Kinetics of Magnetite (Fe3O4) Oxidation to Hematite (Fe2O3) in Air for Chemical Looping Combustion

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• 作者：Esmail R. Monazam ; Ronald W. Breault ; Ranjani Siriwardane
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：August 27, 2014
• 年：2014
• 卷：53
• 期：34
• 页码：13320-13328
• 全文大小：551K
• ISSN：1520-5045

文摘

Thermogravimetric analysis (TGA) of magnetite (Fe₃O₄) oxidation was conducted at temperatures ranging from 750 to 900 掳C over 10 oxidation cycles. Oxidation experiments were carried out in a continuous stream of air for period of 30 min. The oxidized magnetite (Fe₃O₄), which resulted in formation of hematite (Fe₂O₃), was then reduced by using continuous stream of CO (5% and 10%) with N₂ balance. The rate of oxidation was determined by the oxygen weight gain. Analysis of the data indicated that the oxidation behavior followed a two-stage process. The initial oxidation, which was very fast, took place in 2 min and was described using nucleation and growth processes with a low activation energy of about 4.21 卤 0.45 kJ/mol. As the reaction developed within the surface, oxygen transport through the product layer become the rate-controlling step with activation energy of 53.58 卤 3.56 kJ/mol.