Synthesis Gas Generation by Chemical-Looping Reforming in a Circulating Fluidized Bed Reactor Using Perovskite LaFeO3-Based Oxygen Carriers

Perovskite-based LaFeO3/Al2O3 Kaolin oxygen carriers, prepared by a wet-mixing kneading method, have been examined for chemical-looping reforming over a microfixed bed reactor and a circulating fluidized bed reactor. An oxygen carrier containing 60% LaFeO3 over 15Al(2)O(3)-25Kaolin exhibits higher reactivity, and can converted methane to syngas with high selectivity. The addition of Al2O3-Kaolin improves the oxygen migration rate from bulk to surface, and increases the amount of the very reactive oxygen species for CO2 formation. The CH4 conversion and CO selectivity rely heavily on reaction temperature and bed height. Increasing the fuel reactor temperature and bed height is beneficial for the reforming application with natural gas as fuel over a bubbling fluidized bed reactor. Preliminary results on the circulating fluidized bed reactor show that the CH4 conversion is about 25%, and CO selectivity is about 70% at an oxygen carrier-fuel molar ratio (1.32) and 900 degrees C. It is helpful to improve the redesign of the experimental facility and optimization of process parameters in further research. There is still a high potential for further improvement in mechanical strength and attrition resistance of perovskite-based oxygen carrier by optimization of binder and support.