Discriminating trickle-flow hydrodynamic models: Some recommendations

The forecasting ability of five one-dimensional (1-D) two-fluid phenomenolo gical models far liquid holdup and two-phase pressure drop in trickle-flow reactors was evaluated using the most comprehensive trickle-flaw regime dat abase. All of these models, namely, the permeability model, the slit model, the extended slit model, the 1-D CFD model, and the double-slit model can be used to predict liquid holdup. Among them, the permeability and the slit models, because of a much simpler structure, are recommended. The extended slit model based on Iliuta et al. (Ind. Eng. Chem. Res. 1998, 37, 4542) sh ear and slip constitutive relationships can be employed for two-phase press ure drop predictions. When the knowledge of wetting efficiency becomes esse ntial at very low liquid flow rates, the double-slit model is recommended.