Industrial & Engineering Chemistry Research, Vol.50, No.5, 2706-2714, 2011
High-Pressure Modeling of Unsteady-State Hydrodynamics in Cocurrent Gas-Liquid Trickle-Bed Reactor
In the present study, a computational modeling approach capable of simultaneously tracking the multiphase attributes of trickle flow is accomplished at high-pressure by means of computational fluid dynamics (CFD) codes. The morphological features of the gas-liquid structure accounted for by the CFD framework were embedded with a volume-of-fluid (VOF)-based interface capturing methodology for monitoring the gas liquid interface dynamics supplemented with the droplets and rivulets formation triggered at unsteady-state conditions. Our research effort on transient operated trickle-bed reactors (TBRs) relied on assured benefits of their performance enhancement that ultimately investigated the application of the VOF model with the purpose to quantify the relationship between bed structure and downstream flow distribution in cocurrent packed beds. To accomplish this concept, first we evaluated the influence of model tuning parameters. Second, the effect of process liquid flow rates and operating pressures was examined thoroughly on liquid holdup and two-phase frictional pressure drop. Finally, we have performed a three-dimensional analysis of interstitial flow hydrodynamics that enabled us to identify the inhomogeneous nature of the multiphase flow environment on the catalytic packing scale.