In the chemical looping hydrogen generation (CLHG) system, methane acts as an important reducing gas, whereas iron oxide has poor reactivity with methane, resulting in the inefficiency of the system. Thus, the fundamental reaction behavior between methane and iron oxide is of great importance. In this paper, applying a high/low-weight hourly space velocity technique, the reaction behavior in a dynamically operated packed-bed system was investigated based on the outlet gas concentration profiles. As the reduction process proceeded, complete oxidation, partial oxidation, and methane decomposition dominated in sequence. The results also validated that the CO/CO₂ relative mole fractions followed the equilibrium diagrams of the Fe–C–O system. The reaction behavior in the packed-bed reactor was a combination of thermodynamic limitation and the reaction front movement. This study suggested that the deep reduction CLHG technology is suitable for increasing the conversion of CH₄ in the packed-bed system.

中文翻译：

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使用高/低WHSV值揭示化学循环制氢过程中填充床中甲烷与氧化铁之间的反应行为

在化学循环制氢（CLHG）系统中，甲烷起着重要的还原性气体的作用，而氧化铁与甲烷的反应性差，导致系统效率低下。因此，甲烷和氧化铁之间的基本反应行为非常重要。在本文中，应用高/低重量时空技术，基于出口气体浓度分布图，研究了动态操作填充床系统中的反应行为。随着还原过程的进行，完全氧化，部分氧化和甲烷分解依次占主导地位。结果还证实了CO / CO ₂相对摩尔分数遵循Fe–C–O系统的平衡图。填充床反应器中的反应行为是热力学限制和反应前沿运动的结合。这项研究表明，深度还原CLHG技术适用于提高填充床系统中CH ₄的转化率。