CFD modeling of catalytic reactions in open-cell foam substrates

Open cell foams are regarded with interest for applications as catalytic substrates for combustion, reformers and after-treatment converters for the pollutant emissions control. In this context, CFD represents a reliable and convenient tool for investigating and understanding the physical phenomena occurring at the micro-scale, in order to design and optimize these substrates. A CFD model for the simulation of the catalytic reactions occurring over the surface of open-cell foams is implemented and validated. The approach is based on a coupled finite-volume/finite-area strategy capable to describe the fluid-dynamic and the chemical phenomena occurring in both the fluid phase and solid phases. The adsorption/desorption of the reactants on the active sites and the surface reaction is modeled on the basis of a Langmuir-Hinshelwood mechanism. The model is able to describe the reactants conversion under both kinetics and diffusion control, allowing to predict the light-off curve characterizing the catalyst-coated foam substrate.