The development of a highly reactive, stable, economic and environmentally friendly oxygen carrier is considered the key issue in the large scale application of chemical looping combustion. The availability of Iron, besides being cheap, nontoxic and environmentally friendly made it commercially attractive for CLC application. The main objective of this work is to improve the reactivity of Fe.
The oxygen carriers were synthesized using incipient wetness technique . The starting materials are γ-Al2O3, Ce(NO3)3.6H2O and Fe(NO3)3.9H2O. The preparation of the oxygen carrier consists of four major steps: impregnation, drying, reduction and finally calcination. First the support was modified using 1 wt% Ce before loading the metal in 4 cycles, 5 wt% each to reach a final concentration of 20 wt%.
The oxygen carrier reactivity and its ability to withstand the repeated oxidation/reduction cycles are investigated through successive TPO/TPR experiments. The samples reducibility and oxygen carrying capacity can be also extracted from TPR profiles. The reduction profile of the oxygen carrier shows a slightly narrow peak at around 357 ºC and a wider peak at 564 ºC. The first reduction peak corresponds to the reduction of Fe2O3 to Fe3O4 while the second corresponds to the transition of Fe3O4 to FeO to Fe. The reduction percentage of the oxygen carrier is around 88%, which remained stable through 10 TPR/TPO cycles.
See more of this Group/Topical: Topical Conference: Innovations of Green Process Engineering for Sustainable Energy and Environment