An experimental and computational study of hydrodynamics and mass transfer in gas-liquid bubble columns

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This thesis presents experimental measurements and CFD modeling validations to simulate hydrodynamics and mass transfer in gas-liquid bubble columns using ANSYS CFX. The experiments were conducted in a laboratory-scale bubble column, divided into two parts: first, investigating hydrodynamics, including the axial dispersion coefficient and gas hold-up relative to varying flow rates of gas and liquid; second, examining mass transfer, specifically the volumetric mass transfer coefficient under different flow conditions. Following these studies, a CFD model employing the Eulerian-Eulerian approach with a single-sized bubble as the disperse phase was developed to simulate the flow field. Various closure models, including turbulence and drag models, were assessed and compared with experimental data. Additionally, a mass transfer model was created to account for phase interactions, incorporating volumetric mass transfer coefficients derived from experiments into the CFD model for numerical calculations. The simulations validated the CFD model under the experimental flow conditions, revealing that hydrostatic pressure significantly influences mass transfer between phases. Ultimately, the results indicate that the Euler model, despite its simplifications, remains a suitable and cost-effective method for numerically simulating two-phase flow in bubble column reactors.