HYDROGEN PRODUCED FROM HYDROCARBON FUELS MUST BE PURIFIED BEFORE IT CAN BE USED TO POWER PHOSPHORIC ACID OR CARBONATE FUEL CELLS.

HYDROGEN PRODUCED FROM HYDROCARBON FUELS MUST BE PURIFIED BEFORE IT CAN BE USED TO POWER PHOSPHORIC ACID OR CARBONATE FUEL CELLS. TYPICALLY, THESE HYDROGEN STREAMS CONTAIN LESS THAN 80% HYDROGEN TOGETHER WITH CARBON MONOXIDE, METHANE, CARBON DIOXIDE, AND VARIOUS SULFUR GASES. FOR EFFICIENT FUEL CELL OPERATION, A STREAM CONTAINING >99% HYDROGEN AND ESSENTIALLY FREE OF HYDROGEN SULFIDE IS REQUIRED. WE PROPOSE TO USE A NOVEL COMPOSITE PALLADIUM MEMBRANE TO ACHIEVE THIS SEPARATION. PALLADIUM MEMBRANES ARE KNOWN TO HAVE THE REQUIRED PERMSELECTIVITY FOR HYDROGEN OVER THE OTHER GASES AND ARE CAPABLE OF OPERATION AT THE HIGH TEMPERATURES REQUIRED FOR AN ATTRACTIVE FUEL CELL GAS SEPARATION DEVICE. DURING PHASE I A NUMBER OF THESE PALLADIUM MEMBRANES WOULD BE PREPARED, AND THE FEASIBILITY OF THE CONCEPT WOULD BE DEMONSTRATED IN SMALL LABORATORY PERMEABILITY CELLS. IN PHASE II THE MEMBRANE PREPARATION PROCEDURE WOULD BE SCALED UP TO A CONTINUOUS PROCESS AND MEMBRANE MODULES PRODUCED AND EVALUATED.