디젤엔진의 NOx 저감을 위한 SCR DeNOx 촉매의 수치 해석

Abstract

The reaction kinetics which can describe the NH3 slip from a selective catalytic reduction (SCR) reactor as well as the maximum conversion of NOx over a wide range of reaction temperatures has been investigated over a commercial V2O5/TiO2 catalyst. The chemical phenomena are described by global reactions for the oxidation of ammonia and the reduction of NOx using Langmuir-Hinshelwood reaction rate expressions. In order to account for the influence of transport effects, the reaction kinetics is coupled with a fully transient one-dimensional monolith channel model. The steady-state chemical reaction scheme used in the present mathematical model has been validated extensively with experimental data, selective NOx reduction efficiency for a wide range of inlet conditions such as space velocity, oxygen concentrations, water concentration, and NO2/NO ratio. We also performed parametric investigations to examine how the NH3 slip from a SCR DeNOx catalyst and the conversion of NOx were affected by the reaction temperature, NH3/NOx feed ratio, and space velocity for feed gas compositions with NO2/NOx ratios of 0 and 0.5.