Chemical Looping Combustion over a Lanthanum Nickel Perovskite-Type Oxygen Carrier with Facilitated O^2– Transport

Chemical looping combustion (CLC) can achieve the benefits of efficient conversion of hydrocarbon fuels and zero-energy CO₂ capture using oxygen carriers (OCs) with facilitated oxygen transport properties. The current study details the use of Cu- and Ca-doped lanthanum nickel perovskite-type materials as the OC in CLC processes. By incorporation of lanthanum nickel oxide with copper and calcium, the oxygen storage capacity and average transport rate of La_1–yCa_yCu_xNi_1–xO₃ are up to 7.8 wt % and 0.82 wt % min^–1, respectively, during the methane CLC process at 400 °C, whereas undoped LaNiO₃ cannot react with methane at a low temperature. Simultaneously, substituted lanthanum nickel oxides can decrease the oxygen transport temperature by about 70 °C compared to undoped lanthanum nickel oxide. X-ray diffraction, Brunauer–Emmett–Teller, and scanning electron microscopy of the samples were characterized in terms of particle properties and morphology to unveil the rational reasons of the high oxygen transport at lower temperatures. The enhancement of the specific surface area and stable porous morphology in La_1–yCa_yCu_xNi_1–xO₃ can both facilitate the oxygen transport in CLC processes. Experiments were executed to investigate the reactivity of the redox materials on the standpoints of oxygen capacity, stability, and regenerability. Hydrogen and methane as the fuels are both considered in this study. La_1–yCa_yCu_xNi_1–xO₃ showed favorable reactivity and stability in the successive redox cycles at low temperatures. These experimental results indicate that La_1–yCa_yCu_xNi_1–xO₃ can facilitate O^2– transport and have the potential to be used as the promising OC for low-temperature CLC processes.