Patent ID: 8783013

Claim:
A method of treating an exhaust flow including nitrogen oxides in a turbine engine, the turbine engine having a selective catalytic reduction system having a catalyst, the turbine engine operating under steady state conditions, the method comprising the steps of: predicting a molar flow of nitrogen oxides in the exhaust flow; measuring a molar flow of nitrogen oxides in the exhaust flow; detecting a disturbance in the steady state operation of the turbine; determining the difference between the measured molar flow of nitrogen oxides in the exhaust flow and the predicted molar flow of nitrogen oxides in the exhaust flow to yield an error factor; applying the error factor to the predicted molar flow of nitrogen oxides in the exhaust flow so that the predicted molar flow equals the measured molar flow; and responsive to detecting a disturbance, supplying a reducing agent to the exhaust flow upstream of the catalyst relative to the direction of exhaust flow and based on the predicted molar flow of nitrogen oxides with the error factor applied in the exhaust flow.