MATHEMATICAL MODELING OF MASS TRANSFER AND REACTION IN AN INNOVATIVE SOLID OXIDE FUEL CELL

IDEAL-Cell is an innovative concept of a solid oxide fuel cell (SOFC), which is supposed to possess some advantages over conventional SOFCs by building an independent compartment to evacuate water that normally is present either at the anode in ACFCs or at the cathode in PCFCs. The namely advantages have been demonstrated by thermodynamic analysis in chapter 1 that IDEAL cell can potentially provide 15% higher Nernst potential than PCFCs and 30% higher Nernst potential than ACFCs at high fuel utilizations. Modelling activities in this innovative fuel cell are mainly concentrated on its peculiar feature: dual membrane which consists of two dense electrolytes and central membrane in the middle. This particular design brings many challenges for describing complex phenomenon of mass transfer and mechanism of ionic recombination reaction, whose understanding requires dedicated experimental and theoretical work. In this thesis, a series of mathematic models for characterizing mass transfer in dense electrolyte (chapter 2), mass transfer in porous composite central membrane (chapter 3), and kinetic reaction in central membrane (chapter 4) have been built and preliminarily validated by experimental results. These models enable one to theoretically explain electrochemical processes, to indicate technique difficulties confronted in processing and to predict steady-state response of the IDEAL-Cell under varying operating conditions (temperatures and gas atmospheres). In the presence of more effective data to validate and modify, these models are useful to support the design of materials, components and IDEAL-Cell prototype as well.