Comparison of nickel and iron-based oxygen carriers supported on alumina in syngas-fueled chemical looping combustion.

摘要

Chemical looping is considered as a novel technology capable of resolving both energy and environmental problems in combustion process. The possibility of using oxides of nickel (Ni) and iron (Fe) as oxygen carriers was investigated. Solid oxygen carriers were prepared by deposition of metal oxides on gamma-Alumina (Al2O3) particles by incipient wet impregnation method. The reactivity of metal oxides was examined in a thermogravimetric analyzer (TGA), where they were exposed to syngas (34% CO, 66% H2) and steam for reduction, and to air (79% N2, 21% O2) for oxidation at temperature ranging from 700°C to 900°C. Fe and Ni particles showed high reactivity at high temperatures with reduction rate of 95%/min and 85%/min, respectively. Oxidation rate for both metal oxides were 100%/min. Furthermore, nickel oxide showed promising potential to be used under cyclic conditions since it showed high strength under multiple cycles while Fe particles show sign of agglomeration which affect their reactivity during multiple cycles.