Simulation of an industrial-scale process for the SCR of NOx based on the loop reactor concept

Abstract

This paper investigates the possibility of using an adiabatic loop reactor to carry out the Selective Catalytic Reduction of NOx with NH3. The advantages of this technology with respect to more traditional reactors operated in steady-state are discussed: when the temperature of the feed is low, a lower amount of heat is required to get full NOx conversion; moreover, the catalyst can be used to store a high amount of NH3 during the operation, thus preventing NH3 slip and/or NOx emissions when the feed composition changes. Both issues are investigated, using the design of an industrial-scale reactor as case study.

The role of reaction kinetics and mass transfer in the selective catalytic reduction of NO with NH3 in monolithic reactors

“…The model is heterogeneous, which means that it accounts separately for the gas and solid phases by means of the corresponding species mass balances. This allows prediction of the dynamics of the ammonia adsorbed on the catalyst …”

“…This model is composed of accumulation, convection and (intrinsic) reaction terms. The reaction mechanism assumed in this work is a simplification of the one presented by Topsoe and Dumesic, in which only the adsorption of ammonia and adsorbed ammonia reaction with NO are assumed to be kinetically relevant (Equations and ) . In addition, ammonia reaction with NO is assumed to be irreversible.…”

Selective catalytic reduction of NO in a reverse-flow reactor: Modelling and experimental validation

“…A one-dimensional (1D) heterogeneous dynamic model has been found to be satisfactory for reverse-flow reactors in previous works [33,35,36]. In heterogeneous models, fluid and solid are described separately using the corresponding property balances which results in better description of the NH 3 dynamics.…”

“…Other simulation studies were developed by Snyder and Subramanian [31], who focused on the influence of ammonia feeding and concentration, and switching time (or semi-cycle duration) on the concentration profiles in the reactor, Fissore et al [32,33], who compared RFR to reactors network (a system composed of several fixed bed units, the feed switching periodically among them) using a non-isothermal model, and Iancu et al [34] proposed an advanced control system.…”

Systematic study of the performance of a reverse flow reactor for the treatment of lean hydrocarbon emissions

“…Reverse flow reactors (RFR) belong, as chromatographic reactors, 1 loop reactors and reactor networks, 2,3 among others, to the family of chemical reactors that work under forced unsteady state conditions. The RFR principle is based on the difference of speed between a flowing gas and a temperature front, travelling through a solid bed.…”