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本文使用化学吸附仪研究Fe_2O_3/Al_2O_3氧载体与H_2的反应机理。在化学吸附仪中氧载体与H2在不同升温速率下发生程序升温还原反应(TPR),通过氢气消耗量计算氧载体转化率X,结合热力学平衡模拟辨识不同转化率区间的主导性反应;进而利用热分析动力学的积分法并结合双外推法研究各部分的反应机理。结果表明,转化率X为0～0.35时,反应可用二级化学反应速率方程来描述,机理函数为G(X)=(1-X)~(-1)-1,而在X为0 35～0 95时,反应可用成核-核生长模型来描述,机理函数表示为G(X)=[-ln(1-X)]~(3/4)。
In this paper, the reaction mechanism of Fe 2 O 3 / Al 2 O 3 oxygen carrier with H 2 was studied by chemisorbing. In the chemisorbed oxygen carrier, the temperature-programmed reduction reaction (TPR) of oxygen carrier and H2 occurs at different heating rates, and the oxygen carrier conversion rate X is calculated from the hydrogen consumption. Based on the thermodynamic equilibrium simulation, the dominant reactions of different conversion rates are identified. The integral method of thermal analysis kinetics and the double extrapolation method are used to study the reaction mechanism of each part. The results show that when the conversion rate X is 0 ~ 0.35, the reaction can be described by the second-order chemical reaction rate equation with the mechanism function G (X) = (1-X) -1, while when X is 0 35 ~ 0 95, the reaction can be described by the nucleation-growth model. The mechanism function is expressed as G (X) = [- ln (1-X)] ~ (3/4).