Application of functional group modified nano-microspheres in catalysis of CO2 absorption-desorption of alcohol amine system

Abstract

The invention provides application of functional group modified nano microspheres in catalysis of CO2 absorption-desorption of an alcohol amine system, and belongs to the technical field of CO2 capture. A one-step hydrothermal method is adopted, metal elements are doped into carbon-based nanometer microspheres, then a functional group modifying reagent is used for modifying a metal-doped carbon sphere precursor, and the functional group modified nanometer microspheres are obtained. Through doping of metal elements, active electrons are utilized to promote generation of intermediate products of CO2 absorption and desorption reactions, and modified functional groups are introduced into the nano-microspheres to provide reaction active sites for CO2 absorption or desorption. The functional group modified nano-microspheres are used as a catalyst and used for alcohol amine solution CO2 trapping equipment, the mass transfer process of an alcohol amine solution in the absorption and desorption process can be accelerated, the activation energy and the desorption temperature are reduced, the absorption and desorption rate is increased, and the carbon trapping cost is reduced; and the same catalyst is adopted in the absorption and desorption processes, so that frequent replacement of the catalyst is avoided, and the carbon capture efficiency is favorably improved.

Description

Technical Field

[0001] The invention relates to the technical field of CO2 capture, and in particular to the application of functional group-modified nano-microspheres in catalyzing CO2 absorption-desorption in an alcohol amine system. Background Art

[0002] The large amount of carbon dioxide (CO2) emissions has led to a serious greenhouse effect. Carbon capture is urgent. The CO2 concentration in the flue gas emitted by factories and power plants is low and the total amount is large. Low-concentration CO2 capture technology is of great significance for carbon emission reduction. The ethanolamine (MEA) method is currently the most widely used method in the amine system. MEA is a colorless viscous liquid with an ammonia-like odor. It can be dissolved in water in any proportion. It has strong alkalinity and a fast reaction rate with CO2. It has the characteristics of fast absorption speed and strong absorption capacity. However, its desorption energy consumption is too large, which limits its industrialization to a certain extent. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide the application of functional group-modified nano-microspheres in catalyzing CO2 absorption-desorption of alcohol amine system. The present invention uses functional group-modified nano-microspheres as catalysts to accelerate the mass transfer process of alcohol amine solution in the CO2 absorption and desorption process, reduce the desorption energy consumption, and thus reduce the cost of carbon capture.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides the application of functional group-modified nano-microspheres in catalyzing CO2 absorption-desorption in an alcohol amine system;

[0006] The method for preparing the functional group-modified nanoparticles comprises the following steps:

[0007] (1) mixing a metal source, a sugar carbon source, and a first solvent to obtain a mixed solution; the metal element in the metal source includes one or more of Cu, Ni, and Fe;

[0008] (2) subjecting the mixed solution to a hydrothermal reaction to obtain a metal-doped microsphere precursor after solid-liquid separation;

[0009] (3) mixing the metal-doped microsphere precursor with a functional group modification reagent and a second solvent to perform a functional group doping reaction to obtain functional group-modified nano-microspheres; the functional group modification reagent includes one or more of titanium tetrachloride, sulfuric acid, sodium hydroxyethyl sulfonate, phosphoric acid, nitric acid and hydrochloric acid.

[0010] Preferably, the step (3) is:

[0011] calcining the metal-doped microsphere precursor to obtain a metal-doped porous microsphere precursor;

[0012] The metal-doped porous microsphere precursor is mixed with a functional group modification reagent and a second solvent to perform a functional group doping reaction to obtain functional group-modified porous nano-microspheres;

[0013] The calcination atmosphere includes one or more of an oxidizing atmosphere, a reducing atmosphere and an inert atmosphere;

[0014] The calcination includes one-stage calcination or two-stage calcination; the temperature of the one-stage calcination is 400-800°C, and the insulation time is 2-6h; the two-stage calcination includes a first stage calcination and a second stage calcination performed sequentially; the temperature of the first stage calcination is 200-300°C, and the insulation time is 20-40min; the temperature of the second stage calcination is 450-850°C, and the insulation time is 50-70min.

[0015] Preferably, the method further comprises repeatedly subjecting the metal-doped microsphere precursor to calcination and functional group doping reactions to obtain functional group-modified nano-microspheres having a multi-level pore structure.

[0016] Preferably, the carbohydrate carbon source includes one or more of glucose, fructose and sucrose;

[0017] The mass ratio of the sugar carbon source to the metal source is 4 to 25:1;

[0018] The temperature of the hydrothermal reaction is 150-180° C. and the time is 10-12 hours.

[0019] Preferably, the mass ratio of the metal-doped carbon sphere precursor to the functional group modification reagent is 10:1 to 400;

[0020] The functional group doping reaction time is 15 minutes to 24 hours.

[0021] Preferably, the first solvent is a mixture of water and isopropanol, or a mixture of water and ethanol;

[0022] The volume ratio of water to isopropanol is 90-98:10-2;

[0023] The volume ratio of water to ethanol is 90-98:10-2.

[0024] Preferably, the particle size of the functional group-modified nanospheres is 100-800 nm, and the specific surface area is 200-800 m 2 g -1 .

[0025] Preferably, the pore size of the functional group-modified porous nanospheres is 0.6-1.2 nm.

[0026] Preferably, the application method comprises the following steps:

[0027] The functional group-modified nano-microspheres or the functional group-modified porous nano-microspheres are placed in an alcohol amine solution to sequentially absorb and desorb carbon dioxide.

[0028] Preferably, the mass concentration of the alcoholamine solution is 30%;

[0029] The mass of the functional group-modified nano-microspheres is 0.0375-0.1% of the mass of the alcoholamine solution;

[0030] The mass of the functional group-modified porous nano-microspheres is 0.0375-0.1% of the mass of the alcoholamine solution.

[0031] The present invention provides the application of functional group-modified nano-microspheres in catalyzing CO2 absorption-desorption of alcohol amine system. The present invention adopts a one-step hydrothermal method to dope metal elements (one or more of Cu, Ni and Fe) into carbon-based nano-microspheres, and then uses a functional group modification reagent to modify the metal-doped carbon sphere precursor, introduces sulfate, isethionate, phosphate, nitrate, chloride ion or titanium metal, and obtains functional group-modified nano-microspheres. The present invention can promote the generation of intermediates of CO2 absorption and desorption reactions by using active electrons through the doping of metal elements, and can provide reactive sites for CO2 absorption or desorption by introducing modified functional groups into nano-microspheres. The present invention uses functional group-modified nano-microspheres as catalysts for alcohol amine solution CO2 capture equipment, which can accelerate the mass transfer process of alcohol amine solution in the absorption and desorption process, reduce activation energy and desorption temperature, and increase absorption and desorption rates, thereby reducing carbon capture costs; and the same catalyst is used in both absorption and desorption processes, avoiding frequent replacement of catalysts, which is conducive to improving carbon capture efficiency.

[0032] Furthermore, the present invention adopts a one-step hydrothermal method to dope metal elements into carbon-based nano-microspheres, and then uses a modification reagent to modify the metal-doped carbon sphere precursor, which is simple to operate and low in cost to obtain nano-microspheres modified with metal elements and functional groups. The present invention can regulate the morphology of the obtained carbon spheres by controlling the type of solvent for the hydrothermal reaction. Specifically, when the solvent is water+isopropanol, the obtained metal-doped carbon sphere precursor is a round nano-carbon sphere, and when the solvent is water+ethanol, the obtained metal-doped carbon sphere precursor is a worm-like nano-carbon sphere. These two types of carbon spheres have a large specific surface area, can enhance the CO2 absorption and desorption kinetics, and improve the absorption and desorption rates.

[0033] Furthermore, after obtaining the metal-doped microsphere precursor, the present invention adds a calcination step and then performs a functional group doping reaction, thereby obtaining porous nano-microspheres with rich pore structures and functional group modified porous nano-microspheres; by repeating the calcination-functional group doping reaction process, nano-microspheres with multi-level pore structures are obtained. The rich pore structure / multi-level pore structure can increase the specific surface area of ​​the microspheres, further accelerate the mass transfer process of the alcohol amine solution in the absorption and desorption process, and increase the absorption and desorption rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the infrared spectrum of Ni-C-SO4 obtained in Example 4;

[0035] Figure 2 This is the infrared spectrum of Cu-C-SO3H obtained in Example 5;

[0036] Figure 3 The performance test graphs of carbon dioxide absorption by the blank group, the Cu-C-Ti group obtained in Example 6, the Cu-C-SO4 group obtained in Example 3, the Cu-C-SO3H group obtained in Example 5, the calcined porous Cu-C-SO4 obtained in Example 7, and the calcined porous Cu-C-Ti obtained in Example 8;

[0037] Figure 4 The performance test graphs of carbon dioxide desorption of the blank group, the Cu-C-Ti group obtained in Example 6, the Cu-C-SO4 group obtained in Example 3, the Cu-C-SO3H group obtained in Example 5, the calcined porous Cu-C-SO4 obtained in Example 7, and the calcined porous Cu-C-Ti obtained in Example 8;

[0038] Figure 5 This is the performance test diagram of the blank group, Ni-C group, Ni-C-SO4 group, Ni-C-NO3 group, and Ni-C-Cl group on carbon dioxide absorption;

[0039] Figure 6 This is the performance test chart of the blank group, Ni-C group, Ni-C-SO4 group, Ni-C-NO3 group, and Ni-C-Cl group for carbon dioxide desorption. DETAILED DESCRIPTION

[0040] The present invention provides the application of functional group-modified nano-microspheres in catalyzing CO2 absorption-desorption of an alcohol amine system. In the present invention, the preparation method of the functional group-modified nano-microspheres comprises the following steps:

[0041] (1) mixing a metal source, a sugar carbon source, and a first solvent to obtain a mixed solution; the metal element in the metal source includes one or more of Cu, Ni, and Fe;

[0042] (2) subjecting the mixed solution to a hydrothermal reaction to obtain a metal-doped microsphere precursor after solid-liquid separation;

[0043] (3) mixing the metal-doped microsphere precursor with a functional group modification reagent and a second solvent to perform a functional group doping reaction to obtain functional group-modified nano-microspheres; the functional group modification reagent includes one or more of titanium tetrachloride, sulfuric acid, sodium hydroxyethyl sulfonate, phosphoric acid, nitric acid and hydrochloric acid.

[0044] Unless otherwise specified, the raw materials used in the present invention are all commercially available.

[0045] The present invention mixes a metal source, a sugar carbon source and a first solvent to obtain a mixed solution; the metal elements in the metal source include one or more of Cu, Ni and Fe.

[0046] In the present invention, the metal source is preferably one or more of ferric chloride, cupric acetate, nickel nitrate, copper acetylacetonate, ferric acetylacetonate and nickel acetylacetonate. In the present invention, the carbohydrate carbon source preferably includes one or more of glucose, fructose and sucrose. In the present invention, the mass ratio of the carbohydrate carbon source to the metal source is preferably 4 to 25:1, more preferably 8 to 22.5:1, and further preferably 10 to 15:1.

[0047] In the present invention, the first solvent is preferably a mixture of water and isopropanol, or a mixture of water and ethanol. In the present invention, when the first solvent is a mixture of water and isopropanol, the volume ratio of water to isopropanol is preferably 90-98:10-2, more preferably 92:8. In the present invention, when the first solvent is water+isopropanol, the obtained metal-doped microsphere precursor is a round nano-microsphere.

[0048] In the present invention, when the first solvent is a mixture of water and ethanol, the volume ratio of water to ethanol is preferably 90-98:10-2, more preferably 92:8. In the present invention, when the first solvent is a mixture of water and ethanol, the obtained metal-doped microsphere precursor is a worm-like nano-microsphere.

[0049] In the present invention, the mass ratio of the sugar carbon source to the first solvent is preferably 3-5:100, more preferably 4:100.

[0050] In the present invention, the mixing is preferably carried out in a reactor, and the mixing method is preferably stirring mixing and / or ultrasonic mixing. In the present invention, the stirring rate of the stirring mixing is preferably 300-450r / min, more preferably 350-400r / min, and the time is preferably 10-20min, more preferably 15min. In the present invention, the time of the ultrasonic mixing is preferably 10-20min, more preferably 15min.

[0051] After obtaining the mixed solution, the present invention performs a hydrothermal reaction on the mixed solution, and obtains a metal-doped microsphere precursor after solid-liquid separation.

[0052] In the present invention, the hydrothermal reaction is preferably carried out in a hydrothermal kettle, and the volume of the mixed solution is preferably one-half of the volume of the hydrothermal kettle. In the present invention, the temperature of the hydrothermal reaction is preferably 150-180°C, more preferably 160-170°C; the time is preferably 10-12h, more preferably 11h.

[0053] In the present invention, the solid-liquid separation method is preferably centrifugation, and the centrifugal speed is preferably 8000-11000 r / min, more preferably 10000 r / min; the time is preferably 10-20 min, more preferably 15 min.

[0054] After the solid-liquid separation, the present invention preferably washes, dries and grinds the obtained solid. In the present invention, the washing liquid used for the washing is preferably a mixture of water and ethanol, and the volume ratio of water to ethanol in the mixture is preferably 1:1. In the present invention, the washing method is preferably centrifugal washing, and the number of centrifugal washing is preferably multiple times until the supernatant is clear.

[0055] In the present invention, the drying temperature is preferably 60 to 90° C., more preferably 70 to 80° C., and the drying time is preferably 5 to 10 hours, more preferably 6 to 8 hours. The present invention has no special requirements for the grinding method, and any grinding method known to those skilled in the art can be used.

[0056] After obtaining the metal-doped microsphere precursor, the present invention also preferably calcines the metal-doped microsphere precursor to obtain a metal-doped porous microsphere precursor. In the present invention, the calcination is preferably carried out in a tube furnace, and the calcination atmosphere preferably includes one or more of an oxidizing atmosphere, a reducing atmosphere and an inert atmosphere. In the present invention, the oxidizing atmosphere is preferably air, the reducing atmosphere is preferably hydrogen, and the inert atmosphere is preferably argon. In the present invention, when the calcination atmosphere is a reducing atmosphere and an inert atmosphere, the volume ratio of the reducing atmosphere to the inert atmosphere is preferably 5:95.

[0057] In the present invention, the calcination preferably includes one-stage calcination or two-stage calcination. In the present invention, the temperature of the one-stage calcination is preferably 400-800°C, more preferably 500-700°C; the holding time is preferably 2-6h, more preferably 3-5h. In the present invention, the two-stage calcination preferably includes a first-stage calcination and a second-stage calcination carried out in sequence; the temperature of the first-stage calcination is preferably 200-300°C, more preferably 250°C; the holding time is preferably 20-40min, more preferably 30min; the temperature of the second-stage calcination is preferably 450-850°C, more preferably 650-800°C; the holding time is preferably 50-70min, more preferably 60min. In the present invention, the heating rate of heating to the calcination temperature is preferably 2-7°C / min, more preferably 5°C / min. The present invention can form pores in the metal-doped microsphere precursor through the calcination.

[0058] After obtaining the metal-doped microsphere precursor or the metal-doped porous microsphere precursor, the present invention mixes the metal-doped microsphere precursor or the metal-doped porous microsphere precursor with a functional group modification reagent and a second solvent to perform a functional group doping reaction to obtain functional group-modified nano-microspheres. In the present invention, the functional group modification reagent includes one or more of titanium tetrachloride, sulfuric acid, sodium isethionate, phosphoric acid, nitric acid and hydrochloric acid.

[0059] In the present invention, the mass ratio of the metal-doped carbon sphere precursor to the functional group modification agent is preferably 10:1 to 400, more preferably 10:10 to 300, and further preferably 10:100 to 200. When the metal-doped carbon sphere precursor is calcined before the functional group doping reaction, the mass ratio of the metal-doped porous microsphere precursor obtained by calcination to the functional group modification agent is preferably 10:1 to 400, more preferably 10:100 to 300.

[0060] In the present invention, the second solvent is preferably water and / or ethanol. The present invention has no special requirements for the mixing method, and any mixing method known in the art can be used, such as stirring and mixing.

[0061] In the present invention, the temperature of the functional group doping reaction is preferably room temperature, and the time is preferably 15 min to 24 h, more preferably 8 h to 20 h, and further preferably 10 h to 16 h.

[0062] After the functional group doping reaction, the present invention preferably performs post-treatment on the obtained functional group doping reaction product, and the post-treatment preferably includes the following steps:

[0063] The obtained functional group doping reaction product is subjected to solid-liquid separation, and the obtained solid is washed, dried and ground.

[0064] In the present invention, the solid-liquid separation method is preferably centrifugation, and the centrifugal speed is preferably 8000-11000r / min, more preferably 10000r / min; the time is preferably 10-20min, more preferably 15min. In the present invention, the washing liquid used for washing is preferably a mixture of water and ethanol, and the volume ratio of water to ethanol in the mixture is preferably 1:1. In the present invention, the washing method is preferably centrifugal washing, and the number of centrifugal washings is preferably multiple times until the supernatant is clear. In the present invention, the drying temperature is preferably 80°C, and the time is preferably 6h. The present invention has no special requirements for the grinding method, and the grinding method familiar to those skilled in the art can be used.

[0065] The present invention also preferably includes repeatedly performing calcination and functional group doping reaction on the metal-doped microsphere precursor to obtain functional group-modified nano-microspheres with a multi-level pore structure. In the present invention, the number of repetitions is preferably 2 times.

[0066] In the present invention, the particle size of the functional group-modified nanospheres is 100 to 800 nm, more preferably 200 to 500 nm; the specific surface area is preferably 200 to 800 m 2 g -1 , more preferably 400 to 600 m 2 g -1 .

[0067] In the present invention, the pore size of the functional group-modified porous nanospheres is preferably 0.6 to 1.2 nm, more preferably 0.8 to 1 nm.

[0068] In the present invention, the chemical composition of the functional group-modified nanospheres or the functional group-modified porous nanospheres is expressed as MCX, wherein M is one or more of Cu, Ni and Fe, C represents nanospheres, and X represents one or more of sulfate, isethionate, phosphate, nitrate, -Cl and Ti.

[0069] In the present invention, the application method preferably comprises the following steps:

[0070] The functional group-modified nano-microspheres or the functional group-modified porous nano-microspheres are placed in an alcohol amine solution to sequentially absorb and desorb carbon dioxide.

[0071] In the present invention, the mass concentration of the alcoholamine solution is preferably 30%;

[0072] The mass of the functional group-modified nanospheres is preferably 0.0375-0.1% of the mass of the alcoholamine solution, more preferably 0.075%; the mass of the functional group-modified porous nanospheres is preferably 0.0375-0.1% of the mass of the alcoholamine solution, more preferably 0.075%.

[0073] In the present invention, the flow rate of the carbon dioxide is preferably 100 to 200 sccm.

[0074] The application of the functional group-modified nano-microspheres provided by the present invention in catalyzing CO2 absorption-desorption in an alcohol amine system is described in detail below in conjunction with the examples, but they should not be construed as limiting the scope of protection of the present invention.

[0075] Example 1

[0076] The preparation method of the functional group-modified nano-microspheres Fe-C-SO4 is carried out by the following steps:

[0077] ① Weigh 0.883g of ferric acetylacetonate and 4.5g of glucose, and then dissolve them in a mixed solution of 92:8 = water: isopropanol, with a volume of 102.19mL, and dissolve them into a uniform mixed solution by stirring (350r / min, 15min) and ultrasonication (15min);

[0078] ② Add the obtained mixed solution to the hydrothermal kettle, add half the volume of the kettle, place the hydrothermal kettle in a drying oven and heat at 180℃ for 12h;

[0079] ③ The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain Fe-doped carbon sphere precursor (Fe-C) and grinded;

[0080] ④ Weigh 100 mg of Fe-C, 20 mL of water, 20 mL of anhydrous ethanol, and 3.14 g of dilute sulfuric acid, stir and mix at room temperature for 4 h, and then carry out the centrifugation, washing, and drying process in step ③ to obtain Fe-C-SO4.

[0081] Example 2

[0082] The preparation method of worm-like nano-microspheres Fe-C-SO4 adopts the following steps:

[0083] ① Weigh 0.883g of ferric acetylacetonate and 4.5g of glucose, and then dissolve them in a mixed solution of 92:8 = water:ethanol, with a volume of 102.19mL, and dissolve them into a uniform mixed solution by stirring (350r / min, 15min) and ultrasonication (15min);

[0084] ② Add the obtained mixed solution to the hydrothermal kettle, add half the volume of the kettle, place the hydrothermal kettle in a drying oven and heat at 180℃ for 12h;

[0085] ③ The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain Fe-doped carbon sphere precursor (Fe-C) and grinded;

[0086] ④ Weigh 100 mg of Fe-C, 20 mL of water, 20 mL of anhydrous ethanol, and 3.95 g of dilute sulfuric acid, stir and mix at room temperature for 4 h, and then carry out the centrifugation, washing, and drying process in step ③ to obtain Fe-C-SO4.

[0087] Example 3

[0088] The preparation method of functional group-modified nano-microspheres Cu-C-SO4 adopts the following steps:

[0089] ① Weigh 0.654g copper acetylacetonate and 4.5g glucose, and then dissolve them in a mixed solution of 92:8 = water:ethanol, with a volume of 100, and dissolve them into a uniform mixed solution by stirring (450r / min, 15min) and ultrasonication (15min);

[0090] ② Add the obtained mixed solution to the hydrothermal kettle, add half the volume of the kettle, place the hydrothermal kettle in a drying oven and heat at 180℃ for 12h;

[0091] ③ The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Cu-doped carbon sphere precursor (Cu-C) and grinded;

[0092] ④ Weigh 100 mg of Cu-C, 20 mL of water, 20 mL of anhydrous ethanol, and 3.95 g of dilute sulfuric acid, stir and mix at room temperature for 4 h, and then carry out the centrifugation, washing, and drying process in step ③ to obtain Cu-C-SO4.

[0093] Example 4

[0094] The preparation method of functional group-modified nano-microsphere Ni-C-SO4 adopts the following steps:

[0095] ① Weigh 0.642g nickel acetylacetonate and 4.5g glucose, and then dissolve them in a mixed solution of 92:8 = water: ethanol, with a volume of 100mL, and dissolve them into a uniform mixed solution by stirring (400r / min, 15min) and ultrasonication (10min);

[0096] ② Add the obtained mixed solution to the hydrothermal kettle, add half the volume of the kettle, place the hydrothermal kettle in a drying oven and heat at 180℃ for 12h;

[0097] ③ The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Ni-doped carbon sphere precursor (Ni-C) and grinded;

[0098] ④ Weigh 100 mg of Ni-C, 20 mL of water, 20 mL of anhydrous ethanol, and 3.95 g of dilute sulfuric acid, stir and mix at room temperature for 4 h, and then carry out the centrifugation, washing, and drying process in step ③ to obtain Ni-C-SO4.

[0099] The infrared spectrum of the obtained Ni-C-SO4 is as follows Figure 1 As shown by Figure 1 It can be seen that Ni-C-SO4 contains O=S=O functional groups, indicating that the functional group modification reagent (dilute sulfuric acid) is successfully loaded.

[0100] Example 5

[0101] The preparation method of functional group-modified nano-microspheres Cu-C-SO3H comprises the following steps:

[0102] ① Weigh 0.654g copper acetylacetonate and 4.5g glucose, and then dissolve them in a mixed solution of 92:8 = water: ethanol, with a volume of 100mL, and dissolve them into a uniform mixed solution by stirring (350r / min, 15min) and ultrasonication (15min);

[0103] ② Add the obtained mixed solution to the hydrothermal kettle, add half the volume of the kettle, place the hydrothermal kettle in a drying oven and heat at 180℃ for 12h;

[0104] ③ The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Cu-doped carbon sphere precursor (Cu-C) and grinded;

[0105] ④ Weigh 100 mg of Cu-C, 20 mL of water, 20 mL of anhydrous ethanol, and 1.5 g of sodium hydroxyethyl sulfonate, stir and mix at room temperature for 4 h, and then carry out the centrifugation, washing, and drying process in step ③ to obtain Cu-C-SO3H.

[0106] The infrared spectrum of the obtained Cu-C-SO3H is as follows Figure 2 As shown by Figure 2 It can be seen that Cu-C-SO3H contains O=S=O functional groups, indicating that the functional group modification reagent (sodium isethionate) is successfully loaded.

[0107] Example 6

[0108] The preparation method of functional group-modified Cu-C-Ti nano-microspheres comprises the following steps:

[0109] ① Weigh 0.654g copper acetylacetonate and 4.5g glucose, and then dissolve them in a mixed solution of 92:8 = water: ethanol, with a volume of 100mL, and dissolve them into a uniform mixed solution by stirring (350r / min, 15min) and ultrasonication (15min);

[0110] ② Add the obtained mixed solution to the hydrothermal kettle, add half the volume of the kettle, place the hydrothermal kettle in a drying oven and heat at 180℃ for 12h;

[0111] ③ The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Cu-doped carbon sphere precursor (Cu-C) and grinded;

[0112] ④ Weigh 100 mg of Cu-C, 20 mL of water, 20 mL of anhydrous ethanol, and 0.012 g of titanium tetrachloride, stir and mix at room temperature for 4 h, and then perform the centrifugation, washing, and drying process in step ③ to obtain Cu-C-Ti.

[0113] Example 7

[0114] The preparation method of the functional group-modified porous nano-microspheres Cu-C-SO4 comprises the following steps:

[0115] Compared with Example 3, a tubular furnace calcination step is added before the functional group doping step to obtain calcined functional group-modified porous nano-microspheres Cu-C-SO4.

[0116] The tubular furnace calcination steps are as follows: put the Cu-doped carbon ball precursor Cu-C into a porcelain boat, seal the tubular furnace tightly, then introduce Ar-H2 (H2 volume ratio is 5%, Ar volume ratio is 95%), set the temperature to 500°C, calcine for 2h, and the heating rate is 5°C / min.

[0117] Example 8

[0118] The method for preparing the functional group-modified porous nano-microspheres Cu-C-Ti comprises the following steps:

[0119] Compared with Example 6, a tubular furnace calcination step is added before the functional group doping step to obtain calcined functional group-modified porous nano-microspheres Cu-C-Ti.

[0120] The tubular furnace calcination steps are as follows: put the Cu-doped carbon ball precursor Cu-C into a porcelain boat, seal the tubular furnace tightly, then introduce Ar-H2 (H2 ratio is 5%, Ar ratio is 95%), set the temperature to 500°C, calcine for 2h, and the heating rate is 5°C / min.

[0121] Example 9

[0122] The method for preparing the functional group-modified porous nano-microsphere Ni-C-Cl comprises the following steps:

[0123] ① Dissolve 2.7 g of glucose and 0.12 g of Ni(NO3)2·6H2O in 60 mL of water / ethanol (volume ratio of 29 / 1) solution, mix them evenly using an ultrasonic device, and pour them into a hydrothermal reactor. Then place the reactor in a forced air drying oven for hydrothermal reaction at 180°C for 6 h.

[0124] ② The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water mixed in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Ni-doped carbon sphere precursor (Ni-C) and grinded;

[0125] ③ Place the ground Ni-C into a tubular furnace, introduce an Ar / H2 atmosphere (H2 volume ratio is 5%, Ar volume ratio is 95%, flow rate is 80mL / min), and use a two-stage heating method to prepare the catalyst (the first stage of the tubular furnace is heated to 250°C, the holding time is 30min, the second stage is heated to 450°C, the holding time is 60min, and the heating rate is 5°C / min). Then, 100 mg of the calcined sample was mixed with 10 mL of water, 10 mL of ethanol, and 300 mg of a hydrochloric acid solution with a molar concentration of 2 mol / L and stirred at room temperature for 15 min to perform a functional group doping reaction. The system after the functional group doping reaction was placed in a centrifuge and centrifuged for 15 min at a speed of 10000 r / min. The supernatant was then removed, and the precipitate was repeatedly washed with a solution mixed with ethanol and water in a ratio of 1:1, centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven, dried at 80°C for 8 h, and ground into a sample to obtain porous nano-microspheres Ni-C-Cl.

[0126] Example 10

[0127] The preparation method of functional group-modified porous nano-microspheres Ni-C-SO4 adopts the following steps:

[0128] ① Dissolve 2.7 g of glucose and 0.12 g of Ni(NO3)2·6H2O in 60 mL of water / ethanol (volume ratio of 29 / 1) solution, mix them evenly using an ultrasonic device, and pour them into a hydrothermal reactor. Then place the reactor in a forced air drying oven for hydrothermal reaction at 180°C for 6 h.

[0129] ② The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water mixed in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Ni-doped carbon sphere precursor (Ni-C) and grinded;

[0130] ③ The ground Ni-C was placed in a tubular furnace, and an Ar / H2 atmosphere (H2 volume ratio of 5%, Ar volume ratio of 95%, flow rate of 80mL / min) was introduced to prepare the catalyst by two-stage heating (the first stage of the tubular furnace was heated to 250°C, the insulation time was 30min, the second stage was heated to 450°C, the insulation time was 60min, and the heating rate was 5°C / min). Then 100mg of the calcined sample was mixed with 10mL of water, 10mL of ethanol, and 400mg of a 2mol / L sulfuric acid solution and stirred for 30min for functional group doping reaction. The system after functional group doping reaction was placed in a centrifuge for 15min at a speed of 10000r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water mixed in a ratio of 1:1, centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven, dried at 80°C for 8h, ground into a sample, and porous nanospheres Ni-C-SO4 were obtained.

[0131] Embodiment 11

[0132] The preparation method of the functional group-modified porous nano-microsphere Ni-C-NO3 adopts the following steps:

[0133] ① Dissolve 2.7 g of glucose and 0.12 g of Ni(NO3)2·6H2O in 60 mL of water / ethanol (volume ratio of 29 / 1) solution, mix them evenly using an ultrasonic device, and pour them into a hydrothermal reactor. Then place the reactor in a forced air drying oven for hydrothermal reaction at 180°C for 6 h.

[0134] ② The obtained hydrothermal reaction liquid was placed in a centrifuge and centrifuged for 15 minutes at a speed of 10000 r / min, and then the supernatant was removed, and the precipitate was repeatedly washed with a solution of ethanol and water mixed in a ratio of 1:1, and centrifuged until the supernatant was clear, and then the obtained solid was placed in an oven and dried at 80°C for 6 hours to obtain a Ni-doped carbon sphere precursor (Ni-C) and grinded;

[0135] ③ Place the ground Ni-C into a tubular furnace, introduce an Ar / H2 atmosphere (H2 volume ratio is 5%, Ar volume ratio is 95%, flow rate is 80mL / min), and use a two-stage heating method to prepare the catalyst (the first stage of the tubular furnace is heated to 250°C, and the holding time is 30min; the second stage is heated to 450°C, 650°C, or 850°C, and the holding time is 60min. The heating rate is 5°C / min). Then, 100 mg of the calcined sample was mixed with 10 mL of water, 10 mL of ethanol, and 400 mg of a 2 mol / L nitric acid solution and stirred for 30 min for a functional group doping reaction. The system after the functional group doping reaction was placed in a centrifuge and centrifuged for 15 min at a speed of 10,000 r / min. The supernatant was then removed, and the precipitate was repeatedly washed with a solution mixed with ethanol and water in a ratio of 1:1, and centrifuged until the supernatant was clear. The resulting solid was then placed in an oven, dried at 80°C for 8 h, and ground into a sample to obtain porous nanospheres Ni-C-NO3.

[0136] Comparative Example 1

[0137] Compared with Example 5, copper acetylacetonate was not added during the hydrothermal reaction, and the remaining operations were the same to obtain C-SO3H.

[0138] Comparative Example 2

[0139] Compared with Example 5, the step of adding sodium isethionate was omitted to obtain Cu-C.

[0140] Performance Testing

[0141] The operation process of absorbing and desorbing CO2 with amine solution is as follows:

[0142] Prepare a 30wt% alcohol amine (MEA) solution, add 0.075wt% of the carbon ball material obtained in the embodiment or comparative example, put the solution into a beaker and stir evenly, pour the liquid into a three-necked flask after the ventilation with the instrument device is stable, turn on the CO2 analyzer for analysis, turn off the analyzer after the solution is fully absorbed, put the three-necked flask that has absorbed CO2 directly into a heated (90°C) desorption water bath, turn on the CO2 analyzer again, and turn off the analyzer after all desorption is completed. The data is processed using origin software.

[0143] In the following tests, the blank group is a control group in which no catalyst is added to MEA.

[0144] ① The performance test diagram of carbon dioxide absorption by the blank group, the Cu-C-Ti group obtained in Example 6, the Cu-C-SO4 group obtained in Example 3, the Cu-C-SO3H group obtained in Example 5, the calcined porous Cu-C-SO4 obtained in Example 7, and the calcined porous Cu-C-Ti obtained in Example 8 is shown in the figure Figure 3 As shown. Figure 3 It can be seen that compared with the blank group, the other groups have a certain promoting effect on the CO2 absorption process, among which the Cu-C-SO4 group has the best effect.

[0145] ② The performance test diagram of carbon dioxide desorption of the blank group, the Cu-C-Ti group obtained in Example 6, the Cu-C-SO4 group obtained in Example 3, the Cu-C-SO3H group obtained in Example 5, the calcined porous Cu-C-SO4 obtained in Example 7, and the calcined porous Cu-C-Ti obtained in Example 8 is shown in the figure Figure 4 As shown. Figure 4 It can be seen that compared with the blank group, the functional group-modified nano-microspheres obtained in the present invention have a certain promoting effect on the CO2 desorption process, among which the Cu-C-SO4 group has the best effect.

[0146] ③The performance test diagram of carbon dioxide absorption of the blank group, Ni-C group, Ni-C-SO4 group, Ni-C-NO3 group and Ni-C-Cl group is shown in the figure Figure 5 As shown. Figure 5 It can be seen that compared with the blank group, the Ni-C group, Ni-C-SO4 group, Ni-C-NO3 group and Ni-C-Cl group all have a certain promoting effect on the CO2 absorption process.

[0147] ④The performance test diagram of carbon dioxide desorption of the blank group, Ni-C group, Ni-C-SO4 group, Ni-C-NO3 group and Ni-C-Cl group is shown in the figure Figure 6 As shown. Figure 6 It can be seen that compared with the blank group, the Ni-C group, Ni-C-SO4 group, Ni-C-NO3 group and Ni-C-Cl group all have a certain promoting effect on the CO2 desorption process.

[0148] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of functional group-modified nanoparticles in catalytic CO2 absorption-desorption of alcoholamine system; The method for preparing the functional group-modified nanoparticles comprises the following steps: (1) mixing a metal source, a sugar carbon source, and a first solvent to obtain a mixed solution; the metal element in the metal source includes one or more of Cu, Ni, and Fe; (2) subjecting the mixed solution to a hydrothermal reaction to obtain a metal-doped microsphere precursor after solid-liquid separation; (3) mixing the metal-doped microsphere precursor with a functional group modification reagent and a second solvent to perform a functional group doping reaction to obtain functional group-modified nano-microspheres; the functional group modification reagent includes one or more of titanium tetrachloride, sulfuric acid, sodium hydroxyethyl sulfonate, phosphoric acid, nitric acid and hydrochloric acid.

2. The use according to claim 1, characterized in that: The step (3) is: calcining the metal-doped microsphere precursor to obtain a metal-doped porous microsphere precursor; The metal-doped porous microsphere precursor is mixed with a functional group modification reagent and a second solvent to perform a functional group doping reaction to obtain functional group-modified porous nano-microspheres; The calcination atmosphere includes one or more of an oxidizing atmosphere, a reducing atmosphere and an inert atmosphere; The calcination includes one-stage calcination or two-stage calcination; the temperature of the one-stage calcination is 400-800°C, and the insulation time is 2-6h; the two-stage calcination includes a first stage calcination and a second stage calcination performed sequentially; the temperature of the first stage calcination is 200-300°C, and the insulation time is 20-40min; the temperature of the second stage calcination is 450-850°C, and the insulation time is 50-70min.

3. The use according to claim 2, characterized in that: The method also includes repeatedly performing calcination and functional group doping reaction on the metal-doped microsphere precursor to obtain functional group-modified nano-microspheres with a multi-level pore structure.

4. The use according to claim 1 or 2, characterized in that: The sugar carbon source includes one or more of glucose, fructose and sucrose; The mass ratio of the sugar carbon source to the metal source is 4 to 25:1; The temperature of the hydrothermal reaction is 150-180° C. and the time is 10-12 hours.

5. The use according to claim 1 or 2, characterized in that: The mass ratio of the metal-doped carbon sphere precursor to the functional group modification reagent is 10:1 to 400; The functional group doping reaction time is 15 minutes to 24 hours.

6. The use according to claim 1 or 2, characterized in that: The first solvent is a mixture of water and isopropanol, or a mixture of water and ethanol; The volume ratio of water to isopropanol is 90-98:10-2; The volume ratio of water to ethanol is 90-98:10-2.

7. The use according to claim 1, characterized in that: The particle size of the functional group-modified nanospheres is 100-800 nm, and the specific surface area is 200-800 m 2 g -1 .

8. The use according to claim 2, characterized in that: The pore size of the functional group-modified porous nano-microspheres is 0.6-1.2 nm.

9. The use according to claim 1 or 2, characterized in that: The application method comprises the following steps: The functional group-modified nano-microspheres or the functional group-modified porous nano-microspheres are placed in an alcohol amine solution to sequentially absorb and desorb carbon dioxide.

10. The use according to claim 9, characterized in that: The mass concentration of the alcoholamine solution is 30%; The mass of the functional group-modified nano-microspheres is 0.0375-0.1% of the mass of the alcoholamine solution; The mass of the functional group-modified porous nano-microspheres is 0.0375-0.1% of the mass of the alcoholamine solution.

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