Analysis on Chemical Reaction Kinetics of CuO/SiO2 Oxygen Carriers for Chemical Looping Air Separation

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• 作者：Hui Song ; Kalpit Shah ; Elham Doroodchi ; Terry Wall ; Behdad Moghtaderi
• 刊名：Energy & Fuels
• 出版年：2014
• 出版时间：January 16, 2014
• 年：2014
• 卷：28
• 期：1
• 页码：173-182
• 全文大小：523K
• ISSN：1520-5029

文摘

Chemical looping air separation (CLAS) offers an energy-efficient and cost-effective option for oxygen generation in several advanced power generation systems, such as integrated gasification combined cycle (IGCC), oxy-fuel combustion, and solid oxide fuel cells (SOFCs). In our previous study, CuO/SiO₂ has been identified as one of the most efficient oxygen carriers for the CLAS process because of its higher reactivity, greater oxygen transport capacity, and lower inventory requirement. In the current study, the kinetic analysis of CuO/SiO₂ oxygen carriers under a CLAS process environment has been conducted. The CuO/SiO₂ oxygen carriers with a varying CuO content of 18鈥?8 wt % were prepared by a dry impregnation method. The redox behavior was investigated under N₂ and air separately for the temperature range of 800鈥?75 掳C in a thermogravimetric analyzer (TGA). The reduction rate was found to increase gradually with an increasing temperature, while in contrast, a drop in the oxidation rate was observed. Furthermore, the chemical reaction kinetics of 18 wt % CuO/SiO₂ for reduction and oxidation was attained by fitting various gas鈥搒olid reaction mechanisms with the obtained experimental data. Among all studied gas鈥搒olid reaction mechanisms, it was observed that the Avrami鈥揈rofe鈥檈v random nucleation and subsequence growth model (A2) and phase boundary reaction model (R2) fitted well with reduction and oxidation experimental data, respectively. In addition, relevant kinetic parameters, such as activation energy, pre-exponential factor, and reaction order, were also determined.