Hydrodynamics, Mass Transfer and Chemical Reactions in Bubble Column Reactors using Euler/Lagrange Approach

ISBN-13: 9783844085648 / Angielski / Miękka / 2022 / 158 str.

Manuel Alejandro Taborda Ceballos

Opis

This work concerns studies of modeling bubble column reactors during the different phases that can be found when simulating it, such as hydrodynamics, mass transfer and species transport, and finally including chemical reactions. Highlighting the importance of considering local bubble dynamics and its effect on liquid-phase hydrodynamics and turbulence.A Computational Fluid Dynamic (CFD) model was designed, developed, verified, and used for predicting flow hydrodynamics, mass transfer, species concentration when considering also reactive systems within the frame of Euler/Lagrange approach using Large Eddy Simulations (LES) for solving the instantaneous flow fields. The models were implemented in the open-source platform OpenFOAM®. For validating the model extensions thorough numerical computations were conducted for several experimental test cases with air and N2 bubbles as well as CO2 absorption followed by chemical reactions considering single bubble rise and bubble swarms in laboratory bubble columns. Furthermore, simulations of Fe(edta)-NO system, based on a system studied only for single bubbles, is presented here numerically for a bubble column.It is demonstrated that for point-particle approaches the modelling of bubble dynamics in motion and mass transfer is essential for accurate predictions. Only with this extension it is possible to obtain correct bubble lateral dispersion and a remarkably higher mass transfer provoked by the larger surface area of deformed bubbles. Thereby, bubble and liquid velocities, gas volume fraction, species concentration as well as bubble size distribution variations along the bubble column in a reactive system can be predicted with a very good agreement compared to experimental measurements.