Molten Carbonate Fuel Cells

Fuel cells are energy conversion devices that continuously transform the chemical energy of a fuel and an oxidant into electrical energy. This energy conversion process is accomplished by means of an electrochemical reaction whereby the reactants are consumed, by-products are expelled, and heat may be released or consumed. Fuel cells will continue to generate electricity as long as both fuel and oxidant are available. In a molten carbonate fuel cell (MCFC), carbonate salts are the electrolyte. Heated to 650 degrees C, the salts melt and conduct carbonate ions (CO3) from the cathode to the anode. At the anode, hydrogen reacts with the ions to produce water, carbon dioxide, and electrons. The electrons travel through an external circuit, providing electrical power along the way, and return to the cathode. There, oxygen from air and carbon dioxide recycled from the anode react with the electrons to form CO3 ions that replenish the electrolyte and transfer current through the fuel cell. The operating principles for a carbonate fuel cell are simple in concept. The reactants fuel and an oxidant, in this case, air are fed to the cell’s electrodes. Ions are transported through the electrolyte sandwiched between the electrodes, creating a current equal to the amount of electric energy needed by the system connected to the fuel cell (also called load). The the overall reaction with hydrogen, is: H2+0.5O2+CO2(cathode)< == > H2O+CO2(anode)