Assessment of CFD Euler–Euler method for trickle-bed reactor modelling in the catalytic wet oxidation of phenolic wastewaters

Trickle-bed reactors (TBRs) are envisaged as a breakthrough technology in industrial wastewater treatment plants. According to the literature, the generous research in environmental reaction engineering has indicated that scale-up of TBR is erroneous if one considers isothermal operation and uses either a pseudo-homogeneous or a heterogeneous model with plug flow for gas and liquid phases. Even though axial dispersion model may account for liquid distribution non-uniformity, the reaction parameters are strongly dependent on the reactor fluid dynamics.In our case study, we develop an Eulerian CFD (computational fluid dynamics) framework based on empirical interphase coupling parameters in the momentum balance equation. After the hydrodynamic validation, the catalytic wet oxidation of phenolic wastewaters was taken as an example to evaluate axial and radial profiles for the total organic carbon depletion and temperature along the packed bed. The theoretical calculations were compared against experimental data taken from a trickle-bed reactor pilot plant. The Eulerian computations have shown promising results on how fluid dynamics can be correlated with chemical reaction, namely on the prediction of total organic carbon conversions attained at different temperatures.