Full-Scale Evaluation of Mercury Control Technologies with PRB Coals

Data indicate that plants firing Powder River Basin (PRB) coals achieve very low native mercury removal when configured with electrostatic precipitators (ESP) or spray dryer absorbers followed by fabric filters (SDA/FF). In addition, full-scale demonstrations show that the performance of non-chemically treated activated carbon may be limited in these applications. ADA-ES, Inc., with support from DOE NETL, EPRI and industry partners, is conducting a mercury control demonstration at two units that fire PRB coal: Sunflower Electric's Holcomb Station, and AmerenUE's Meramec Station. Holcomb Station is a 360 MW unit and has a SDA and FF for emission control. Meramec Unit 2 is a 140 MW unit and has low NOx burners and an ESP for emission control. This paper presents results showing that 1) blending PRB with bituminous coal, 2) injecting alternative sorbents specifically designed to operate in a halogen deficient flue gas, and 3) injecting chemical additives onto the coal are viable approaches for high levels of mercury control in these configurations.