Mass transfer modeling and simulation of a transient homogeneous bubbly flow in a bubble column

Abstract

Bubble columns have wide applicability in the industry as contactors such as absorbers, strippers, and multiphase reactors. Despite their simple construction and operation, the success in the design of bubble columns requires deep knowledge of transport phenomena applied to multiphase flow. Modeling and simulating the fluid dynamics through numerical methods may circumvent the high cost of empirical methods when analyzing key parameters for the design and scale-up of bubble columns. The main objective of this work is to model and simulate the interfacial mass transfer in a bubble column, for both steady-state and transient analysis. The equations of mass, momentum, and species conservation are described in a Euler-Euler framework using a one-dimensional Two-Fluid Model (TFM), taking adequate closure relations for modeling interfacial transport phenomena. The equations are integrated by the Finite Volume Method (FVM) in an algorithm developed by the authors and the numerical results obtained are compared with experimental data found in the literature. The simulations are predictive and run with no need for matching experimental data, which is the main contribution of this work. The results obtained showed good agreement when compared with experimental data. Additionally, a high-order in space (TVD) and time (Crank-Nicolson) is developed to capture the gradients of gas fraction and composition, providing a remarkable tool for transient analysis.