Alliant Energy will use a combination of technologies to address nitrogen oxide (NOx), sulfur dioxide (SO2) and mercury (Hg). In addition, emerging rules require attention to other hazardous air pollutants (HAPs).
Selective Catalytic Reduction (SCR) is a post-combustion process that injects ammonia or urea into the stream of gases leaving the generating facility boiler to convert NOx emissions into nitrogen and water. The use of a catalyst enhances the effectiveness of the conversion enabling NOx emissions reductions of up to 90%.
Baghouse/carbon injection process is a post-combustion process that injects carbon particles into the stream of gases leaving the generating facility boiler to facilitate the capture of mercury in filters or bags. A baghouse / carbon injection process can remove more than 85% of mercury emissions.
Scrubber is a post-combustion process that injects lime or lime slurry into the stream of gases leaving the generating facility boiler to remove SO2 and capture it in a solid or liquid waste by-product. A scrubber typically removes more than 90% of the SO2 emissions.