(64d) Hydrodynamics of Trickle-Bed Reactors With Particle Size Distributions

For trickle-bed reactors, it is desirable to characterize the hydrodynamics to enable operation under conditions for uniform distribution of flow, efficient wetting of catalyst, desired flow-regime, and adequate heat and mass transfer.  CFD models describing these phenomena¹ and models of transient imbibition/drainage² have been reported in the literature, while the ideal of a predictive and generally applicable model for maldistribution has yet to be attained.  Precedent and foundational to these endeavors is the study and modeling of the hydrodynamics under uniform trickling flow. Accurate representation of the influence of bed and operating variables on the hydrodynamics (as described by pressure drop and liquid holdup) is vital.  Modeling results are used for design purposes and the model itself is used in closure equations of CFD and transient models.   To date, experimental studies on trickle-bed hydrodynamics have been restricted to beds packed with uniform catalyst supports.  This data set omits catalyst supports having a particle size distribution, as is the case with granular activated carbon.  In this work, effect of particle size distribution on trickle-bed reactor hydrodynamics is studied under uniform flow.  By appropriate definition of force interactions, existing models are adapted to provide improved predictions of pressure drop and liquid holdup for the attained experimental data where particle size distribution is varied.

[1]  Kuzeljevic, Z. V.; Dudukovic, M. P.  Ind. Eng. Chem. Res., 2012, 51 (4) 1663-1671.

[2]  Iliuta, I.; Hamidipour, M.; Larachi, F. AIChE J. 2012, 58 (10) 3123-3134.