【摘要】 载氧体稳定性差是限制化学链制氢技术发展的主要因素之一，针对此问题，通过提高载体-活性组分之间的相互作用，抑制反应过程中的烧结团聚来增强载氧体稳定性。制备了Fe₂O₃/MgAl₂O₄载氧体，以甲烷为原料，在小型流化床反应器上模拟双床（甲烷还原/水蒸气氧化）化学链制氢过程，探究氧化铁含量和反应条件对载氧体甲烷化学链制氢反应性能的影响。结果表明，Fe₂O₃/MgAl₂O₄载氧体中氧化铁最佳质量分数为20%,最佳工艺条件为：CH₄体积分数5%,温度900℃,水蒸气体积分数20%。XRD、SEM等表征和实验结果表明，Fe离子融入了MgAl₂O₄尖晶石的体相内并增强了载氧体稳定性，当氧化铁质量分数高于20%时，载氧体会因烧结团聚迅速失活，高体积分数甲烷会因裂解速率高于载氧体释氧速率而产生大量积炭，升高温度可增强反应活性，但温度过高则会影响载氧体的稳定性。更多还原

【Abstract】 Poor stability of oxygen carrier is one of the main factors restricting the development of chemical looping hydrogen generation technique. In view of this, the stability of oxygen carrier was improved by enhancing the interaction between carrier and active component and inhibiting sintering agglomeration during reaction. Using the prepared Fe₂O₃/MgAl₂O₄ oxygen carrier as oxygen carriers and CH₄ as feedstock, the dual-bed（CH₄ reduction/steam oxidation） hydrogen production process was simulated in a small fluidized bed reactor, so as to explore the effects of Fe₂O₃ content and reaction conditions on the reaction performance of CH₄ chemical looping hydrogen generation by oxygen carrier. The results indicate that the optimal mass fraction of Fe₂O₃ in the oxygen carrier Fe₂O₃/MgAl₂O₄ is 20% and the optimal processing conditions are 5% CH₄ and 20% steam at 900 ℃. The XRD, SEM characterizations and experiment results show that Fe ion is integrated into MgAl₂O₄ lattice and can enhance the stability of oxygen carrier. When Fe₂O₃ mass fraction is higher than 20%, the oxygen carrier will be quickly deactivated due to sintering agglomeration. In addition, CH₄ with a high volume fraction will lead to a large amount of carbon deposition due to the fact that pyrolysis rate is higher than the oxygen release rate of oxygen carrier; reaction activity can be boosted by increasing temperature, and the stability of oxygen carrier tends to decrease under overtemperature.更多还原