Abstract This study aims to investigate the kinetic compensation effects during the char-O2 reaction in a fluidised-bed reactor for two particle sizes of 0.80–1.0 mm and 2.0–3.35 mm. The rate of char-O2 reaction was determined by analysing the gasification product gas composition in a quadrupole mass spectrometer. The char-O2 reaction exhibited different kinetic compensation effects between apparent activation energy and apparent pre-exponential factor in the kinetics-controlled, diffusion-controlled and mixed regimes for both particle sizes. The same reaction mechanism is followed during the char-O2 reaction in the kinetic regime at same or at different pyrolysis temperatures as revealed by the kinetic compensation effects. In the mixed regime, higher diffusion limitations increased the m and c values in the kinetic compensation effect lnAapp = mEapp + c for any given particle size. Due to higher rates of reaction at higher char conversions, the char-O2 reaction switched from kinetics-controlled to mixed regimes, resulting in higher slopes ‘m’ and y-intercepts ‘c’ in the kinetic compensation effects. The absence of isokinetic temperature at higher conversions indicates that char properties changed significantly at higher conversions compared with those at lower conversions.

中文翻译：

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生物炭在氧气中气化过程中化学反应控制和传质控制的动力学补偿效应

摘要 本研究旨在研究流化床反应器中炭-O2 反应过程中的动力学补偿效应，两种粒径为 0.80-1.0 mm 和 2.0-3.35 mm。通过在四极杆质谱仪中分析气化产物气体组成来确定炭-O2 反应的速率。炭-O2 反应在动力学控制、扩散控制和混合状态下两种粒径的表观活化能和表观指数前因子之间表现出不同的动力学补偿效应。正如动力学补偿效应所揭示的那样，在相同或不同热解温度下的动力学状态下，在炭-O2 反应过程中遵循相同的反应机制。在混合体制下，对于任何给定的粒径，较高的扩散限制增加了动力学补偿效应 lnAapp = mEapp + c 中的 m 和 c 值。由于在较高的炭转化率下反应速率较高，炭-O2 反应从动力学控制转变为混合状态，导致动力学补偿效应中更高的斜率“m”和 y 截距“c”。在较高转化率下不存在等速温度表明与较低转化率下的炭特性相比，较高转化率下的焦炭性质发生了显着变化。