DIRECT SULFUR REDUCTION IN ADVANCED COAL CONVERSION PROCESSES

ELIMINATION OF SULFUR CONTAMINANTS FROM HOT COAL GAS AND THEIR SUBSEQUENT REDUCTION OR DISPOSALIS AN ESSENTIAL STEP FOR THE VIABLE APPLICATION OF ADVANCED COAL CONVERSION TECHNOLOGIES, SUCH AS INTEGRATED GASIFICATION COMBINED CYCLE STYSTEMS. MIXED METAL OXIDE SORBENT BEDS HAVE BEEN SHOWN TO BE VERY EFFECTIVE FOR HOT FUEL GAS CLEANUP WITH OVERALL SULFUR REMOVAL EFFICIENCIES EXCEEDING 95%. HOT OFF GAS RESULTING FROM SORBENT BED REGENERATION CONTAINS, DEPENDING ON THE PROCESS, FROM 1 TO 12% SULFUR DIOXIDE, WHICH IS THEN PREFERENTIALLY CONVERTED TO AN ECONOMICALLY USABLE FORM. SINCE ELEMENTAL SULFUR IS EASILY HANDLED,HAS A LARGE MARKET, AND PRESENTS NO SLUDGE DISPOSAL POBLEM, COST-EFFECTIVE DIRECT SULFUR REDUCTION PROCESSES (DSRP) AREBEING INVESTIGATED. THE RESEARCH COVERED BY THIS PROJECT IS TO DETERMINE WHETHER A NEW ELECTRODELESS RADIO FREQUENCY PLASMA SYSTEM DESCRIBED AS PLASMA ELECTRON DISSOCIATION (PED) WOULD BE A VIABLE DSRP TO BE USED IN CONJUCTION WITH MIXED METAL OXIDE SYSTEMS TO PRODUCE ELEMENTAL SULFUR FROM THE HOT REGENERATION OFF GAS. PLANNED WORK INPHASE I INCLUDES CONDUCTINGTESTS WITH SIMULATED GAS INPUT TO EVALUATE OPERATING PERFORMANCE (e.g., CONVERSION RATE VS. THROUGHPUT), ESTIMATE OPERATING COSTS, AND PROJECT CAPITAL COSTS FOR SCALED-UP SYSTEMS. THE PROJECT WILL INCLUDE TESTING A COMPUTER MODELOF THE PLASMA OPERATION AND VALIDATING IT WITH EXPERIMENTAL DATA.