Effect of calcination temperature on the performance of hexaaluminate supported CeO2 for chemical looping dry reforming
Effect of calcination temperature on the performance of hexaaluminate supported CeO2 for chemical looping dry reforming
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DOI：
10.1016/j.fuproc.2021.106873
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发表时间：
2021-05-01
影响因子：
7.5
通讯作者：
Wang, Xiaodong
中科院分区：
文献类型：
--
作者：
Cheng, Zheng;Zhang, Li;Wang, Xiaodong
甲烷化学循环干式重整是一种新型的氧载体循环合成气和CO2利用技术。在这项工作中，BaFe3Al9O19 （BF3）六铝酸盐负载CeO2作为CLDR的氧载体。结合一系列表征，仔细研究了CeO2与六铝酸盐的相互作用随煅烧温度（700、800、900和1000℃）的变化对CLDR性能的影响，并提出了可能的反应机理。结果表明：新鲜的CeO2/BF3由CeO2、β - al2o3和六铝酸磁铁矿（MP）组成；将煅烧温度从700℃提高到900℃，有利于提高CeO2与六铝酸盐之间的相互作用强度，有利于晶格氧向表面扩散。然而,1000年。C煅烧导致氧载体烧结，阻碍了晶格氧的迁移。在CeO2/BF3-T （T = 700 ~ 1000℃）中，CeO2/BF3-900℃不仅甲烷转化率高（接近85%），合成气产率高（1.28 ~ 2.02 mmol/g），具有理想的H-2/CO比（接近2），而且在CH4/CO2周期性氧化还原循环中具有优异的CO2活化能力和循环稳定性。其主要原因是Ce3+和Fe2+浓度较高，氧空位丰富，形成了CeFexAl1-xO3。
The chemical looping dry reforming (CLDR) of methane is a novel syngas production and CO2 utilization technology via the circulation of oxygen carrier. In this work, BaFe3Al9O19 (BF3) hexaaluminate supported CeO2 serves as oxygen carrier for CLDR. Combined with a series of characterization, the effect of interaction between CeO2 and hexaaluminate as a function of calcination temperatures (700, 800, 900 and 1000 degrees C) on the CLDR performance was carefully investigated, and then the possible reaction mechanism was proposed. The results show that fresh CeO2/BF3 is composed of CeO2, beta-Al2O3 and magnetoplumite (MP) hexaaluminate. Increasing the calcination temperature from 700 to 900 degrees C is conducive to enhancing the interaction strength between CeO2 and hexaaluminate, which favors the diffusion of lattice oxygen to the surface. However, 1000. C calcination leads to the sintering of oxygen carrier, which hinders the migration of lattice oxygen. Among CeO2/BF3-T (T = 700-1000 degrees C), CeO2/BF3-900 degrees C presents not only a high methane conversion (similar to 85%), high syngas yield (1.28-2.02 mmol/g) with ideal H-2/CO ratio (similar to 2), but also excellent CO2 activation ability and cyclic stability in the periodic CH4/CO2 redox cycles. The results were mainly attributed to the highest concentration of Ce3+ and Fe2+, abundant oxygen vacancies and the formation of CeFexAl1-xO3.