Deep-eutectic solvent for absorbing carbon dioxide as well as preparation method and application of deep-eutectic solvent

Abstract

The invention provides an ionic eutecticevaporate solvent for absorbing carbon dioxide. The eutecticevaporate solvent comprises a hydrogen bond donor component and a ketone component, the ketone component is selected from 2-pyrrolidone and / or N-methyl pyrrolidone; the hydrogen bond donor component is selected from ether group-containing polycyclic amine, functional ionic liquid or a mixture of the ether group-containing polycyclic amine and the functional ionic liquid. The deep-eutectic solvent is simple in synthesis step and convenient to prepare on a large scale, CO2 absorption can rapidly reach saturation, the large saturation absorption amount can be achieved, and the circulation desorption rate gt can be achieved; 95%.

Description

Technical Field

[0001] The invention belongs to the technical field of gas separation, and in particular relates to a low eutectic solvent for absorbing carbon dioxide, a preparation method and use thereof. Background Art

[0002] As the greenhouse effect continues to intensify, extreme weather such as floods and typhoons are frequent around the world, CO 2 As the main contributor to the enhanced greenhouse effect, how to control CO 2 The emission of CO has attracted wide attention from the whole society. 2 The sources of CO can be divided into two categories: Natural sources: including CO 2 Emissions from natural processes such as volcanic eruptions, plant respiration, and decomposition of organic matter. 2 Usually it can be balanced by natural systems and will not have a significant impact on the environment; Anthropogenic sources: including CO generated by human activities 2 , such as the burning of fossil fuels such as oil, natural gas, coal, and the production of CO2 in industrial production, transportation, construction, agriculture, etc. 2 These anthropogenic sources of CO 2 The emission is very large, which will have a serious impact on the global climate and environment, and is one of the main causes of global climate change. Therefore, in order to alleviate the catastrophic problems caused by the global greenhouse effect, measures must be taken to capture CO2 emitted by human sources in the atmosphere. 2 .

[0003] Ionic deep eutectic solvents are liquid salts composed of cations and anions, and are widely used in many chemical and industrial fields. In recent years, some researchers have tried to apply ionic deep eutectic solvents to carbon dioxide storage and capture. Ionic deep eutectic solvents can be used as ionic liquids for absorbing carbon dioxide, and have many advantages, such as high solubility, good stability, and recyclability. In addition, ionic deep eutectic solvents can also change their absorption of CO by adjusting their chemical structure. 2 performance.

[0004] Some literature reports that can chemically absorb CO 2 A low eutectic solvent, 201910304938.5 A functional ionic low eutectic solvent for efficient absorption of carbon dioxide: a low eutectic solvent composed of a double negatively charged anion functional ionic liquid as a hydrogen bond acceptor and a polyol as a hydrogen bond donor, wherein the double negatively charged anion functional ionic liquid is synthesized in one step, and the strong negative charge and alkalinity of the anions in the ionic liquid and the synergistic effect of weak acid-base and hydrogen bonds between the alcohol hydroxyl groups in the polyol and carbon dioxide contribute to the efficient absorption of carbon dioxide. Therefore, in industrial production practice, there is still an urgent need for greater CO 2Absorption capacity, better cycle performance of CO 2 Absorb the solvent. Summary of the invention

[0005] The present invention adopts a low eutectic solvent for absorbing carbon dioxide, which includes a hydrogen bond donor component and a ketone component. The low eutectic solvent reduces the viscosity of the system and weakens the CO 2 The interaction between the active sites of the amine group reduces the regeneration energy consumption of the low eutectic solvent.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a deep eutectic solvent for absorbing carbon dioxide, wherein the deep eutectic solvent comprises a hydrogen bond donor component and a ketone component;

[0008] The ketone component is selected from 2-pyrrolidone and / or N-methylpyrrolidone;

[0009] The hydrogen bond donor component is selected from an ether-containing polycyclic amine having a structure as shown in formula (I), or a functional ionic liquid having a structure as shown in formula (II), or a mixture thereof:

[0010]

[0011] Among them, G 1 , G 2 , G 3 , G 4 and G 5 are each independently selected from N or C(R); R, R', R 1 , R 2 , R 3 , R 4 and R 5 are independently selected from the following substituted or unsubstituted groups: hydrogen atom, C 0 -C 6 Alkylene-amino, C 0 -C 6 Alkylene-hydroxyl, C 1 -C 6 Alkyl, C 1 -C 6 Alkoxy, C 0 -C 6 Alkylene-NH-C 1 -C 6 Alkyl, C 0 -C 6 Alkylene-N(C 1 -C 6 alkyl) 2 , C 1 -C 6 Alkylene-OC1 -C 6 Alkyl, or C 1 -C 6 Alkylene-OC 0 -C 6 Alkyl-amino; when G 1 , G 2 , G 3 , G 4 and G 5 When all are selected from C(R), R, R', R 1 , R 2 , R 3 , R 4 and R 5 At least one selected from the following substituted or unsubstituted groups: C 0 -C 6 Alkylene-amino, C 0 -C 6 Alkylene-NH-C 1 -C 6 Alkyl, C 0 -C 6 Alkylene-N(C 1 -C 6 alkyl) 2 , or C 1 -C 6 Alkylene-OC 0 -C 6 Alkyl-amino;

[0012] When R, R', R 1 , R 2 , R 3 , R 4 and R 5 When each is independently selected from a substituted group, the substituent is selected from amino, hydroxyl, C 1 -C 6 Alkyl, C 1 -C 6 One or more of alkoxy groups;

[0013] X - Selected from Cl - Br - ,I - , BF 4 - PF 6 - 、NO 3 - NTf 2 - , ClO 4 - , HSO 3- , HSO 4 - , H 2 PO 4 - , CH 3 COO - , CH 3 (CH 2 ) n COO - 、SCN - , SbF 6 - , AsF 6 - CF 3 - CF 3 COO - , CH 3 SO 4 - , C 2 H 6 SO 4 - , C 8 H 17 SO 4 - , C 4 F 9 SO 3 - CF 3 (CF 2 ) n SO 3 - ,(CF 3 SO 2 ) 3 C - , (C 2 F 5 SO 2 ) 2 N - ,(CF 3 SO 2 ) 2 N - , CH 3 CH(OH)COO - , dodecyl sulfonate, benzene sulfonate, p-toluene sulfonate or more, wherein n is independently selected from an integer of 0 to 12.

[0014] The ether-containing polycyclic amine or functional ionic liquid, or a mixture thereof, is used as a hydrogen bond donor component. The hydrogen bond donor component has a specific conjugated structure and is easy to form N positive ions, making the eutectic solvent CO2-free compared to the conventional linear alcohol amine eutectic solvent. 2Higher absorption efficiency, CO 2 The absorption capacity is larger. The ketone component acts as a hydrogen bond acceptor. Since the electronegative site on pyrrolidone binds to CO 2 The strong chemical reaction between pyrrolidone and CO 2 The physical interaction between the N-heterocyclic structure of the ketone component and CO 2 The interaction weakens CO 2 The interaction between the amine groups enables CO 2 High capacity absorption and selective separation, while the addition of high boiling point solvents can also reduce the viscosity of the ionic liquid system and promote CO 2 The desorption cycle makes the regeneration process of the deep eutectic solvent easier and reduces the regeneration energy consumption.

[0015] X in the functional ionic liquid of formula (II) - It can also act as a hydrogen bond acceptor, X in functional ionic liquids - The strong electronegativity of the ether-containing multi-ring hydrogen bond donor component works together to provide more CO absorption 2 site, increasing CO 2 absorption capacity.

[0016] Preferably, in formula (I), G 1 , G 2 , G 3 , G 4 and G 5 At least one of them is N, and R, R 1 , R 2 , R 3 , R 4 and R 5 At least one independently selected from the following substituted or unsubstituted groups: C 0 -C 6 Alkylene-amino, C 0 -C 6 Alkylene-NH-C 1 -C 6 Alkyl, C 0 -C 6 Alkylene-N(C 1 -C 6 alkyl) 2 , or C 1 -C 6 Alkylene-OC 0 -C 6 Alkyl-amino; when R, R 1 , R 2 , R 3 , R 4 and R 5When each is independently selected from a substituted group, the substituent is selected from amino, hydroxyl, C 1 -C 6 Alkyl, C 1 -C 6 One or more of alkoxy groups.

[0017] The polycyclic amine containing ether groups contains oxygen atoms of ether groups and nitrogen atoms. The substituent structure of the polycyclic amine still contains nitrogen atoms or oxygen atoms, which can enhance the conjugation of each atom and make it easier to form N positive ions, thereby further making the low eutectic solvent CO 2 Higher absorption efficiency, CO 2 Greater absorption capacity.

[0018] In some preferred embodiments, in the formula (I), R, R 1 , R 2 , R 3 , R 4 and R 5 Each independently selected from -H, -NH 2 、-CH 3 , -C 2 H 5 、-(CH 2 ) 2 -CH 3 、-CH(CH 3 ) 2 、-(CH 2 ) 3 -CH 3 、-CH 2 -CH(CH 3 )-CH 3 、-(CH 3 )CHCH 2 CH 3 、-CH 2 OH, -OCH 3 、-OC 2 H 5 、-O-(CH 2 ) 2 -CH 3 、-CH 2 -NH 2 、-(CH 2 ) 2 -NH 2 、-(CH 2 ) 3 -NH 2 、-NH-CH 3 、-NH-C 2 H 5 、-NH-(CH 2 )3 -CH 3 、-CH 2 -O-CH 2 -NH 2 、-CH 2 -O-(CH 2 ) 2 -NH 2 、-CH 2 -O-C(CH 3 ) 2 -NH 2 、-CH 2 -O-CH(NH 2 ) 2 、-(CH 2 ) 2 -O-NH 2 、-O-CH 2 -NH 2 、-O-(CH 2 ) 2 -NH 2 、-NH-CH 2 -O-CH 3 、-CH 2 -NH-O-CH 3 、-CH(CH 2 -NH 2 ) 2 、-CH(OH)-CH 2 -NH 2 、-CH(CH 2 OH)-(CH 2 ) 2 -NH 2 、-CH(CH 3 )-CH 2 -NH 2 、-CH(OH)-C(CH 3 ) 2 -NH 2 、-CH 2 -C(CH 3 ) 2 -NH 2 、-CH(CH 3 )-CH(CH 3 )-NH 2 或-(CH 2 ) 2 -NH-CH 2 CH(OCH 3 ) 2 ;当G 1 、G 2 、G 3 、G4 and G 5 When both are selected from C(R), R, R 1 , R 2 , R 3 , R 4 and R 5 At least one selected from -NH 2 、-CH 2 -NH 2 、-(CH 2 ) 2 -NH 2 、-(CH 2 ) 3 -NH 2 、-NH-CH 3 、-NH-C 2 H 5 、-NH-(CH 2 ) 3 -CH 3 、-CH 2 -O-CH 2 -NH 2 、-CH 2 -O-(CH 2 ) 2 -NH 2 、-CH 2 -OC(CH 3 ) 2 -NH 2 、-CH 2 -O-CH(NH 2 ) 2 、-(CH 2 ) 2 -O-NH 2 、-O-CH 2 -NH 2 、-O-(CH 2 ) 2 -NH 2 、-NH-CH 2 -O-CH 3 、-CH 2 -NH-O-CH 3 、-CH(CH 2 -NH 2 ) 2 、-CH(OH)-CH 2 -NH 2 、-CH(CH 2 OH)-(CH 2 ) 2 -NH 2 、-CH(CH 3 )-CH2 -NH 2 、-CH(OH)-C(CH 3 ) 2 -NH 2 、-CH 2 -C(CH 3 ) 2 -NH 2 、-CH(CH 3 )-CH(CH 3 )-NH 2 or -(CH 2 ) 2 -NH-CH 2 CH(OCH 3 ) 2 .

[0019] Preferably, in formula (I), G 1 , G 2 , G 3 , G 4 and G 5 At least one of them is N, and R, R 1 , R 2 , R 3 , R 4 and R 5 At least one selected from -NH 2 、-CH 2 -NH 2 、-(CH 2 ) 2 -NH 2 、-(CH 2 ) 3 -NH 2 、-NH-CH 3 、-NH-C 2 H 5 、-NH-(CH 2 ) 3 -CH 3 、-CH 2 -O-CH 2 -NH 2 、-CH 2 -O-(CH 2 ) 2 -NH 2 、-CH 2 -OC(CH 3 ) 2 -NH 2 、-CH 2 -O-CH(NH 2 ) 2 、-(CH 2 )2 -O-NH 2 、-O-CH 2 -NH 2 、-O-(CH 2 ) 2 -NH 2 、-NH-CH 2 -O-CH 3 、-CH 2 -NH-O-CH 3 、-CH(CH 2 -NH 2 ) 2 、-CH(OH)-CH 2 -NH 2 ,

[0020] -CH(CH 2 OH)-(CH 2 ) 2 -NH 2 、-CH(CH 3 )-CH 2 -NH 2 、-CH(OH)-C(CH 3 ) 2 -NH 2 、-CH 2 -C(CH 3 ) 2 -NH 2 、-CH(CH 3 )-CH(CH 3 )-NH 2 or

[0021] -(CH 2 ) 2 -NH-CH 2 CH(OCH 3 ) 2 .

[0022] In some preferred embodiments, the ether-containing polycyclic amine has a structure as shown in the following formula:

[0023]

[0024]

[0025] In some preferred embodiments, in the formula (II), R, R', R 1 , R 2 , R 3 , R 4 , R 5 Each independently selected from -H, -NH 2、-CH 3 、-C 2 H 5 、-(CH 2 ) 2 -CH 3 、-CH(CH 3 ) 2 、-(CH 2 ) 3 -CH 3 、-CH 2 -CH(CH 3 )-CH 3 、-(CH 3 )CHCH 2 CH 3 、-CH 2 OH、-OCH 3 、-OC 2 H 5 、-O-(CH 2 ) 2 -CH 3 、-CH 2 -NH 2 、-(CH 2 ) 2 -NH 2 、-(CH 2 ) 3 -NH 2 、-NH-CH 3 、-NH-C 2 H 5 、-NH-(CH 2 ) 3 -CH 3 、-CH 2 -O-CH 2 -NH 2 、-CH 2 -O-(CH 2 ) 2 -NH 2 、-CH 2 -OC(CH 3 ) 2 -NH 2 、-CH 2 -O-CH(NH 2 ) 2 、-(CH 2 ) 2 -O-NH 2 、-O-CH 2 -NH 2 、-O-(CH 2 ) 2 -NH 2、-NH-CH 2 -O-CH 3 、-CH 2 -NH-O-CH 3 、-CH(CH 2 -NH 2 ) 2 、-CH(OH)-CH 2 -NH 2 、-CH(CH 2 OH)-(CH 2 ) 2 -NH 2 、-CH(CH 3 )-CH 2 -NH 2 、-CH(OH)-C(CH 3 ) 2 -NH 2 、-CH 2 -C(CH 3 ) 2 -NH 2 、-CH(CH 3 )-CH(CH 3 )-NH 2 or -(CH 2 ) 2 -NH-CH 2 CH(OCH 3 ) 2 ;

[0026] Preferably, the X - Selected from NTf 2 - 、NO 3 - , CH 3 COO - , BF 4 - One or more of .

[0027] In some preferred embodiments, the functional ionic liquid has a structure as shown in the following formula:

[0028]

[0029]

[0030] In some preferred embodiments, in the low eutectic solvent, the mass ratio of the hydrogen bond donor component to the ketone component is (1-10):1; preferably, the mass ratio of the hydrogen bond donor component to the ketone component is (1-5):1; more preferably, the mass ratio of the hydrogen bond donor component to the ketone component is (1-3):1. The selection of the above mass ratio makes it easier for the hydrogen bond donor component to form N positive ions, and can better play the role of the N heterocyclic structure of the ketone component with CO 2 The interaction weakens CO 2 The interaction between the amine groups promotes CO 2 The desorption cycle makes the regeneration process of the deep eutectic solvent easier and reduces the regeneration energy consumption.

[0031] When the hydrogen bond donor component is selected from a mixture of the ether-containing polycyclic amine and the functional ionic liquid, the ether-containing polycyclic amine and the functional ionic liquid act together as hydrogen bond donors, which has a higher CO 2 The absorption capacity and absorption efficiency of X - Together with the ketone component, it acts as a hydrogen bond acceptor, further enhancing the electronegativity of the mixture and providing more CO absorption 2 site, increasing CO 2 In some preferred embodiments, when the hydrogen bond donor component is selected from a mixture of the ether-containing polycyclic amine and the functional ionic liquid, the mass ratio of the ether-containing polycyclic amine to the functional ionic liquid is (1-5):1, preferably (1-2):1.

[0032] The third aspect of the present invention provides a method for preparing the above-mentioned low eutectic solvent, wherein the hydrogen bond donor component and the ketone component are stirred and mixed at 50-80° C. for 5-8 hours to prepare a low eutectic solvent.

[0033] A fourth aspect of the present invention provides a method for applying the above-mentioned deep eutectic solvent or the deep eutectic solvent prepared by the above-mentioned preparation method to CO 2 absorption, separation or capture.

[0034] In some preferred embodiments, CO is absorbed at an absorption temperature of 40-60°C. 2 ; Release CO at a desorption temperature of 90-110°C 2 .

[0035] The technical solution provided by the present invention has the following beneficial effects:

[0036] (1) The present invention provides an ether-containing polycyclic amine, or a functional ionic liquid, or a mixture thereof as a hydrogen bond donor component. The hydrogen bond donor component has a specific conjugated structure and is more likely to form N positive ions, making the eutectic solvent CO2-free compared to conventional linear alcohol amine eutectic solvents. 2Higher absorption efficiency, CO 2 The absorption capacity is larger. By providing the ketone component as a hydrogen bond acceptor, the electronegative site on the pyrrolidone can bind to CO 2 The strong chemical reaction between pyrrolidone and CO 2 The physical interaction between them and the ether-containing polycyclic amines can achieve CO 2 High capacity absorption and selective separation, while pyrrolidone as a high boiling point solvent can also reduce the viscosity of the ionic liquid system and promote CO 2 The desorption cycle, CO 2 The absorption mass transfer efficiency is higher.

[0037] (2) The present invention uses X in the functional ionic liquid - As a hydrogen bond acceptor, X in functional ionic liquids - The strong electronegativity of the nitrogen cations formed by the hydrogen bond donor components work together to provide more CO absorption 2 site, increasing CO 2 absorption capacity.

[0038] (3) The present invention uses a low eutectic solvent comprising a hydrogen bond donor component and a ketone component as CO 2 Absorbent, simple synthesis steps, convenient for large-scale preparation, CO 2 The absorption can reach saturation quickly and can achieve a large saturation absorption capacity, and the cycle desorption rate is >95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 CO used in one embodiment of the present invention 2 Schematic diagram of the absorption equipment structure.

[0040] Explanation of the reference numerals: 1 - air intake device; 2 - stirring device; 3 - heating device; 4 - analysis device. DETAILED DESCRIPTION

[0041] The present invention is further described below by means of specific embodiments. The embodiments of the present invention are only used as illustrations of the present invention and do not mean that the scope of the present invention is limited thereto.

[0042] The grouting material provided by the present invention can be prepared and / or used by equipment known in the art, preferably by the following equipment:

[0043] Figure 1 The CO used in the absorbent in one embodiment of the present invention is shown. 2 Absorption equipment, the CO 2The absorption device is a phase equilibrium device, which includes: an air intake device 1, a stirring device 2, a heating device 3 and an analysis device 4.

[0044] The air intake device 1 is used to transfer CO 2 With N 2 The simulated mixed gas was introduced into CO 2 The absorption device comprises a stirring device 2 for stirring a mixture of a functional ionic liquid and a ketone or a mixture of an ether-containing polycyclic amine and a ketone, a heating device 3 for heating the mixture of a functional ionic liquid and a ketone or a mixture of an ether-containing polycyclic amine and a ketone, and an analyzing device 4 for determining and controlling CO 2 Various performance parameters during absorption and desorption processes.

[0045] Instrument: Both absorption and desorption are read by CO analyzer 2 The concentration and flow rate are obtained by integrating them over time.

[0046] Example 1

[0047] Example 1-1

[0048] 50 g of N-aminopropylmorpholine①, 50 g of N-butyl-N-aminopropylmorpholine acetate (1) and 50 g of 2-pyrrolidone were added to a phase equilibrium apparatus and stirred at 50°C for 8 h to obtain a low eutectic solvent. The absorption temperature was set at 40°C and CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration is about 14%, and it reaches saturation in about 25 minutes. The saturation absorption capacity is 4 mol CO 2 / L solvent; during the desorption process, the solution was heated to 90°C and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.2 L / min, and desorption was completed in about 20 minutes, with a desorption rate of >95%.

[0049] Example 1-2

[0050] 50 g of N-aminopropylmorpholine①, 50 g of N-butyl-N-aminopropylmorpholine acetate (1) and 50 g of 2-pyrrolidone were added to a phase equilibrium apparatus and stirred at 60°C for 7 h to obtain a low eutectic solvent. The absorption temperature was set at 50°C, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 24 minutes, with a saturation absorption of 3.7 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2The flow rate was set at 1.2 L / min, and desorption was completed in about 20 minutes, with a desorption rate of >95%.

[0051] Examples 1-3

[0052] Add 50 g of N-aminopropylmorpholine①, 50 g of N-butyl-N-aminopropylmorpholine bistrifluoromethanesulfonyl imide salt (2) and 50 g of 2-pyrrolidone into a phase equilibrium apparatus and stir and mix at 80°C for 5 h to obtain a low eutectic solvent. Set the absorption temperature to 60°C, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 22 minutes, with a saturation absorption of 3.4 mol CO 2 / L solvent; during the desorption process, the solution was heated to 110℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.2 L / min, and desorption was completed in about 20 minutes, with a desorption rate of >95%.

[0053] Examples 1-4

[0054] 50 g of N-aminopropylmorpholine①, 50 g of N-butyl-N-aminopropylmorpholine acetate (1) and 50 g of 2-pyrrolidone were added to a phase equilibrium apparatus and stirred at 50°C for 8 h to obtain a low eutectic solvent. The absorption temperature was set at 40°C and CO 2 Flow rate 0.25L / min, N 2 Flow rate 3.3L / min, stirring speed 300r / min, CO 2 The concentration is about 14%, and it reaches saturation in about 15 minutes. The saturation absorption capacity is 3.0 mol CO 2 / L solvent; during the desorption process, the solution was heated to 90°C and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.2 L / min, and desorption was completed in about 20 minutes, with a desorption rate of >95%.

[0055] It can be seen from Examples 1-1 to 1-4 that: 2 Flow rate 0.25-0.47L / min, N 2 The flow rate is 3.1-3.3L / min, and the absorption temperature is 40-60℃. 2 Saturation is reached within 25 minutes, and the saturation absorption capacity is greater than 3.0 mol CO 2 / L solvent; at the decomposition temperature of 90-110℃, N 2 The desorption of carbon dioxide gas was completed in about 20 minutes at a flow rate of 1.2-1.5 L / min, and the desorption rate was >95%.

[0056] Example 2

[0057] Add 100g of ether-containing polycyclic amine② and 50g of 2-pyrrolidone into the phase equilibrium device, stir and mix at 50℃ for 8h to obtain a low eutectic solvent. Set the absorption temperature to 40℃, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 20 minutes, with a saturated absorption capacity of 3.6 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 18 minutes, with a desorption rate of >95%.

[0058] Example 3

[0059] Add 100g of ether-containing polycyclic amine ③ and 50g of 2-pyrrolidone into the phase equilibrium device, stir and mix at 50℃ for 8h to obtain a low eutectic solvent. Set the absorption temperature to 40℃, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 18 minutes, with a saturation absorption of 3.4 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 16 minutes, with a desorption rate of >95%.

[0060] Example 4

[0061] Add 50g of N-aminopropylmorpholine①, 50g of tetrafluoroborate of ether-containing polycyclic amine (3) and 50g of 2-pyrrolidone into a phase equilibrium apparatus and stir and mix at 50℃ for 8h to obtain a low eutectic solvent. Set the absorption temperature to 40℃, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 20 minutes, with a saturation absorption of 4.1 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 20 minutes, with a desorption rate of >95%.

[0062] Example 5

[0063] Add 100g of ether-containing polycyclic amine④ and 50g of 2-pyrrolidone into the phase equilibrium device, stir and mix at 50℃ for 8h to obtain a low eutectic solvent. Set the absorption temperature to 40℃, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 20 minutes, with a saturated absorption capacity of 3.65 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 20 minutes, with a desorption rate of >95%.

[0064] Example 6

[0065] Add 100g of ether-containing polycyclic amine⑤ and 50g of 2-pyrrolidone into the phase equilibrium device, stir and mix at 50℃ for 8h to obtain a low eutectic solvent. Set the absorption temperature to 40℃, CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 20 minutes, with a saturated absorption capacity of 3.6 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 18 minutes, with a desorption rate of >95%.

[0066] Example 7

[0067] 100 g of N-butyl-N-aminopropylmorpholine bistrifluoromethanesulfonyl imide salt (2) and 50 g of 2-pyrrolidone were added to a phase equilibrium apparatus and stirred at 50 °C for 8 h to obtain a low eutectic solvent. The absorption temperature was set at 40 °C and CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration is about 14%, and it reaches saturation in about 20 minutes. The saturation absorption capacity is 4 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 18 minutes, with a desorption rate of >95%.

[0068] It can be seen from Examples 1 to 7 that by providing an ether-containing polycyclic amine as a hydrogen bond donor and pyrrolidone as a hydrogen bond acceptor, a CO absorbing 2 A low eutectic solvent, such as Example 1-6, or by providing a nitrogen cation containing an ether group polycyclic ring in a functional ionic liquid as a hydrogen bond donor, X in the functional ionic liquid - is a hydrogen bond acceptor, and the addition of ketones, such as Example 7, increases CO 2 The absorption capacity of CO 2 The absorption mass transfer efficiency is higher. 2 Saturation is reached within 25 minutes, and the saturation absorption capacity is greater than 3.0 mol CO 2 / L solvent; desorption was completed in about 20 minutes, and the desorption rate was >95%.

[0069] Comparative Example 1

[0070] Add 150 g of 30% ethanolamine solution into the phase equilibrium device and stir at 50 °C for 8 h to obtain a low eutectic solvent. Set the absorption temperature to 40 °C and CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration was about 14%, and it reached saturation in about 35 minutes, with a saturation absorption of 2.46 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 30 minutes, with a desorption rate of 88%.

[0071] Comparative Example 2

[0072] Add 150 g of N-butyl-N-aminopropylmorpholine acetate to the phase balance device and stir at 50 °C for 8 h to obtain a low eutectic solvent. Set the absorption temperature to 40 °C and CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration is about 14%, and it reaches saturation in about 35 minutes. The saturation absorption capacity is 5 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 50 min, with a desorption rate of 80%.

[0073] Comparative Example 3

[0074] Add 150 g of 2-pyrrolidone into the phase balance device and stir at 50 °C for 8 h to obtain a low eutectic solvent. Set the absorption temperature to 40 °C and CO 2 Flow rate 0.47L / min, N 2 Flow rate 3.1L / min, stirring speed 300r / min, CO 2 The concentration is about 14%, and it reaches saturation in about 10 minutes. The saturation absorption capacity is 0.05 mol CO 2 / L solvent; during the desorption process, the solution was heated to 100℃ and kept at a constant temperature, with the rotation speed unchanged, N 2 The flow rate was set at 1.5 L / min, and desorption was completed in about 10 minutes, with a desorption rate of 100%.

[0075] In Comparative Example 1, since ethanolamine is a straight-chain amine, CO 2 The time to reach saturation increases, the absorption amount decreases, and the desorption time increases, and the desorption rate decreases. In Comparative Example 2, only functional ionic liquids are used, the desorption time increases significantly, the desorption rate decreases significantly, and the recycling effect is poor. In Comparative Example 3, only ketone CO 2 The absorption capacity is significantly reduced, and it is unable to solve the problem of absorbing CO 2 problem.

[0076] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A low eutectic solvent for absorbing carbon dioxide, characterized in that: The deep eutectic solvent comprises a hydrogen bond donor component and a ketone component; The ketone component is selected from 2-pyrrolidone and / or N-methylpyrrolidone; The hydrogen bond donor component is selected from an ether-containing polycyclic amine having a structure as shown in formula (I), or a functional ionic liquid having a structure as shown in formula (II), or a mixture thereof: Wherein, G1, G2, G3, G4 and G5 are each independently selected from N or C(R); R, R', R1, R2, R3, R4 and R5 are each independently selected from the following substituted or unsubstituted groups: hydrogen atom, C0-C6 alkylene-amino, C0-C6 alkylene-hydroxyl, C1-C6 alkyl, C1-C6 alkoxy, C0-C6 alkylene-NH-C1-C6 alkyl, C0-C6 alkylene-N(C1-C6 alkyl)2, C1-C6 alkylene-O-C1 -C6 alkyl, or C1-C6 alkylene-O-C0-C6 alkyl-amino; when G1, G2, G3, G4 and G5 are all selected from C(R), at least one of R, R', R1, R2, R3, R4 and R5 is selected from the following substituted or unsubstituted groups: C0-C6 alkylene-amino, C0-C6 alkylene-NH-C1-C6 alkyl, C0-C6 alkylene-N(C1-C6 alkyl)2, or C1-C6 alkylene-O-C0-C6 alkyl-amino; When R, R', R1, R2, R3, R4 and R5 are each independently selected from a substituted group, the substituent is selected from one or more of amino, hydroxyl, C1-C6 alkyl, C1-C6 alkoxy; X - Selected from Cl - Br - ,I - 、BF4 - PF6 - 、NO3 - NTf2 - 、ClO4 - 、HSO3 - 、HSO4 - 、H2PO4 - 、CH3COO - 、CH3(CH2) n COO - 、SCN - 、SbF6 - 、AsF6 - CF3 - CF3COO - 、CH3SO4 - 、C2H6SO4 - 、C8H 17 SO4 - 、C4F9SO3 - CF3(CF2) n SO3 - 、(CF3SO2)3C - 、(C2F5SO2)2N - 、(CF3SO2)2N - 、CH3CH(OH)COO - , dodecyl sulfonate, benzene sulfonate, p-toluene sulfonate or more, wherein n is independently selected from an integer of 0 to 12.

2. The deep eutectic solvent according to claim 1, characterized in that In the formula (I), R, R1, R2, R3, R4 and R5 are each independently selected from -H, -NH2, -CH3, -C2H5, -(CH2)2-CH3, -CH(CH3)2, -(CH2)3-CH3, -CH2-CH(CH3)-CH3, -(CH3)CHCH2CH3, -CH2OH, -OCH3, -OC2H5, -O-(CH2)2-CH3, -CH2-NH2, -(CH2)2-NH2, -(CH2)3-NH2, -NH-CH3, -NH-C2H5, -NH-(CH2)3-CH3, -CH2-O-C H2-NH2, -CH2-O-(CH2)2-NH2, -CH2-OC(CH3)2-NH2, -CH2-O-CH(NH2)2, -(CH2)2-O-NH2, -O-CH2-NH2, -O-(CH2)2-NH2, -NH-CH2-O-CH3, - CH2-NH-O-CH3, -CH(CH2-NH2)2, -CH(OH)-CH2-NH2, -CH(CH2OH)-(CH2)2-NH2, -CH(CH3)-CH2-NH2, -CH(OH)-C(CH3)2-NH2, -CH2-C(CH3) 2-NH2, -CH(CH3)-CH(CH3)-NH2 or -(CH2)2-NH-CH2CH(OCH3)2; when G1, G2, G3, G4 and G5 are all selected from C(R), at least one of R, R1, R2, R3, R4 and R5 is selected from -NH2, -CH2-NH2, -(CH2)2-NH2, -(CH2)3-NH2, -NH-CH3, -NH-C2H5, -NH-(CH2)3-CH3, -CH2-O-CH2-NH2, -CH2-O-(CH2)2-NH2, -CH2-OC(CH3)2-NH2, -CH2-O-C H(NH2)2, -(CH2)2-O-NH2, -O-CH2-NH2, -O-(CH2)2-NH2, -NH-CH2-O-CH3, -CH2-NH-O-CH3, -CH(CH2-NH2)2, -CH(OH)-CH2-NH2, -CH(CH2O H)-(CH2)2-NH2, -CH(CH3)-CH2-NH2, -CH(OH)-C(CH3)2-NH2, -CH2-C(CH3)2-NH2, -CH(CH3)-CH(CH3)-NH2 or -(CH2)2-NH-CH2CH(OCH3)2.

3. The deep eutectic solvent according to claim 1 or 2, characterized in that , the ether-containing polycyclic amine has a structure as shown in the following formula:

4. The deep eutectic solvent according to any one of claims 1 to 3, characterized in that In the formula (II), R, R', R1, R2, R3, R4, and R5 are each independently selected from -H, -NH2, -CH3, -C2H5, -(CH2)2-CH3, -CH(CH3)2, -(CH2)3-CH3, -CH2-CH(CH3)-CH3, -(CH3)CHCH2CH3, -CH2OH, -OCH3, -OC2H5, -O-(CH2)2-CH3, -CH2-NH2, -(CH2)2-NH2, -(CH2)3-NH2, -NH-CH3, -NH-C2H5, -NH-(CH2)3-CH3, -CH2-O-CH2-NH2, -CH2-O-(CH2)2-NH2, -CH2-OC(CH3)2-NH2, -CH 2-O-CH(NH2)2, -(CH2)2-O-NH2, -O-CH2-NH2, -O-(CH2)2-NH2, -NH-CH2-O-CH3, -CH2-NH-O-CH3, -CH(CH2-NH2)2, -CH(OH)-CH2-NH2, -CH(CH2OH)-(CH2)2-NH2, -CH(CH3)-CH2-NH2, -CH(OH)-C(CH3)2-NH2, -CH2-C(CH3)2-NH2, -CH(CH3)-CH(CH3)-NH2 or -(CH2)2-NH-CH2CH(OCH3)2; Preferably, the X - Selected from NTf2 - 、NO3 - 、CH3COO - 、BF4 - One or more of .

5. The deep eutectic solvent according to any one of claims 1 to 4, characterized in that , the functional ionic liquid has a structure as shown in the following formula:

6. The deep eutectic solvent according to any one of claims 1 to 5, characterized in that , in the low eutectic solvent, the mass ratio of the hydrogen bond donor component to the ketone component is (1-10): 1; Preferably, the mass ratio of the hydrogen bond donor component to the ketone component is (1-5):1; More preferably, the mass ratio of the hydrogen bond donor component to the ketone component is (1-3):

1.

7. The deep eutectic solvent according to claim 6, characterized in that When the hydrogen bond donor component is selected from a mixture of the ether-containing polycyclic amine and the functional ionic liquid, the mass ratio of the ether-containing polycyclic amine to the functional ionic liquid is (1-5):1, preferably (1-2):

1.

8. A method for preparing a deep eutectic solvent according to any one of claims 1 to 7, characterized in that: The hydrogen bond donor component and the ketone component are stirred and mixed at 50-80° C. for 5-8 hours to prepare a low eutectic solvent.

9. The low eutectic solvent according to any one of claims 1 to 7 or the low eutectic solvent prepared by the preparation method according to claim 8 is used for the absorption, separation or capture of CO2.

10. The low eutectic solvent according to any one of claims 1 to 7 or the low eutectic solvent prepared by the preparation method according to claim 8, which absorbs CO2 at an absorption temperature of 40-60°C; and releases CO2 at a desorption temperature of 90-110°C.

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