Permeability of Gases in the Anode of an Anode Supported SOFC
The present work aims at determining experimentally anodes gas permeability as a function of the experimentally determined percolation, tortuosity and volume fraction of the pores, assuming that the diffusion of gases is described by the Darcy Law. Anodes with varying porosity ensured by different quantities of the pore former were obtained by cold pressing and sintering. SEM image analysis, mercury intrusion porosimetry and permeability measurements for different gases were performed. The obtained results show that permeability increases with the volume fraction of the pore former. However, non-linearity as a function of the gases molecular weight is observed and discussed as a function of the mean free path and thus of possible mixed Darcy and Knudsen diffusion.