SULFUR POISONING IN MOLTEN CARBONATE FUEL CELL FED WITH BIOGAS

Alternative energy sources have to be considered to overcome problems such as energy security and climate change associated with fossil fuel. Biomass is one of the most interesting alternative sources because is renewable, sustainable and widely available. Also biomass which is carbon-based differs from the other renewable energy sources because of their utilization for the energy carrier supply obtained by biological or thermochemical process. Biofuels need high efficient energy conversion technologies such as fuel cells because of their low energy content. Fuel cells are clean, efficient and silent, but need pure hydrogen as fuel. High temperature fuel cells (HTFCs) are more suitable for application of biofuel because they can include an internal reforming which give them fuel flexibility and because their electrodes are more tolerance against fuel contaminants. The research is focussed on molten carbonate fuel cell (MCFC) because of its technology that is more advanced than Solid Oxide Fuel Cell (SOFC) and because of its soon appearing at the marketplace as a commercial product. The most suitable biofuel for MCFC is biogas because reformed methane and carbon monoxide are fuels and carbon dioxide is a diluent. Biogas impurities such as sulphur compounds, mercaptanes, siloxanes and halogenated hydrocarbons affect cell performances. Hydrogen sulphide, which is the most important biogas impurities, reacts either chemically or electrochemically with the electrolyte and the anode affecting the power density and lifetime of the cell [1-4]. The aim of this work is to study the mechanism and the kinetic of hydrogen sulphide poisoning to be able to select alternative anode materials with high sulphur tolerance and high regenerative capability