基于CoFe2O4载氧体的生物质化学链气化热力学分析及实验研究

对基于CoFe₂O₄载氧体的生物质化学链气化反应进行了热力学分析，研究了载氧体添加量、温度及水蒸气含量对气化反应特性的影响。同时应用热重分析仪对CoFe₂O₄和生物质的气化反应特性进行了实验研究，并利用XRD对反应前后载氧体的物相组成进行分析。热力学研究表明，CoFe₂O₄在气化反应中能够提供晶格氧，有效促进生物质气化，提高碳转化率。随着反应温度升高，合成气中H₂和CO的含量增加，CO₂的含量减少。随着水蒸气含量增加，H₂和CO₂含量会增加，CO含量减少。添加水蒸气能够提高合成气中H₂和CO的比值，改善合成气的品质。热重实验及XRD结果表明，钴优先于铁被还原，钴与铁存在协同作用，钴能够促进铁的进一步还原。随着载氧体添加量的增加，载氧体被还原的程度会降低，载氧体与生物质的最佳质量比为0.8。

Thermodynamic analysis and experimental studies on chemical looping gasification of biomass with CoFe2O4 as oxygen carrier

The reactivity of biomass with CoFe₂O₄ oxygen carrier was investigated through thermodynamic analysis. The effects including amount of oxygen carrier, temperature and steam content on gasification characteristics of biomass were examined. Meanwhile, the reaction was experimentally investigated using thermogravimetric analysis. The phase of fresh and reacted oxygen carrier was characterized by X-ray diffraction (XRD).Thermodynamic analysis results show that CoFe₂O₄ can provide lattice oxygen and effectively improve gasification of biomass and carbon conversion efficiency. As the temperature goes up, amount of H₂ and CO increases, while CO₂ decreases. With amount of steam increases, H₂ and CO₂ yield increases while CO yield decreases. The ratio of H₂ to CO increases and high quality syngas can be obtained with the addition of steam. Thermogravimetric analysis and XRD results show that cobalt can be first reduced which can promote the further reduction of iron due to the synergistic effect. With the amount of oxygen carrier increases, reduction degree of oxygen carrier decreases. The optimal mass ratio of oxygen carrier to biomass is 0.8.