Performance of Perovskite-Type Oxides as Oxygen-Carrier Materials for Chemical Looping Combustion in the Presence of H2S

In this study, the redox behavior and the effect of the presence of sulfur on the performance of the CaTixMn0.9-xMg0.1O3 perovskite-type system were investigated. A detailed thermodynamic and thermogravimetric approach combined with post-characterization was utilized. Ti doping positively influenced the reduction reaction rate and broadened the operation window of the oxygen carrier material (OCM) to lower temperatures. Although sulfur accumulation during the chemical looping with oxygen uncoupling conditions was thermodynamically inevitable owing to sulfate formation, deep redox cycles were shown to remove the accumulated sulfur from the OCM after the sour cycles. Post-characterization by scanning electron microscopy and sulfur mapping confirmed the effectiveness of this treatment.