Characterization of adsorption-desorption properties of oxygen & water on mixed oxides

Ateş, Cihan
The scope of this study includes the development of a methodology to determine a candidate material for two step thermochemical heat storage applications via fundamental principles of thermodynamics. The feasibility of utilizing stored thermochemical energy to produce CO from CO2 and H2 from H2O was demonstrated theoretically and experimentally. Metal oxide selection criteria were chosen as transport, kinetic and thermodynamic constraints. As a result Co3O4 was considered worthy of further investigation. Thermal decomposition kinetics of Co3O4 to CoO were measured experimentally. CO2 and H2O were used as oxidants to reoxidize cobalt oxide reduced by thermal decomposition in repeated experiments. Co3O4/CoO redox couple has shown outstanding results for water splitting reaction compared to presented alternatives in the recent literature. Further studies on heat and mass transfer limitations in macroscopic scale were performed using COMSOL® Multiphysics platform. Finally, syngas production using cobalt membrane reactors was probed theroretically. Modeling studies on membrane reactors indicated promising results for cobalt oxide.


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The objective of this study is to observe the effect of the critical design parameters, velocities of inlet gases (hydrogen and air) and the conductivity of polymer membrane, on the performance of a high temperature PEM fuel cell. A consistent and systematic mathematical model is developed in order to study the effect of these parameters. The model is applied to an isothermal, steady state, three-dimensional PEM fuel cell in order to observe concentration profiles, current density profiles and polarization ...
Citation Formats
C. Ateş, “Characterization of adsorption-desorption properties of oxygen & water on mixed oxides,” M.S. - Master of Science, Middle East Technical University, 2015.