378678 Carbon Dioxide Capture Using Amine-Functionalized Multi-Walled Carbon Nanotubes: Adsorption/Desorption Kinetics Studies and Effects of Flue Gas Contaminants

Tuesday, November 18, 2014
Galleria Exhibit Hall (Hilton Atlanta)
Qing Liu, Junjie Shi, Mengna Tao, Yi He and Yao Shi, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China

Industrial grade multi-walled carbon nanotubes (IG-MWCNTs) impregnated with tetraethylenepentamine (TEPA) are promising materials for solid sorbent-based CO2 capture from large point sources. In this work, the adsorption/desorption kinetics of amine-impregnated IG-MWCNTs were examined at various temperatures, CO2 partial pressure, and amine loadings. After evaluating four kinetic models for CO2 adsorption, it was found that Avrami's fractional order kinetic model provided the best fitting for the adsorption behavior of CO2. In order to find the optimal regeneration method, three desorption methods were evaluated for the regeneration of solid sorbents. Moreover, the tolerance of amine-impregnated IG-MWCNTs to trace flue gas contaminants was also investigated. It was found that H2O, NO, and SO2 had a minimal impact on CO2 adsorption capacity at 323K, while CO2 adsorption capacity decreased with increasing SO2 concentration at high temperature. Further analysis showed that irreversible sulphate/bisulphite deposited onto the solid sorbent might contribute to the decrease of CO2 adsorption capacity. Compared with silica-based adsorbents, the loss of CO2 capacity of IG-MWCNTs-50 (9.530%) was much lower than that of MCM-41-50 (40.430%) under SO2 concentration of 200 ppm in the presence of water vapor after 5 cycles.

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