Selective Catalytic Reduction of Nitric Oxide by Ammonia over V2O5/TiO2 in a Hollow Cylindrical Catalyst under Enhancing Effect of Electrohydrodynamics: A Kinetic Modeling Study

Abstract

Emissions of nitrogen oxides (NOx) in fuel combustion from stationary and mobile sources contribute to the greenhouse effects and cause a variety of environmentally harmful results. Meanwhile, the selective catalytic reduction (SCR) of NOx using ammonia over a vanadia-based catalyst in heterogeneous reactors is still a well-proven technique for NOx abatement. However, to meet forthcoming restrictive legislation, greater De-NOx performance can be achieved by eliminating operational setbacks such as diffusion resistance, poor catalyst activity at low temperatures, etc. In this study, an electrohydrodynamic (EHD)-SCR model was developed to evaluate the enhancing effect of the EHD technique on NH3-SCR of NO through a hollow cylindrical catalyst. Computational investigations were performed based on the proposed model in different operational conditions to examine the effect of various operating parameters on SCR enhancement. Simulation results showed that catalyst utilization was intensified significantly by EHD application and generation of additional flow known as EHD-induced secondary flow through the catalyst porous layer, which undermined the proposed drawbacks of the catalyst medium and provided higher catalyst effectiveness with greater NO conversion. Results also indicated that the maximum enhancement of almost 4.2-fold could be obtained for NO conversion with electric potentials and operating temperatures of 150–270 V and 150–165 °C, respectively.