Methane combustion by moving bed fuel reactor with Fe2O3/Al2O3 oxygen carriers

• Published in: Applied energy 2014-01, Vol.113, p.1909-1915
• Main Authors: Ku, Young, Wu, Hsuan-Chih, Chiu, Ping-Chin, Tseng, Yao-Hsuan, Kuo, Yu-Lin
• Format: Article
• Language: English
• Subjects: Chemical looping combustion; Iron-based oxygen carriers; Methane combustion; Moving bed reactor
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2013.06.014

•Moving bed reactor employed to methane combustion using iron-based oxygen carrier.•Fe2O3/Al2O3 oxygen carriers was prepared and provided with applicable performance.•Carbon formation was enhanced with increased retention time at 900°C.•Full CH4 conversion was reached without carbon formation by moving bed operation.•FeO and FeAl2O4 were formed in the reacted oxygen carriers out of the reactor. Fe2O3/Al2O3 composite oxygen carriers were prepared for chemical looping combustion (CLC) with methane in a lab-scale moving bed fuel reactor provided with reasonable crush strength, reactivity and recyclability. Carbon formation was observed during the combustion process in the empty bed at 900°C through methane decomposition reaction, and was enhanced for experiments conducted with increased retention time. Carbon formation was obviously reduced for experiments conducted in the moving bed fuel reactor with oxygen carrier-to-fuel ratio (ϕ) higher than 1.14. The oxygen carriers that moving out of the moving bed reactor were composed of mainly FeO and FeAl2O4, characterized by X-ray diffraction (XRD) analysis. The formation of FeO and FeAl2O4 indicated that further utilization of oxygen in iron-based oxygen carriers can be achieved by moving bed operation.