Considerations about the gas fraction in two-phase electrochemical reactors by using a rigorous hydrodynamic model

Abstract

The experimental evidence that a limiting value of gas fraction is achieved in a gas-liquid dispersion as the gas volumetric flow rate is increased is explained by means of a rigorous hydrodynamic model. The mathematical treatment, based on the Eulerian concept applied to each phase, considers a population balance with a range of bubble sizes allowing the coalescence and breakup between them; and it is implemented in the OpenFOAM framework. It is concluded that the limiting gas fraction is a consequence of the increase of the gas velocity and the constancy of the drag term of the interfacial exchange moment as the volumetric gas flow is enlarged. A simplified hydrodynamic model is also reported that closely matches both the rigorous one and the experimental results under limiting operating conditions.