Characteristics of Copper-based Oxygen Carriers Supported on Calcium Aluminates for Chemical-Looping Combustion with Oxygen Uncoupling (CLOU)
Characteristics of Copper-based Oxygen Carriers Supported on Calcium Aluminates for Chemical-Looping Combustion with Oxygen Uncoupling (CLOU)
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DOI：
10.1021/acs.iecr.5b01172
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发表时间：
2015-07-08
影响因子：
4.2
通讯作者：
Dennis, John S.
中科院分区：
文献类型：
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作者：
Donat, Felix;Hu, Wenting;Dennis, John S.
通过湿混合，然后在1000 ℃下煅烧，合成了八种不同的氧载体（OC），其含有CuO（60wt%）和不同质量比的CaO与Al2O3作为载体。所使用的合成方法涉及钙铝水合物相的形成，并确保Ca2+和Al3+离子在分子水平上在载体中的均匀混合。在热重分析仪（TGA）和流化床反应器中评估了OC在800至950 ℃的温度范围内进行多达100次还原和氧化循环的性能。在这些循环实验中，对于所有OC，总是实现OC从CuO到Cu的完全转化，反之亦然。材料的反应性是如此之高，以至于在TGA中没有观察到失活，由于传质限制。结果表明，当载体中CaO与Al_2O_3的质量比大于0.55时，制备的OC在流化床中发生团聚，在25次循环后，在所有温度下均表现出明显的失活。高比例的质量CaO的Al 2 O3的支持导致CuO与CaO相互作用，形成混合氧化物，具有低的熔化温度，这解释了这些材料的倾向，团聚。当载体中的CaO与Al2O3的质量比为
Eight different oxygen carriers (OC) containing CuO (60 wt %) and different mass ratios of CaO to Al2O3 as the support were synthesized by wet-mixing followed by calcination at 1000 degrees C. The method of synthesis used involved the formation of calcium aluminum hydrate phases and ensured homogeneous mixing of the Ca2+ and Al3+ ions in the support at the molecular level. The performance of the OCs for up to 100 cycles of reduction and oxidation was evaluated in both a thermogravimetric analyzer (TGA) and a fluidized bed reactor, covering a temperature range of 800 to 950 degrees C. In these cycling experiments, complete conversion of the OC, from CuO to Cu and vice versa, was always achieved for all OCs. The reactivity of the materials was so high that no deactivation could be observed in the TGA, owing to mass transfer limitations. It was found that OCs prepared with a mass ratio of CaO to Al2O3 in the support >0.55 agglomerated in the fluidized bed, resulting in an apparent deactivation over 25 cycles for all temperatures investigated. High ratios of mass of CaO to Al2O3 in the support resulted in CuO interacting with CaO, forming mixed oxides that have low melting temperatures, and this explains the tendency of these materials to agglomerate. This behavior was not observed when the mass ratio of CaO to Al2O3 in the support was