Processing and utilization of wet flue gas desulfurization material

摘要

Cooperative Power's Coal Creek Station (CCS) became fully operational in 1981. The two 550-MW units at CCS burn North Dakota lignite. The resulting by-products are fly ash, bottom ash, and wet FGD material. Although disposal of the coal combustion by-products (CCBs) was included in the original site plant at CCS, even early on, consideration was given to utilization of the fly ash as a mineral admixture for concrete and as a partial sorbent replacement for the wet scrubbing system. CCS fly ash has been successfully marketed into North Dakota, Minnesota, and the surrounding region as a construction material that is environmentally benign, highly consistent, and an excellent performer in numerous construction applications. Attempts to use CCS fly ash as part of the scrubbing medium in the wet scrubbing system at the site were not as successful as first hoped, primarily due to the abrasive nature of the fly ash. Currently, CCS scrubbers use lime as the scrubbing medium for SO(sub 2) removal. CCS's efforts to market its fly ash have been successful, so with increased awareness of the economic advantages of by-product utilization, the favorable US Environmental Protection Agency (EPA) regulatory determination that CCBs are not hazardous, and the improved understanding of potential local and regional markets, Cooperative Power has taken additional steps to investigate the processing and utilization of its wet FGD material. These steps are discussed.