Simulated biogas for nickel-based solid oxide fuel cells

Abstract

Biogas is composed of variable gases including hydrogen, nitrogen and sulphur, with methane and carbon dioxide as the main components. The common ratio of methane to carbon dioxide is 60/40 in volume and this high amount of methane causes carbon deposition when biogas is used in solid oxide fuel cells. To prevent carbon deposition, dry reforming, steam reforming or partial oxidation is the common method. In this paper, a nickel cermet solid oxide fuel cell was investigated with a simulated biogas based on 63% CH4 and 37% CO2, which was obtained by presuming 80% fuel utilisation and 25% recirculation of anode gas. Supplied with a 30 ml/min of simulated biogas, the cell generated a maximum power density of 856 mW cm-2 at 850 °C. The cell ran stably at loads of 100 mA cm-2, 300 mA cm-2and 500 mA cm-2 over a period of 16 hours at each level.