Application of a circulating fluidized bed absorber for retrofit control of sulfur dioxide

The electric utility industry is known to be the largest source of SO{sub 2} emissions in the United States. The national SO{sub 2} emissions from electric utilities in 1982 was estimated to be about 16 million tons per year of which about 90% was attributed to the combustion of coal. Also, the region where SO{sub 2} emissions are the highest in the nation is in the area of 31 states east of the Mississippi River where over 90% of the electric utility emissions are produced. Recent legislative attempts at reducing these emissions from existing sources have not proven successful. Current legislative proposals call for a 5 million ton reduction of SO{sub 2} from these existing sources by 1993 and an additional 5 million tons by 1997. This paper introduces a new concept, entitled the circulating fluidized bed absorber (CFBA) which is currently under investigation. This system offers promise as a low cost retrofit SO{sub 2} control device. The project has just entered into the operational stage and is currently evaluating low temperature sorbents for reaction with SO{sub 2}.