Degradation Behavior of Solid Oxide Fuel Cell (SOFC) with Trace Hydrocarbons

Abstract

The effects of hydrocarbon-contained in fuel gas on SOFC with Ni-YSZ as anode are evaluated in this study. Low concentration of toluene was mixed with 96.9％ hydrogen and 3.1％ steam to simulate bio-syngas, corresponding to current developments of biomass gasification technology. Power generation performance was investigated under Galvano-static-mode with toluene concentrations from 0 mg/Nm³ to 1900 mg/Nm³ at 850 °C for 30 hours. Impedance spectroscopy under OCV conditions was also conducted to assess SOFC’s internal resistance. As the result, SOFC shows a good stability and generation performance without toluene exposure. However, the voltage decreases even under a low concentration of 380 mg/Nm³ while keeping current density constant at 200 mA/cm². Furthermore, this degradation tends to be serious as concentration of toluene increases. Dramatic voltage drop and visible carbon deposition should not be insignificant when toluene’s concentration was 1900 mg/Nm³. This performance loss seems to be recovered to a certain extent without serious structure destruction on anode.