Influence of Hydrogen Sulfide in Fuel on Electric Power of Solid Oxide Fuel Cell

摘要

Terminal voltage, electric power density and overpotential were measured for the solid oxide fuel cell with gadolinium-doped ceria electrolyte (Ce_(0.8)Gd_(0.2)O_1.9), GDC), 30 vol%Ni-GDC anode and Pt cathode using a H_2 fuel orbiogas (CH_4 47, CO_2 31, H_219 vol %) at 1073 K. Addition of 1 ppm H_2S in the 3vol % H_2O-containing H_2 fuel gave no change in the open circuit voltage (0.79 - 0.80 V) and the maximum power density (65 - 72 mW/cm~2). Furthermore, no reaction between H_2S and Ni in the anode was suggested by the thermodynamic calculation. On the other hand, the terminal voltage and electric power density decreased when 1 ppm H_2S gas was mixed with the biogas. After the biogas with 1 ppm H_2S flowed into the anode for 8 h, the electric power density decreased from 125 to 90 mW/cm~2. The reduced electric power density was also recovered by passing 3 vol % H_2O-containing H_2 fuel for 2 h.