Performance of anode supported cells with Ni-ScSZ anode for low S/C methane and ethane fuels

Possibility of stable operation of SOFCs with methane and ethane fuels at a low steam/carbon (S/C) ratio (containing 1.2 mol% H₂O) was investigated for anode supported SOFCs with a scandia stabilized zirconia (ScSZ) electrolyte and a Ni-ScSZ anode. For methane, severe carbon deposition was observed around the anode after cell tests at T = 1073 K. The effect of carbon deposition became smaller with decreasing operation temperature, and a stable cell operation was achieved without severe carbon deposition for 88 h at higher fuel utilization rate around 50%. For ethane, nickel was heavily disintegrated accompanied with severe carbon deposition even at T = 973 K. With decreasing operation temperature, the disintegration became less. As a result, a stable cell operation was achieved only with a slight amount of deposited carbon at the fuel injection part for over a week at U_f = 54 - 46% at T = 826 K.