Preparation of sulfonamide ionic liquid and application of sulfonamide ionic liquid in reversible capture of carbon dioxide

Abstract

The invention discloses sulfonamide ionic liquid as well as a preparation method and application thereof. The sulfonamide ionic liquid comprises one or more of quaternary ammonium cations, quaternary phosphonium cations, trimethyl hydroxyethyl ammonium ions and protonated organic alkali. And one or more of benzene sulfonamide anions and substituted benzene sulfonamide anions; substituted benzene sulfonamide is selected as an anion for the first time, and the variety of ionic liquid is developed; the ionic liquid has the advantages of easily available raw materials, easy preparation, high thermal stability and chemical stability; the sulfonamide ionic liquid has alkalescence, can capture CO2 through chemical action, is high in capture amount and easy to desorb, and has a good recycling effect; the diluent is selected, the molecular weight is small, the chemical stability is high, and the amount of CO2 captured by each kilogram of ionic liquid can be effectively increased; the ionic liquid provided by the invention is mixed with a diluent according to a certain molar ratio for CO2 capture, so that the viscosity of a system can be effectively reduced, the mass transfer of CO2 in the system is enhanced, and the CO2 capture amount is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture from gases, and specifically to the preparation of a novel sulfonamide-based ionic liquid and its application in the reversible capture of carbon dioxide. Background Art

[0002] As the current main energy source, the combustion of fossil fuels releases CO2, which has caused global climate change, thus triggering a series of inevitable environmental problems. Currently, the chemical absorption method using alkanolamines as solvents is commonly used in industry for CO2 capture, which has problems such as high energy consumption, strong corrosion, and easy degradation of the solvent. Therefore, developing new absorbents with high efficiency, reversibility, and low energy consumption is a major challenge in the field of CO2 capture. Ionic liquids, as a class of frontier green chemical materials, have been widely used in catalysis, extraction, electrochemistry, gas capture, etc. due to their structural designability, high thermal stability and chemical stability, wide electrochemical window, and low volatility. Currently, ionic liquids have been widely used as CO2 capture agents and have shown good effects.

[0003] However, although ionic liquid CO2 capture, as an emerging technology, shows good application prospects, there are still some defects and challenges, such as:

[0004] 1. Cost issue: The preparation and purification processes of ionic liquids may be relatively complex, and the raw material prices are high, resulting in a relatively high initial cost. In addition, since some ionic liquids with specific structures usually have relatively high melting points and exist in solid form at room temperature, if pure ionic liquids are used to capture CO2, it needs to be carried out at a relatively high temperature, so additional energy consumption may be required to maintain their liquid properties, increasing the usage cost.

[0005] 2. Efficiency issue: Although functionalized ionic liquids have a relatively high absorption capacity for carbon dioxide, due to their relatively high viscosity, their absorption rate may not be as fast as that of traditional solvents in practical applications. Therefore, reducing the viscosity of ionic liquids and improving the efficiency of ionic liquids in capturing carbon dioxide are the keys to realizing industrial applications.

[0006] 3. Stability issue: Some ionic liquids may decompose or degrade during the process of capturing carbon dioxide, resulting in a decline in their performance. Therefore, developing ionic liquids with good stability is the key to realizing long-term and effective carbon dioxide capture.

[0007] 4. Scalability issue: Currently, most of the technologies for ionic liquid carbon dioxide capture are at the laboratory scale, and further technological development and optimization are required to achieve large-scale industrial applications.

[0008] Based on the above problems, it is very necessary to develop a CO2 capture system that is easy to synthesize, environmentally friendly, and efficient. Summary of the Invention

[0009] In order to overcome the problems in the prior art such as the complex synthesis process of ionic liquids, the difficult mass transfer in CO2 capture, and the small adsorption capacity, the present invention discloses an ionic liquid system and a synthesis method with a simple synthesis method, good thermal stability, and high CO2 capture ability.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] The first object of the present invention is to provide a sulfonamide ionic liquid, including a cation and a sulfonamide anion. The cation is one or more of a quaternary ammonium cation, a quaternary phosphonium cation, a trimethylhydroxyethylammonium ion, and a protonated organic base; the sulfonamide anion is one or more of a benzenesulfonamide anion and a substituted benzenesulfonamide anion, and the substituted benzenesulfonamide anion includes a para-substituted benzenesulfonamide anion, an ortho-substituted benzenesulfonamide anion, and a meta-substituted benzenesulfonamide anion.

[0012] Further, the quaternary ammonium cation has the structure shown in formula (1):

[0013] where n is 1, 2, 3, or 4;

[0014] The quaternary phosphonium cation has the structure shown in formula (2) or formula (3):

[0015] where n is 1, 2, 3, or 4;

[0016] The trimethylhydroxyethylammonium ion has the structure shown in formula (4):

[0017]

[0018] The protonated organic base is one or more of the compounds shown in formula (5) to formula (9);

[0019]

[0020] Further, the benzenesulfonamide anion has the structure shown in formula (10):

[0021]

[0022] The para-substituted benzenesulfonamide anion has the structure shown in formula (11):

[0023]

[0024] The ortho-substituted benzenesulfonamide anion has the structure shown in formula (12):

[0025]

[0026] The meta-substituted benzenesulfonamide anion has the structure shown in formula (13):

[0027]

[0028] Wherein the R groups are each one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl.

[0029] Furthermore, the sulfonamide-based ionic liquid is selected from one or more of the following ionic liquid groups:

[0030] Ionic liquid - 1: The cation is The anion is

[0031] Ionic liquid - 2: The cation is The anion is Wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0032] Ionic liquid - 3: The cation is The anion is Wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0033] Ionic liquid - 4: The cation is The anion is Wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0034] Ionic liquid - 5: The cation is n is 1, 2, 3 or 4, and the anion is

[0035] Ionic liquid - 6: The cation is n is 1, 2, 3 or 4, and the anion is Wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0036] Ionic liquid - 7: The cation is n is 1, 2, 3 or 4, and the anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0037] Ionic liquid-8: cation is n is 1, 2, 3 or 4, and the anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0038] Ionic liquid-9: cation is n is 1, 2, 3 or 4, and the anion is

[0039] Ionic liquid-10: cation is n is 1, 2, 3 or 4, and the anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0040] Ionic liquid-11: cation is n is 1, 2, 3 or 4, and the anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0041] Ionic liquid-12: cation is n is 1, 2, 3 or 4, and the anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0042] Ionic liquid-13: cation is The anion is

[0043] Ionic liquid-14: cation is The anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0044] Ionic liquid-15: cation is The anion is Wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0045] Ionic liquid - 16: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0046] Ionic liquid - 17: The cation is The anion is

[0047] Ionic liquid - 18: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0048] Ionic liquid - 19: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0049] Ionic liquid - 20: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0050] Ionic liquid - 21: The cation is The anion is

[0051] Ionic liquid - 22: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0052] Ionic liquid - 23: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0053] Ionic liquid - 24: The cation is The anion is where the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0054] Ionic liquid - 25: The cation is The anion is

[0055] Ionic liquid - 26: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0056] Ionic liquid - 27: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0057] Ionic liquid - 28: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0058] Ionic liquid - 29: The cation is The anion is

[0059] Ionic liquid - 30: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0060] Ionic liquid - 31: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0061] Ionic liquid - 32: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0062] Ionic liquid - 33: The cation is The anion is

[0063] Ionic liquid - 34: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0064] Ionic liquid - 35: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl;

[0065] Ionic liquid - 36: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl.

[0066] The second object of the present invention is to provide a preparation method of sulfonamide ionic liquid, and the preparation method includes the following steps: reacting a cationic compound with a sulfonamide anionic compound at 20 - 50 °C for 12 - 24 h to obtain the ionic liquid;

[0067] The cationic compound is one or more of a P - or N - containing compound and an organic base. The P - or N - containing compound is tetraalkylphosphonium hydroxide, tetraalkylammonium hydroxide, trimethylhydroxyethylammonium hydroxide (choline hydroxide), or trihexyltetradecylphosphonium hydroxide. Among them, the alkyl groups contained in the tetraalkylphosphonium hydroxide and tetraalkylammonium hydroxide are one or more of methyl, ethyl, propyl, butyl, hexyl, and tetradecyl; the organic base is one or more of tetramethylguanidine, 1,8 - diazabicyclo[5.4.0]undec - 7 - ene, 1,5 - diazabicyclo[4.3.0]-5 - nonene, triethylenediamine, and 4 - dimethylaminopyridine;

[0068] The sulfonamide anionic compound is one or more of benzenesulfonamide, p - toluenesulfonamide, p - ethylbenzenesulfonamide, p - propylbenzenesulfonamide, p - butylbenzenesulfonamide, 4 - chlorobenzenesulfonamide, 4 - methoxybenzenesulfonamide, 4 - nitrobenzenesulfonamide, sulfanilamide, o - methylbenzenesulfonamide, o - ethylbenzenesulfonamide, o - propylbenzenesulfonamide, o - butylbenzenesulfonamide, 2 - chlorobenzenesulfonamide, 2 - methoxybenzenesulfonamide, 2 - nitrobenzenesulfonamide, 2 - aminobenzenesulfonamide, m - methylbenzenesulfonamide, m - ethylbenzenesulfonamide, m - propylbenzenesulfonamide, m - butylbenzenesulfonamide, 3 - chlorobenzenesulfonamide, 3 - methoxybenzenesulfonamide, 3 - nitrobenzenesulfonamide, and 3 - aminobenzenesulfonamide.

[0069] Furthermore, the molar ratio of the cationic compound to the sulfonamide anionic compound is 1 - 2:1.

[0070] Furthermore, the preparation method further includes subjecting the obtained reaction product to vacuum distillation to remove the solvent (ethanol), and subjecting the residue to vacuum drying to obtain the corresponding ionic liquid. The conditions for vacuum drying include: a vacuum pressure of -0.01 MPa to -0.05 MPa and a temperature of 60 - 100 °C.

[0071] The third object of the present invention is to provide an application of the sulfonamide ionic liquid as described above in CO2 capture.

[0072] Furthermore, the method of the application includes: mixing the sulfonamide ionic liquid with a diluent at a molar ratio of 1:1 - 4, and introducing CO2 for capture; the diluent includes propylene carbonate and polyethylene glycol.

[0073] The fourth object of the present invention is to provide a method for capturing CO2 with a sulfonamide ionic liquid. The method includes: mixing the sulfonamide ionic liquid with a diluent at a molar ratio of 1:1 - 4, continuously introducing CO2 for capture, monitoring the change in the mass of the system, and obtaining the amount of CO2 captured by the ionic liquid under certain conditions; the ionic liquid is the sulfonamide ionic liquid as described above, and the diluent includes propylene carbonate and polyethylene glycol.

[0074] Furthermore, the conditions for capture include: a capture pressure of 0.1 - 0.5 MPa, a temperature of 20 - 50 °C, and a time of 2 - 5 h.

[0075] Furthermore, the conditions for CO2 desorption after capture include: a desorption pressure of 0.1 - 0.5 MPa, a temperature of 60 - 90 °C, and a time of 1 - 3 h.

[0076] Compared with the prior art, the beneficial effects of the present invention are:

[0077] For the sulfonamide ionic liquid described in the present invention, substituted benzenesulfonamide is selected as the anion for the first time, which expands the types of ionic liquids. The pKa value of the sulfonamide compound is about 10, which can undergo acid-base neutralization with strong basic compounds, and the ionic liquid can be synthesized by a one-step method. The raw materials of this type of ionic liquid are easily available, easy to prepare, and have high thermal stability and chemical stability.

[0078] The present invention selects the products after chemical fixation of CO2, propylene carbonate (PC) and polyethylene glycol, as diluents. They have a small molecular weight and high chemical stability, and can effectively increase the amount of CO2 captured per kilogram of ionic liquid.

[0079] The sulfonamide ionic liquid described in the present invention has weak basicity, can capture CO2 through chemical action, has a high capture amount, is easy to desorb, and has a good recycling effect.

[0080] The ionic liquid provided by the present invention is mixed with a diluent in a certain molar ratio and used for CO2 capture, which can effectively reduce the viscosity of the system, enhance the mass transfer of CO2 in the system, and increase the CO2 capture amount. For example, 4444 [4-methoxybenzenesulfonamide] is mixed with propylene carbonate in a molar ratio of 1:2. Under the conditions of a pressure of 0.1 MPa, a temperature of 25 °C, and a CO2 flow rate of 80 mL / min, the CO2 capture amount can reach 1.377 mol / mol IL.

[0081] In addition, the ionic liquid provided by the present invention has good recyclability. For example, the [P 4444 [4-methoxybenzenesulfonamide] ionic liquid prepared in Example 2 has a slightly reduced ability to capture CO2 after being recycled to absorb CO2 four times. Description of the Drawings

[0082] Figure 1 is a comparison of the CO2 capture performance of different ionic liquids;

[0083] Figure 2 is the recycling of the ionic liquid. Detailed Embodiments

[0084] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0085] Tetraalkylphosphonium hydroxide can be prepared by ion exchange of tetraalkylphosphonium chloride with a hydroxide-form anion exchange resin. The specific steps can be as follows:

[0086] Dissolve tetraalkylphosphonium chloride in absolute ethanol (concentration: 0.03 mol / L), and pass the resulting solution through a hydroxide-form ion exchange resin. Then, before using the prepared tetraalkylphosphonium hydroxide, determine that the ion exchange is complete with an aqueous silver nitrate solution. The content of tetraalkylphosphonium hydroxide is determined by 1 1H NMR.

[0087] The present invention will be described in detail below through examples. In the following examples, the prepared ionic liquid can be determined by 1 1HNMR, 13 13CNMR, IR, and MS analysis to obtain the structure.

[0088] The CO2 (99.99%) raw material is a commercially available product from Nanjing Special Gases Company;

[0089] Tetrabutylammonium hydroxide is a commercially available product from Shanghai Aladdin Reagent Co., Ltd.;

[0090] Tetrabutylphosphonium chloride is a commercially available product from Shanghai Aladdin Reagent Co., Ltd.;

[0091] Trihexyltetradecylphosphonium chloride is a commercially available product from Shanghai Aladdin Reagent Co., Ltd.;

[0092] Trimethyl(2-hydroxyethyl)ammonium hydroxide (choline hydroxide) is a commercially available product from Shanghai Aladdin Reagent Co., Ltd.;

[0093] Benzenesulfonamide, p-toluenesulfonamide, p-ethylbenzenesulfonamide, p-propylbenzenesulfonamide, p-butylbenzenesulfonamide, 4-chlorobenzenesulfonamide, 4-methoxybenzenesulfonamide, 4-nitrobenzenesulfonamide, sulfanilamide, o-methylbenzenesulfonamide, o-ethylbenzenesulfonamide, o-propylbenzenesulfonamide, o-butylbenzenesulfonamide, 2-chlorobenzenesulfonamide, 2-methoxybenzenesulfonamide, 2-nitrobenzenesulfonamide, 2-aminobenzenesulfonamide, m-methylbenzenesulfonamide, m-ethylbenzenesulfonamide, m-propylbenzenesulfonamide, m-butylbenzenesulfonamide, 3-chlorobenzenesulfonamide, 3-methoxybenzenesulfonamide, 3-nitrobenzenesulfonamide, 3-aminobenzenesulfonamide are all commercially available products from Anhui Anengji Chemical Reagent Co., Ltd.;

[0094] Propylene carbonate, polyethylene glycol 200, and polyethylene glycol 400 are all commercially available products from Shanghai Aladdin Reagent Co., Ltd.

[0095] Example 1

[0096] Dissolve trihexyltetradecylphosphonium chloride (0.75 mmol) in 25 mL of anhydrous ethanol, and slowly pass the solution through a column packed with three times the molar amount of Amberlite IRN78 hydroxide form ion exchange resin (the hydroxide form ion exchange resin was previously washed thoroughly with anhydrous ethanol and air was removed). Control the flow rate. After two anion exchange operations, replace the fresh hydroxide form ion exchange resin and perform anion exchange again. Use silver nitrate solution to detect whether the anion exchange is complete. The specific method is as follows: Take a small amount of trihexyltetradecylphosphonium hydroxide, acidify it with dilute nitric acid, and use an aqueous-ethanol solution of silver nitrate to determine whether the ion exchange is complete. If not, the ion exchange experiment needs to be carried out again. The content of trihexyltetradecylphosphonium hydroxide is determined by 1 HNMR.

[0097] Weigh the stoichiometric amount of sulfonamide (the specific sulfonamide and the molar ratio of the feed are shown in Table 1), add it to the above ethanol solution containing trihexyltetradecylphosphonium hydroxide, stir at 20 - 35 °C for 24 h, remove the solvent by vacuum distillation, and dry the residue under vacuum at 60 °C and -0.01 MPa for 24 h to obtain the ionic liquid with the corresponding structure.

[0098] Table 1

[0099]

[0100]

[0101] Example 2

[0102] Dissolve tetrabutylphosphonium chloride (0.75 mmol) in 25 mL of absolute ethanol, and slowly pass the solution through a column packed with three times the molar amount of Amberlite IRN78 hydroxide form ion exchange resin (the hydroxide form ion exchange resin was previously thoroughly washed with absolute ethanol and the air therein was removed). Control the flow rate. After ion exchange twice, replace with fresh hydroxide form ion exchange resin and perform the exchange again. Use silver nitrate solution to detect whether the anion exchange is complete. The specific method is as follows: Take a small amount of tetrabutylphosphonium hydroxide, acidify it with dilute nitric acid, and use an aqueous-ethanol solution of silver nitrate to determine whether the ion exchange is complete. If not, the ion exchange experiment needs to be carried out again. The content of tetrabutylphosphonium hydroxide is determined by 1 1H NMR.

[0103] Weigh the stoichiometric amount of sulfonamide (the specific sulfonamide and the molar ratio of feed are shown in Table 2), add it to the above-mentioned ethanol solution containing tetrabutylphosphonium hydroxide, stir at 20 - 35 °C for 24 h, remove the solvent by vacuum distillation, and dry the residue at 60 °C under vacuum of -0.01 MPa for 24 h to obtain the ionic liquid with the corresponding structure.

[0104] Table 2

[0105] Number Sulfonamide Sulfonamide: Tetrabutylphosphonium Hydroxide Molar Ratio Ionic Liquid-8 p-Toluenesulfonamide 1：1 Ionic Liquid-9 Sulfanilamide 1：1 Ionic Liquid-10 Benzenesulfonamide 1：1 Ionic Liquid-11 4-Methoxybenzenesulfonamide 1：1 Ionic Liquid-12 4-Chlorobenzenesulfonamide 1：1 Ionic Liquid-13 4-Nitrobenzenesulfonamide 1：1 Ionic Liquid-14 2-Nitrobenzenesulfonamide 1：1

[0106] Example 3

[0107] Preparation of quaternary ammonium ionic liquid

[0108] Add 25 mL (25 mmol) of tetrabutylammonium hydroxide (1 M, methanol) to a 100 mL conical flask, then add sulfonamide (25 mmol) (the specific sulfonamide and the molar ratio of feed are shown in Table 3), stir at 20 - 35 °C for 24 h, then remove the solvent by vacuum distillation, and dry the obtained ionic liquid at 60 °C under vacuum of -0.01 MPa for 24 h to obtain a white solid.

[0109] Table 3

[0110]

[0111]

[0112] Example 4

[0113] Preparation of trimethylhydroxyethylammonium sulfonamide ionic liquid

[0114] Add choline hydroxide (44 wt.% in water, 25 mmol) to a 100 mL conical flask, then add sulfonamide (25 mmol) (the specific sulfonamide and feeding molar ratio are shown in Table 4), stir at 20 - 35 °C for 24 h, then distill off the solvent under reduced pressure, and dry the obtained ionic liquid at 60 °C under vacuum of -0.01 MPa for 24 h to obtain a white solid.

[0115] Table 4

[0116] Number Sulfonamide Sulfonamide: Choline Hydroxide Molar Ratio Ionic Liquid-22 p-Toluenesulfonamide 1：1 Ionic Liquid-23 Sulfanilamide 1：1 Ionic Liquid-24 Benzenesulfonamide 1：1 Ionic Liquid-25 4-Methoxybenzenesulfonamide 1：1 Ionic Liquid-26 4-Chlorobenzenesulfonamide 1：1 Ionic Liquid-27 4-Nitrobenzenesulfonamide 1：1 Ionic Liquid-28 2-Nitrobenzenesulfonamide 1：1

[0117] Example 5

[0118] Ionic liquid for CO2 capture: gravimetric method

[0119] Add 0.002 mol of the ionic liquid - 1 in Example 1, i.e., [P 66614 [p - toluenesulfonamide] ionic liquid, to a 25 mL round - bottom flask, then add 0.004 mol of propylene carbonate and stir evenly. Continuously introduce CO2 into the system at a rate of 80 mL / min, and weigh the mass at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h to calculate the amount of CO2 captured by the ionic liquid. By calculation, it is found that per mole of [P 66614 [p - toluenesulfonamide] mixed solvent can capture 1.205 mol of CO2 at 25 °C and atmospheric pressure.

[0120] Example 6

[0121] Ionic liquid for CO2 capture: gravimetric method

[0122] Add 0.002 mol of the ionic liquid - 8 in Example 2, i.e., [P 4444 [p - toluenesulfonamide] ionic liquid, to a 25 mL round - bottom flask, then add 0.004 mol of propylene carbonate and stir evenly. Continuously introduce CO2 into the system at a rate of 80 mL / min, and weigh the mass at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h to calculate the amount of CO2 captured by the ionic liquid. By calculation, it is found that per mole of [P 4444 [p - toluenesulfonamide] mixed solvent can capture 1.347 mol of CO2 at 25 °C and atmospheric pressure.

[0123] Example 7

[0124] Ionic liquid for CO2 capture: gravimetric method

[0125] Add 0.002 mol of the ionic liquid - 11 in Example 2, i.e., [P 4444[4-Methoxybenzenesulfonamide] ionic liquid, and then 0.004 mol of propylene carbonate was added and stirred evenly. CO2 was continuously introduced into the system at a rate of 80 mL / min. Weights were taken at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h, and the amount of CO2 captured by the ionic liquid was calculated. By calculation, per mole of [P 4444 [4-Methoxybenzenesulfonamide] mixed solvent can capture 1.377 mol of CO2 at 25 °C and atmospheric pressure.

[0126] Example 8

[0127] CO2 capture by ionic liquid: Gravimetric method

[0128] 0.002 mol of the ionic liquid-11 in Example 2, i.e., [P 4444 [4-Methoxybenzenesulfonamide] ionic liquid, was added to a 25 mL round-bottom flask, and then 0.004 mol of polyethylene glycol 200 was added and stirred evenly. CO2 was continuously introduced into the system at a rate of 80 mL / min. Weights were taken at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h, and the amount of CO2 captured by the ionic liquid was calculated. By calculation, per mole of [P 4444 [4-Methoxybenzenesulfonamide] mixed solvent can capture 1.36 mol of CO2 at 25 °C and atmospheric pressure.

[0129] Example 9

[0130] CO2 capture by ionic liquid: Gravimetric method

[0131] 0.002 mol of the ionic liquid-11 in Example 2, i.e., [P 4444 [4-Methoxybenzenesulfonamide] ionic liquid, was added to a 25 mL round-bottom flask without adding a diluent. CO2 was continuously introduced into the system at a rate of 80 mL / min. Weights were taken at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h, and the amount of CO2 captured by the ionic liquid was calculated. By calculation, per mole of [P 4444 [4-Methoxybenzenesulfonamide] ionic liquid can capture 0.915 mol of CO2 at 25 °C and atmospheric pressure, and the capture effect is significantly reduced. Therefore, the present invention uses a mixed solvent of ionic liquid and diluent.

[0132] Example 10

[0133] Comparison of CO2 capture performance of different ionic liquids: Gravimetric method

[0134] 0.002 mol of the ionic liquid-1 in Example 1, i.e., [P 66614[N] [p-toluenesulfonamide]), trimethylhydroxyethylammonium and p-toluenesulfonamide synthesized 111 OH 22 ][p-toluenesulfonamide], the ionic liquid-15 ([N 4444 ][p-toluenesulfonamide]), the ionic liquid-8 in Example 2 ([P 4444 ][p-toluenesulfonamide]), ionic liquid-10([P 4444 ][benzenesulfonamide]), ionic liquid-11([P 4444 ][4-methoxybenzenesulfonamide]), ionic liquid-12([P 4444 ][4-chlorobenzenesulfonamide]), ionic liquid-14([P 4444 ][2-nitrobenzenesulfonamide]), then added 0.004 mol of propylene carbonate and stirred evenly to compare the CO2 capture performance of different ionic liquids. CO2 was continuously introduced into the system at a rate of 80 mL / min. The mass was weighed at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h, and the amount of CO2 captured by the ionic liquid was calculated. Through calculation, the CO2 capture ability of different ionic liquids was ranked from high to low as follows: [P 4444 ][4-Methoxybenzenesulfonamide](1.377mol CO2 / mol IL&2PC)>[P 4444 ][p-Toluenesulfonamide](1.347mol CO2 / mol IL&2PC)>[P 4444 ][Benzenesulfonamide](1.326mol CO2 / mol IL&2PC)>[P 4444 ][4-Chlorobenzenesulfonamide](1.296molCO2 / mol IL&2PC)>[N 4444 ][p-Toluenesulfonamide](1.249mol CO2 / mol IL&2PC)>[P 4444 ][2-nitrobenzenesulfonamide](1.244mol CO2 / mol IL&2PC)>[P 66614 ][p-Toluenesulfonamide](1.205mol CO2 / mol IL&2PC)>[N 111 OH 22 [p-Toluenesulfonamide] (0.722 mol CO2 / mol IL&2PC). The experimental results are as follows Figure 1 shown.

[0135] Example 11

[0136] Ionic Liquid Capture of CO2 for Recycling: Gravimetric Method

[0137] Add 0.002 mol of the ionic liquid-11 in Example 2, namely [P 4444 [4-methoxybenzenesulfonamide] ionic liquid, to a 25 mL round-bottom flask, and then add 0.004 mol of propylene carbonate and stir evenly. Continuously introduce CO2 into the system at a rate of 80 mL / min, and weigh the mass at 0 min, 10 min, 30 min, 60 min, 2 h, 3 h, and 4 h to calculate the amount of CO2 captured by the ionic liquid. Through calculation, it is obtained that each mole of [P 4444 [4-methoxybenzenesulfonamide] ionic liquid can capture 1.377 mol of CO2 in the first absorption at 25 °C and atmospheric pressure. Subsequently, conduct the first CO2 desorption experiment. Continuously introduce N2 into the system at a rate of 80 mL / min at 80 °C and atmospheric pressure, and weigh the mass at 0 min, 5 min, 10 min, 30 min, and 60 min to calculate the amount of CO2 desorbed by the ionic liquid. After all the CO2 is desorbed and the ionic liquid is cooled to room temperature, repeat the second CO2 absorption experiment. Through calculation, it is obtained that each mole of [P 4444 [4-methoxybenzenesulfonamide] ionic liquid can capture 1.357 mol of CO2 in the second absorption at 25 °C and atmospheric pressure. After the second desorption is completed, cool the ionic liquid to room temperature and repeat the third CO2 absorption experiment. Through calculation, it is obtained that each mole of [P 4444 [4-methoxybenzenesulfonamide] ionic liquid can capture 1.337 mol of CO2 in the third absorption at 25 °C and atmospheric pressure. After the third desorption is completed, cool the ionic liquid to room temperature and repeat the fourth CO2 absorption experiment. Through calculation, it is obtained that each mole of [P 4444 [4-methoxybenzenesulfonamide] mixed solvent can capture 1.332 mol of CO2 in the fourth absorption at 25 °C and atmospheric pressure, as Figure 2 shown.

[0138] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent in such process, method, article or device.

[0139] It should be noted that the above content only illustrates the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. For those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements all fall within the protection scope of the claims of the present invention.

Claims

1. A sulfonamide ionic liquid, characterized in that, It includes cations and sulfonamide anions. The cations are one or more of quaternary ammonium cations, quaternary phosphonium cations, trimethylhydroxyethylammonium ions, and protonated organic bases; the sulfonamide anions are one or more of benzenesulfonamide anions, para-substituted benzenesulfonamide anions, ortho-substituted benzenesulfonamide anions, and meta-substituted benzenesulfonamide anions.

2. The sulfonamide ionic liquid according to claim 1, wherein The quaternary ammonium cation has the structure shown in formula (1): where n is 1, 2, 3 or 4; The quaternary phosphonium cation has the structure shown in formula (2) or formula (3): where n is 1, 2, 3 or 4; The trimethylhydroxyethylammonium ion has the structure shown in formula (4): The protonated organic base is one or more of the compounds shown in formula (5) to formula (9); 3. The sulfonamide ionic liquid according to claim 1, wherein The benzenesulfonamide anion has the structure shown in formula (10): The para-substituted benzenesulfonamide anion has the structure shown in formula (11): The ortho-substituted benzenesulfonamide anion has the structure shown in formula (12): The meta-substituted benzenesulfonamide anion has the structure shown in formula (13): Wherein, the R groups are respectively one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl.

4. A sulfonamide ionic liquid according to any one of claims 1-3, characterized in that, It is one or more selected from the following groups of ionic liquids: Ionic liquid - 1: The cation is The anion is Ionic liquid - 2: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 3: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 4: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 5: The cation is where n is 1, 2, 3 or 4, and the anion is Ionic liquid - 6: The cation is where n is 1, 2, 3 or 4, and the anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 7: The cation is where n is 1, 2, 3 or 4, and the anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 8: The cation is where n is 1, 2, 3 or 4, and the anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 9: The cation is where n is 1, 2, 3 or 4, and the anion is Ionic liquid - 10: The cation is where n is 1, 2, 3 or 4, and the anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 11: The cation is where n is 1, 2, 3 or 4, and the anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 12: The cation is where n is 1, 2, 3 or 4, and the anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 13: The cation is The anion is Ionic liquid - 14: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 15: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 16: The cation is and the anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 17: The cation is The anion is Ionic liquid - 18: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 19: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 20: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 21: The cation is The anion is Ionic liquid - 22: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 23: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 24: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 25: The cation is The anion is Ionic liquid - 26: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 27: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 28: The cation is The anion is wherein, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 29: The cation is The anion is Ionic liquid - 30: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 31: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 32: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 33: The cation is The anion is Ionic liquid - 34: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 35: The cation is The anion is wherein the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl; Ionic liquid - 36: The cation is The anion is Among them, the R group is one of -CH3, -C2H5, -C3H7, -C4H9, -OCH3, -NO2, -NH2, -Cl.

5. A preparation method of a sulfonamide ionic liquid, characterized in that, The preparation method includes the following steps: reacting a cationic compound with a sulfonamide anion compound at 20 - 50 °C for 12 - 24 h to obtain the ionic liquid; The cationic compound is one or more of a P- or N-containing compound and an organic base. The P- or N-containing compound is tetraalkylphosphonium hydroxide, tetraalkylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, or trihexyltetradecylphosphonium hydroxide. Among them, the alkyl groups contained in the tetraalkylphosphonium hydroxide and tetraalkylammonium hydroxide are one or more of methyl, ethyl, propyl, butyl, hexyl, and tetradecyl; the organic base is one or more of tetramethylguanidine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]-5-nonene, triethylenediamine, and 4-dimethylaminopyridine; The sulfonamide anion compound is one or more of benzenesulfonamide, p-toluenesulfonamide, p-ethylbenzenesulfonamide, p-propylbenzenesulfonamide, p-butylbenzenesulfonamide, 4-chlorobenzenesulfonamide, 4-methoxybenzenesulfonamide, 4-nitrobenzenesulfonamide, sulfanilamide, o-methylbenzenesulfonamide, o-ethylbenzenesulfonamide, o-propylbenzenesulfonamide, o-butylbenzenesulfonamide, 2-chlorobenzenesulfonamide, 2-methoxybenzenesulfonamide, 2-nitrobenzenesulfonamide, 2-aminobenzenesulfonamide, m-methylbenzenesulfonamide, m-ethylbenzenesulfonamide, m-propylbenzenesulfonamide, m-butylbenzenesulfonamide, 3-chlorobenzenesulfonamide, 3-methoxybenzenesulfonamide, 3-nitrobenzenesulfonamide, and 3-aminobenzenesulfonamide.

6. The preparation method of a sulfonamide ionic liquid according to claim 5, characterized in that, The molar ratio of the cationic compound to the sulfonamide anion compound is 1 - 2:

1.

7. Application of a sulfonamide ionic liquid in CO2 capture, characterized in that, The sulfonamide ionic liquid is the sulfonamide ionic liquid according to any one of claims 1 - 4.

8. Use of a sulfonamide ionic liquid according to claim 7 in CO2 capture, characterized in that, The application method includes: mixing the sulfonamide ionic liquid with a diluent at a molar ratio of 1:1 - 4, and introducing CO2 for capture; The diluent includes propylene carbonate and polyethylene glycol.

9. A method for capturing CO2 by a sulfonamide ionic liquid, characterized in that, The method includes: mixing the sulfonamide ionic liquid and the diluent in a molar ratio of 1:1 - 4, and continuously introducing CO2 for capture; the ionic liquid is the sulfonamide ionic liquid described in any one of claims 1 - 4, and the diluent includes propylene carbonate and polyethylene glycol.

10. A method for capturing CO2 with a sulfonamide-based ionic liquid according to claim 9, characterized in that, The conditions for capture include: the capture pressure is 0.1 - 0.5 MPa, the temperature is 20 - 50 °C, and the time is 2 - 5 h.

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