Lattice Boltzmann modeling of carbon deposition in porous anode of a solid oxide fuel cell with internal reforming

Abstract

A pore scale Lattice Boltzmann (LB) model is developed for multi-component mass transport and carbon deposition in the porous anode of a solid oxide fuel cell (SOFC) fed with methane. In this model, the reforming and electrochemical reactions are discretely coupled via local molar fluxes of reactive gas species at catalytically active sites and triple phase boundaries (TPBs). By considering the heterogeneity of anode microstructure, the present pore scale LB model is capable of quantitatively predicting the local distributions of both the position and the amount of deposited carbon in the irregular porous anode. Using this model, the characteristics of carbon deposition in the anode are investigated. It is found that the heterogeneity of anode microstructure has significant influence on mass transport and carbon deposition. Increasing the pre-reforming extent of methane and decreasing the operating temperature are beneficial for the suppression of carbon deposition, whereas they will cause a relatively inferior cell performance. The LB model and results presented in this study are beneficial to mechanism investigation of carbon deposition. Furthermore, they are also helpful for studying the correlations between anode microstructure and carbon deposition and then bridging the manufacture of SOFC electrodes and their performance, which is useful to propose effective suggestions for avoiding performance degradation of SOFC induced by carbon deposition.