SCR Deactivation Kinetics for Model-Based Control and Accelerated Aging Applications – Final Update

Gordon  Bartley, Southwest Research Institute

SCR catalysts will be used to reduce NOx emissions from IC engines in a number of applications. SwRI has completed an Internal Research & Development Project to study SCR catalyst thermal deactivation. The study included a V/W/TiO2 formulation, a Cu-zeolite formulation and a Fe-zeolite formulation.

This final update fromthe the work describes NH3 storage capacity measurement data as a function of aging time and temperature. Addressing one objective of the work, these data may be used in model-based control algorithms to calculate the current NH3 storage capacity based on time and temperature history. The model-based control then uses the calculated value for effective DEF control and prevention of excessive NH3 slip. Addressing a second objective of the work, accelerated thermal aging of catalysts may be achieved by elevating temperatures above normal operating temperatures. Time and temperature correlations use the Arrhenius equation, which requires a formulation-specific deactivation energy value. The NH3 storage capacity data were used to calculate a deactivation energy value (Ed) for each of the three formulations.

Download Presentation: