基于改性铁矿石载氧体的煤化学链转化

Chemical Looping Conversion of Coal Using Modified Iron Ore Oxygen Carrier

采用混合煅烧法分别合成了K、Na、Ca、Ni、Mn、Cu修饰改性的铁矿石载氧体,利用X射线衍射(XRD)和H 2程序升温还原(H 2-TPR)对其理化性质进行表征,并基于热重实验考察改性载氧体与褐煤的反应性能。结果表明:由于固溶体新物相的生成,6种改性后铁矿石载氧体的反应活性均明显高于改性前;其中K改性铁矿石载氧体的反应性能优于Na、Ca改性铁矿石载氧体,Cu、Ni改性铁矿石载氧体的反应性能优于Mn改性铁矿石载氧体;铁矿石载氧体与褐煤混合质量比在5/5至6/4时反应性能最佳;K改性铁矿石载氧体与褐煤的反应性能高于Ni改性铁矿石载氧体的。

Oxygen carriers modified by K,Na,Ca,Ni,Mn and Cu were synthesized by the mixed calcination method.The physical and chemical properties of the oxygen carriers were firstly characterized using the X-ray diffraction(XRD)and H 2 temperature programmed reduction(H 2-TPR),and then the reaction performance of the modified oxygen carriers with lignite was studied based on the thermogravimetric experiments.The H 2-TPR experiments found that the reactivity of six modified oxygen carriers was significantly higher than that of unmodified oxygen carrier due to the formation of new phases in solid solution.The reactivity of K-modified iron ore is better than that of Na-and Ca-modified iron ore and the reactivity of Cu-and Ni-modified iron ore is better than that of Mn-modified iron ore.The thermogravimetric experiments found that the best reaction performance between the iron ore and the lignite is achieved at the mixed ratio of 5∶5-6∶4.The K-modified iron ore has a higher reactivity than the Ni-modified iron ore for lignite conversion.