Development of a hybrid pressure drop and liquid holdup phenomenological model for trickle bed reactors based on two‐phase volume averaged equations

Abstract

AbstractA model with a high predictive quality to estimate pressure drops and liquid holdups in trickle bed reactors (TBR) is yet necessary to assist in design, up scaling, and the implementation of new processes tasks. The currently available models to estimate pressure drops and liquid holdups on TBRs exhibit important deviations, which lead to uncertainties in their applicability. To overcome the limitations in prediction deviations in the currently available models, a new model is developed based on the volume averaged two‐phase transport equations in a porous media, as developed by Whitaker. In order to develop a model that could simultaneously predict pressure drops and liquid holdup with a high accuracy, the developed model was coupled with a modification of the extended slit model reported in the literature, leading to a new hybrid model with enhanced predictability. Experimentally determined pressure drops and liquid holdup in a column with a 0.14 m internal diameter and a height of 2 m, packed with different extrudate geometries, cylinders, trilobes, and quadlobes, were used to determine the model parameters and to verify the quality of the proposed hybrid model predictions. The developed model, when compared with the experimentally determined data of pressure drops showed mean squared errors (MSE) of 0.89%, 2.31%, and 1.22% for the cylinders, trilobes, and quadlobes particles, respectively, while the liquid holdups were predicted with MSEs of 0.03%, 0.16%, and 0.01% for the cylinders, trilobes, and quadlobes particles, respectively.