Mass transfer in hydrogen-fed anode-supported SOFCs

A comprehensive numerical study of the mass-transfer mechanisms inside the anode of a hydrogen-fed Solid-Oxide Fuel-Cell (SOFC) is presented. The study is based on a detailed mathematical model of the channel and anode, using for the latter the equations of the Dusty Gas Model (DGM) to describe mass transfer in the porous medium.The physical meaning and relative importance of the fluxes present in the DGM have been researched; the outcome is a better understanding of the physical phenomena involved in the several species transfer to and from the reaction layer. The relevance of the convective flux and the contribution of the pressure-driven DGM one in the SOFC anode has been numerically and analytically estimated for the most common SOFC operating conditions; it has been found that these fluxes may not be negligible in many cases.