An online monitoring and simulation tool (OMST) is used to determine, analyse, simulate and predict the multiphase flow behaviour in an extraction column within the context of model predictive control (MPC). The simulation was done with the droplet population model OPOSPM using an adapted moments method for online simulation. For validation, steady-state and transient experiments are performed, where rotor speed and dispersed volume flow rate are changed using the EFCE system toluene-water. OMST deviations are between 3% (droplet sizes in steady state) and 20% (hold-up in dynamic step-changes) which are highly dependent on the quality of the parameter estimation.