Kinetic and two-dimensional reactor modeling of catalytic reduction of nitrogen oxides in a monolith honeycomb reactor.

摘要

Emission of nitrogen oxides (NOx) is of primary environmental concern in the power plant and oil sands industries. Selective catalytic reduction (SCR) is one of the best NOx reduction technologies. The present study discusses the development of a mechanistic kinetic model for SCR of NOx to describe the kinetics of V2O 5/TiO2 catalysis at atmospheric pressure and a temperature of 623K in a monolith honeycomb reactor. This work describes the details of a predictive model specifically designed for SCR used in the experimental study. Correlations for reaction kinetics are based on pore diffusion resistance and an Arrhenius expression for the reaction rate coefficient. Correlations for mass transfer are based on the dimensional numbers. Information is also provided on the correlation of the physical properties of reactant to pressure drop and conversion efficiency.;Good agreement between experimental and model results has been obtained for rate of reaction and NOx to ammonia ratio. A heterogeneous numerical model consisting of coupled mass and momentum balance equations was solved using the finite elements method. The operating range for the catalyst relics on the NO conversion and emission. The optimum operating range for the best performance of the reactor is discussed.;Computational fluid dynamics (CFD) is a field of knowledge and techniques used to solve mathematical models of fluid dynamics using digital computing resources. The modeling results impart insight into the significance of the diffusion with reaction steps and guidance for optimal monolith design for SCR. The validated expression predicts the conversion performance of the catalysts for different values of temperature inlet and ammonia concentration.