Lattice Boltzmann model for multi-component mass transfer in a solid oxide fuel cell anode with heterogeneous internal reformation and electrochemistry

Abstract

Recent advances in the lattice Boltzmann method (LBM) have made possible the simulation of multi-component gas transport in complex geometries like porous solid oxide fuel cell (SOFC) electrodes. As an example application, a five species LBM mass diffusion model is coupled with a multi-step reaction mechanism for heterogeneous reformation at chemically active sites and electrochemistry at the triple phase boundaries (TPB). A state-of-the-art imaging technique employing high resolution 42.7 nm x-ray computed tomography (XCT) is used to reconstruct the porous anode to provide geometry input to the LBM model. The result is a pore-scale LBM tool that has the potential to simulate the SOFC mass transfer process in unprecedented detail. Some preliminary, two-dimensional (2D) results are presented for mass transfer in an anode-supported SOFC with direct internal reforming of methane. It is seen that the LBM predictions for species concentrations are qualitatively consistent. Future work involves extending the LBM to three dimensions (3D), incorporating detailed geometric information about active sites and TPB location and validation of model predictions with experiments.