Estimation of volumetric mass transfer coefficient (kLa)-Review of classical approaches and contribution of a novel methodology

The volumetric mass transfer coefficient, usually denoted by k(L)a, is an important parameter for both the design, scale-up and monitoring of aerated bioreactors. Significant research efforts have been expended over the last decades in order to develop reliable and easy to apply methodologies for determining k(L)a using aeration experiment and fast oxygen (polarographic) probes. These methodologies have been reviewed in this study followed by the presentation of a new and promising methodology for k(L)a determination, which can be used when data from step experiments are not available. Step and aeration experiments have been carried out in laboratory scale bioreactors and the experimental data were used for the validation of the proposed methodology and also to critically assess all alternative methodologies for estimating k(L)a.