Exploratory work previously had shown a range of conditions under which sulfur is trapped by a shallow fluidized bed of lime in which fuel oil is undergoing partial combustion and gasification. The possibility of regenerating the lime had also been demonstrated. Thus the framework had been established for a process to eliminate SO2 pollution during combustion of high sulfur fuel oils. The process is designated CAFB for Chemically Active Fuel Bed. Batch reactor studies have extended the understanding of the Chemically Active Fluid Bed (CAFB) gasification process, the effects of its variables, and some of its limitations. A US fuel oil and one US limestone (BCR 1691) have been found to be satisfactory for the (CAFB) process, but a second US stone (BCR 1690) is not favorable. Two new batch reactors have been constructed. The adsorption of iron, vanadium, and sodium from the fuel by the limestone is mentioned. (Author)