铜基复合载氧体化学链氧解耦协同机制及氧迁移机理研究

The Cu-based oxygen carrier has high reduction temperature and agglomeration will occur when used in high temperatures. In order to improve the thermodynamic properties of Cu-based oxygen carrier, widen the reduction temperatures and heighten the sintering temperatures, other oxides are added to CuO to prepare combined Cu-based oxygen carriers. The oxides which are suitable to prepare the combined Cu-based oxygen carriers will be selected through thermodynamic and density functional analysis method preliminarily. The thermodynamic properties of the new combined Cu-based oxygen carriers will be obtained too. Based on the characterization methods, the effects of the preparation method and preparation parameters on the physical and chemical properties of the combined Cu-based oxygen carrier will be investigated. The optimized preparation parameters will be determined. Through mechanism experiments and density functional analysis, the kinetic models of the reduction and oxidation reactions of the combined Cu-based oxygen carriers will be established and the oxygen transport mechanism during the reduction and oxidation processes will be explored. The lab-scale experimental platform will be set up and the effects of operating parameters on reduction and oxidation reactivity of the oxygen carrier will be investigated. The macro-kinetics models of the reduction and oxidation reactions of the oxygen carrier will be established. The micro characteristics of oxygen carrier during the cycles will be analyzed. The highest sintering temperature and the lifetime of the combined oxygen carrier will be predicted. The ideas of this study is novel and it can provide a reference for the research of other types oxygen carriers. The CLAS, CLOU technologies will be promoted in industrial applications and it is important to energy conservation and emission reduction.

针对铜基载氧体化学链应用中释氧温度高，易烧结的问题，本项目提出复合的方式构筑铜基复合载氧体以改善载氧体热力性质，拓宽载氧体使用温度区间，并提高载氧体烧结温度的研究思路。采用热力学分析和密度泛函理论，对复合基氧化物进行筛选，并获得新型载氧体的热力性质；研究制备方法和制备参数对载氧体释氧、吸氧及机械组织性能的影响，确定复合基氧化物种类和添加比例，并优选载氧体的制备工艺路线；机理实验和密度泛函理论相结合，建立载氧体微观反应动力学模型，探索载氧体释氧和吸氧过程氧传递机理；搭建热态实验平台，研究操作参数对载氧体释氧和吸氧性能的影响并建立载氧体反应的宏观动力学模型；研究载氧体循环过程中微观性能的变化及相迁移规律，确定载氧体的最高烧结温度及使用寿命，为工业应用提供基础数据。以上研究为化学链载氧体的研究提供一种新的思路，并将有效推进CLOU、CLAS技术的工业应用，为国家节能减排工作做出重要贡献。

针对铜基载氧体化学链应用中释氧温度高，易烧结的问题，本项目提出复合的方式构筑铜基复合载氧体以改善载氧体热力性质，拓宽载氧体使用温度区间，并提高载氧体烧结温度的研究思路。研究了Mn2O3、Co3O4、Pb3O4、Cr2O3复合CuO后氧化物的氧解耦性能，确定铜锰复合为最优复合类型；确定最优复合比例为CuO:Mn2O3=1.5:1，煅烧温度为950℃，煅烧时间为6h；DFT计算表明，铜锰复合后Cu4O4团簇中Cu–O的平均键长由1.983增加到2.047Å，电荷从Cu4O4转移到Mn3O4（001），吸附能为-3.749ev，复合体系具有好的稳定性和抗烧结性；确定了铜锰复合载氧体吸释氧反应的热力学和动力学数据，G = -0.119T + 150.41 kJ/mol，Kp = exp(14.31 –18090.8/T)，吸释氧反应遵循分段反应动力学模型，可分别用缩核机理和化学反应机理加以描述，建立了微观反应动力学模型；进行了复合载氧体吸释氧反应热态实验研究，考察了反应温度、气体流量、氧气浓度等因素对宏观反应特性影响，建立了宏观反应动力学模型；循环实验结果表明，该载氧体在900℃下保持了很好循环稳定性，微观组织性能保持稳定。以上研究为化学链载氧体的研究提供一种新的思路，并将有效推进CLOU、CLAS技术的工业应用，为国家节能减排工作做出重要贡献。