CO2 trapping device for lime kiln flue gas and method for testing absorption capacity of CO2 absorbent

Abstract

The invention discloses a CO2 trapping device for lime kiln flue gas and a method for testing the absorption capacity of a CO2 absorbent, and belongs to the field of carbon dioxide trapping and utilization, and the method comprises the following steps: preparing the absorbent in a reactor of the CO2 trapping device; lime kiln flue gas is continuously input into the absorbent, and the absorption capacity of the absorbent is calculated; when the absorption process is stopped, the absorbent absorption efficiency is calculated based on the absorption time. According to the method for determining the absorption capacity of the absorbent through the mass change of the system, the pollution to the absorbent is avoided, the test process is simplified, the component composition of the absorbent is preferably selected, and the popularization and application of carbon capture, utilization and storage technologies are promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon dioxide capture and utilization, and particularly relates to a CO capture device for lime kiln flue gas and a method for testing the absorption capacity of an absorbent. 2 capture device and CO 2 absorbent absorption capacity test method. Background Art

[0002] The lime industry directly emits more than 300 million tons of CO annually, making it the second largest carbon-emitting industry in the building materials industry after cement. Recycling the CO in lime kiln flue gas through carbon capture, utilization, and storage technology (CCUS) is an effective way to achieve carbon emission reduction. Currently, chemical absorption is an important means for CO capture, with amine absorbents being the main type. For such absorbents, there is a lack of a measurement standard for their absorption capacity and corresponding test methods. In the prior art, the acid titration method and the flux calculation method both have problems such as contaminating the absorbent, high environmental requirements, and complex measurement methods. Therefore, researching a test method for the absorption capacity of amine absorbents in lime kiln flue gas is of great significance for promoting carbon emission reduction in the lime industry. 2 directly emissions exceeding 300 million tons, is the second largest carbon-emitting industry in the building materials industry after cement. By carbon capture, utilization and storage technology (Carbon Capture, Utilization and Storage, CCUS) for the CO in lime kiln flue gas 2 for recycling is an effective way to achieve carbon emission reduction. At present, chemical absorption method is an important means for CO capture 2 and among them, amine absorbents are mainly used. For such absorbents, there is a lack of a measurement standard for their absorption capacity and corresponding test methods. In the existing technology, both the acid titration method and the flux calculation method have problems such as contaminating the absorbent, high environmental requirements, and complex measurement methods. Therefore, researching a test method for the absorption capacity of amine absorbents in lime kiln flue gas is of great significance for promoting carbon emission reduction in the lime industry. Summary of the Invention

[0003] To solve the above technical problems, the present invention proposes a CO capture device for lime kiln flue gas and a method for testing the absorption capacity of an absorbent to solve the problems existing in the above prior art. 2 capture device and CO 2 absorbent absorption capacity test method.

[0004] To achieve the above object, the present invention provides a method for testing the absorption capacity of an absorbent for lime kiln flue gas CO, including: 2 configuring an absorbent in a reactor of a CO capture device;

[0005] continuously inputting lime kiln flue gas into the absorbent and calculating the absorption capacity of the absorbent; 2 configuring an absorbent in the reactor of the CO capture device;

[0006] continuously inputting lime kiln flue gas into the absorbent and calculating the absorption capacity of the absorbent;

[0007] when the absorption process stops, calculating the absorption efficiency of the absorbent based on the absorption time.

[0008] Optionally, the carbon dioxide concentration in the lime kiln flue gas is 15% - 40%, the flue gas flux is set to 200 - 1000 SCCM, and the absorption temperature is 40 - 70°C.

[0009] Optionally, the absorbent is prepared from amine organic components, alkali metal inorganic components, and deionized water;

[0010] Among them, the amine organic components include one or several of triethanolamine, diethanolamine, monoethanol diisopropanolamine, and diethanol monoisopropanolamine, and the concentration of the amine organic components is 5% to 10%;

[0011] The alkali metal inorganic components include one or several of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, and potassium carbonate, and the concentration of the alkali metal inorganic components is 15% to 30%.

[0012] Optionally, the calculation formula for the absorption capacity of the absorbent is:

[0013]

[0014] In the formula, I represents the absorption capacity of the absorbent, m t represents the instantaneous mass of the system, m s represents the initial mass of the system, m 0 represents the mass of the prepared absorbent.

[0015] Optionally, the condition for stopping the absorption process is that the mass change of the system within 30 minutes does not exceed 0.5% of the mass of the prepared absorbent.

[0016] Optionally, the expression for calculating the absorption efficiency of the absorbent is:

[0017]

[0018] In the formula, E represents the absorption efficiency of the absorbent, S represents the flue gas flux, and t represents the absorption time.

[0019] The present invention also provides a CO 2 capture device for a lime kiln flue gas, used to implement a CO 2 absorbent absorption capacity test method for a lime kiln flue gas, and the CO 2 capture device includes: a gas cylinder group, a gas distribution device, a washing bottle, a gas blowing device, a kettle reactor, a stirring device, and a heating device;

[0020] Among them, the process of performing a CO 2 absorbent absorption capacity test based on the CO 2 capture device includes:

[0021] The lime kiln flue gas is subjected to desulfurization, denitrification, and dust removal treatment through the gas cylinder group and the gas distribution device to obtain the treated lime kiln flue gas;

[0022] The treated lime kiln flue gas is introduced into the washing bottle for gas humidification and then into the gas blowing device to continuously blow gas into the kettle reactor; the kettle reactor is filled with the prepared absorbent;

[0023] The stirring device stirs the autoclave reactor, and at the same time, the heating device is used to heat the autoclave reactor, and the mass and absorption time of the absorbent are recorded;

[0024] The absorption capacity of the absorbent is obtained based on the mass and absorption time of the absorbent.

[0025] Optionally, the ratio of the inner diameter of the bottom of the air-blowing device to that of the autoclave reactor ranges from 5 to 15.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The present invention provides a test method for the absorption capacity of an absorbent, which has a simple process, a simple method, low requirements for test equipment, does not pollute the absorbent, can directly process or recycle the absorbent, thereby reducing the consumption and waste of energy and resources, and is beneficial to environmental protection. Description of the Drawings

[0028] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0029] Figure 1 It is a schematic diagram of a carbon dioxide capture process device according to an embodiment of the present invention;

[0030] Marking description: 1. Gas cylinder group; 2. Gas distribution device; 3. Washing bottle; 4. Air-blowing device; 5. Autoclave reactor; 6. Stirring device; 7. Heating device; a. Pipeline between the gas cylinder group and the gas distribution device; b. Pipeline between the gas distribution device and the washing bottle; c. Pipeline between the washing bottle and the autoclave reactor. Detailed Embodiments

[0031] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0032] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0033] Embodiment 1

[0034] As Figure 1 shown, in this embodiment, a CO2 capture device for lime kiln flue gas and a test method for the absorption capacity of a CO2 absorbent are provided, including the following steps: In CO 2An absorbent is configured in the reactor of the capture device; lime kiln flue gas is continuously input into the absorbent, and the absorption capacity of the absorbent is calculated; when the absorption process stops, the absorption efficiency of the absorbent is calculated based on the absorption time. As a specific implementation manner of this embodiment, it includes:

[0035] S1. Build a CO 2 capture device, prepare an amine absorbent in the reactor, and select the CO 2 concentration and flux according to the actual situation, and continuously bubble gas into the absorbent while stirring;

[0036] S2. Record the mass m 0 of the prepared absorbent, the initial mass m s of the system, and the instantaneous mass m t of the system. The calculation formula for the absorption capacity I of the absorbent is as follows:

[0037]

[0038] where m 0 and m s shall satisfy the following formula:

[0039]

[0040] m s = m 0 + m device #(3)

[0041] In the formula, m absorb , and m device are the masses of the absorbent component, deionized water, and the autoclave reactor respectively, with the unit of g.

[0042] S3. When the absorption process stops, record the absorption time t, with the unit of min. The calculation formula for the absorption efficiency E of the absorbent is as follows:

[0043]

[0044] In the formula, S is the flue gas flux, with the unit of L / min.

[0045] The absorption capacity I and absorption efficiency E of the absorbent truly reflect the absorption effect of the unit absorbent. This method of measuring the absorption capacity of the absorbent by the change in the system mass avoids the pollution of the absorbent, simplifies the test process, helps to optimize the component composition of the absorbent, and promotes the popularization and application of carbon capture, utilization, and storage technologies.

[0046] Furthermore, the carbon dioxide capture process device in S1 includes a flue gas simulation device and an absorption reaction device.

[0047] The flue gas simulation device is composed of a gas distributor 2 and a washing bottle 3.

[0048] The absorption reaction device is composed of a kettle - type reactor 5 and a gas - blowing device 4. The gas - blowing device 4 is in a straight - tube shape, and the ratio of the inner diameter of the gas - blowing device 4 to the bottom of the reactor is 5 - 15. During the gas - blowing process, the stirring speed is maintained at 200 - 400 r / min. To prevent mass loss caused by liquid evaporation due to the rising temperature of the absorption liquid during the absorption process, the absorption reaction device should be properly sealed.

[0049] Furthermore, the actual situation of the flue gas in S1 is the active lime kiln tail flue gas after desulfurization, denitrification, and dust removal, where the carbon dioxide concentration is 15% - 40%. The flue gas flux is set to 200 - 1000 SCCM, and the absorption temperature is 40 - 70 °C. The CO 2 capture device and flue gas simulation adopted in the present invention can truly reflect the CO 2 capture process of lime kiln flue gas and the high - temperature absorption situation of the absorbent, which is beneficial to improving the accuracy of the absorbent absorption capacity test.

[0050] The absorbent in S1 is prepared from common amine - type organic components, alkali - metal - type inorganic components, and deionized water.

[0051] Furthermore, the amine - type organic components include one or more of triethanolamine (TEA), diethanolamine (DEA), monoethanol diisopropanolamine (EDIPA), and diethanol monoisopropanolamine (DEIPA), and the concentration range is 5% - 10%; the alkali - metal - type inorganic components include one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, and potassium carbonate, and the concentration range is 15% - 30%.

[0052] Furthermore, the absorption capacity and absorption efficiency calculated in S2 and S3 are only related to the absorbent itself and are dimensionless.

[0053] Furthermore, the determination condition for the absorption process to stop in S3 is that the mass change of m t within 30 min does not exceed 0.5% of the mass m 0 of the absorbent.

[0054] The present invention proposes a measurement standard for the absorption capacity of an absorbent and a test method. It quantitatively evaluates the absorption capacity of the absorbent, directly reflects the absorption efficiency of the absorbent, and is applicable to the CO 2 absorbent of lime kiln flue gas, which helps to optimize the absorbent components and further promotes the iterative progress of CCUS industrial technology.

[0055] The present invention provides a test method for the absorption capacity of an absorbent, which has a simple process, is easy to operate, requires low requirements for test equipment, does not contaminate the absorbent, and can directly process or recycle the absorbent, thereby reducing the consumption and waste of energy and resources and being beneficial to environmental protection.

[0056] As a specific implementation manner of this embodiment, a gas cylinder group 1 and a gas distribution device 2 are used to simulate the lime kiln flue gas after desulfurization, denitrification, and dust removal, with a CO 2 concentration of 22%, a CO concentration of 1.2%, and a flow rate of 500 SCCM.

[0057] After passing the above-simulated lime kiln tail flue gas into the washing bottle 3 to moisten the gas, continuous gas injection is carried out into the autoclave reactor 5 through the gas injection device 4. The ratio of the diameter of the gas injection device 4 to the inner diameter of the bottom surface of the autoclave reactor 5 is 10. The autoclave reactor 5 is filled with a common amine absorbent, and the mass ratio of the alkanolamine organic component to deionized water is 1:1, where the alkanolamine organic component is diethanolamine.

[0058] The stirring device 6 stirs the autoclave reactor 5 at a stirring speed of 300 r / min. The heating device 7 continuously heats the autoclave reactor 5 to simulate the high temperature of the lime kiln tail flue gas, and the reactor temperature is 70 °C.

[0059] Record the mass of the prepared absorbent, and calculate the amount m 0 = 210 g according to formula (2). Record the mass of the autoclave reactor and the stirring device, and calculate the initial mass m s = 451.0 g according to formula (3).

[0060] Measure m t every 30 min. When the mass change of m t is less than or equal to 0.5%, the absorption stops. Record the instantaneous mass m t = 471.2 g of the system at the end of absorption. Calculate the absorption capacity I = 0.09 of the carbon dioxide absorbent according to formula (1). Record the gas flux S = 0.2 L / min and the absorption time of 60 min, and calculate E = 85.7% according to formula (11), that is, the measurement of the absorption capacity of the absorbent liquid is realized.

[0061] Example Two

[0062] As another specific implementation manner of this embodiment, a test method for the absorption capacity of a CO 2 absorbent for lime kiln flue gas specifically includes the following steps:

[0063] (1) Use the gas cylinder group 1 and the gas distribution device 2 to simulate the lime kiln flue gas after desulfurization, denitrification, and dust removal, with a CO 2The concentration is 22%, the CO concentration is 1.2%, and the flow rate is 500 SCCM.

[0064] (2) After passing the simulated lime kiln tail gas into the washing bottle 3 to wet the gas, continuously blow air into the autoclave reactor 5 through the air-blowing device 4. The ratio of the diameter of the air-blowing device 4 to the inner diameter of the bottom surface of the autoclave reactor 5 is 10. The autoclave reactor 5 is filled with a composite amine absorbent, and the mass ratio of the alkanolamine organic component, the alkali metal inorganic component, and deionized water is 1:6:9. Among them, the alkanolamine organic component is diethanol monoisopropanolamine, and the alkali metal inorganic component is sodium hydroxide.

[0065] (3) The stirring device 6 stirs the autoclave reactor 5 at a stirring speed of 300 r / min. Continuously heat the autoclave reactor 5 using the heating device 7 to simulate the high temperature of the lime kiln tail gas, and the reactor temperature is 70 °C.

[0066] (4) Record the mass of the prepared absorbent, and calculate the amount m 0 = 193.5 g according to formula (2). Record the mass of the autoclave reactor 5 and the stirring device 6, and calculate the initial mass m of the system s = 448.3 g according to formula (3).

[0067] Measure m every 30 minutes t , and when the mass change of m t is less than or equal to 0.5%, stop absorption. Record the instantaneous mass m of the system when absorption is completed t = 493.2 g, and calculate the absorption capacity I = 0.23 of the carbon dioxide absorbent according to formula (1). Record the gas flux S = 0.5 L / min and the absorption time of 60 minutes, and calculate E = 76.2% according to formula (11), that is, the measurement of the absorption capacity of the absorbent solution is realized.

[0068] Example Three

[0069] As another specific implementation manner of this example, a test method for the absorption capacity of a CO 2 absorbent for lime kiln flue gas specifically includes the following steps:

[0070] (1) Use the gas cylinder group 1 and the gas distribution device 2 to simulate the lime kiln flue gas after desulfurization, denitrification, and dust removal. The CO 2 concentration is 22%, the CO concentration is 1.2%, and the flow rate is 500 SCCM.

[0071] (2) After passing the above-simulated lime kiln tail gas into the washing bottle 3 to moisten the gas, continuous air injection is carried out into the autoclave reactor 5 through the air injection device 4. The ratio of the caliber of the air injection device 4 to the inner diameter of the bottom surface of the autoclave reactor 5 is 10. The autoclave reactor is filled with a composite amine absorbent, and the mass ratio of the alkanolamine organic component, the alkali metal inorganic component, and deionized water is 1:5:10. Among them, the alkanolamine organic component is a mixture of diethanol monoisopropanolamine and diethanolamine with a mass ratio of 1:1, and the alkali metal inorganic component is sodium hydroxide.

[0072] (3) The stirring device 6 stirs the autoclave reactor 5 at a stirring speed of 300 r / min. The heating device 7 continuously heats the autoclave reactor 5 to simulate the high temperature of the lime kiln tail gas, and the reactor temperature is 70 °C.

[0073] (4) Record the mass of the prepared absorbent, and calculate the amount m according to formula (2) 0 = 201.9 g. Record the mass of the autoclave reactor and the stirring device, and calculate the initial mass m of the system according to formula (3) s = 451.6 g.

[0074] Measure m every 30 minutes t , and when the mass change of m t is less than or equal to 0.5%, the absorption stops. Record the instantaneous mass m of the system when the absorption is completed t = 488.9 g, and calculate the absorption capacity I of the carbon dioxide absorbent as 0.18 according to formula (1). Record the gas flux S = 0.5 L / min and the absorption time of 60 min, and calculate E = 63.3% according to formula (11), that is, the measurement of the absorption capacity of the absorbent solution is realized.

[0075] Under the same conditions, the absorption capacities of the absorbents in Examples 1 to 3 were tested by the acid titration method, and the results are compared in Table 1 as follows.

[0076] Table 1

[0077]

[0078]

[0079] From the comparison results in Table 1, it can be seen that the accuracy of the method for testing the absorption capacity of the absorbent for lime kiln flue gas CO 2 proposed by the present invention is similar to the conventional method, and it does not pollute the absorbent solution. The test process is simple, and it accurately and efficiently determines the absorption capacity of the absorbent for lime kiln flue gas CO 2 , which contributes to the selection of the optimal absorbent components and the promotion of the progress of the CCUS technology.

[0080] The above are only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for testing the CO2 absorbent absorption capacity of lime kiln flue gas, characterized in that: The following steps are involved: exist An absorbent is arranged in the reactor of the CO2 capture device; Continuously inputting lime kiln flue gas into the absorbent and calculating the absorption capacity of the absorbent; When the absorption process is stopped, the absorbent absorption efficiency is calculated based on the absorption time.

2. The method for testing the CO2 absorbent absorption capacity of lime kiln flue gas according to claim 1, characterized in that: The carbon dioxide concentration in the lime kiln flue gas is 15% to 40%, the flue gas flux is set to 200 to 1000 SCCM, and the absorption temperature is 40 to 70°C.

3. The method for testing the CO2 absorbent absorption capacity of lime kiln flue gas according to claim 1, characterized in that: The absorbent is prepared from an amine organic component, an alkali metal inorganic component and deionized water; Wherein, the amine organic component includes: one or more of triethanolamine, diethanolamine, monoethanol diisopropanolamine and diethanol monoisopropanolamine, and the concentration of the amine organic component is 5% to 10%; The alkali metal inorganic component includes one or more of sodium hydroxide, potassium hydroxide, hydrogenated lime, sodium carbonate and potassium carbonate, and the concentration of the alkali metal inorganic component is 15% to 30%.

4. The method for testing the CO2 absorbent absorption capacity of lime kiln flue gas according to claim 1, characterized in that: The calculation formula of the absorption capacity of the absorbent is: In the formula, I represents the absorption capacity of the absorbent, m t Represents the instantaneous mass of the system, m s represents the initial mass of the system, and m0 represents the mass of the prepared absorbent.

5. The method for testing the CO2 absorbent absorption capacity of lime kiln flue gas according to claim 4, characterized in that: The condition for stopping the absorption process is that the instantaneous mass change of the system within 30 minutes does not exceed 0.5% of the mass of the prepared absorbent.

6. The method for testing the CO2 absorbent absorption capacity of lime kiln flue gas according to claim 5, characterized in that: The expression for calculating the absorption efficiency of the absorbent is: In the formula, E represents the absorption efficiency of the absorbent, S represents the flue gas flux, and t represents the absorption time.

7. A CO2 capture device for lime kiln flue gas, characterized in that: A method for testing the absorption capacity of a CO2 absorbent for lime kiln flue gas according to any one of claims 1 to 6, wherein the CO2 capture device comprises: a gas cylinder group (1), a gas separation device (2), a gas washing bottle (3), an air blowing device (4), a kettle reactor (5), a stirring device (6), and a heating device (7); The process of testing the absorption capacity of the CO2 absorbent based on the CO2 capture device includes: The lime kiln flue gas is subjected to desulfurization, denitrification and dust removal treatments through the gas cylinder group (1) and the gas separation device (2) to obtain treated lime kiln flue gas; The treated lime kiln flue gas is passed into a gas washing bottle (3) for gas humidification and then passed into an aeration device (4) for continuous aeration into a kettle reactor (5); the kettle reactor (5) is filled with a configured absorbent; The stirring device (6) stirs the autoclave reactor (5), and at the same time, the heating device (7) heats the autoclave reactor (5) to record the mass of the absorbent and the absorption time; The absorption capacity of the absorbent is obtained based on the mass of the absorbent and the absorption time.

8. The CO2 capture device for lime kiln flue gas according to claim 7, characterized in that: The ratio of the bottom inner diameter of the aerator (4) to that of the kettle reactor (5) is in the range of 5 to 15.

Images