Single droplet experiments in Kühni compartment for five different liquid systems were used to evaluate Schmidt breakage model parameters. Based on these optimised parameters, Coulaloglou and Tavlarides coalescence model parameters were obtained by an inverse solution of population balance model (PBM) using the extended fixed-pivot technique. The estimated interaction parameters were used to study the hydrodynamics of a pilot Kühni column. For online prediction purposes the One Primary and One Secondary Particle Model (OPOSPM), which is essentially a reduced population balance model (PBM), was used as an alternative to the computational expensive detailed PBM. Different test systems and column geometries were used for steady and transient state validation where OPOSPM was found to produce remarkable good results.