Modeling of Copper-Zeolite and Iron-Zeolite Selective Catalytic Reduction (SCR) Catalysts at Steady State and Transient Conditions

Selective Catalytic Reduction (SCR) is effective over a wide temperature window to reduce NOx emissions from engine exhaust during lean operations. In this study, different supplier SCR catalysts are investigated and modeled. A global Ammonia SCR reaction mechanism has been used, and kinetic parameters for selective catalytic reduction of NOx by Ammonia were developed for both Copper (Cu)-zeolite and Iron (Fe)-zeolite SCR catalysts. The kinetic analysis was performed using a commercial one dimensional (1-D) aftertreatment code, coupled with an optimizer. The optimized kinetics have been validated extensively with laboratory reactor data for various operating conditions on three supplier catalysts - two Copper and one Iron based formulations. Both steady state and transient tests are performed and the developed SCR models are shown to agree with the experimental measurements reasonably well.