Patent ID: 6706246
Filing Date: 2004-03-16
Classification: B01D,C10G,F23J

Abstract:
A system for the selective catalytic reduction of nitrogen oxide in a furnace flue gas stream having an initial concentration of nitrogen oxide, which comprises:a) a combustion zone, a convection section positioned above the combustion zone, and a stack positioned above the convection section, b) a first heat recovery section positioned in the convection section for reducing the temperature of the furnace flue gas stream exiting the combustion zone to not less than about 400Â° F., c) a fan positioned downstream of the first heat recovery section for moving flue gas from the convection section to the stack, d) a reactor for the selective catalytic reduction of nitrogen oxide in the flue gas stream positioned in the stack downstream of the fan, said reactor including an injector for introducing a reducing agent into the flue gas stream and containing at least one nitrogen oxide conversion catalyst for the selective catalytic reduction of nitrogen oxide in the flue gas stream upon contact therewith to provide a treated gas stream of reduced nitrogen oxide concentration; e) a treated gas stream outlet through which treated gas is discharged; and, f) a second heat recovery section positioned in the stack downstream of the reactor for reducing the temperature of the treated gas and connected to the first heat recovery section by a piping tie-in for permitting the flow of a fluid therebetween.