Abstract: These studies support the development studies for atmospheric and pressurized fluidized-bed coal combustion. Laboratory and bench-scale studies aimed at providing needed information on combustion optimization, regeneration process development, solid waste disposal, synthetic SO/sub 2/-sorbent studies, emission control, limestones and dolomites from various parts of the country for suitability in fluidized-bed combustors is also included. Reduction in solid waste volumes to reduce the environmental impact of the waste sulfated limestone is one of the major goals of this program. These studies are designed to supply data essential for the application of fluidized-bed combustion units to public utility and industrial systems. This report presents information on: a 10-cycle combustion-regeneration experiment, bench-scale regeneration experiments using Greer limestone, bed defluidization, regeneration kinetics, preparation of synthetic SO/sub 2/-sorbents containing metal oxides, limestone characterization, coal combustion reactions, the enhancement of the sulfation rate of limestone by NaCl, evaluation of on-line particle analyzers, and status of flue-gas cleaning studies.