Mathemetical model development for the Urea SCR
Jeong Kim, Ford Motor Co.
This presentation includes the development of the analytical model to complement the laboratory based experiments for better understanding NH3 adsorption and desorption characteristics as well as NOx reduction mechanisms. The model was calibrated based on the measured data from the NH3 adsorption/desorption test as well as NOx reduction performance test over the selected SCR catalyst formulations in a laboratory flow reactor. The selected SCR samples for the tests are the base metals supported on zeolites. The vehicle data were selected for further validation of the model as well as a few parametric study. The model considered energy and mass balances with the description of NH3 adsorption/desorption algorithms, NH3 oxidation as well as several selective NH3 reactions with NOx species.