由於石化燃料的大量使用，全球二氧化碳濃度逐年增高，造成溫室效應日益嚴重，使人類生存與生態環境面臨重大的威脅，二氧化碳的減排已是全球關注的議題。在二氧化碳捕捉的方法中，化學吸收捕捉二氧化碳為目前工業上最廣為使用的方法，商業化的吸收劑中又以醇胺水溶液最為常見。理想的吸收劑，應該在吸收過程不沉澱的情況下，具有高的吸收負載與快的吸收速率，脫附過程擁有高的循環負載量及少量的溶劑損失，最重要是低的再生能耗。本研究以30wt%乙醇胺水溶液作為吸收劑的標準品，四烷基銨如Tetramethylammonium ([N1111])、Tetraethylammonium ([N2222])、Methyl-triethylammonium ([N2221])、Methyl-tributylammonium ([N1444])及(1-Butyl)triethylammonium ([N2224])作為陽離子，氨基酸如L-丙氨酸(L-Alanine)、β-丙氨酸(β-Alanine)、甘氨酸(Glycine)、肌氨酸(Sarcosine)及脯氨酸(L-proline)作為陰離子，合成25 wt%四烷基銨氨基酸離子液體水溶液，進行二氧化碳的吸附及再生實驗，結果發現 [N1444][L-Ala]在80℃循環過程中不會有沉澱的問題，同時達到良好的吸收與脫附效率，再生能耗也很低，此吸收劑在二氧化碳捕捉上有很大潛力的應用。

Increasing CO2 emissions from using fossil fuels and the resulting greenhouse effect have received extensive concerns, and the reduction of CO2 has become the global trend. One of the most important CO2 capture methods is the chemical absorption, which are widely applied to industrial plants. Amine-based solutions are considered as common absorbents to effectively capture CO2. Although these absorbents have high absorption reactivity, there are certain serious problems such as high energy cost during the regeneration process. An ideal absorbent should have high cyclic loading and low solvent consumption amount without suffering precipitation. Low regeneration energy penalty is the most important economic factor in a CO2 capture process. In this study, 30wt% monoethanolamine (MEA) solution was used as a basic standard to evaluate CO2 capture performance of new absorbents. Cations (tetramethylammonium [N1111], tetraethylammonium [N2222], methyl-triethylammonium[N2221], Methyl-tributylammonium [N1444], and (1-Butyl)triethylammonium [N2224]) and anions (L-Alanine, β-Alanine, Glycine, Sarcosine, and L-proline) were combined to yield 25 wt% tetra-alkyl-ammonium amino acid ionic liquid aqueous solutions, and then CO2 absorption and regeneration performances of new absorbents were investigated. The results show that [N1444][L- Alanine] have both high absorption and desorption efficiency without precipitation problem. Regeneration energy penalty of this absorbent is lower than heat of amine-based solutions. Thus, [N1444][L- Alanine] can be considered as a potential candidate for CO2 capture.

1. Allali, A.; Bojariu, R.; Diaz, S.; Elgizouli, I.; Griggs, D.; Hawkins, D.; Hohmeyer, O.; Jallow, B. P.; Kajfez4-Bogataj, L. k.; Leary, N.; Lee, H.; Wratt, D. Climate Change 2007:Synthesis Report; 2007.
2. Rochelle, G. T., Amine Scrubbing for CO2 Capture. Science 2009, 325 (5948), 1652-1654.
3. Strazisar, B. R.; Anderson, R. R.; White, C. M., Degradation pathways for monoethanolamine in a CO2 capture facility. Energ Fuel 2003, 17 (4), 1034-1039.
4. Eustaquio-Rincon, R.; Rebolledo-Libreros, M. E.; Trejo, A.; Molnar, R., Corrosion in aqueous solution of two alkanolamines with CO2 and H2S: N-methyldiethanolamine plus diethanolamine at 393 K. Ind Eng Chem Res 2008, 47 (14), 4726-4735.
5. Marsh, K. N.; Boxall, J. A.; Lichtenthaler, R., Room temperature ionic liquids and their mixtures - a review. Fluid Phase Equilibr 2004, 219 (1), 93-98.
6. Mathieu, P., The IPCC special report on carbon dioxide capture and storage. ECOS 2006: Proceedings of the 19th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, Vols 1-3 2006, 1611-1617.
7. Pires, J. C. M.; Martins, F. G.; Alvim-Ferraz, M. C. M.; Simoes, M., Recent developments on carbon capture and storage: An overview. Chem Eng Res Des 2011, 89 (9), 1446-1460.
8. Keith, D. W., Why Capture CO2 from the Atmosphere? Science 2009, 325 (5948), 1654-1655.
9. Brennecke, J. E.; Gurkan, B. E., Ionic Liquids for CO2 Capture and Emission Reduction. J Phys Chem Lett 2010, 1 (24), 3459-3464.

10. Caplow, M., Kinetics of Carbamate Formation and Breakdown. J Am Chem Soc 1968, 90 (24), 6795-6803.
11. Danckwerts, P. V., Reaction of CO2 with Ethanolamines. Chem Eng Sci 1979, 34 (4), 443-446.
12. Versteeg, G. F.; Van Dijck, L. A. J.; Van Swaaij, W. P. M., On the kinetics between CO2 and alkanolamines both in aqueous and non-aqueous solutions. An overview. Chem Eng Commun 1996, 144, 113-158.
13. Blauwhoff, P. M. M.; Versteeg, G. F.; Vanswaaij, W. P. M., A Study on the Reaction between CO2 and Alkanolamines in Aqueous-Solutions. Chem Eng Sci 1983, 38 (9), 1411-1429.
14. Sartori, G.; Savage, D. W., Sterically Hindered Amines for CO2 Removal from Gases. Ind Eng Chem Fund 1983, 22 (2), 239-249.
15. Chowdhury, F. A.; Okabe, H.; Yamada, H.; Onoda, M.; Fujioka, Y., Synthesis and selection of hindered new amine absorbents for CO2 capture. 10th International Conference on Greenhouse Gas Control Technologies 2011, 4, 201-208.
16. Supap, T.; Idem, R.; Tontiwachwuthikul, P.; Saiwan, C., Analysis of monoethanolamine and its oxidative degradation products during CO2 absorption from flue gases: A comparative study of GC-MS, HPLC-RID, and CE-DAD analytical techniques and possible optimum combinations. Ind Eng Chem Res 2006, 45 (8), 2437-2451.
17. Hook, R. J., An investigation of some sterically hindered amines as potential carbon dioxide scrubbing compounds. Ind Eng Chem Res 1997, 36 (5), 1779-1790.
18. Penny, D. E.; Ritter, T. J., Kinetic-Study of the Reaction between Carbon-Dioxide and Primary Amines. J Chem Soc Farad T 1 1983, 79, 2103-2109.

19. Seddon, K. R., Ionic liquids for clean technology. J Chem Technol Biot 1997, 68 (4), 351-356.
20. Plechkova, N. V.; Seddon, K. R., Applications of ionic liquids in the chemical industry. Chem Soc Rev 2008, 37 (1), 123-150.
21. Kumar, S.; Cho, J. H.; Moon, I., Ionic liquid-amine blends and CO2BOLs: Prospective solvents for natural gas sweetening and CO2 capture technology-A review. Int J Greenh Gas Con 2014, 20, 87-116.
22. Blanchard, L. A.; Hancu, D.; Beckman, E. J.; Brennecke, J. F., Green processing using ionic liquids and CO2. Nature 1999, 399 (6731), 28-29.
23. Blanchard, L. A.; Gu, Z. Y.; Brennecke, J. F., High-pressure phase behavior of ionic liquid/CO2 systems. J Phys Chem B 2001, 105 (12), 2437-2444.
24. Anthony, J. L.; Maginn, E. J.; Brennecke, J. F., Solubilities and thermodynamic properties of gases in the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate. J Phys Chem B 2002, 106 (29), 7315-7320.
25. Kamps, A. P. S.; Tuma, D.; Xia, J. Z.; Maurer, G., Solubility of CO2 in the ionic liquid [bmim][PF6]. J Chem Eng Data 2003, 48 (3), 746-749.
26. Bates, E. D.; Mayton, R. D.; Ntai, I.; Davis, J. H., CO2 capture by a task-specific ionic liquid. J Am Chem Soc 2002, 124 (6), 926-927.
27. Gurkan, B. E.; de la Fuente, J. C.; Mindrup, E. M.; Ficke, L. E.; Goodrich, B. F.; Price, E. A.; Schneider, W. F.; Brennecke, J. F., Equimolar CO2 Absorption by Anion-Functionalized Ionic Liquids. J Am Chem Soc 2010, 132 (7), 2116-+.
28. Goodrich, B. F.; de la Fuente, J. C.; Gurkan, B. E.; Zadigian, D. J.; Price, E. A.; Huang, Y.; Brennecke, J. F., Experimental Measurements of Amine-Functionalized Anion-Tethered Ionic Liquids with Carbon Dioxide. Ind Eng Chem Res 2011, 50 (1), 111-118.

29. Yu, H.; Wu, Y. T.; Jiang, Y. Y.; Zhou, Z.; Zhang, Z. B., Low viscosity amino acid ionic liquids with asymmetric tetraalkylammonium cations for fast absorption of CO2. New J Chem 2009, 33 (12), 2385-2390.
30. 周震宇. 四烷基銨氨基酸鹽型離子液體水溶液的蒸氣壓與其應用. 義守大學, 2014.
31. 林柏含. 高濃度之胺類/醇/水混合溶液應用於二氧化碳捕捉. 清華大學, 2013.
32. Lail, M.; Coleman, L.; Jamal, A.; Lesemann, M.; Gupta, R.; Riemann, C.; Sugavanam, K.; Spengeman, T., Novel non-aqueous CO2 solvents and capture process with substantially reduced energy penalties. In the 1st Post-Combustion Capture Conference, Abu Dhabi, 2011.
33. Smith, J. M.; Ness, H. C. V.; Abbot, M. M., Introduction to Chemical Engineering Thermodynamics. 7th ed.; McGraw-Hill: 2004.
34. Maham, Y.; Hepler, L. G.; Mather, A. E.; Hakin, A. W.; Marriott, R. A., Molar heat capacities of alkanolamines from 299.1 to 397.8 K - Group additivity and molecular connectivity analyses. J Chem Soc Faraday T 1997, 93 (9), 1747-1750.
35. Chiu, L. F.; Liu, H. F.; Li, M. H., Heat capacity of alkanolamines by differential scanning calorimetry. J Chem Eng Data 1999, 44 (3), 631-636.