Computational Approach to Characterize the Mass Transfer between the Counter-Current Gas-Liquid Flow

Structured packed columns are widely used in the chemical industry for distillation and absorption. However, the understanding of the transfer mechanism behind the counter‐current gas‐liquid flow in structured packed columns is still limited. In this work, a three‐dimensional CFD model that considers the local absorption and the local momentum transfer mechanism is developed for a film flow on a small plate with a counter‐current gas flow. The model, based on the Volume of Fluid (VOF) method, is built up on the basis of a pressure drop model and the penetration theory to quantitatively investigate the instantaneous hydrodynamics and mass transfer characteristics of the liquid phase. Simulations and experiments are carried out for a system consisting of propane and toluene. A comparison of the simulation results with the experimental data for the outlet concentrations shows good agreement. Based on the pressure drop model and the penetration theory, a three‐dimensional, transient CFD model is developed to consider the local drag force and the local mass transfer between the liquid phase and the counter‐current gas phase. The characteristics of the instantaneous hydrodynamics and the concentration profile are investigated in detail.