Hydrogen production from chemical looping reforming of methane: A screening of Ni-based oxygen carriers

The simultaneous increase in energy use and CO2 emissions poses a serious environmental threat. Efficient technologies that produce low-carbon energy vectors from methane through CO2 recycling offer promising solutions. Hydrogen, a lightweight energy vector with high energy content, ease of storage, and large-scale production potential, emits no direct pollutants and can be generated from various low-carbon sources. Chemical looping technologies are effective for hydrogen production due to their high energy efficiency and inherent CO2 capture. This study investigates chemical looping technologies for hydrogen production through multiple redox cycles, alternating methane fuel steps with oxidation steps in air or CO2 to restore the catalysts and remove carbon. For this reason, five nickel-based catalysts were tested: Ni coprecipitated with cerium oxide, Ni impregnated on lab-made ceria, NiMgAl and NiCaAl mixed oxides from hydrotalcite-like precursors, and a LaNi0.8Co0.2O3 perovskite oxide. Results show hydrogen production efficiency and catalyst stability are strongly influenced by the oxidation atmosphere as well as by the materials redox properties and the nickel chemical environment.