The report gives results of an experimental study of the pressurized combustion of coal in a fluidized bed of limestone and regeneration of sulfated limestone. The study is part of a program to develop fluidized-bed coal combustion as a means of desulfurizing flue gas in-situ and generating clean power at low cost. The process, including regeneration of spent limestone by reduction to lime, produces a gas stream containing a sufficient concentration of SO2 to be fed to a by-product sulfur recovery unit. Initial SO2 removal rates were about 85%. The regeneration step was studied at pressures up to 10 atm and temperatures up to 2100F. High conversion of sulfated material to lime was achieved by injecting air into the bed, by forming adjacent reducing and oxidizing zones, and by minimizing formation of undesired CaS.