Model of Reactive Transport within a Light Photocatalytic Textile

Abstract

Abstract This paper deals with the 3D-modeling of the reactive transport within a light photocatalytic textile used to decontaminate industrial effluents. The model consists of the coupling of fluid flow governing equations, species convection diffusion equations and a heterogeneous reaction equation. It is solved numerically on a Representative Volume Element (RVE) of the textile, i.e. at the microscopic scale regarding the industrial photocatalytic reactor using Comsol Multiphysics software. In a preliminary approach, the reactive transport model was first applied in a 2D simple geometry to verify its accuracy in terms of mass balance of the species. Then successive simulations using pseudo-periodic boundary conditions were performed in the RVE and the depollution efficiency along the textile length is analysed in terms of pollutant concentration. A sensitivity analysis was done to reveal the relative importance of the kinetic and hydrodynamic parameters in prediction of pollutant concentration fields in the RVE. It was found that a high adsorption rate associated with a low permeable fabric maximizes the amount of treated fluid. Finally the performances of a typical reactor composed of a stack of textiles were investigated. Results show a significant improvement of depollution efficiency of this particular configuration compared to single textiles in parallel.