Numerical modeling of ethanol-fueled solid oxide fuel cells with a Ni-BaZr0.1Ce0.7 Y0.1Yb0.1O3-δ external reformer

A numerical model is developed to evaluate ethanol-fueled solid oxide fuel cells (E-SOFCs) with a Ni-BaZr0.1Ce0.7Y0.1Yb0.1O3-delta (Ni-BZCYYb) external reformer owing to its high hydrophilia, carbon deposition resistance, and catalytic properties. This model is validated by the ethanol conversion and product selectivity with the introduction of the steam for adjusting the water-carbon ratio. The simulated E-SOFCs provide a suitable porosity and thickness for the Ni-BZCYYb external reformer, and the optimal control conditions are that the porosity is around 0.4, and the thickness is more than 4 mm for the best reforming effect, which can decrease the concentration polarization loss and improve cell performance. The carbon deposition boundaries and the equilibrium composition can be predicted by the thermodynamic equilibria calculation for E-SOFCs. The proposed model can give the optimization of the geometry design and operating conditions to avoid carbon deposition and improve the electrochemical performance of E-SOFCs.