COPPER BASED SORBENTS FOR HOT GAS CLEANUP

OVER THE PAST DECADE THERE HAS BEEN A CONTINUING EFFORT BY DOE/METC (MORGANTOWN ENERGY TECHNOLOGY CENTER) AND ITS CONTRACTORS TO DEFINE AN APPROPRIATE HIGH TEMPERATURE REGENERABLE DESULFURIZING AGENT. SUCCESSFUL SORBENTS SHOULD PROVIDE EFFICIENT DESULFURIZATION AND REGENERATION KINETICS, A REDUCTION OF H2S CONCENTRATIONS TO 1 PPM OR LESS, AND PHYSICAL AND CHEMICAL STABILITY IN BOTH DESULFURIZATION AND REGENERATION GAS ATMOSPHERES AT TEMPERATURES OF 500 DEGREE(C) AND ABOVE. IT IS PLANNED TO INVESTIGATE COPPER- AND MANGANESE-BASED MIXED OXIDES (CU2O AND MNO)--AN INNOVATIVE INTEGRATION OF TWO TECHNOLOGIES THAT WERE EXAMINED INDIVIDUALLY AND ABANDONED. COPPER BY ITSELF IS NOT ATTRACTIVE FOR LOW LEVEL SULFUR REMOVAL BUT CAN BE STABILIZED TO CUPROUS OXIDE IN THE PRESENCE OF OTHER OXIDES. THE MNO SYSTEM SHOWS AN UNPRECEDENTEDLY HIGH LEVEL OF SCRUBBING CAPACITY AND REGENERATION EFFICIENCY BUT MODERATE SCRUB EFFICIENCY. THE INCLUSION OF CU2O IN MNO SHOULD PROVIDE THE APPROPRIATE SORBENT CHARACTERISTICS. THE CHEMICAL FEASIBILITY OF SUCH ASYSTEM WILL BE ESTABLISHED. THIS WILL INCLUDE THE DEMONSTRATION OF VERY LOW LEVEL SULFUR CONTENT IN THE EFFLUENT STREAM, HIGH SULFUR UPTAKE CAPACITY, AND REGENERABILITY. IN PHASE II BENCH-SCALE EVALUATION WILL BE ADDRESSED FOR STRUCTURAL AND MECHANICAL STABILITY TO SURVIVE A PROTRACTED SERIES OF HIGH TEMPERATURE SULFIDATION/REGENERATION DUTY CYCLES IN FIXED AS WELL MOVING OR FLUIDIZED BED REACTORS. SUCH TESTING WOULD CRITICALLY CONSIDER CERTAIN OPERATION PARAMETERS, SUCH AS GAS COMPOSITION, TEMPERATURE, PRESSURE, PRESENCE OF ORGANIC SULFUR AND OTHER TRACE CONTAMINANTS.