Simulation of a bubble column reactor using CFD approach. Application: ferrous biooxidation
Multi-scale and/or multi-disciplinary approach to process-product innovation
CFD & Multiscale Modelling in Chemical Engineering (T3-4P)
Keywords: CFD simulation; Bubble column; Eulerian model; velocity field; Ferrous biooxidation
Understanding the complexity of the fluid dynamics in bubble column and airlift reactors is important due to their application in the chemical and bioprocess industries. Knowledge of the hydrodynamics of such reactors helps to determine the efficiency of biochemical production rates through transport processes such as inter-phase oxygen transfer, mixing of nutrients and reactants plus the effects that pH has on micro-organisms growth, metabolic pathways and cell lyses. In view of the fact that the microbial oxidation of ferrous iron to the ferric form is an essential sub-process in many biological processes, the developing of an understanding to obtain optimum conditions for this sub-process is critical. The objective of this research was to develop a fundamental understanding of the hydrodynamics and interactions with the chemistries involved in the bubble column reactor to maximize overall efficiency for the ferrous biooxidation. In the present attempt bacterial oxidation of Fe+2 to Fe+3 in a bubble column reactor was simulated using a commercially available computational fluid dynamics package (FLUENT). Gas-liquid interactions were modeled using an Eulerian model in three dimensions. The velocity field, air volume fraction as well as ferrous to ferric conversion in the column were predicted. To validate the model simulation data were compared with the experimental data obtained by a column reactor where the superficial gas velocity was adjusted between 0.01 and 0.5 m s-1. In the experiments Acidithiobacillus ferrooxidans was used as an inoculum. The numerical results are in good agreement with experimental data. According to the simulation inlet air velocity of 0.1 m s-1 and pH of 1.5 were resulted as the best conditions. In these conditions the maximum ferrous conversion was predicted 100%. In the experiment tests at mentioned conditions the maximum ferrous biooxidation value, 90%, was obtained.
Presented Tuesday 18, 13:30 to 15:00, in session CFD & Mutliscale Modelling in Chemical Engineering (T3-4P).
