Use of CFD for Pressure Drop, Liquid Saturation and Wetting Predictions in Trickle Bed Reactors for Different Catalyst Particle Shapes

Hanane Bouras (1, 2) , Yacine Haroun (1) , Francisco Fortunato Bodziony (1) , Régis Philippe (2) , Pascal Fongarland (2) , Frédéric Augier (1)

1 IFPEN - IFP Energies nouvelles
2 CP2M - Catalyse, Polymérisation, Procédés et Matériaux

The characterization of hydrodynamics in Trickle-Bed-Reactors is a complex task due to the opacity of the medium. In particular, the determination of pressure drop, liquid saturation , wetting of the catalyst surface and catalyst shape effect on these parameters is very important for optimal catalyst use and reactor operation. Measurements under industrial conditions are limited to indirect estimations, and direct measurement methods are limited to near-ambient conditions. In this context, the objective of the present article is to use Computational-Fluid-Dynamics to investigate pressure drop, liquid saturation and wetting efficiency in Trickle-Bed-Reactors and to improve existing correlations, with a special focus on the catalyst shape effect and wetting prediction. The Volume-Of-Fluid approach was used to simulate two-phase flow through particle loadings of spherical, trilobe and quadrilobe-shaped particles. The numerical model was validated against literature correlations in terms of pressure drop, liquid holdup and wetting efficiency. The CFD model was then employed to explore two effects that does not reach out a consensus in existing literature, i.e effects of particle shape and gas-phase velocity on wetting efficiency. As a result, it was shown that CFD provides good predictions of pressure drop and liquid saturation for different catalyst particle shapes, the achieved deviations between CFD results and correlation estimations are below 20%. A new wetting efficiency correlation is also proposed. This new correlation is able to predict wetting efficiency with a precision of 6.99% for a wide range of liquid velocities (from 0.2 to 0.8 cm/s) and gas velocities (from 5 to 20 cm/s) and three particle shapes.

Mots clés: Trickle Bed Reactors; Pressure Drop; Liquid Saturation; Wetting Efficiency; Catalyst Shape; CFD; Volume of Fluid Method; Multiphase Reactor; Hydrocarbon

Domaines: Catalyse; Sciences de l'environnement

Hanane Bouras, Yacine Haroun, Francisco Fortunato Bodziony, Régis Philippe, Pascal Fongarland, et al.. Use of CFD for Pressure Drop, Liquid Saturation and Wetting Predictions in Trickle Bed Reactors for Different Catalyst Particle Shapes. Chemical Engineering Science, 2022, 249, pp.117315. ⟨10.1016/j.ces.2021.117315⟩. ⟨hal-03519911⟩