Absorbent having antioxidant degradation resistance and method of making same
By adding an oxidative degradation inhibitor to the absorbent, the problem of oxidative degradation of alkanolamine solution during CO2 absorption was solved, thereby improving the stability and cost-effectiveness of the absorbent.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF MINING & TECH
- Filing Date
- 2026-04-25
- Publication Date
- 2026-07-14
Smart Images
Figure CN122377249A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of carbon dioxide capture technology, specifically to an absorbent with antioxidant degradation properties and its preparation method. Background Technology
[0002] In the current field of carbon capture technology, amine solutions are a technologically mature choice among supporting reagents, exhibiting excellent absorption rates and effectiveness in CO2 absorption. However, with continued research, it has been found that traditional amine solutions undergo degradation during CO2 absorption under the combined effects of O2 presence and high temperatures. This not only depletes the solvent itself but also leads to equipment corrosion, ultimately increasing operating costs.
[0003] Taking monoethanolamine (MEA) as an example, when MEA reacts with CO2, it degrades to produce degradation products such as glycolic acid, propionic acid, formic acid, oxalic acid, and acetic acid. In pilot-scale tests, the loss of monoethanolamine for every ton of CO2 captured reached as high as 1.4 kg. Therefore, studying and controlling the degradation of absorbents has significant industrial application value for reducing operating costs and optimizing the carbon capture process. Summary of the Invention
[0004] The purpose of this invention is to provide an absorbent with antioxidant degradation function and its preparation method. The process is simple to operate, and the resulting absorbent has antioxidant degradation properties, which can significantly reduce the degradation rate of the absorbent, thereby extending its service life and reducing the cost of carbon dioxide capture.
[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.30% to 0.70% of the absorbent by mass; the absorbent is composed of the main absorbent N-methyldiethanolamine, the compatibilizer diethylenetriamine, and the activator piperazine; the oxidative degradation inhibitor is composed of thymol / hydroquinone and potassium sodium tartrate; or the oxidative degradation inhibitor is composed of ethylenediaminetetraacetic acid, sodium metavanadate, and butylated hydroxytoluene.
[0006] Preferably, the absorbent is formulated with 18% by mass of a main absorbent, 5% by mass of an activator and 7% by mass of a compatibilizer.
[0007] Preferably, the mass ratio between thymol / hydroquinone and potassium sodium tartrate is 2.5:(1.0~4.5).
[0008] Preferably, the mass ratio of ethylenediaminetetraacetic acid, sodium metavanadate, and butylated hydroxytoluene is (1.0~3.0):1:1.
[0009] To achieve the above-mentioned objective, the present invention also provides a method for preparing the above-mentioned absorbent with antioxidant degradation function. First, the main absorbent, the expander and the activator are mixed evenly according to the formula to obtain the absorbent; then, the raw materials for preparing the antioxidant degradation inhibitor are mixed evenly according to the formula to obtain the antioxidant degradation inhibitor; finally, the antioxidant degradation inhibitor is added to the absorbent according to the formula amount to obtain the absorbent with antioxidant degradation performance.
[0010] In this invention, the main absorbent N-methyldiethanolamine (MDEA) is the base absorbent, used to absorb most of the CO2 in flue gas and ensure CO2 absorption rate; the compatibilizer diethylenetriamine (DETA) has polyamine groups and high amine reactivity, which can increase the absorption capacity; the activator is piperazine (PZ), which can significantly improve the reactivity of the absorbent with other components, making the mixture more uniform and enhancing the overall performance; the oxidative degradation inhibitor is used to protect the organic amine components in the absorbent, preventing oxidative degradation under O2 and thermal degradation at high temperatures.
[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: The absorbent with antioxidant degradation properties prepared by this invention has relatively stable absorption and desorption performance after the laboratory degradation cycle. The absorption performance of the blank control decreased by nearly 25.7% after 2 weeks of degradation. The absorption performance of the absorbent after adding oxidative degradation inhibitor decreased by about 3.8% to 12%. The oxidative degradation inhibitor can effectively reduce the degradation rate of the absorbent, thereby increasing the service life of the absorbent and reducing the cost of CO2 capture. Attached Figure Description
[0012] Figure 1 Comparison of degradation absorption and degradation desorption of the absorbents prepared in Example 1 and Blank Group 1 for capturing and absorbing CO2; (a) Comparison of degradation absorption; (b) Comparison of degradation desorption; Figure 2 Comparison of degradation absorption and degradation desorption for CO2 capture and absorption by the absorbents prepared in Example 2 and Blank Group 1; (a) Comparison of degradation absorption; (b) Comparison of degradation desorption; Figure 3 Comparison of degradation absorption and degradation desorption of the absorbents prepared in Example 3 and Blank Group 3 for capturing and absorbing CO2; (a) Comparison of degradation absorption; (b) Comparison of degradation desorption; Figure 4 Comparison of degradation absorption and degradation desorption of the absorbents prepared in Example 4 and Blank Group 4 for capturing and absorbing CO2; (a) Comparison of degradation absorption; (b) Comparison of degradation desorption; Figure 5Comparison of degradation absorption and degradation desorption of the absorbents prepared in Example 5 and Blank Group 5 for capturing and absorbing CO2; (a) Comparison of degradation absorption; (b) Comparison of degradation desorption; Figure 6 Comparison of degradation absorption and degradation desorption of the absorbents prepared in Example 6 and Blank Group 6 for capturing and absorbing CO2; (a) Comparison of degradation absorption; (b) Comparison of degradation desorption. Detailed Implementation
[0013] The present invention will be further described in detail below with reference to specific embodiments. Example 1
[0014] An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.30% of the absorbent by mass; the absorbent is prepared by N-methyldiethanolamine with a mass fraction of 18%, piperazine with a mass fraction of 5%, and diethylenetriamine with a mass fraction of 7%; the oxidative degradation inhibitor is composed of thymol and potassium sodium tartrate in a mass ratio of 2.5:1.0.
[0015] The preparation method is as follows: First, the main absorbent, activator and compatibilizer are mixed evenly according to the formula to obtain the absorbent. Then, the raw materials for preparing the oxidative degradation inhibitor are mixed evenly according to the formula to obtain the oxidative degradation inhibitor. Finally, the oxidative degradation inhibitor is added to the absorbent according to the formula amount to obtain the absorbent with antioxidant degradation function.
[0016] Blank Group 1 Unlike Example 1, it does not include oxidative degradation inhibitors.
[0017] The absorbents prepared in Example 1 and Blank Group 1 were subjected to CO2 capture and oxidative degradation inhibition experiments according to the parameters in Tables 1 and 2, respectively. Specifically, absorption experiments were conducted at a purge rate of 100 ml / min, and desorption experiments were conducted at 120 °C. Both absorption and desorption experiments were performed at atmospheric pressure. The oxidative degradation inhibition experiment was conducted with a surface pressure of 0.1 MPa and an internal temperature of 120 °C. The results are as follows: Figure 1 As shown.
[0018] from Figure 1 (a) It can be seen that, in the presence of O2, the absorbent prepared in blank group 1 showed a significant decrease in absorption rate and degradation, while the absorbent prepared in Example 1 had relatively stable absorption performance, with only a slight decrease; from Figure 1 (b) It can be seen that the absorbent prepared in blank group 1 degrades under the action of O2, and the desorption rate decreases significantly, while the absorbent prepared in Example 1 has a more stable desorption performance.
[0019] Table 1. Operating parameters for CO2 capture and purification experiment Table 2 Experimental parameters for oxidative degradation inhibition Example 2
[0020] An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.7% of the absorbent by mass; the absorbent is prepared by N-methyldiethanolamine (18% by mass), piperazine (5% by mass), and diethylenetriamine (7% by mass); the oxidative degradation inhibitor is composed of thymol and sodium potassium tartrate in a mass ratio of 2.5:4.5.
[0021] Its preparation method is the same as that in Example 1.
[0022] Blank Group 2 Unlike Example 2, it does not include oxidative degradation inhibitors.
[0023] The absorbents prepared in Example 2 and Blank Group 2 were subjected to CO2 capture and oxidative degradation inhibition experiments according to the parameters in Tables 1 and 2, respectively. The experimental procedures were the same as those in Example 1 and Blank Group 1, and the results are as follows: Figure 2 As shown.
[0024] from Figure 2 (a) It can be seen that the absorption rate of the absorbent prepared in blank group 2 decreased significantly after degradation by O2, while the absorbent prepared in Example 2 showed stable absorption performance; from Figure 2 (b) It can be seen that the desorption rate of the absorbent prepared in blank group 2 decreased significantly after decomposition under the action of O2, while the desorption performance of the absorbent prepared in Example 2 was more stable. Example 3
[0025] An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.30% of the absorbent by mass; the absorbent is prepared by N-methyldiethanolamine (18% by mass), piperazine (5% by mass), and diethylenetriamine (7% by mass); the oxidative degradation inhibitor is composed of hydroquinone and sodium potassium tartrate in a mass ratio of 2.5:1.0.
[0026] Its preparation method is the same as that in Example 1.
[0027] Blank Group 3 Unlike Example 3, it does not include oxidative degradation inhibitors.
[0028] The absorbents prepared in Example 3 and Blank Group 3 were subjected to CO2 capture and oxidative degradation inhibition experiments according to the parameters in Tables 1 and 2, respectively. The experimental procedures were the same as those in Example 1 and Blank Group 1, and the results are as follows: Figure 3 As shown.
[0029] from Figure 3 (a) It can be seen that the absorption rate of the absorbent prepared in blank group 3 decreased significantly after degradation by O2, while the absorbent prepared in Example 3 had more stable absorption performance; from Figure 3 (b) It can be seen that the desorption rate of the absorbent prepared in blank group 3 decreased significantly after decomposition under the action of O2, while the desorption performance of the absorbent prepared in Example 3 was more stable. Example 4
[0030] An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.7% of the absorbent by mass; the absorbent is prepared by N-methyldiethanolamine (18% by mass), piperazine (5% by mass), and diethylenetriamine (7% by mass); the oxidative degradation inhibitor is composed of hydroquinone and sodium potassium tartrate in a mass ratio of 2.5:4.5.
[0031] Its preparation method is the same as that in Example 1.
[0032] Blank Group 4 Unlike Example 4, it does not include oxidative degradation inhibitors.
[0033] The absorbents prepared in Example 4 and Blank Group 4 were subjected to CO2 capture and oxidative degradation inhibition experiments according to the parameters in Tables 1 and 2, respectively. The experimental procedures were the same as those in Example 1 and Blank Group 1, and the results are as follows: Figure 4 As shown.
[0034] from Figure 4 (a) It can be seen that the absorption rate of the absorbent prepared in blank group 4 decreased significantly after degradation by O2, while the absorbent prepared in Example 4 had more stable absorption performance; from Figure 4 (b) It can be seen that the desorption rate of the absorbent prepared in blank group 4 decreased significantly after decomposition under the action of O2, while the desorption performance of the absorbent prepared in Example 4 was more stable. Example 5
[0035] An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.30% of the absorbent by mass; the absorbent is prepared by N-methyldiethanolamine with a mass fraction of 18%, piperazine with a mass fraction of 5%, and diethylenetriamine with a mass fraction of 7%; the oxidative degradation inhibitor is composed of ethylenediaminetetraacetic acid, sodium metavanadate, and dibutylhydroxytoluene in a mass ratio of 3:1:1.
[0036] Its preparation method is the same as that in Example 1.
[0037] Blank Group 5 Unlike Example 5, it does not include oxidative degradation inhibitors.
[0038] The absorbents prepared in Example 5 and Blank Group 5 were subjected to CO2 capture and oxidative degradation inhibition experiments according to the parameters in Tables 1 and 2, respectively. The experimental procedures were the same as those in Example 1 and Blank Group 1, and the results are as follows: Figure 5 As shown.
[0039] from Figure 5 (a) It can be seen that the absorption rate of the absorbent prepared in blank group 5 decreased significantly after degradation by O2, while the absorbent performance of the degradation agent prepared in Example 5 was more stable; from Figure 5 (b) It can be seen that the desorption rate of the absorbent prepared in blank group 5 decreased significantly after decomposition under the action of O2, while the desorption performance of the absorbent prepared in Example 5 was more stable. Example 6
[0040] An absorbent with antioxidant degradation function includes an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.30% of the absorbent by mass; the absorbent is prepared by N-methyldiethanolamine with a mass fraction of 18%, piperazine with a mass fraction of 5%, and diethylenetriamine with a mass fraction of 7%; the oxidative degradation inhibitor is composed of ethylenediaminetetraacetic acid, sodium metavanadate, and dibutylhydroxytoluene in a mass ratio of 1:1:1.
[0041] Its preparation method is the same as that in Example 1.
[0042] Blank Group 6 Unlike Example 6, it does not include oxidative degradation inhibitors.
[0043] The absorbents prepared in Example 6 and Blank Group 6 were subjected to CO2 capture and oxidative degradation inhibition experiments according to the parameters in Tables 1 and 2, respectively. The experimental procedures were the same as those in Example 1 and Blank Group 1, and the results are as follows: Figure 6 As shown.
[0044] from Figure 6 (a) It can be seen that the absorption rate of the absorbent prepared in blank group 6 decreased significantly after degradation by O2, while the absorbent performance of the degradation agent prepared in Example 6 was more stable; from Figure 6 (b) It can be seen that the desorption rate of the absorbent prepared in blank group 6 decreased significantly after decomposition under the action of O2, while the desorption performance of the absorbent prepared in Example 6 was more stable.
[0045] In summary, the absorbent used in this invention exhibits excellent absorption and desorption performance due to its inherent properties. However, to further enhance its performance, a specific ratio of inhibitor was cleverly added during the actual preparation process. Specifically, this oxidative degradation inhibitor plays a crucial role, effectively preventing the absorbent from reacting with oxygen (O2) to a certain extent. Through this key measure, the degradation rate of the absorbent was successfully controlled at a low level, thereby ensuring that the absorbent can maintain a stable and smooth operating state over a longer period, greatly extending the service life of the absorbent. This undoubtedly has significant positive implications for reducing capture costs.
[0046] In-depth comparative studies revealed a stark contrast between the absorbent with antioxidant properties successfully prepared in this invention and the blank control group. In the blank control group, the absorbent without any added antioxidants showed a 26.89% decrease in absorption performance and a 20.76% decrease in desorption performance after just two weeks. Among several antioxidant formulations, after repeated experiments and evaluations, the thymol and hydroquinone formulation exhibited superior stability. Particularly noteworthy is that when the antioxidant was composed of hydroquinone and potassium sodium tartrate in a mass ratio of 2.5:1.0, the absorbent's absorption performance decreased by only 9.43% and its desorption performance by only 4.65% after two weeks. This demonstrates that the formulation provides excellent protection for the absorbent, enabling it to maintain good performance over a longer period, thus providing a strong guarantee for the widespread application of the absorbent.
Claims
1. An absorbent with antioxidant properties, characterized in that it comprises an absorbent and an oxidative degradation inhibitor, wherein the oxidative degradation inhibitor accounts for 0.30% to 0.70% of the absorbent by mass fraction; The absorbent is formulated from the main absorbent N-methyldiethanolamine, the compatibilizer diethylenetriamine, and the activator piperazine. The oxidative degradation inhibitor is composed of thymol / hydroquinone and potassium sodium tartrate; or the oxidative degradation inhibitor is composed of ethylenediaminetetraacetic acid, sodium metavanadate, and butylated hydroxytoluene.
2. The absorbent with antioxidant degradation properties according to claim 1, characterized in that, The absorbent is formulated with 18% main absorbent, 5% activator and 7% compatibilizer by mass fraction.
3. An absorbent with antioxidant degradation properties according to claim 1 or 2, characterized in that, The mass ratio of thymol / hydroquinone to potassium sodium tartrate is 2.5:(1.0~4.5).
4. An absorbent with antioxidant degradation properties according to claim 1 or 2, characterized in that, The mass ratio of ethylenediaminetetraacetic acid, sodium metavanadate, and butylated hydroxytoluene is (1.0~3.0):1:
1.
5. A method for preparing an absorbent with antioxidant degradation properties as described in any one of claims 1 to 4, characterized in that, First, the main absorbent, expander, and activator are mixed evenly according to the formula to obtain the absorbent. Then, the raw materials for preparing the oxidative degradation inhibitor are mixed evenly according to the formula to obtain the oxidative degradation inhibitor. Finally, the oxidative degradation inhibitor is added to the absorbent according to the formula to obtain the absorbent with antioxidant properties.