Heterogeneous Ammonia Storage Model for NH3-SCR Modeling

Single- and dual-site ammonia storage models are initially developed and calibrated from ammonia TPD experiments. The dual-site model gives better agreement with the experimental measurements, but neither of these models is able to adequately represent the observed ammonia storage trends over a wide range of temperatures. An alternative heterogeneous single-site model considering the heterogeneity of ammonia storage sites is proposed that more accurately predicts ammonia storage in the temperature window of 150 degrees C-400 degrees C. When the heterogeneous storage site model is combined with kinetics for NH3 and NO oxidation for simulating standard SCR, the NH3 and DeNO(x) trends as well as the NH3 inventories during reaction conditions reported for lab reactor studies are replicated.