Isothermal differential characteristics of gas–solid reaction in micro-fluidized bed reactor
Isothermal differential characteristics of gas–solid reaction in micro-fluidized bed reactor
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DOI：
10.1016/j.fuel.2011.09.060
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发表时间：
2013
期刊：
影响因子：
7.4
通讯作者：
Jian Yu;Xi Zeng;Juwei Zhang;M. Zhong;Guangyi Zhang;Yin Wang;Guangwen Xu
中科院分区：
文献类型：
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作者：
Jian Yu;Xi Zeng;Juwei Zhang;M. Zhong;Guangyi Zhang;Yin Wang;Guangwen Xu
利用自行研制的微流化床反应分析仪(MFBRA)研究了微流化床反应器中气固反应的等温微分特性。以微米级石墨粉的燃烧为模型反应，其内扩散可以忽略不计，化学反应简单。在内外扩散抑制最小的情况下，用等温动力学方法分析了MFBRA中的反应，得到反应的活化能为165kJ/m ol，指前因子为1061/S，并进一步发现该反应符合G(α)=−ln(1−α))的成核与生长模型。用程序升温方法测量TG中的该反应，得到相似的活化能和相同的反应函数模型(通过外推到零转化率)。与非等温热分析方法需要复杂的数学计算相比，MFBRA的等温差分方法允许温度效应(即反应速率常数)和动力学函数模型的分离，从而提供了一种简单可靠的气固反应动力学测定方法。
The isothermal differential characteristics of the gas–solid reaction occurring in a micro-fluidized bed reactor were studied using the indigenously developed Micro-Fluidized Bed Reaction Analyzer (MFBRA). The combustion of graphite powder in micrometers was taken as the model reaction because of its negligible internal diffusion and chemical-reaction simplicity. With minimized inhibitions from both the internal and external diffusions, the reaction in MFBRA at a preset temperature was analyzed by using the isothermal kinetic approach, resulting in an activation energy of 165kJ/mol and a pre-exponential factor of 1061/s. The reaction was further found to be subject to the nucleation and growth model expressed by G(α)=−ln(1−α). Measuring this reaction in TG via the programmed heating method resulted in the similar activation energy and the same reaction function model (by extrapolating to zero conversion). Comparing with the non-isothermal approach for TG that involves complicated mathematical calculations, the isothermal differential approach for MFBRA allowed the separation of the temperature effect (i.e., the reaction rate constant) and kinetic function model, thus providing a simple and reliable determination of the gas–solid reaction kinetics.