REMEDIATION OF CHLORIDE-INDUCED ELECTROLYTE LOSS IN MOLTEN CARBONATE FUEL CELLS

THE UTILIZATION EFFICIENCY OF COAL FOR LARGE SCALE ELECTRIC POWER PRODUCTION CAN BE GREATLY INCREASED THROUGH THE USE OF MOLTEN CARBONATE FUEL CELLS (MCFCS) RUNNING ON COAL GAS. A MAJOR OBSTACLE TO THIS APPLICATION IS THE PRESENCE OF COAL-DERIVED CONTAMINANTS IN THE GASEOUS FUEL STREAM. THESE CONTAMINANTS PRODUCE SIGNIFICANT DECREASES IN MCFC PERFORMANCE AND LIFE UNLESS THEY ARE GREATLY REDUCED IN CONCENTRATION. THIS PROJECT ADDRESSES A SIMPLE AND INEXPENSIVE MEANS FOR CONTROLLING FUEL CELL DETERIORATION DUE TO CHLORIDE CONTAMINANTS IN THE FUEL. CHLORIDE DISSOLVES READILY IN THE MOLTEN LITHIUM-POTASSIUM CARBONATE ELECTROLYTE USED IN MCFCS. THIS DISSOLVED CHLORIDE GREATLY INCREASES THE RATE OF ELECTROLYTE VAPOR LOSS AND COMPOSITION CHANGE. THIS APPROACH FOR SOLVING THIS PROBLEM CONSISTS OF USING ALKALI-CONTAINING ADDITIVES IN THE ANODE GAS STREAM TO OFFSET THE VAPOR LOSSES AND STABILIZE THE ELECTROLYTE COMPOSITION. IN PHASE I, A REALISTIC MODEL OF CHLORIDE-INDUCED MCFC PERFORMANCE DECAY WILL BE EXTENDED AND APPLIED. RESULTS OF THESE CALCULATIONS WILL BE ANALYZED TO DETERMINE THE MOST EFFECTIVE ADDITIVES AND OPERATING STRATEGIES. IN PHASE II, EXPERIMENTAL TESTING USING THERMOGRAVIMETRY AND LAB SCALE FUEL CELLS WILL BE UNDERTAKEN TO VERIFY THE BEHAVIOR OF THE MOST PROMISING ADDITIVES.