High-Temperature CO2 Adsorption On LiXZrYOZ Ceramics

Tuesday, November 9, 2010
Hall 1 (Salt Palace Convention Center)
Qin-Hui Zhang, Xian-Sheng Yin and Jian-Guo Yu, College of Chemical Engineering, East China University of Science and Technology, Shanghai, China

CO2 is one of the major greenhouse gases (GHG) and the largest contributor to the global warming effects (about 60% in regard of its amount in the atmosphere), and coal-burning power plant is the major source of CO2 generation with the typical CO2 content about 10-13%, thus, CO2 adsorption from the flue gas might be an effective approach for CO2 Capture and Storage (CCS). Various materials have been proposed as CO2 captors, including zeolites, carbon-based adsorbent, hydrotalcites and metal oxides. However, the temperature of the flue gas vent is about 573-773 K depended on various follow-up process of waste heat utilization, it is highly desired to separate CO2 directly from flue gas at high temperature so as to use it as a feedstock for the synthesis of methanol and other chemicals, and the adsorbents should generally have high selectivity and adsorption capacity for CO2 at high temperature, as well as good adsorption-regeneration kinetics and high multi-cycle stability. In this paper, pure monoclinic Li6Zr2O7 and rhombohedral Li8ZrO6 with fraction of Li6Zr2O7 are synthesized via co-precipitation method and characterized by SEM, TGA, and high-temperature CO2 adsorption-desorption measurement. The adsorbents exhibit slow CO2 uptake rate since the inhibited diffusion of CO2 in the solid carbonate shell at T<973 K, as T>983 K (the Li2CO3 melting point), the CO2 uptake rate enhances remarkably with 12.3% and 35.0% weight gain within 15 min at 1073 K respectively. The possible pathway of the adsorption process is further proposed. The Li6Zr2O7 and Li8ZrO6 are promising candidates for CO2 high-temperature adsorption.

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