Patent ID: 7776297
Filing Date: 2010-08-17
Classification: B01D,Y02P

Abstract:
1. A method for the selective catalytic reduction of nitrogen oxides, comprising: introducing a reducing agent into a flue gas containing nitrogen oxides; after the introducing and before passing the flue gas and reducing agent through a heat exchanger, passing the flue gas, at a first gas velocity, through at least a first layer of nitrogen oxide reducing catalyst where an amount of nitrogen oxides in said flue gas is reduced; after the passing the flue gas through the at least a first layer, passing the flue gas, at a second gas velocity that is higher than the first gas velocity, through at least one heat exchanger that removes heat from the flue gas and also mixes the flue gas and the reducing agent; wherein the heat removed from the flue gas is transferred to a water heater; and after the passing the flue gas through the heat exchanger, passing the flue gas through at least one additional layer of nitrogen oxide reducing catalyst where an additional amount of nitrogen oxides in the flue gas is reduced.