves of the thermal degradation inhibitors in Examples 1-3 are as follows: Figure 2 As shown, the addition of 10% thermal degradation inhibitor improves the retention rate and stability of amines compared to the absence of inhibitor, and the inhibitor itself does not degrade.

[0080] The method for determining CO2 absorption saturation is as follows: using an infrared gas analyzer, the volume concentration of CO2 in the gas flowing out of the absorbent is monitored in real time. When the volume concentration of CO2 in the flowing out gas is close to the volume concentration of CO2 in the mixed gas introduced, and the data is stable and no longer changes, it indicates that absorption is saturated.

[0081] The formula for calculating retention rate is:

[0082]

[0083] : Retention rate of component i;

[0084] The concentration of component i after thermal degradation was determined by gas chromatography.

[0085] The concentration of component i before thermal degradation was determined by gas chromatography.

[0086] Table 1

[0087]

[0088] The results above show that the composition provided by the present invention has the characteristics of low thermal degradation rate of long-chain amines and good stability. Under high temperature and high loading conditions, the long-chain amines can still maintain a high amine retention rate.

[0089] Test Example 2

[0090] The CO2 absorption and desorption performance of the compositions obtained in Example 1 and Comparative Example 1 was compared.

[0091] (1) During the absorption stage, 30 g of the absorbent composition was placed in a bubbling flask, and the flask was immersed in a constant temperature water bath maintained at 313.15 K (±0.5 K). The CO2 flow rate was controlled at 120 mL / min, the N2 flow rate at 880 mL / min, and the total gas flow rate at 1000 mL / min (all with an accuracy of 1%) using a mass flow controller. After the gas was fully mixed in a mixing tank, it was introduced into the bubbling reactor. Part of the CO2 was absorbed by the absorbent, and the unabsorbed gas was successively condensed, acid-washed, and dried, and then introduced into an infrared CO2 gas analyzer (accuracy of 1%) for measurement. The outlet CO2 concentration was recorded every two seconds. When the outlet CO2 concentration reached 12%, the absorption was considered to have reached saturation.

[0092] The formulas for calculating CO2 absorption rate and absorption capacity are as follows:

[0093]

[0094] The above formula is a substitution formula for volumetric flow rate and molar flow rate, where Q is the molar flow rate of a certain gas component in mol / s, V is the volumetric flow rate of a certain gas component in mL / s, and T is the temperature in K.

[0095] Assuming the N2 flow rate remains constant before and after absorption, the molar flow rate of CO2 at the reactor outlet after passing through the absorbent is calculated as follows:

[0096] Here, and These represent the molar flow rates (mol / s) of CO2 and N2 at the outlet of the bubbling bottle, respectively. This indicates the mole fraction of CO2 at the reactor outlet, i.e., the reading of the CO2 analyzer.

[0097] The instantaneous absorption rate of CO2 is given by the following formula:

[0098] in, This represents the instantaneous absorption rate of CO2 (mol / kg / s). and represents the flow rate (mol / s) at the reactor inlet and outlet, respectively, and m represents the mass (kg) of the added composition.

[0099] The absorption capacity of a solution is the integral of the instantaneous absorption rate over time.

[0100]

[0101] in, This indicates the absorption capacity of the solution (mol / kg). Indicates the absorption time (s).

[0102] (2) During the desorption stage, 10 g of saturated homogeneous absorbent was added to a 100 mL three-necked flask. The flask was placed in an oil bath and heated to 393.15 K. Magnetic stir bar was placed in both the oil bath and the flask, and the stirring speed was controlled at 500 rpm. N2 was introduced at a flow rate of 300 mL / min using a mass flow controller for purging. The purged gas was first condensed, then acid-washed and dried, and finally the CO2 concentration in the tail gas was measured using an infrared CO2 analyzer.

[0103] The amount and rate of CO2 desorption can be calculated using the following formulas:

[0104]

[0105]

[0106] in, This represents the instantaneous desorption rate of CO2 (mol / kg·s). This indicates the mole fraction of CO2 at the reactor outlet, i.e., the reading of the CO2 analyzer. This represents the molar flow rate (mol / s) of N2 at the outlet of the bubbling bottle. Indicates the solution in time The desorption amount at that time (mol / kg).

[0107] Figure 3 This is a comparison graph showing the CO2 absorption rates of the compositions in Example 1 and Comparative Example 1 of the present invention. Figure 4 This is a comparison chart of the CO2 absorption capacity of the compositions in Example 1 and Comparative Example 1 of the present invention. Figure 5 This is a comparison graph showing the CO2 desorption rates of the compositions in Example 1 and Comparative Example 1 of the present invention. Figure 6 This is a comparison chart of the CO2 desorption capacity of the compositions in Example 1 and Comparative Example 1 of the present invention. (By...) Figure 3 and Figure 4 It can be seen that the fastest absorption rate and absorption capacity of the composition with added inhibitors in this invention are basically the same as those in Comparative Example 1, while the absorption rate decays more gradually, thus maintaining excellent absorption performance. Figure 5 It can be seen that the desorption rate of the embodiment is always higher than that of the comparative example. Figure 6 It can be seen that the addition of the inhibitor actually promotes desorption and increases the desorption capacity. Therefore, the composition provided by this invention can improve the desorption rate and desorption capacity while maintaining absorption performance, and inhibit the decomposition of organic amines, thereby improving the stability of CO2 capture.

[0108] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composition for CO2 capture, characterized in that, The composition includes an organic amine and a thermal degradation inhibitor; the thermal degradation inhibitor is a nonionic organic compound, and the nonionic organic compound includes at least one five-membered aromatic nitrogen heterocycle containing pyrrole nitrogen; The nonionic organic compound is the compound shown in formula (1); Equation (1), Wherein, R1 is selected from hydrogen atoms or is a substituent of at least one of alkyl or aryl groups containing C1-C3; R2, R3, R4, and R5 are at least one of hydrogen atom, C1-C3 alkyl group, and nitro group, respectively; The organic amine is at least one of the compounds represented by formula (3). Equation (3), In this context, each R is selected from any one of hydrogen atoms, methyl, and ethyl atoms; x and y are integers greater than or equal to 3; and n is an integer from 1 to 5.

2. The composition according to claim 1, wherein, R1 is selected from any one of hydrogen atom, methyl, ethyl, n-propyl, isopropyl, phenyl, and benzyl; R2, R3, R4, and R5 are at least one of hydrogen atom, methyl, ethyl, n-propyl, and isopropyl, respectively.

3. The composition according to claim 1, wherein, The nonionic organic compound is selected from at least one of pyrrole, N-methylpyrrole, N-ethylpyrrole, 1-(1-methylethyl)-1H-pyrrole, and N-benzylpyrrole.

4. The composition according to any one of claims 1-3, wherein, Based on the total mass of the composition, the content of the organic amine is 15-45 wt%; the content of the thermal degradation inhibitor is 5-20 wt%.

5. The composition according to any one of claims 1-3, wherein, The organic amine is selected from at least one of N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, 3,3'-iminobis(N,N-dimethylpropylamine), N,N-bis(3-aminopropyl)methylamine, N-[3-(dimethylamino)propyl]-N,N',N'-trimethyl-1,3-propanediamine, N,N',N”,N’”-tetramethyltripropylenetetramine, bis3-aminopropyl-1,3-propanediamine, and N,N-bis[3-(methylamino)propyl]methylamine.

6. The composition according to any one of claims 1-3, wherein, The composition also contains a solvent selected from water; Based on the total mass of the composition, the solvent content is 35-85 wt%.

7. A method for CO2 absorption and desorption, characterized in that, The method includes: S1. Contact the CO2-containing raw gas with the composition for CO2 capture described in any one of claims 1-6 to perform CO2 absorption and obtain a CO2-rich absorbent liquid. S2. Desorb the CO2-rich absorbent to obtain CO2 and the desorbent.

8. The method according to claim 7, wherein, In step S1, the conditions for CO2 absorption include: a temperature of 20-60℃ and a pressure of 0.01-0.2MPa; And / or, the flow rate ratio of the CO2-containing feed gas to the composition is 1 Nm³. 3 / h: 20-50L / h; And / or, the volume content of CO2 in the CO2-containing feed gas is 5-20%; And / or, in step S2, the desorption conditions include: a temperature of 100-150℃ and a pressure of 0-400kPa.

9. The method according to claim 7 or 8, wherein, The method further includes returning the desorption solution obtained in step S2 to step S1 to provide the composition.

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