SOFC versus MCFC

The interest in the SOFC, compared with the MCFC, might be questioned in view of the thermodynamic limitation of operation at 1000o C, which reduces the cell operating potential by 100mV, or about 15 %. The answer is that the SOFC is electrochemically simpler than the MCFC, since it does not require CO2 feedback from the anode exit to the cathode inlet. Its solid electrolyte eliminates electrolyte management problems, and it may be more resistant to contaminants such as H2S. With the correct materials, it may be capable of a lifetimes up to 100,000 hours or more (tested with no apparent degradation to almost 35,000 hours operation at Brown Boveri). At the higher operating temperature, diffusion and kinetic limitations are minimized, and the cell is essentially limited only by IR drop.