Carbon dioxide absorbent and carbon dioxide absorption method using same

Abstract

The present invention relates to a carbon dioxide absorbent. Specifically, in order to complement a short gas / liquid contact time of an RPB device, the carbon dioxide absorbent includes: a first compound and a second compound including two different alkanolamines; and a third compound including a cyclic tertiary amine, in specified contents, thereby maintaining low heat of reaction and improving absorption capacity and absorption rate.

Description

Carbon dioxide absorbent and carbon dioxide absorption method using the same

[0001] The present invention relates to a carbon dioxide absorbent and a method for absorbing carbon dioxide using the same.

[0002]

[0003] The RPB, also known as a Rotating Packed Bed, is a device developed for efficient mass transfer between gas and liquid. It utilizes high-speed rotating packing material to finely disperse the liquid and create a large contact area, significantly enhancing the reaction rate between gas and liquid. This structure allows for miniaturization compared to traditional stationary packed beds and provides high mass transfer efficiency.

[0004] However, existing absorbents have low thermal stability, consume a lot of energy during the regeneration process, and may deteriorate with long-term use. Therefore, there is a need to develop an absorbent that satisfies the characteristics suitable for RPB devices, such as high CO₂ absorption rate, stable operation inside the RPB, low-energy regeneration, and environmentally friendly components.

[0005]

[0006] The present invention aims to increase the capture rate of carbon dioxide in an RPB device by utilizing an absorbent comprising Aminoethylethanolamine (AEEA), 2-(ethylamino)ethanol (EAE), and Piperazine (PZ) to compensate for the short gas / liquid contact time of the RPB.

[0007] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0008]

[0009] As a technical means for achieving the aforementioned technical problem, one aspect of the present invention provides a carbon dioxide absorbent characterized by comprising: a first compound and a second compound comprising two different types of alkanolamines; and a third compound comprising a cyclic tertiary amine.

[0010] The above alkanolamines are aminoethylethanolamine (AEEA), 2-(ethylamino)ethanol (EAE), 3-methylaminopropylamine (MAPA), diethylenetriamine (DETA), N,N-dimethyl-1,3-propanediamine (DMAPA), N,N-diethyl-1,3-diaminopropane (DEAPA), 2-(methylamino)ethanol (MAE), 2-(butylamino)ethanol (BAE), 2-(isopropylamino)ethanol (IPAE), and 2-tert-butylamino)ethanol. It may include one or more selected from the group consisting of TBAE) and combinations thereof.

[0011] The first compound may be aminoethylethanolamine, and the second compound may be 2-(ethylamino)ethanol.

[0012] The above-mentioned cyclic tertiary amine may comprise one or more selected from the group consisting of piperazine (PZ), 1-methylpiperazine (1-MPZ), 2-methylpiperazine (2-MPZ), N-(2-hydroxyethyl)piperazine (HEP), 1-(2-aminoethyl)piperazine (1-(2-Aminoethyl)piperazine (AEP), 2-piperidine ethanol (2-PE), trans-2,5-dimethylpiperazine (DMPZ), and combinations thereof.

[0013] The third compound mentioned above may be piperazine.

[0014] The above carbon dioxide absorbent may further contain a solvent.

[0015] The above solvent may include water.

[0016] Based on a total content of 100% by weight of the carbon dioxide absorbent, it may comprise 5 to 20% by weight of a first compound, 15 to 35% by weight of a second compound, 0.1 to 15% by weight of a third compound, and 40 to 70% by weight of a solvent.

[0017] The above carbon dioxide absorbent may be an absorbent for a Rotating Packed Bed (RPB) device.

[0018] The above carbon dioxide absorbent may have a carbon dioxide absorption capacity of 0.10 mol·CO2 / mol·Amine or more.

[0019] The above carbon dioxide absorbent has a carbon dioxide absorption rate of 0.003 mol / (m 2 It may be greater than ·kPa·s.

[0020] As a technical means for achieving the aforementioned technical problem, another aspect of the present invention provides a carbon dioxide absorption method characterized by comprising: a step of introducing the aforementioned carbon dioxide absorbent into a rotary packed bed reactor (RPB); a step of introducing carbon dioxide into the reactor after the temperature and pressure of the reactor have reached equilibrium; and a step of stirring and reacting the absorbent with the carbon dioxide.

[0021] The carbon dioxide absorption capacity absorbed by the above carbon dioxide absorption method may be 0.10 mol·CO2 / mol·Amine or more.

[0022] The absorption rate of carbon dioxide absorbed by the above carbon dioxide absorption method is 0.003 mol / (m 2 It may be greater than ·kPa·s.

[0023] The reaction heat of the above carbon dioxide absorbent may be 80 kJ / mol·CO2 or less.

[0024]

[0025] A carbon dioxide absorbent according to one embodiment of the present invention is an absorbent for an RPB device. Since the RPB device is a very small device, less than 1 / 10 the size of a conventional PB, it is an absorbent with a fast absorption rate suitable for the RPB device and low regeneration energy. In particular, when experiments were conducted in a combined form of three materials including AEEA, EAE, and PZ, it showed a fast absorption rate in the RPB absorption tower (75% improvement compared to the existing one), and also had excellent effects in terms of absorption heat and absorption rate.

[0026] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0027]

[0028] FIG. 1 is a schematic diagram briefly illustrating a carbon dioxide absorption method according to one embodiment of the present invention.

[0029]

[0030] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0031]

[0032] Preparation Example

[0033] The process schematic diagram used is shown in Fig. 1. Using gas emitted from Fluid Catalytic Cracking (FCC) among the various flue gases emitted from the oil refining industry as a representative flue gas, a laboratory-scale study of 4 Nm² was conducted. 3 The study was conducted on / h. The main components of FCC flue gas were simulated using gas cylinders and air. The main components are carbon dioxide (CO2), nitrogen (N2), oxygen (O2), and water (H2O), and the compositions were set at 13.9%, 62.4%, 16.6%, and 7.1%.

[0034] In particular, water is continuously supplied by filling the bubbler (101) with water and passing the exhaust gas through it so that saturated water vapor can mix with the exhaust gas. The pressure is introduced into the device at atmospheric pressure, and the temperature is introduced into the Rotating Packed Bed (102, RPB) at 30 to 40°C from the bubbler (101).

[0035] The injected simulation exhaust gas is supplied with saturated steam through a bubbler (101), and the temperature of the gas is adjusted to the operating temperature of the RPB (102). The RPB (102) is filled with packing material inside and continuously rotated by a rotary motor to create internal centrifugal force, thereby forcing gas-liquid contact. Through this, it is possible to selectively capture carbon dioxide, the target substance, even though it is less than 1 / 10 the size of a conventional Packed Bed (PB). After capturing carbon dioxide, the gas containing a small amount is condensed through the condenser (110) at the top of the RPB to condense the absorbent contained in the steam, and the remaining gas is discharged outside the device. The absorbent that has captured carbon dioxide is pressurized to 0.5 barg by a pump (103) and passes through a heat exchanger (104) to raise its temperature as much as possible to facilitate operation in the desorption tower (105). In the desorption tower (105), the absorption injected into the tank undergoes separation of carbon dioxide and absorbent through heat. The desorbed carbon dioxide is discharged to the outside of the device after removing as much water vapor and some absorbent from the inside as possible through the upper condenser (106). The reboiler (107) serves to adjust the temperature to a temperature where the absorbent can be properly desorbed. The absorbent from which carbon dioxide has been sufficiently removed in the desorption tower is pressurized again (0.5 barg) through the pump (108), removes as much internal heat as possible through the heat exchanger (104), and is adjusted to the operating temperature (20~40 ℃) in the RPB (102) through the heat exchanger (109) connected to the cooling water.

[0036] Examples and comparative examples were prepared with the compositions of [Table 1] below through the above process.

[0037] Classification Composition (Unit: weight%) Example 1: AEEA 12, EAE 28, PZ 8, and the remainder of water Comparative Example 1: MEA 30, and the remainder of water Comparative Example 2: MEA 50, and the remainder of water Comparative Example 3: AEEA 15, EAE 35, and the remainder of water Comparative Example 4: AEEA 25, EAE 25, and the remainder of water Comparative Example 5: AEEA 35, EAE 15, and the remainder of water

[0038] Experimental Example 1: Measurement of Carbon Dioxide Absorption (Kinetic) Rate

[0039] An experiment was conducted to measure the carbon dioxide absorption rate using a WWC (Wet Wall Column) device, and the results are shown in Table 2.

[0040] Classification absorption rate (Unit: mol / (m²) 2 ·kPa·s)) Example 10.00359 Comparative Example 10.00205 Comparative Example 20.00292 Comparative Example 30.00268 Comparative Example 40.00246 Comparative Example 50.00229

[0041] Based on this, the absorption rate of Example 1 is 000359 mol / (m 2 0.00205~0.00292 mol / (m²) as ·kPa·s) 2 It can be confirmed that it has a carbon dioxide absorption rate that is at least 75% faster than Comparative Examples 1 to 5 (·kPa·s).

[0042]

[0043] Experimental Example 2: Measurement of Average Renewable Energy

[0044] An experiment was conducted to measure the average renewable energy, and the results are shown in Table 3.

[0045] Classification Average Renewable Energy (Unit: kW) Example 11.597 Comparative Example 12.007

[0046] When looking at the measured values ​​of the regeneration heat of the reboiler (107), Comparative Example 1 showed a distribution of 1.92 to 2.086 kW, and the average regeneration energy was measured as 2.007 kW. On the other hand, Example 1 showed a distribution of 1.472 to 1.719 kW, and the average regeneration energy was measured as 1.597 kW, showing a regeneration heat reduction effect of -20.5% compared to Comparative Example 1.

[0047] Experimental Example 3: Measurement of Heat of Reaction

[0048] An experiment was conducted to measure the heat of reaction using a DRC (Differential Reaction Column) device, and the results are shown in Table 4.

[0049] Classification △H (Unit: kJ / mol·CO2) Example 1 73.66 Comparative Example 180.85 Comparative Example 2 100.17

[0050] Based on this, it can be confirmed that carbon dioxide was separated in an environment where the heat of reaction was relatively lower in Example 1 than in Comparative Examples 1 and 2, and the heat of absorption was relatively lower in Example 1.

[0051] Experimental Example 4: Measurement of Cyclic Capacity

[0052] An experiment was conducted to measure the absorption capacity using a TOC (Total Organic Carbon) device, and the results are shown in Table 5.

[0053] Classification absorption capacity (Unit: mol·CO2 / mol·amine) Example 10.139 Comparative Example 10.09 Comparative Example 20.09

[0054] Based on this, it can be seen that the absorption capacity of the example is much larger than that of comparative examples 1 and 2.

[0055] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0056] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

[0057]

[0058] The present invention will be described in more detail below. However, the present invention may be implemented in various different forms and is not limited by the embodiments described herein, and is defined only by the claims set forth below.

[0059] Additionally, the terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. Throughout the specification of this invention, the term 'comprising' any component means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0060]

[0061] The first aspect of the present invention is,

[0062] A carbon dioxide absorbent is provided comprising: a first compound and a second compound comprising two different types of alkanolamines; and a third compound comprising a cyclic tertiary amine.

[0063] Hereinafter, a carbon dioxide absorbent according to the first aspect of the present invention will be described in detail.

[0064]

[0065] In one embodiment of the present invention, the alkanolamine may comprise one or more selected from the group consisting of aminoethylethanolamine (AEEA), 2-(ethylamino)ethanol (EAE), 1-methylpiperazine (1-MPZ), 2-methylpiperazine (2-MPZ), N-(2-hydroxyethyl)piperazine (HEP), 1-(2-aminoethyl)piperazine (1-(2-Aminoethyl)piperazine (AEP), 2-piperidine ethanol (2-PE), trans-2,5-dimethylpiperazine (DMPZ), and combinations thereof.

[0066] In one embodiment of the present invention, the first compound may be aminoethylethanolamine, and the second compound may be 2-(ethylamino)ethanol.

[0067] In one embodiment of the present invention, the cyclic tertiary amine may comprise one or more selected from the group consisting of piperazine (PZ), 1-methylpiperazine (1-MPZ), 2-methylpiperazine (2-MPZ), N-(2-hydroxyethyl)piperazine (HEP), 1-(2-aminoethyl)piperazine (1-(2-Aminoethyl)piperazine (AEP), 2-piperidine ethanol (2-PE), trans-2,5-dimethylpiperazine (DMPZ) and combinations thereof.

[0068] In one embodiment of the present invention, the third compound may be piperazine.

[0069] In one embodiment of the present invention, in the case of a carbon dioxide absorbent in which the first compound is aminoethylethanolamine, the second compound is 2-(ethylamino)ethanol, and the third compound is piperazine as described above, it has the effect of having a fast absorption rate, low regeneration energy, and low high absorption capacity.

[0070] In one embodiment of the present invention, the carbon dioxide absorbent may further comprise a solvent.

[0071] In one embodiment of the present invention, the solvent may include water.

[0072] In one embodiment of the present invention, based on 100% by weight of the total carbon dioxide absorbent content, the composition may comprise 5 to 20% by weight of a first compound, 15 to 35% by weight of a second compound, 0.1 to 15% by weight of a third compound, and 40 to 70% by weight of a solvent. If the content range falls outside the above range, there may be problems such as increased use of absorbent and increased regeneration heat due to reduced carbon dioxide absorption performance.

[0073] In one embodiment of the present invention, the absorbent may be an absorbent for a Rotating Packed Bed (RPB) device.

[0074] The Rotating Packed Bed (RPB) device is a very compact device, less than 1 / 10 the size of the commonly used Packed Bed (PB) device. Therefore, unlike absorbents for PB devices, absorbents for RPB devices require technology that selectively captures carbon dioxide from flue gas within a very short contact time. Furthermore, since the regeneration heat in the regeneration tower must be kept low, complex factors such as absorption rate, reaction heat, and boiling point must be considered. Accordingly, an absorbent having a fast absorption rate and low regeneration energy must be used, and the absorbent according to the present invention possesses the above effects.

[0075] In one embodiment of the present invention, the carbon dioxide absorbent has a carbon dioxide absorption rate of 0.00250 mol / (m 2 It may be greater than ·kPa·s).

[0076] In one embodiment of the present invention, the carbon dioxide absorbent may have an average regenerative energy of 2.0 kW or less.

[0077]

[0078] The second aspect of the present invention is,

[0079] A method for absorbing carbon dioxide is provided, comprising the steps of: introducing the aforementioned carbon dioxide absorbent into a rotary packed bed reactor (RPB); introducing carbon dioxide into the reactor after the temperature and pressure of the reactor have reached equilibrium; and stirring the absorbent and carbon dioxide to react.

[0080] Detailed explanations have been omitted for parts that overlap with the first aspect of the present invention; however, the content described in the first aspect of the present invention may be applied equally even if such explanations are omitted in the second aspect.

[0081] Hereinafter, a carbon dioxide absorption method according to the second aspect of the present invention will be described in detail.

[0082]

[0083] In one embodiment of the present invention, the temperature of the reactor is maintained in a range of 273 to 343 K, more specifically 293 to 323 K, and the stirring may be performed at a speed of 200 to 1,800 rpm, specifically 300 to 800 rpm.

[0084] In one embodiment of the present invention, the carbon dioxide absorption capacity absorbed by the carbon dioxide absorption method may be 0.10 mol·CO2 / mol·Amine or more.

[0085] In one embodiment of the present invention, the absorption rate of the carbon dioxide absorbent is 0.003 mol / (m 2 It can be greater than ·kPa·s).

[0086] In one embodiment of the present invention, the reaction heat of the carbon dioxide absorbent may be 80 kJ / mol·CO2 or less.

[0087]

[0088] According to an embodiment of the present invention, in order to compensate for the short gas / liquid contact time of the RPB device, the reaction heat can be kept low and the absorption capacity and absorption rate can be improved through a carbon dioxide absorbent comprising a specific amount of a first compound and a second compound comprising two different types of alkanolamines; and a third compound comprising a cyclic tertiary amine.

Claims

1. A first compound and a second compound comprising two different types of alkanolamines; and A carbon dioxide absorbent characterized by comprising a third compound containing a cyclic tertiary amine.

2. In Paragraph 1, A carbon dioxide absorbent comprising one or more selected from the group consisting of aminoethylethanolamine (AEEA), 2-(ethylamino)ethanol (EAE), 1-methylpiperazine (1-MPZ), 2-methylpiperazine (2-MPZ), N-(2-hydroxyethyl)piperazine (HEP), 1-(2-aminoethyl)piperazine (1-Aminoethyl)piperazine (AEP), 2-piperidine ethanol (2-PE), trans-2,5-dimethylpiperazine (DMPZ), and combinations thereof.

3. In Paragraph 1, The first compound above is aminoethylethanolamine, and A carbon dioxide absorbent in which the second compound is 2-(ethylamino)ethanol.

4. In Paragraph 1, A carbon dioxide absorbent comprising one or more selected from the group consisting of piperazine (PZ), 1-methylpiperazine (1-MPZ), 2-methylpiperazine (2-MPZ), N-(2-hydroxyethyl)piperazine (HEP), 1-(2-aminoethyl)piperazine (1-(2-Aminoethyl)piperazine (AEP), 2-piperidine ethanol (2-PE), trans-2,5-dimethylpiperazine (DMPZ), and combinations thereof.

5. In Paragraph 1, The above-mentioned third compound is a carbon dioxide absorbent, wherein the compound is piperazine.

6. In Paragraph 1, A carbon dioxide absorbent that further contains a solvent.

7. In Paragraph 6, The above solvent is a carbon dioxide absorbent containing water.

8. In Paragraph 6, Based on a total carbon dioxide absorbent content of 100% by weight, 5 to 20 weight% of the first compound, 15 to 35 weight% of the second compound, 0.1 to 15 weight% of the third compound, and A carbon dioxide absorbent comprising 40 to 70 weight percent of a solvent.

9. In Paragraph 1, A carbon dioxide absorbent that is an absorbent for a Rotating Packed Bed (RPB) device.

10. In Paragraph 1, The absorption rate is 0.00250 mol / (m 2 A carbon dioxide absorbent having a value of ☐kPa·s or higher.

11. In Paragraph 1, A carbon dioxide absorbent having an average renewable energy of 2.0 kW or less.

12. A step of introducing the carbon dioxide absorbent of claim 1 into a rotating packed bed reactor (RPB); After the temperature and pressure of the reactor reach equilibrium, a step of introducing carbon dioxide into the reactor; and A carbon dioxide absorption method characterized by including the step of stirring and reacting the above absorbent with carbon dioxide.

13. In Paragraph 12, A carbon dioxide absorption method in which the carbon dioxide absorption capacity absorbed by the above carbon dioxide absorption method is 0.10 mol·CO2 / mol·Amine or more.

14. In Paragraph 12, The absorption rate of carbon dioxide absorbed by the above carbon dioxide absorption method is 0.003 mol / (m 2 A carbon dioxide absorption method that is greater than or equal to ·kPa·s.

15. In Paragraph 12, A carbon dioxide absorption method in which the reaction heat of the carbon dioxide absorbent is 80 kJ / mol·CO2 or less.

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