Theoretical analysis of selective catalytic reduction catalysts

Abstract

A theoretical analysis of the selective catalytic reduction (SCR) process is presented to assist in the selection of a catalyst for efficient control of NOx from flue gases. It is a two-dimensional (2D) numerical model accounting for the simultaneous effects of external diffusion and catalytic chemical kinetics. Experimental data of SCR performance employing different types of catalysts are taken from the literature and analyzed for their NH3 adsorption constant and effective-rate constant. The catalysts' characteristics are then used to predict their SCR performance. Good agreement is obtained between model results and experimental observations on the NO removals. The activites of the catalysts are compared and strategies affecting SCR performance are discussed. It is shown that the effective reaction rate of a catalyst is the key parameter influencing its activity. The catalyst preparation procedure as well as the V2O5 content are important for determining its NO removal rate.