The report gives results of an engineering and laboratory study to evaluate the environmental impact of disposing of solid residue (spent SO2 sorbent and fuel ash) from fluidized-bed combustion (FBC) processes. The quantity and composition of spent sorbents produced by six reference FBC processes were projected. The experimental investigation considered residue from atmospheric and pressurized FBC processes, with and without sorbent regeneration, and with and without processing of the residue. Laboratory tests were conducted to determine residue characteristics, leaching behavior, and thermal activity. The environmental impact from land disposal of the residue was assessed by comparing the leaching and thermal activity results with both available drinking water standards and the behavior of natural gypsum. Processing of the spent sorbent and ash, through fixation of the residue as a cement-like material, was investigated as a way to reduce the environmental impact, and to provide alternatives for potential utilization. The potential for at-sea disposal was also assessed.

Contract no. 68-02-2132, program element no. EHE623A. "March 1978." "EPA/600-7-78-049." Includes bibliographical references.