Study on Internal Phenomena of Solid Oxide Fuel Cells Using Liquefied Natural Gas as Fuel

This study analyzed the internal phenomena of solid oxide fuel cells driven by liquefied natural gas. Reforming reactions of liquefied natural gas constituent in the solid oxide fuel cells were examined. First, the performance of solid oxide fuel cells using liquefied natural gas was compared to those using methane as fuel. Liquefied natural gas-driven solid oxide fuel cells outperformed methane-driven solid oxide fuel cells under all current conditions, with a maximum performance difference of approximately 12.8%. Then, the effect of inlet composition ratio on the internal phenomena in the solid oxide fuel cells was examined. The lower the steam-to-carbon ratio, the higher the steam reforming reaction in the cell. By changing the ratio, 7.1% of more hydrogen could be reformed. Finally, the effect of reformer operation on the internal phenomena in the solid oxide fuel cells was examined. Under 0.35 A/cm2, lower pre-reforming rate of reformer enhance the performance of solid oxide fuel cells. At high current density region, however, a higher pre-reforming rate of reforming is more favorable because the reforming reaction is rare in solid oxide fuel cells. This research can provide guidelines for achieving high power output of solid oxide fuel cells with high fuel flexibility.