Reduced liquid discharge in wet flue gas desulfurization

摘要

One aspect of the invention relates to a method for removing contaminants from a flue gas stream ( 22 ). The method includes: removing fly ash from a flue gas stream ( 22 ) utilizing a particle collector ( 24 ); contacting the flue gas stream with an alkaline reagent in a wet scrubber ( 26 ); discharging a purge liquid ( 30 ) from the wet scrubber ( 26 ); combining at least a portion of the purge liquid ( 30 ) with at least a portion of the fly ash ( 48 ) to form moistened fly ash ( 60 ); and injecting at least a portion of the moistened fly ash ( 60 ) into the flue gas stream ( 22 ) upstream of the particle collector ( 24 ), whereby the moistened fly ash ( 60 ) removes at least a portion of contaminants present in the flue gas stream ( 22 ).