Perspectives on the Use of Molten Carbonate Fuel Cells with Renewable Energy Sources

This paper presents the state of the art and the perspectives of the use of molten carbonate fuel cells with renewable energy sources. The molten carbonate fuel cell is the only technology that can use fuels containing carbon monoxide and carbon dioxide in the anode gas. It has been even shown in experimental tests in single cells that carbon monoxide can be considered as a fuel in this type of fuel cell. The fuels that can be used in MCFC are landfill gas, biogas from anaerobic digestion processes and syngas from gasification of biomass and waste. The commercial size of MCFC stacks (125 to 250 kW) is the right size for use with such fuels which are generally not available for power plants with output larger than some MW. All the above fuels are characterized by the presence of contaminants that need be removed before their use in the fuel cell. Among the contaminants hydrogen sulfide and chlorine compounds seem to cause the worst damage. To be used with such fuels, MCFC still need to be deeply investigated and duration tests are needed to determine the highest tolerable concentrations in the anode gases.