Abstract: A method for removing pollutants from flue gas generated by a plant having one or more burners located at an inlet end of a vertically extending stack, the flue gas being discharged through an outlet end of the stack. The pollutants are removed by an emission treatment system which includes a major component module and inlet and outlet ductwork providing fluid communications between the stack and the major component module. The major component module includes an SCR segment, a heat exchanger segment, and an ID fan, the SCR segment having at least one catalyst unit composed of materials for selectively catalyzing at least one pollutant. The method comprises the steps of drawing the flue gas from the stack and through the major component module with the ID fan, removing the pollutant from the flue gas with the SCR segment to produce a clean flue gas, and discharging the clean flue gas to the stack with the ID fan.

Abstract: An emission treatment system for removing NOx from flue gas includes a diversion member that closes the stack at a position intermediate the inlet and outlet ends. A major component module includes a first sub-module, having an inlet and an SCR segment, a second sub-module, having a heat exchange segment, and a third sub-module, having an ID fan and an outlet, forming a flue gas flow path extending from the inlet to the outlet. Inlet ductwork, which is in fluid communication with the stack at a position intermediate the inlet end of the stack and the diversion member, provides a passageway from the stack to the inlet. Outlet ductwork, which is in fluid communication with the stack at a position intermediate the diversion member and the outlet end of the stack, provides a passageway from the outlet to the stack. An ammonia addition subsystem injects ammonia vapor into the inlet ductwork.