The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on two coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices: tangential and cyclone fired. Work on a third unit, wall fired, is on hold'' because of funding limitations. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percent in SO{sub x} emissions, by a combination of two developed technologies, gas reburning (GR) and sorbent injection (SI). With GR, about 80{endash}85 percent of the coal fuel is fired in the primary combustion zone. The balance of the fuel is added downstream as natural gas to create a slightly fuel rich environment in which NO{sub x} is converted to N{sub 2}. The combustion process is completed by overfire air addition. SO{sub x} emissions are reduced by injecting dry sorbents (usually calcium based) into the upper furnace. The sorbents trap SO{sub x} as solid sulfates that are collected in the particulate control device.

The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on two coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices: tangential and cyclone fired. Work on a third unit, wall fired, is ``on hold`` because of funding limitations. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percent in SO{sub x} emissions, by a combination of two developed technologies, gas reburning (GR) and sorbent injection (SI). With GR, about 80{endash}85 percent of the coal fuel is fired in the primary combustion zone. The balance of the fuel is added downstream as natural gas to create a slightly fuel rich environment in which NO{sub x} is converted to N{sub 2}. The combustion process is completed by overfire air addition. SO{sub x} emissions are reduced by injecting dry sorbents (usually calcium based) into the upper furnace. The sorbents trap SO{sub x} as solid sulfates that are collected in the particulate control device.