The open cycle magnetohydrodynamic (MHD) coal-fired powerplants have the potential to provide substantial improvements inthe thermal efficiency of electric power generation, but severalkey engineering issues must be resolved before these improvementscan be achieved. One of these is efficient processing of theseed added to the combustion products to render them electricallyconducting. This seed has to be reprocessed and, in the process,the conditions exist for chloride buildup, The chloridesresulting from the spent seed material must be removed, or theirconcentration reduced, to control their buildup in the recycledseed. Further, the system in which this is done must be capableof integration into the MHD/steam combined cycle without adverseeffect on its performance. To dechlorinate the spent seedwithout losing potassium, the University of Tennessee SpaceInstitute (UTSI) has developed an anion exchange resin-basedconcept. This concept is simple, uses mild operating conditions,and is based on existing technology of water softening. Itoffers a potentially attractive method to carry outsimultaneously the desulphurization and the dechlorination of MHDspent seed at an overall cost significantly lower than theprocess currently being developed. Phase I resulted in theselection of two suitable resins and a preliminary demonstrationof the feasibility of the process. In Phase 11, system analysiswill be conducted to identify the preferred operating conditionsof the seed reprocessing system, a process demonstration unitwill be built and operated on the Coal-Fired Flow Facility, andengineering data on its operation will be obtained. These datawill be used to undertake the conceptual design of an MHD plantincorporating the UTSI process. The process is particularly suited to high sulphur coal. Tofacilitate comparison with conceptual designs, the Scholz Planthas been selected to provide the MHD/steam interface for the integrated conceptual design. The project will includethe development of a data base designed for prototype andcommercial scale plants.Anticipated Results/Potential Commercial Applications as described by the awardee:Successful completion of the projectwill provide a technically attractive option to simultaneouslydechlorinate and desulfurize the MHD spent seed material at anoverall cost considerably lower than what can be expected for theapproach currently under development. It will resolve a criticaltechnical issue and greatly improve the prospects for acceptanceof MHD technology by the electric industry and its suppliers.
