Investigation of BaFe2O4 oxygen carrier modified by supports in chemical looping gasification of biochar

Abstract

BaFe2O4 (BF) is a promising oxygen carrier (OC) for chemical looping gasification (CLG), but its stability is low due to serious sintering. The novelty of this work is to investigate the potential of adding different supports (Al2O3, MgAl2O4, and ZrO2) with BF to enhance performance and stability in the CLG of biochar. The results demonstrated that the addition of the supports had enhanced sintering resistance, surface area, pore properties, and oxygen vacancies on the surface simultaneously with positive effects on CLG performance. Among all supports, MgAl2O4 with 50% content displayed the greatest syngas yield (0.088 mol/g) and carbon conversion (80.76%), attributed to the highest surface area and total pore volume, as confirmed by BET results. Moreover, despite the slight decline in the reactivity due to ash deposition, the BF/MgAl2O4 showed stable CLG performance during the multiple cycles, which can be ascribed to the resistance of sintering provided by MgAl2O4.