Enhanced methane conversion in chemical looping partial oxidation systems using a copper doping modification

Chemical looping partial oxidation (CLPO) is a promising strategy of methane conversion to syngas with low cost and minimal environmental impact. A major challenge is the development of oxygen carriers that have high reactivity, high oxygen carrying capacity, and recyclability. We demonstrate that the addition of a low concentration (1%) of copper dopant to iron-based oxygen carriers can dramatically enhance the reactivity in CLPO process at low temperatures while maintaining the recyclability of these carriers. With the dopant, the methane conversion rate at 700 degrees C is 470% higher than that of carriers without the dopant. These results are substantiated by ab initio DFT + U and thermochemistry analyses. It is noted that operating a chemical looping system at 700 degrees C can result in energy consumption savings of similar to 35% as compared to a chemical looping operation at 1000 degrees C. Thus, our findings provide a pathway to significantly lowering the methane reaction temperature in chemical looping systems, which will lead to substantial energy savings with desired oxygen carrier recyclability.