Abstract
Direct feeding of several hydrocarbon fuels was carried out at 800°C for a SOFC with scandia stabilized zirconia (ScSZ) electrolyte and nickel–ScSZ (Ni–ScSZ) cermet anode. Liquid hydrocarbons as n-dodecane (paraffin type C12H26) and low sulfur content kerosene were used and fed to the anode at steam/carbon ratio (S/C) of 2. Continuous operation was achieved for more than 120 h with n-dodecane without anode degradation. However, the Ni–ScSZ anode completely detached from the electrolyte when low sulfur kerosene was used as fuel. After operation with the kerosene, nickel particles grew more than 3 μm in diameter although particle growth was about 1 μm under the n-dodecane. The nickel sintering seems to be enhanced by aromatic hydrocarbons and/or sulfur compounds in the kerosene. From thermodynamic consideration, liquid NiS could form under SOFC operation conditions with 30 ppm of sulfur containing hydrocarbon fuels.
