REGENERATION OF LIME-BASED SORBENTS IN A KILN WITH SOLID REDUCTANTS.

Processes based on apparent solid-solid reactions in a kiln-type reactor for regenerating the lime-based sorbents were developed. The specific process investigated reacts the sulfated lime with fly ash, both from the fluidized-bed ccombustor (FBC). The unburnt carbon in the fly ash is used as the reductant. A major advantage of the fluidized-bed combustion with lime additives is its ability to burn coal cleanly and to produce economically a desulfurized hot gas. Recognition of the potential of this technology has accelerated extensive efforts in research and development in this area. For environmental and economical reasons, however, the regeneration of the lime additives from the spent stone must be considered. The state of the art, including the major problems involved, has been reviewed.