Patent ID: 6408619
Filing Date: 2002-06-25
Classification: B01D,F01N,Y02T

Abstract:
A method for catalytically reducing nitrogen oxides in an exhaust gas of a combustion system by reaction of the nitrogen oxides with a reducing agent in a presence of a catalyst, which comprises the following steps:providing an exhaust gas line and a source of reducing agent, introducing into the exhaust gas line upstream of the catalyst in a flow direction of the exhaust gas an amount of a reducing agent metered in dependence on a concentration of reducing agent in the source and at least one parameter characterizing an operating state of one of the combustion system, the exhaust gas, and the catalyst, conducting the exhaust gas and the reducing agent over the catalyst, and wherein said source is a solution of reducing agent in a storage container and the concentration of the reducing agent in said source is determined discontinuously each time said container is filled with the reducing agent solution and not later than when the reducing agent is introduced into the exhaust gas line and adapting the amount to be metered to the concentration determined in the determining step.