A solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution.

Abstract

The application discloses a solid catalyst for desorption reaction after CO2 absorption of a composite amine solution, and HZSM-5 molecular sieve and gamma-Al2O3 are used as a composite carrier in a mass ratio of 7:3-9:1, and active metal oxides or / and acid catalytic metal salts are loaded on the composite carrier; the active metal oxides are one or more of NiO, CuO and MoO3, and the mass percentage content of the active metal oxides in the solid catalyst is 5%-8%; the acid catalytic metal salts are one or more of NiCl2 and CuSO4, and the mass percentage content of the acid catalytic metal salts in the solid catalyst is 3%-10%; and the porosity of the solid catalyst is 15%-20%. The solid catalyst can reduce the desorption temperature of the CO2 desorption process of the composite amine solution and greatly shorten the desorption time.

Description

Technical Field

[0001] This invention belongs to the field of solid catalyst technology, and mainly relates to a solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution and its preparation method. Background Technology

[0002] Commonly used amine-based CO2 chemical absorbents serve as essential solvents in carbon capture systems, primarily functioning to adsorb and desorb CO2. This process requires heating to desorb the CO2. Taking industrially used ethanolamine as an example, its CO2 absorption reaction rate constant k... + (Approximately 8000 L / mol·s) is the rate constant k for the CO2 desorption reaction. - The desorption rate is more than 200 times that of amines (approximately 35 L / mol·s), requiring a large amount of energy to promote amine desorption. At the same time, excessively high temperatures (approximately 120°C) will accelerate the oxidative and thermal degradation of amines, shortening the lifespan of amine absorbents.

[0003] The essence of CO2 desorption from a complex amine solution is the degradation of carbamates and protonated amines generated during absorption. This process mainly involves: 1. the decomposition of carbamates, products of CO2 capture by the amine solution; 2. the release of MEAH in the reaction system. + The deprotonation process.

[0004] Acidic solid catalysts are substances that play a crucial role in the desorption process of carbon removal absorbents. They possess specific chemical compositions and structures that accelerate the desorption reaction after CO2 adsorption by the carbon removal absorbent, improving the reaction rate and efficiency. These catalysts typically exist in solid form, exhibiting high stability and selectivity, and possessing numerous acidic active sites. They reduce the heat load of the desorption reaction after CO2 adsorption by the carbon removal absorbent, allowing the desorption reaction to occur at lower desorption temperatures. This results in a decrease in the oxidative degradation rate of the carbon removal absorbent and an acceleration of the desorption rate and amount.

[0005] This invention uses HASM-5-Al2O3 as a carrier, adds auxiliary catalytic substances and related promoters to form a catalytic system, and prepares an acidic solid catalyst through certain means, which can accelerate the CO2 desorption rate and reduce the CO2 desorption temperature. Summary of the Invention

[0006] The purpose of this invention is to provide a solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution and its preparation method. Using HASM-5-Al2O3 as a composite support, metal oxides and acidic catalytic metal salts with relevant catalytic effects are added as auxiliary catalysts, and pore-expanding agents and other auxiliaries are added to form a related acidic porous solid catalyst. This can accelerate the desorption reaction rate of the composite amine solution as a decarbonization absorbent solution and reduce the desorption temperature.

[0007] The technical solution of the present invention is as follows:

[0008] A solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution is disclosed, comprising HZSM-5 molecular sieve γ-Al2O3 in a mass ratio of 7:3 to 9:1 as a composite support, wherein an active metal oxide and / or an acidic catalytic metal salt are loaded onto the composite support; the active metal oxide is one or more of NiO, CuO, and MoO3, and its mass percentage in the solid catalyst is 5% to 8%; the acidic catalytic metal salt is one or more of NiCl2 and CuSO4, and its mass percentage in the solid catalyst is 3% to 10%; the porosity of the solid catalyst is 15% to 20%.

[0009] The present invention discloses a method for preparing a solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution, comprising the following steps:

[0010] (1) Add HZSM-5 molecular sieve powder and γ-Al2O3 powder to a ball mill at a mass ratio of 7:3 to 9:1 and grind and mix thoroughly; then add magnesium stearate and grind and mix thoroughly to obtain composite carrier powder;

[0011] (2) The composite carrier powder and the catalyst are mixed at a mass ratio of (6-9):1, and then added to a ball mill to grind the powder thoroughly to obtain a mixed powder of carrier and catalyst.

[0012] (3) Add solid binder and pore-forming agent to the mixed powder of carrier and catalyst, and mix at a rate of 150-300 r / min for 10-15 h to obtain a mixture;

[0013] (4) Add the liquid adhesive to the mixture in step (3) in a spray form to obtain the adhesive material;

[0014] (5) Add the adhesive material into the mold and press it into a blank using an infrared tablet press. After demolding, place the blank in an oven to dry.

[0015] (6) The raw embryo is sent into a muffle furnace for calcination at a temperature of 500-600℃ and a holding time of 5-8h. After the holding time is completed, it is cooled naturally and then taken out of the furnace to obtain a solid catalyst for the desorption reaction of CO2 after absorption by the composite amine solution.

[0016] The catalyst is an active metal oxide NiO, CuO, or MoO3, or an acidic catalytic metal salt of one or more of NiCl2 and CuSO4.

[0017] Preferably, in step (1), the amount of magnesium stearate added is 9% to 11% of the total mass of the mixed powder of HZSM-5 molecular sieve powder and γ-Al2O3; after adding magnesium stearate, the powder is ground and mixed at a speed of 150 to 200 r / min for 2 to 4 hours.

[0018] Preferably, in step (2), the composite support powder and the catalyst are ground and mixed at a rate of 150-250 r / min for 3-5 h to obtain a mixed powder of support and catalyst.

[0019] Preferably, in step (3), the solid binder is kaolin powder and / or boehmite powder; the amount of solid binder added does not exceed 40% of the total mass of the mixed powder of the carrier and the catalyst, nor is it less than 10% of the total mass of the mixed powder.

[0020] Preferably, in step (3), the pore-forming agent is a mixture of acrylic resin and guar gum powder in a mass ratio of 3:7 to 1:9; the vaporization temperature of the pore-forming agent is required to be no more than 90% of the calcination temperature of the solid catalyst; the amount of the pore-forming agent added is 2% to 5.5% of the total mass of the mixed powder of the carrier and catalyst and the solid binder.

[0021] Preferably, in step (4), the liquid binder has a liquid-to-solid ratio of 10% to 15% with respect to the mixture in step (3); the liquid binder is a nano-aluminum sol solution and / or a nano-silica sol solution with a mass concentration of 6% to 12%.

[0022] Preferably, in step (5), the pressure of the mold is 5-10 MPa; after the unmolded embryo is removed from the mold, it is placed in an oven at 100-120°C and dried for 12-24 hours.

[0023] In step (6), in order to ensure the porosity and pore size of the solid catalyst, the heating rate of the muffle furnace is 1 to 1.5 °C / min.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] This invention employs an acidic porous solid catalyst composed of an HZSM-5 and γ-Al2O3 composite support, active metal oxides and acidic active metal salts, a solid binder, a liquid binder, and a pore-forming agent. Leveraging the porous structure of HZSM-5 itself, and with the addition of an appropriate amount of pore-forming agent, the solid catalyst prepared through ball milling and calcination exhibits a dominant microporous structure, thereby increasing the contact area between the solid catalyst and the composite amine solution, enabling rapid catalytic action in the early stages. To further increase the contact area between the catalyst and the composite amine solution, a pore-forming agent is added to the catalytic system to expand the micropores of HZSM-5. Furthermore, gas is generated during calcination to prevent the catalytic material from clogging the pores and causing carbon adsorption. Therefore, the solid catalyst of this invention can lower the desorption temperature of CO2 in the composite amine solution and significantly shorten the desorption time. Attached Figure Description

[0026] Figure 1 This is a microstructure diagram of the solid catalyst in Example 1.

[0027] Figure 2 This is a schematic diagram of a small-scale CO2 adsorption-desorption device. Detailed Implementation

[0028] The following examples illustrate the specific implementation process and effects of the present invention. Those skilled in the art should recognize that these examples are merely illustrative and not intended to limit the invention. Any modifications or variations to the examples within the scope of the present invention are within the scope of the claims.

[0029] Example 1

[0030] A solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution is prepared as follows:

[0031] (1) Add HZSM-5 molecular sieve powder and γ-Al2O3 powder to a ball mill at a mass ratio of 8:2 and grind and mix thoroughly; add magnesium stearate at a mass ratio of 9:1 for the mixed powder of HZSM-5 molecular sieve and γ-Al2O3 to magnesium stearate, and grind and mix the powder at a speed of 150 r / min for 3 h to obtain composite carrier powder;

[0032] (2) The composite carrier powder and the catalyst nickel chloride were mixed at a mass ratio of 9:1 and then added to a ball mill. The mixture was stirred at a speed of 150 r / min for 4 h to obtain a mixed powder of carrier and catalyst.

[0033] (3) Add solid binder kaolin and pore-forming agent to the mixed powder of carrier and catalyst, and mix the powder at a speed of 200 r / min for 15 h to prevent the agglomeration of each component due to uneven mixing during calcination, and obtain a mixture.

[0034] The amount of kaolin added is 40% of the total mass of the mixed powder of carrier and catalyst, and the amount of pore-forming agent added is 5% of the total mass of the mixed powder of carrier and catalyst and solid binder. The pore-forming agent is made by mixing acrylic resin and guar gum powder in a mass ratio of 1:9.

[0035] (4) The liquid binder is added to the mixture in step (3) in a spray form to obtain the adhesive material; the liquid binder is a nano aluminum sol with a mass concentration of 6% and the liquid-solid ratio of the liquid binder to the mixture is 12%;

[0036] (5) Add the adhesive material into the mold and press it into a sheet preform using an infrared tablet press at a pressure of 10 MPa; after demolding, place the preform in an oven and dry it at 120°C for 12 hours.

[0037] (6) The preform was calcined in a muffle furnace at a temperature of 540℃, a heating rate of 1.5℃ / min, and a holding time of 7h. After the holding time, it was allowed to cool naturally, and the solid catalyst for the desorption reaction of CO2 after absorption by the composite amine solution was obtained. The catalyst was then observed under a microscope. Figure 1 .

[0038] Testing revealed that the catalytic metal ion supported on the HZSM-5 molecular sieve and γ-Al2O3 composite support is Ni. + The mass percentage of nickel chloride in the solid catalyst is 5%; the porosity of the solid catalyst is 10%.

[0039] Test Experiment Example 1

[0040] 1. Add the solid catalyst prepared in Example 1 to the following: Figure 2 In the CO2 adsorption-desorption pilot device shown, 200 ml of a mixed compound solution of dihexylethanolamine and hexamethylenediaminetetraacetic acid with a mass ratio of 2:1 was added to the CO2 adsorption-desorption pilot device and weighed; CO2 was introduced into the CO2 adsorption-desorption pilot device for 3 hours, then the CO2 was turned off and weighed again, and the total mass of CO2 absorbed was calculated.

[0041] After absorption is complete, the CO2 adsorption-desorption pilot device is heated using an electric heating mantle until obvious bubbles are generated on the liquid surface. The desorption temperature is then observed and recorded using a digital thermometer.

[0042] After recording, adjust the power to maintain the temperature at the desorption temperature, and record the temperature every 10 minutes. The weight of the flask and the original weight of the flask represent the amount of CO2 desorbed. Calculate the desorption completion time and desorption rate (weight of liquid after desorption / weight of liquid before desorption).

[0043] 2. Perform a blank test without adding a solid catalyst following the steps above.

[0044] Table 1 Comparison of the effects of porous solid catalysts on CO2 desorption

[0045]

[0046] Test Experiment Example 2

[0047] 1. In such Figure 2 Add 200 ml of a mixed compound solution of dihexylethanolamine, hexamethylenediaminetetraacetic acid, and 2-amino-2-methyl-propanol in a mass ratio of 2:1:4 to the CO2 adsorption-desorption small-scale test device shown, and weigh it; introduce CO2 into the CO2 adsorption-desorption small-scale test device for 3 hours, then turn off the CO2 and weigh it again, and calculate the total mass of CO2 absorbed.

[0048] After absorption was complete, the solid catalyst prepared in Example 1 was added to the CO2 adsorption-desorption pilot device. Both devices were heated using an electric heating mantle. When obvious bubbles were generated on the liquid surface, the desorption temperature was observed using a digital thermometer.

[0049] After recording, adjust the power and maintain the temperature to their respective desorption temperatures, and record the temperature every 10 minutes. The weight of the flask and the original weight of the flask represent the amount of CO2 desorbed. Calculate the desorption completion time and desorption rate (weight of liquid after desorption / weight of liquid before desorption).

[0050] 2. Perform a blank test without adding a solid catalyst following the steps above.

[0051] Table 2 Comparison of the effects of porous solid catalysts on CO2 desorption

[0052]

[0053] A comparison of Tables 1 and 2 shows that, in the CO2 adsorption-desorption pilot device, the solid catalyst of the present invention can reduce the desorption temperature of the CO2 desorption process of the composite amine solution and significantly shorten the desorption time when loaded before and after CO2 adsorption.

[0054] Example 2

[0055] A solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution is prepared as follows:

[0056] (1) Add HZSM-5 molecular sieve powder and γ-Al2O3 powder to a ball mill at a mass ratio of 8:2 and grind and mix thoroughly; add magnesium stearate at a mass ratio of 9:1 for the mixed powder of HZSM-5 molecular sieve and γ-Al2O3 to magnesium stearate, and grind and mix the powder at a speed of 150 r / min for 3 h to obtain composite carrier powder;

[0057] (2) The composite carrier powder and the mixed catalyst (nickel chloride and copper oxide) were mixed at a mass ratio of 8:1 and a mass ratio of 1:1. The mixture was then added to a ball mill and mixed at a speed of 150 r / min for 4 h to obtain the mixed powder of the carrier and the catalyst.

[0058] (3) Add solid binder kaolin and pore-forming agent to the mixed powder of carrier and catalyst, and mix the powder at a speed of 200 r / min for 20 h to prevent the agglomeration of each component due to uneven mixing during calcination, and obtain a mixture.

[0059] The amount of kaolin added is 40% of the total mass of the mixed powder of carrier and catalyst, and the amount of pore-forming agent added is 5% of the total mass of the mixed powder of carrier and catalyst and solid binder. The pore-forming agent is made by mixing acrylic resin and guar gum powder in a mass ratio of 1:9.

[0060] (4) The liquid binder is added to the mixture in step (3) in a spray form to obtain the adhesive material; the liquid binder is a nano aluminum sol with a mass concentration of 6% and the liquid-solid ratio of the liquid binder to the mixture is 12%;

[0061] (5) Add the adhesive material into the mold and press it into a sheet preform using an infrared tablet press at a pressure of 10 MPa; after demolding, place the preform in an oven and dry it at 120°C for 12 hours.

[0062] (6) The blank is sent into a muffle furnace for calcination at a temperature of 560℃, a heating rate of 1.2℃ / min, and a holding time of 6h. After the holding time is completed, the blank is cooled naturally and then removed from the furnace to obtain a solid catalyst for the desorption reaction of CO2 after absorption by the composite amine solution.

[0063] Testing revealed that the catalytic metal ion supported on the HZSM-5 molecular sieve and γ-Al2O3 composite support is Ni. + With Cu 2+ The mass percentages of the catalysts nickel chloride and copper oxide in the solid catalyst were 3% and 5%, respectively; the porosity of the solid catalyst was 11.6%.

[0064] Test Experiment Example 3

[0065] 1. In such Figure 2Add 200 ml of a mixed compound solution of dihexylethanolamine, hexamethylenediaminetetraacetic acid, and 2-amino-2-methyl-propanol in a mass ratio of 2:1:4 to the CO2 adsorption-desorption small-scale test device shown, and weigh it; introduce CO2 into the CO2 adsorption-desorption small-scale test device for 3 hours, then turn off the CO2 and weigh it again, and calculate the total mass of CO2 absorbed.

[0066] After absorption was complete, the solid catalyst prepared in Example 2 was added to the CO2 adsorption-desorption pilot device. Both devices were heated using an electric heating mantle. When obvious bubbles were generated on the liquid surface, the desorption temperature was observed using a digital thermometer.

[0067] After recording, adjust the power to maintain the temperature at the desorption temperature, and record the temperature every 10 minutes. The weight of the flask and the original weight of the flask represent the amount of CO2 desorbed. Calculate the desorption completion time and desorption rate (weight of liquid after desorption / weight of liquid before desorption).

[0068] 2. Perform a blank test without adding a solid catalyst following the steps above.

[0069] Table 3 Comparison of the effects of porous solid catalysts on CO2 desorption

[0070]

[0071] Example 3

[0072] A solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution is prepared as follows:

[0073] (1) Add HZSM-5 molecular sieve powder and γ-Al2O3 powder to a ball mill at a mass ratio of 7:3 and grind and mix thoroughly; add magnesium stearate at a mass ratio of 9:1 for the mixed powder of HZSM-5 molecular sieve and γ-Al2O3 to magnesium stearate, and grind and mix the powder at a speed of 150 r / min for 3 h to obtain composite carrier powder;

[0074] (2) The composite carrier powder and the catalyst MoO3 were mixed at a mass ratio of 6:1 and then added to a ball mill. The mixture was stirred at a speed of 150 r / min for 4 h to obtain a mixed powder of carrier and catalyst.

[0075] (3) Add solid binder kaolin and pore-forming agent to the mixed powder of carrier and catalyst, and mix the powder at a speed of 150 r / min for 12 h to prevent the agglomeration of each component due to uneven mixing during calcination, and obtain a mixture.

[0076] The amount of kaolin added is 30% of the total mass of the mixed powder of carrier and catalyst, and the amount of pore-forming agent added is 3% of the total mass of the mixed powder of carrier and catalyst and solid binder. The pore-forming agent is made by mixing acrylic resin and guar gum powder in a mass ratio of 1:9.

[0077] (4) The liquid binder is added to the mixture in step (3) in a spray form to obtain the adhesive material; the liquid binder is a nano silica sol with a mass concentration of 6% and the liquid-solid ratio of the liquid binder to the mixture is 15%;

[0078] (5) Add the adhesive material into the mold and press it into a sheet preform using an infrared tablet press at a pressure of 5 MPa; after demolding, place the preform in an oven and dry it at 80°C for 24 hours.

[0079] (6) The blank is sent into a muffle furnace for calcination at a temperature of 520°C, a heating rate of 1°C / min, and a holding time of 8h. After the holding time is completed, the blank is cooled naturally and then removed from the furnace to obtain a solid catalyst for the desorption reaction of CO2 after absorption by the composite amine solution.

[0080] Testing revealed that the catalytic metal ion supported on the HZSM-5 molecular sieve and γ-Al2O3 composite support was Mo. 4+ The mass percentage of the catalyst MoO3 in the solid catalyst is 6%; the porosity of the solid catalyst is 9%.

[0081] Test Experiment Example 4

[0082] 1. Add the solid catalyst prepared in Example 3 to the following: Figure 2 In the CO2 adsorption-desorption pilot device shown, 200 ml of a mixed compound solution of dihexylethanolamine and hexamethylenediaminetetraacetic acid with a mass ratio of 2:1 was added to the CO2 adsorption-desorption pilot device and weighed; CO2 was introduced into the CO2 adsorption-desorption pilot device for 3 hours, then the CO2 was turned off and weighed again, and the total mass of CO2 absorbed was calculated.

[0083] After absorption is complete, the CO2 adsorption-desorption pilot device is heated using an electric heating mantle until obvious bubbles are generated on the liquid surface. The desorption temperature is then observed and recorded using a digital thermometer.

[0084] After recording, adjust the power to maintain the temperature at the desorption temperature, and record the temperature every 10 minutes. The weight of the flask and the original weight of the flask represent the amount of CO2 desorbed. Calculate the desorption completion time and desorption rate (weight of liquid after desorption / weight of liquid before desorption).

[0085] 2. Perform a blank test without adding a solid catalyst following the steps above.

[0086] Table 4 Comparison of the effects of porous solid catalysts on CO2 desorption

[0087]

[0088] As can be seen from Tables 1-4, the solid catalyst of the present invention can reduce the desorption temperature of CO2 desorption process in composite amine solution and significantly shorten the desorption time.

Claims

1. A solid catalyst for the desorption reaction of CO2 after absorption by a complex amine solution, characterized in that, Using HZSM-5 molecular sieve γ-Al2O3 with a mass ratio of 7:3 to 9:1 as a composite support, active metal oxides and / or acidic catalytic metal salts are loaded onto the composite support; the active metal oxides are one or more selected from NiO, CuO, and MoO3, and their mass percentage in the solid catalyst is 5% to 8%; the acidic catalytic metal salts are one or more selected from NiCl2 and CuSO4, and their mass percentage in the solid catalyst is 3% to 10%; the porosity of the solid catalyst is 15% to 20%. The method for preparing the solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution includes the following steps: (1) Add HZSM-5 molecular sieve powder and γ-Al2O3 powder to a ball mill at a mass ratio of 7:3 to 9:1 and grind and mix thoroughly; then add magnesium stearate and grind and mix thoroughly to obtain composite carrier powder; (2) The composite carrier powder and the catalyst are mixed at a mass ratio of (6-9):1, and then added to a ball mill to grind the powder thoroughly to obtain a mixed powder of carrier and catalyst; the catalyst is an active metal oxide NiO, CuO, MoO3 or an acidic catalytic metal salt of NiCl2 or CuSO4. (3) Add solid binder and pore-forming agent to the mixed powder of carrier and catalyst, and mix at a rate of 150-300 r / min for 10-15 h to obtain a mixture; (4) Add the liquid adhesive to the mixture in step (3) in a spray form to obtain the adhesive material; (5) Add the adhesive material into the mold and press it into a blank using an infrared tablet press. After demolding, place the blank in an oven to dry. (6) The raw embryo is sent into a muffle furnace for calcination at a temperature of 500-600℃ and a holding time of 5-8h. After the holding time is completed, it is cooled naturally and then taken out of the furnace to obtain a solid catalyst for the desorption reaction of CO2 after absorption by the composite amine solution. In step (3), the solid binder is kaolin powder and / or boehmite powder; the amount of solid binder added does not exceed 40% of the total mass of the mixed powder of the carrier and catalyst, nor is it less than 10% of the total mass of the mixed powder; the pore-forming agent is a mixture of acrylic resin and guar gum powder in a mass ratio of 3:7 to 1:9; the vaporization temperature of the pore-forming agent is required to not exceed 90% of the calcination temperature of the solid catalyst; In step (4), the liquid binder has a liquid-to-solid ratio of 10% to 15% with respect to the mixture in step (3); the liquid binder is a nano-aluminum sol solution and / or a nano-silica sol solution with a mass concentration of 6% to 12%.

2. The method for preparing the solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution according to claim 1, characterized in that, In step (1), the amount of magnesium stearate added is 9% to 11% of the total mass of the mixed powder of HZSM-5 molecular sieve powder and γ-Al2O3; after adding magnesium stearate, the powder is ground and mixed at a speed of 150 to 200 r / min for 2 to 4 hours.

3. The method for preparing the solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution according to claim 1, characterized in that, In step (2), the composite support powder and the catalyst are ground and mixed at a rate of 150-250 r / min for 3-5 h to obtain a mixed powder of support and catalyst.

4. The method for preparing the solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution according to claim 1, characterized in that, The amount of the pore-forming agent added is 2% to 5.5% of the total mass of the mixed powder of the carrier and catalyst and the solid binder.

5. The method for preparing the solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution according to claim 1, characterized in that, In step (5), the pressure of the mold is 5-10 MPa; after the unmolded blank is removed, it is placed in an oven at 100-120°C and dried for 12-24 hours.

6. The method for preparing the solid catalyst for the desorption reaction of CO2 after absorption by a composite amine solution according to claim 1, characterized in that, In step (6), the heating rate of the muffle furnace is 1 to 1.5 °C / min.

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