The report gives results of studies supporting the development of atmospheric and pressurized fluidized-bed combustion (FBC) of coal. It includes laboratory and bench-scale studies to provide needed information on combustion optimization, regeneration process development, solid waste disposal, synthetic SO2-sorbent studies, emission control and other tasks. It includes characterization of a variety of limestone and dolomites from various parts of the U.S. for suitability in FB combustors. Reduction in solid waste volumes to reduce the environmental impact of the waste sulfated limestone is a major goal of this program. These studies are to supply data essential for the application of FBC units to public utility and industrial systems. The report gives information on: 10-cycle combustion-regeneration PDU experiments using Greer limestone and Tymochtee dolomite, bed defluidization, flowsheet development, preparation of synthetic SO2-sorbents containing metal oxides, limestone characterization, coal combustion reactions, the enhancement of limestone sulfation by NaCl, evaluation of on-line particle size analyzers, and status of flue gas cleaning studies.