Purnomo Victor, Mei Daofeng, Staničić Ivana, Mattisson Tobias, Leion Henrik
Division of Energy and Materials, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg 412 58, Sweden.
Division of Energy Technology, Department of Space, Earth, and Environment, Chalmers University of Technology, Göteborg 412 58, Sweden.
Energy Fuels. 2024 Jun 20;38(13):11824-11836. doi: 10.1021/acs.energyfuels.4c00928. eCollection 2024 Jul 4.
The role of the oxygen carrier is important in energy conversion processes with fluidized beds, particularly chemical looping technology. It is necessary to establish the relevant kinetics of oxygen carriers that can be applicable for various chemical looping processes. In this study, we analyzed the apparent kinetics of three iron-based oxygen carriers, namely, ilmenite, iron sand, and LD slag, during the conversion of CO, H, and CH in a fluidized bed batch reactor. The effect of both the oxidation degree, presented as the mass conversion degree, and temperature was considered. The results show that the changing grain size (CGS) model is generally applicable in predicting the apparent kinetics of reactions between the investigated iron oxygen carriers and gaseous fuels even at lower oxidation degrees (3-5 wt % reduction). The activation energies of the investigated materials in the conversions of CO, H, and CH obtained from the fittings of the CGS model are about 51-92, 55-251, and 72-211 kJ/mol, respectively. Both the mass conversion degree and temperature influence the reactivity of oxygen carriers in a directly proportional way, especially at temperatures higher than 925 °C. The results of this study are useful for reaction engineering purposes, such as designing a reactor, in chemical looping units, or in any other processes that use oxygen carriers as a bed material.
氧载体在流化床的能量转换过程中，尤其是化学链技术中起着重要作用。有必要建立适用于各种化学链过程的氧载体相关动力学。在本研究中，我们分析了三种铁基氧载体，即钛铁矿、铁砂和转炉渣，在流化床间歇反应器中CO、H和CH转化过程中的表观动力学。考虑了以质量转化率表示的氧化程度和温度的影响。结果表明，即使在较低氧化程度（3-5 wt%还原）下，变粒度（CGS）模型通常也适用于预测所研究的铁氧载体与气态燃料之间反应的表观动力学。通过CGS模型拟合得到的所研究材料在CO、H和CH转化中的活化能分别约为51-92、55-251和72-211 kJ/mol。质量转化率和温度都以正比方式影响氧载体的反应性，特别是在高于925℃的温度下。本研究结果对于反应工程目的很有用，例如在化学链装置中设计反应器，或在任何其他使用氧载体作为床料的过程中。
