Determination of the O₂ and CO₂KLa values in fermenters with the dynamic method measuring the step responses in the gas phase

Simulation studies using the mass balance equations demonstrate that it is possible to determine the K L a values for O 2 and CO 2 from measurements taken in the gas phase. In order to do this, the step change must be applied to the concentrations in the liquid phase. An injection device was developed to generate these step functions. The K L a values for O 2 and CO 2 measured in the presented system are of the same size. These values allow the theoretical step responses to be calculated, which are compared to the experimental ones. It is shown that the gas phase dynamic must be taken into account to avoid calculating K L a values with intolerable errors.