Prediction of Deactivation and Regeneration of DeNOx Catalyst Using Simple Reaction Model - 1st Report : Model for Predicting Deactivation

Abstract

 Selective catalytic reduction (SCR) is an effective technique to reduce nitrogen oxides (NOx) from diesel engine emissions. In this study, a simple reaction model for predicting DeNOx performance deactivation and NH₃ slip on a vanadia-based commercial catalyst is developed to evaluate the effects of the gas component and temperature, and NH₃/NO feed ratio. This model predicted that NOx conversion rate does not depend on the catalyst temperature when the feed ratio becomes small. The calculation results at 250 deg. indicated that high excess air ratios and low NO and SO₂ concentrations suppress the DeNOx performance deactivation. It was also shown that keeping the NH₃/NO feed ratio small is necessary to avoid NH₃ slip.