Ni-Fe supported on CaAl2O4 obtained from eggs shell for chemical looping technology

The development of oxygen carriers with specific properties is one of the main bottlenecks for applicability of chemical looping processes. Considering this, the article presents an investigation of the physicochemical, structural, morphological and reactive properties of four oxygen carriers based on Fe and/or Ni supported on calcium aluminate. Three different calcium aluminates were prepared: one by the conventional Pechini method, the following two using eggshell residue as calcium source, one with the shell in natura and last calcined at 500 °C. The support obtained from the eggshell in natura presented greater surface area and pore volume, being selected for continuity of the research. The active phase was added by the method of incipient wetness impregnation. XRD, TPR results showed that iron interacted with the support forming calcium ferrite, while nickel showed inert to the support. The reactivity by thermogravimetry showed that the OC Ni/CA presented practically 100 % reactivity in the cycles of reduction with methane and oxidation with air, and its structural and morphological properties remained unchanged after its regeneration.