A DECHLORINATION SYSTEM FOR MAGNETO-HYDRODYNAMIC SPENT SEED

IN COAL-FIRED OPEN-CYCLE MAGNETOHYDRODYNAMIC (MHD) POWERPLANTS, A KEY ISSUE IS CHLORIDE BUILDUP. A FURTHER CONSIDERATION IS THAT UNDER THE 1990 CLEAN AIR ACT AMENDMENTS, EMISSION OF HYDROCHLORIC ACID (HCI) GAS/AEROSOL FROM A CONTINUOUS SOURCE MUST BE BROUGHT BELOW 10 TONS/YEAR. POTASSIUM ADDED IN THE MHD SYSTEM UPSTREAM, TO CREATE PLASMA CONDUCTIVITY AND ACHIEVE SULFUR DIOXIDE REMOVAL, CAN ALSO CONTROL HCI EMISSION IF ADDED IN SUFFICIENT QUANTITIES. HOWEVER, THE RESULTING CHLORIDES FROM THE SPENT SEED MATERIALS MUST BE REMOVED OR THEIR CONCENTRATIONS MUST BE REDUCED TO CONTROL THEIR BUILDUP IN THE RECYCLED SEED. TO DECHLORINATE THE SPENT SEED MATERIAL WITHOUT LOSING A SIGNIFICANT QUANTITY OF POTASSIUM, THE UNIVERSITY OF TENNESSEE SPACE INSTITUTE (UTSI) HAS DEVELOPED AN ION-EXCHANGE RESIN-BASED CONCEPT. THIS CONCEPT IS SIMPLE, USES MILD OPERATING CONDITIONS, IS BASED ON EXISTING TECHNOLOGY OF WATER SOFTENING, AND OFFERS A POTENTIALLY ATTRACTIVE OPTION TO SIMULTANEOUSLY CARRY OUT DECHLORINATION AND DESULFURIZATION OF THE MHD SPENT SEED AT AN OVERALL COST SIGNIFICANTLY LOWER THAN THE OPTION CURRENTLY BEING DEVELOPED. IN COOPERATION WITH UTSI, COMMERCIALLY AVAILABLE CANDIDATE RESINS ARE BEING SCREENED IN PHASE I TO SELECT ONE OR TWO FOR FURTHER DEVELOPMENT IN THE PHASE II PERIOD. THE NECESSARY PROCESS FLOW SHEETS ARE ALSO BEING DEVELOPED TO INTEGRATE SEED RECOVERY/REGENERATION OPERATIONS WITH THE PROPOSED DECHLORINATION SYSTEM FOR INTEGRATED MHD PLANT. IN PHASE II OF THE PROJECT, AN INTEGRATED DEMONSTRATION WILL BE UNDERTAKEN USING UTSI FACILITIES; THE RESULTING DECHLORINATED AND DESULFURIZED MATERIALS WOULD BE RECYCLED TO AN MHD COMBUSTOR.