CFD Evaluation of Fuel Lean Gas Reburn (FLGR) and Selective Non-Catalytic Reduction in Owensboro Municipal Utilities’ Elmer Smith Station

A Computational Fluid Dynamics (CFD) modeling study has been conducted to evaluate the application of overfire air (OFA), Fuel Lean Gas Reburn (FLGR), and Selective Non-Catalytic Reduction (SNCR) to reduce NOx emissions from Owensboro Municipal Utilities’ Elmer Smith Station. Smith Station Unit 1 is a nominally rated 150 MWe single-wall cyclone fired boiler with three barrels. FLGR is a NOx control technology for fossil fuel fired boilers developed and licensed by the Gas Research Institute (GRI) that involves injection of natural gas into the fuel lean zone of the upper furnace (Pratapas et al. 1999). The quantity of reburning fuel is less than in conventional reburning processes. The resulting flue gas remains overall fuel lean, and no additional OFA is required. The analyses indicated that OFA alone has the potential to reduce NOx emissions from a baseline level of 1.59 lbs-NOx/MMBtu to 0.39 lbs-NOx/MMBtu with sufficient staging. This presentation summarizes the modeling results associated with utilizing both lean reburning and SNCR in addition to OFA to further reduce the NOx emissions at Elmer Smith Station