A SORBENT INJECTION AND FILTRATION PROCESS FOR HYDROGEN SULFIDE REMOVAL FROM HOT GAS

ADVANCED COAL UTILIZATION AND CONVERSION PROCESSES FOR POWER GENERATION SUCH AS INTEGRATED GASIFICATION COMBINED CYCLE (IGCC) OFFER MANY SIGNIFICANT ADVANTAGES OVER DIRECT COAL-FIRED PLANTS. SOME OF THESE ADVANTAGES INCLUDE HIGHER CYCLE EFFICIENCY AND THE ABILITY TO ATTAIN MORE STRINGENT ENVIRONMENTAL STANDARDS. HIGH TEMPERATURE REMOVAL OF HYDROGEN SULFIDE (H2S) IS IMPERATIVE FOR IGCC TO REDUCE EMISSIONS AND CORROSION OF DOWNSTREAM EQUIPMENT. ALTHOUGH HIGH REMOVAL EFFICIENCIES ARE OBSERVED WITH THE CURRENT HIGH TEMPERATURE SORBENT DESULPHURIZATION APPROACHES, PROBLEMS EXIST WITH THESE SYSTEMS. THE PLANNED APPROACH UTILIZES INJECTION OF FINELY DIVIDED SORBENT INTO THE HOT GAS DUCTING DOWNSTREAM OF A HOT CERAMIC FILTER. THE H2S WOULD REACT WITH THE SORBENT AS THE GAS PASSES THROUGH THE DUCT AND BE REMOVED IN A SECOND CERAMIC FILTER AFTER SUFFICIENT RESIDENCE TIME TO COMPLETE THE SORBENT/H2S REACTION. THE PHASE I EFFORT IS ASSESSING THE APPROACH TO HOT DESULPHURIZATION USING SORBENT INJECTION. THE PROCESS AND LOW COST CERAMIC FILTER IS BEING DEVELOPED AND TESTED UNDER HOT GAS CONDITIONS TO DEMONSTRATE H2S AND PARTICULATE REMOVAL EFFICIENCY. IN PHASE II, LARGER FILTERS WOULD BE PRODUCED, AND THE PROCESS WOULD BE TESTED AT AN OPERATING COAL GASIFICATION PLANT TO DEMONSTRATE LONG-TERM OPERATION.