Fe‐substituted Ba‐hexaaluminates oxygen carrier for carbon dioxide capture by chemical looping combustion of methane

Fe‐substituted Ba‐hexaaluninates (BFA‐x (x = 1–3), x indicates Fe content) oxygen carrier (OC) were found to exhibit excellent sintering‐resistance under cyclic redox atmosphere at 800°C thanks to the reservations of the structure during the CH 4 reduction step, thus preventing the agglomeration of particles during the subsequent reoxidation step. Lattice oxygen highly active for the total combustion of CH 4 was observed in the hexaaluminate structure and its chemical state was influenced by Fe content. The highest amount of active O coordinated with Fe 3+ in the mirror plane (O‐Fe 3+ (M)) for the total combustion was reacted (0.77 mmol/g) for BaFe 3 Al 9 O 19 hexaaluminate OC. As a result, it exhibited the best reactivity with the CH 4 conversion of 83% and CO 2 selectivity of 100%. Moreover, superior regeneration and recyclability was also obtained, which originated from the fully recovery of O‐Fe 3+ (M) in the hexaaluminate structure. © 2015 American Institute of Chemical Engineers AIChE J , 62: 792–801, 2016