Structure-resolved CFD simulations to guide catalyst packing of selective NO reduction

In this work, monolith and packing structures with different particle shapes (cylinder, sphere, trilobe and Raschig ring) are compared to boost selective catalytic reduction (SCR) of NO reaction. The three-dimension structure-resolved reactor model is established to evaluate the influence of mass transfer and NO reaction performance in different industrial applications. The simulation results show that monolithic catalysts shift from transition regime to reaction-controlled regime, while the cylinder-resolved catalysts shift from diffusion-controlled regime to transition regime as the reaction temperature decreases from 240 to 160 °C for SCR of NO. The monolithic catalyst with excellent mass transfer capacity and the catalyst with cylinder packing structure with high bulk density exhibit highest NO removal efficiency in the coking plant (∼240 °C) and boiler system (∼160 °C), respectively. The catalyst with Raschig ring packing structure exhibits the highest NO removal efficiency in the waste incineration plant (∼200 °C) due to the compromise of reaction–diffusion behavior. A strategy of catalyst structures selection for SCR of NO reaction at different industrial applications based on the reaction–diffusion interaction is proposed, which could shed new light on boosting selective catalytic reduction of NO reaction.