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Modification of KNO 3 on the reducibility and reactivity of Fe 2 O 3 ‐based oxygen carriers for chemical‐looping combustion of methane
Author(s) -
Cheng Xianming,
Li Kongzhai,
Wei Yonggang,
Zhu Xing,
Tian Dong
Publication year - 2017
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22831
Subject(s) - chemical looping combustion , oxygen , reactivity (psychology) , methane , chemistry , combustion , inorganic chemistry , x ray photoelectron spectroscopy , potassium , redox , nuclear chemistry , analytical chemistry (journal) , chemical engineering , organic chemistry , medicine , alternative medicine , pathology , engineering
This work presented a comparative study on the Fe 2 O 3 ‐based oxygen carriers modified by different potassium salts (i.e. KNO 3 , K 3 PO 4 , KOH, K 2 CO 3 ) for chemical looping combustion of methane (CLC with methane). The effect of Al 2 O 3 support on the reactivity of Fe 2 O 3 was also investigated. The Fe 2 O 3 ‐based oxygen carriers were prepared by a co‐precipitation method and the potassium salts were added via an incipient wetness impregnation method. The obtained oxygen carriers were characterized by XRD, XPS, H 2 ‐TPR, and CH 4 ‐TPR technologies. It was found that the presence of KNO 3 could improve the reducibility of the Fe 2 O 3 ‐based oxygen carrier in the surface, resulting in relatively high selectivity towards CO 2 during the CLC with methane. The content of KNO 3 also affected the reactivity of oxygen carriers, and 10 % KNO 3 /Fe 2 O 3 sample showed the best activity. Moreover, it was also demonstrated that the addition of Al 2 O 3 support into the 10 % KNO 3 /Fe 2 O 3 oxygen carrier could improve its redox performance, and the stability of 10 % KNO 3 /Fe 2 O 3 /Al 2 O 3 was proved to be favourable after twenty successive cycles for CLC with methane.