Comparison study on strategies to prepare nanocrystalline Li₂ZrO₃-based absorbents for CO₂ capture at high temperatures

Abstract

A comparison study has been conducted on the strategies for synthesizing nanocrystalline Li₂ZrO₃ and K-doped Li₂ZrO₃ absorbents for CO₂ capture at high temperatures, including solid-state and liquid-phase methods, citrate route, and starch-assisted sol-gel method combined with freeze-drying technique. The absorption properties, including uptake rate and absorption capacity, of synthesized absorbents were investigated by thermogravimetric analysis (TGA) at different CO₂ partial pressures. The nanosized Li₂ZrO₃ crystals synthesized by the citrate route exhibit a faster uptake and a higher, nearly stoichiometric absorption capacity than those synthesized by the solid-state and liquid-phase methods. The doping of K into Li₂ZrO₃ can significantly improve the uptake rate of CO₂, especially at low CO₂ partial pressures. For the synthesis of K-doped Li₂ZrO₃, the citrate route has poor reproducibility and scalability, whereas the starch-assisted sol-gel method combined with freeze-drying technique is reproducible and easily scaled up, and the thus synthesized absorbents possess excellent CO₂ capture properties.

Keywords

CO₂ capture / Li₂ZrO₃ / K-doped Li₂ZrO₃ / citrate / starch / freeze-drying technique

References

[1] Moulijn J A, Makkee M, van Diepen A. Chemical Process Technology. New York: Wiley, 2001, 131–142

[2] Hufton J R, Mayorga S, Sircar S. Sorption-enhanced reaction process for hydrogen production. AIChE Journal. American Institute of Chemical Engineers, 1999, 45(2): 248-256

[3] Ochoa-Fernandez E, Haugen G, Zhao T, Ronning M, Aartun I, Borresen B, Rytter E, Ronnekleiv M, Chen D. Process design simulation of H₂ production by sorption enhanced steam methane reforming: evaluation of potential CO₂ acceptors. Green Chemistry, 2007, 9(6): 654-662

[4] Carvill B T, Hufton J R, Anand M, Sircar S. Sorption-enhanced reaction process. AIChE Journal. American Institute of Chemical Engineers, 1996, 42(10): 2765-2772

[5] Lee K B, Beaver M G, Caram H S, Sircar S. Reversible chemisorbents for carbon dioxide and their potential applications. Industrial & Engineering Chemistry Research, 2008, 47(21): 8048-8062

[6] Nakagawa K, Ohashi T. A novel method of CO₂ capture from high temperature gases. Journal of the Electrochemical Society, 1998, 145(4): 1344-1346

[7] Nakagawa K, Ohashi T. A reversible change between lithium zirconate and zirconia in molten carbonate. Electrochemistry, 1999, 67(6): 618-621

[8] Martínez-dlCruz L, Pfeiffer H, 0. Pfeiffer H. Toward understanding the effect of water sorption on lithium zirconate (Li₂ZrO₃) during its carbonation process at low temperatures. Journal of Physical Chemistry C, 2010, 114(20): 9453-9458

[9] Nair B N, Yamaguchi T, Kawamura H, Nakao S I, Nakagawa K. Processing of lithium zirconate for applications in carbon dioxide separation: Structure and properties of the powders. Journal of the American Ceramic Society, 2004, 87(1): 68-74

[10] Ida J, Lin Y S. Mechanism of high-temperature CO₂ sorption on lithium zirconate. Environmental Science & Technology, 2003, 37(9): 1999-2004

[11] Xiong R T, Ida J, Lin Y S. Kinetics of carbon dioxide sorption on potassium-doped lithium zirconate. Chemical Engineering Science, 2003, 58(19): 4377-4385

[12] Yi K B, Eriksen D O. Low temperature liquid state synthesis of lithium zirconate and its characteristics as a CO₂ sorbent. Separation Science and Technology, 2006, 41(2): 283-296

[13] Ochoa-Fernandez E, Ronning M, Grande T, Chen D. Nanocrystalline lithium zirconate with improved kinetics for high-temperature CO₂ capture. Chemistry of Materials, 2006, 18(6): 1383-1385

[14] Ochoa-Fernandez E, Ronning M, Grande T, Chen D. Synthesis and CO₂ capture properties of nanocrystalline lithium zirconate. Chemistry of Materials, 2006, 18(25): 6037-6046

[15] Qi X, Lin Y S, Swartz S L. Electric transport and oxygen permeation properties of lanthanum cobaltite membranes synthesized by different methods. Industrial & Engineering Chemistry Research, 2000, 39(3): 646-653

[16] Xiao Q, Liu Y F, Zhong Y J, Zhu W D. A citrate sol-gel method to synthesize Li₂ZrO₃ nanocrystals with improved CO₂ capture properties. Journal of Materials Chemistry, 2011, 21(11): 3838-3842

[17] Xiao Q, Tang X D, Liu Y F, Zhong Y J, Zhu W D. Citrate route to prepare K-doped Li₂ZrO₃ sorbents with excellent CO₂ capture properties. Chemical Engineering Journal, 2011, 174(1): 231-235

[18] Xiao Q, Tang X D, Zhong Y J, Zhu W D. A facile starch-assisted sol-gel method to synthesize K-doped Li₂ZrO₃ sorbents with excellent CO₂ capture properties. Journal of the American Ceramic Society, 2012, 95(5): 1544-1548

[19] Ochoa-Fernandez E, Ronning M, Yu X F, Grande T, Chen D. Compositional effects of nanocrystalline lithium zirconate on its CO₂ capture properties. Industrial & Engineering Chemistry Research, 2008, 47(2): 434-442

[20] Ida J, Xiong R, Lin Y S. Synthesis and CO₂ sorption properties of pure and modified lithium zirconate. Separation and Purification Technology, 2004, 36(1): 41-51

[21] Fauth D J, Frommell E A, Hoffman J S, Reasbeck R P, Pennline H W. Eutectic salt promoted lithium zirconate: Novel high temperature sorbent for CO₂ capture. Fuel Processing Technology, 2005, 86(14-15): 1503-1521

Acknowledgements

The financial supports from the National Basic Research Program of China (2009CB626607), the National Natural Science Foundation of China (21036006), the Program for Changjiang Scholars and Innovative Research Team in Chinese Universities (IRT0980), and the Program for Zhejiang Leading Team of Science and Technology Innovation (2011R09020-05) are gratefully acknowledged.

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg