CFD Modelling of Trickle-Bed Reactors for Wastewater Treatment

This study aims to incorporate most recent multiphase models in order to investigate the hydrodynamic behaviour of a TBR in terms of pressure drop, liquid holdup and catalyst wetting efficiency. Taking into account transport phenomena such as mass and heat transfer, an Eulerian k-fluid model was developed resulting from the volume averaging of the continuity and momentum equations and solved for a 2D representation of the bed at unsteady state. CFD model predicts hydrodynamic parameters with reaction conditions quite well. Moreover, catalytic performance is investigated in terms of TOC and one can conclude that Eulerian k-fluid model is a rational choice for flow simulation in packed beds, if good closures for fluid/fluid and fluid/particle interactions are incorporated in the CFD model used. The CFD approach can investigate external catalyst wetting in downflow flow mode performing a benchmark of hydrodynamic parameters encountered in the commercial-scale TBR deployment for CWAO technology in advanced wastewater treatment facilities.