Kinetics of the thermal dissociation of ZnO exposed to concentrated solar irradiation using a solar‐driven thermogravimeter in the 1800–2100 K range
Kinetics of the thermal dissociation of ZnO exposed to concentrated solar irradiation using a solar‐driven thermogravimeter in the 1800–2100 K range
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DOI：
10.1002/aic.11765
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发表时间：
2009-06
期刊：
影响因子：
3.7
通讯作者：
L. O. Schunk;A. Steinfeld
中科院分区：
文献类型：
--
作者：
L. O. Schunk;A. Steinfeld
基于Zn/ZnO氧化还原反应的两步H2O裂解热化学循环被认为是太阳能H2生产，包括吸热分解的ZnO，然后由Zn的experimental水解。一个太阳能驱动的热重计，其中的ZnO颗粒的填充床直接暴露于集中的太阳辐射在2400个太阳的峰值太阳能浓度比，同时其重量损失是连续监测，被施加到测量的热分解率在一个设置密切接近的太阳能反应器的传热传质特性。在1834-2109 K范围内进行等温热重试验，并拟合零级阿克里尼乌斯速率定律，表观活化能为361 ± 53 kJ mol−1 K−1，频率因子为14.03 × 106 ± 2.73 × 106 kg m−2 s−1。应用L 'vov的固体分解动力学表达式沿着与对流传质相关产生的动力学参数与来自实验数据的密切一致。© 2009美国化学工程师学会AIChE J，2009
The two-step H2O-splitting thermochemical cycle based on the Zn/ZnO redox reactions is considered for solar H2 production, comprising the endothermal dissociation of ZnO followed by the exothermal hydrolysis of Zn. A solar-driven thermogravimeter, in which a packed-bed of ZnO particles is directly exposed to concentrated solar radiation at a peak solar concentration ratio of 2400 suns while its weight loss is continuously monitored, was applied to measure the thermal dissociation rate in a set-up closely approximating the heat and mass transfer characteristics of solar reactors. Isothermal thermogravimetric runs were performed in the range 1834–2109 K and fitted to a zero-order Arrhenius rate law with apparent activation energy 361 ± 53 kJ mol−1 K−1 and frequency factor 14.03 × 106 ± 2.73 × 106 kg m−2 s−1. Application of L‘vov’s kinetic expression for solid decomposition along with a convective mass transport correlation yielded kinetic parameters in close agreement with those derived from experimental data. © 2009 American Institute of Chemical Engineers AIChE J, 2009