Oxygen transfer in aerobic processes: A review of phenomenological modeling

In this paper, a review of empirical correlations proposed by researchers from 1974 to nowadays is performed. The reviewed correlations allowed to determine the mass transfer coefficient (kL), the volumetric oxygen transfer coefficient (kLa), the interfacial mass transfer area (a), and the bubble diameter (dBS) for aerated tanks with circular and rectangular cross-sectional areas. Theoretical predictions of the volumetric mass transfer coefficient that have been recently proposed were described; finally, different criteria for bioreactor scale-up were considered in the light of the influence of oxygen transfer rate affecting the dissolved oxygen concentration in real bioprocess. From this review it can be concluded that, although there are several studies in this area, still there are difficulties to obtain more explicative models describing the oxygen transfer from a liquid phase to a gas phase.