Defect Chemistry and Chemical Looping Performance of La<sub>1−x</sub>M<sub>x</sub>MnO<sub>3</sub> (M = Sr, Ca, (x = 0–0.5)) Perovskites
Antigoni Evdou,
Theofilos Georgitsis,
Charitini Matsouka,
Eleni Pachatouridou,
Eleni Iliopoulou,
Vassilios Zaspalis
Affiliations
Antigoni Evdou
Laboratory of Inorganic Materials, Laboratory of Environmental Fuels & Hydrocarbons, Chemical Process and Energy Resources Institute, Center for Research and Technology Hellas, 57001 Thessaloniki, Greece
Theofilos Georgitsis
Laboratory of Materials Technology, Faculty of Chemical Engineering, School of Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Charitini Matsouka
Laboratory of Inorganic Materials, Laboratory of Environmental Fuels & Hydrocarbons, Chemical Process and Energy Resources Institute, Center for Research and Technology Hellas, 57001 Thessaloniki, Greece
Eleni Pachatouridou
Laboratory of Inorganic Materials, Laboratory of Environmental Fuels & Hydrocarbons, Chemical Process and Energy Resources Institute, Center for Research and Technology Hellas, 57001 Thessaloniki, Greece
Eleni Iliopoulou
Laboratory of Inorganic Materials, Laboratory of Environmental Fuels & Hydrocarbons, Chemical Process and Energy Resources Institute, Center for Research and Technology Hellas, 57001 Thessaloniki, Greece
Vassilios Zaspalis
Laboratory of Inorganic Materials, Laboratory of Environmental Fuels & Hydrocarbons, Chemical Process and Energy Resources Institute, Center for Research and Technology Hellas, 57001 Thessaloniki, Greece
La1−xMxMnO3 (M = Sr, Ca, (x = 0–0.5)) materials of the perovskite structure are synthesized by a co-precipitation method. They are subsequently investigated for their performance in a chemical looping process (fuel CH4) using thermogravimetric analysis with simultaneous reaction. The goal of this work is to determine the relation between the defect chemistry of the materials and their behavior in chemical looping processes. A defect model is proposed that provides an explanation of the dependency of the Oxygen Transfer Capacity and of the CO2/CO selectivity on composition. It appeared that the fuel may react with various types of oxygen available within the materials, generated by different mechanisms. The relative amounts of each oxygen type determine the CO2/CO selectivity and depend on the material composition as well as on the partial pressure of oxygen used for regenerating the materials.
