Numerical and Experimental Study of Catalyst Loading and Body Effects on a Gas‐Liquid Trickle‐Flow Bed

Abstract

The influence of tortuosity and fluid volume fractions on trickle-flow bed performance was analyzed. Hydrodynamics of the gas-liquid downward flow through trickle beds, filled with industrial trilobe catalysts, were investigated experimentally and numerically. The pressure drop and liquid holdup were measured at different gas and liquid velocities and in two different loading methods, namely, sock and dense catalyst loading. The effect of sharp corners on hydrodynamic parameters was considered in a bed with rectangular cross section. The reactor was simulated, considering a three-phase model, appropriate porosity function, and interfacial forces based on the Eulerian-Eulerian approach. Computational fluid dynamics (CFD) simulation results for pressure drop and liquid holdup agreed well with experimental data. Finally, the velocity distribution in two types of loading and the effect of bed geometry in CFD results demonstrated that pressure drop and liquid holdup were reduced compared to a cylindrical one due to high voidage at sharp corners.

Hydrodynamics of inclined packed beds under flow modulation ‐ CFD simulation and experimental validation

“…Despite a slight over‐prediction, the simulation results showed that the traditional Eulerian multifluid model was able to capture the dynamic pattern of the measured liquid holdup in the case of vertical packed bed (Figures a, a). In line with these results, applicability of the implemented CFD model for the prediction of hydrodynamic behavior of packed beds operating under steady and unsteady state conditions has been demonstrated in some previous studies . Conversely, Figure b revealed an erratic behavior in the model results of the liquid holdup waves for the 15°‐inclined bed.…”

“…Several researchers successfully applied the Eulerian multifluid CFD model along with well‐established interphase interaction forces as closure laws to predict bed overall pressure drop and liquid holdup in conventional vertical gas‐liquid cocurrent downflow packed beds (i.e., trickle‐bed reactors) under steady‐state (i.e., iso‐flow) and unsteady‐state cyclic operation . Hamidipour et al were able to precisely capture the transient hydrodynamic behaviors of trickle‐bed reactors under gas, liquid, and gas/liquid alternating cyclic operations using an unsteady multifluid Euler framework combined with the closure laws developed by Attou et al for fluid‐solid drag forces and fluid‐fluid interaction force.…”

Validation of a novel open-source work-flow for the simulation of packed-bed reactors

“…cylinders and trilobes) can be treated only with cumbersome strategies. This is particularly important because these exotic shapes, such as trilobes, are becoming more and more popular [27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Other interesting alternatives are based on the use of Monte Carlo methods [41][42][43] that solve some of the above mentioned issues.…”

Dynamic Modeling Strategy To Assess Impacts of Hydrodynamic Parameters on Industrial Hydropurification Process by Considering Catalyst Deactivation

“…The velocity distributions revealed that liquid hold up and pressure drop are decreased at sharp corners due to the increased void fraction, influenced by the reactor boundaries. 12 In an experimental study, 13 the hydrodynamic aspects of a TBR filled with paper or ceramic bead catalysts were studied through residence time distribution. The paper composite exhibited a better wettability and internal diffusion for the liquid reactants, compared to the ceramic beads, which is in favor of heterogeneous flow.…”

“…Further, the decrease in the gas flow rate appreciably increased the residence time . Salimi et al studied the effects of tortuosity and fluid volume fractions on the performance of TBR. The hydrodynamic behaviors of a TBR filled with industrial trilobe catalysts were investigated for two different catalyst loadings through conducting the experiments and CFD modeling.…”