A SPONTANEOUS ELECTROCHEMICAL CLAUS PROCESS FOR SULFUR RECOVERY

THIS PROJECT IS DIRECTED TOWARD DEVELOPING THE SCIENTIFIC AND TECHNICAL INSIGHT NECESSARY FOR EVALUATING THE UTILITY OF A SOLID OXIDE FUEL CELL COMPATIBLE WITH THE DIRECT ELECTROCHEMICAL OXIDATION OF H(2)S. THIS APPROACH, WHICH FORMS THE BASIS OF AN ELECTROCHEMICAL CLAUS-TYPE PROCESS FORSULFUR REMOVAL, WILL STUDY CELLS POSSESSING THE GENERAL CONFIGURATIONS: H(2)S,AS(2)/ZRO(2)(8(W)%Y(2)O(3))/LA(0.89)SR(0.10)MNO(3)/PT,O(2)(AIR), AND H(2)S,A(1+X)B(2)-X)S(4)/ZRO(2)(8(W)%Y(2)O(3)/LA(0.89)SR(0.10)MNO(3)/PT,O(2)(AIR)WHERE A AND B REPRESENT TRANSITION METAL SPECIES. FOR THIOSPINELS OF GENERAL COMPOSITION A(1+X)B(2)-X)S(4), COMPOSITIONS WILL BE SYSTEMATICALLY VARIED BETWEEN 0 < X < 0.2. RESEARCH DURING PHASE I IS EXPECTED TO RESULT IN DELINEATING PREFERRED ANODE ELECTROCATALYSTS AND ELECTROCHEMICAL CONDITIONS CONDUCIVE TO ACHIEVING HIGH EFFICIENCY CONVERSION OF H(2)S TO UNIT ACTIVITY SULFUR AND WATER, TOGETHER WITH THE SIMULTANEOUS GENERATION OF ELECTRICAL ENERGY. THIS EFFORT IS EXPECTED TO RESULT IN GAINING INSIGHT INTO THE OVERALL REACTION PATH BEING FOLLOWED AT THE ANODE LEADING TO H(2)S OXIDATION. THE CONTROLLED MEDIATION OF OXYGEN THROUGH THE PROPOSED OXYGEN-VACANCY CONDUCTING SOLID ELECTROLYTE IS EXPECTED TO AFFORD GREATER CONTROL OF H(2)S OXIDATION RATES (COMPARED TO THE CONVENTIONAL CHEMICAL CLAUS PROCESS) AND OF RESULTANT ANODE EFFLUENT GAS COMPOSITION, SO THAT OPTIMUM CONDITIONS MIGHT BE ACHIEVED LEADING TO HIGH EFFICIENCY CONVERSION OF H(2)S TO SULFUR AND WATER. CONVERSION EFFICIENCIES REALIZED FROM THIS ELECTROCHEMICAL CLAUS PROCESS MAY PROVE SUFFICIENTLY HIGH THAT NEED FOR TAIL-GAS CLEAN-UP IN THE COAL GASIFICATION PROCESSES BECOMES DRAMATICALLY REDUCED.