Effect of K_xFe_yO_z on chemical looping catalytic combustion of coal

The calcium aluminate cement as a cheap material was used to produce a novel cement-supported Fe₂O₃ oxygen carrier via mechanically mixing and extrusion method. The ratio of cement addition and the effect of K as additive on the CLC performance of coal were experimentally investigated in a single fluidized bed reactor. The results suggest that there is a stable product of Ca₂Al₂SiO₇ formed in the oxygen carriers. The coal gasification rate and conversion rate are significantly accelerated by K in the oxygen carrier samples. A stable phase of K₂Fe₂₂O₃₄ is found in the oxygen carriers. The catalytic effect of K in the coal CLC process depends on the phase transformation of K₂Fe₂₂O₃₄ and KFeO₂.