FCL5

The molten carbonate fuel cell operates at approximately 650 °C (1200 °F). The high operating
temperature is needed to achieve sufficient conductivity of the carbonate electrolyte, yet allow the use of low-cost metal cell components. A benefit associated with this high temperature is that
noble metal catalysts are not required for the cell electrochemical oxidation and reduction
processes. Molten carbonate fuel cells are being developed for natural gas and coal-based power
plants for industrial, electrical utility, and military applications (MCFCs operate more efficiently with CO2 containing bio-fuel derived gases. Performance loss on the anode due to fuel dilution is compensated by cathode side performance enhancement resulting from CO2 enrichment.). Currently, one industrial corporation is actively pursuing the commercialization of MCFCs in the U.S.: Fuel Cell Energy (FCE). Europe and Japan each have at least one developer pursuing the technology: MTU Friedrichshafen, Ansaldo (Italy), and Ishikawajima-Harima Heavy Industries (Japan).MCFCs differ in many respects from PAFCs because of their higher operating temperature (650
vs. 200 °C) and the nature of the electrolyte. The higher operating temperature of MCFCs
provides the opportunity to achieve higher overall system efficiencies (potential for heat rates
below 7,500 Btu/kWh) and greater flexibility in the use of available fuels. On the other hand, the
higher operating temperature places severe demands on the corrosion stability and life of cell
components, particularly in the aggressive environment of the molten carbonate electrolyte.management in the respective cells. In a PAFC, PTFE serves as a binder and wet-proofing agent to maintain the integrity of the electrode structure and to establish a stable electrolyte/gas interface in the porous electrode. The phosphoric acid is retained in a matrix of PTFE and SiC between the anode and cathode. There are no high temperature, wetproofing materials available for use in MCFCs that are comparable to PTFE.