Liquid−liquid systems research increasingly concentrates on computer simulations. However, the possibility of adequately testing complex theoretical models against experiments is hindered by a lack of reliable reproducibility data for laboratory and pilot-plant measurements. This strongly limits meaningful evaluation of the increasingly complex process and equipment models/algorithms that are being developed. In this work, experimental data are obtained in a pilot-scale Kühni column, and model parameters and simulated data are generated using a drop population balance model and algorithm. The results can be summarized as follows:  (i) As measured by the magnitude of careful random error and corresponding confidence limits estimates, the simulation results exhibit excellent agreement with experimental drop-size distributions and fair conformity with measured dispersed-phase hold-ups. (ii) Both experimental and simulated results show that interdrop coalescence is always present within a column extractor, even at low dispersed-phase hold-ups, and thus cannot be neglected in any physically realistic and accurate modeling.

Given the difficulties normally associated with direct experimentation in liquid-liquid extraction processes, their direct computer simulation has acquired increased relevance and utility, especially when dealing with some of the details of the dispersed-phase hydrodynamics. The possibility of testing very complex theoretical models of such behavior is increasingly attractive to the researcher, as a result of both the power and the availability of personal computing resources. Experimental data obtained in a pilot-scale Ku ¨hni liquid-liquid extraction column and simulated data generated by means of a drop population-balance model and algorithm were used to describe and compute the local drop-size distributions and dispersed-phase holdup profiles. In this work, the applicability of this algorithm to describe the steady-state behavior of a Ku ¨hni liquid-liquid extraction column is illustrated. Data generated using this algorithm exhibit reasonable agreement with experimental data, with physically meaningful model parameter values.

Experimental data obtained in a pilot-scale Kühni liquid−liquid extraction column were used to obtain local drop size distributions, dispersed-phase hold-up profiles, and solute concentrations. To obtain information about the dynamic behavior of the column, several experiments were planned and performed, under both steady and controlled transient conditions, with and without mass transfer. The analysis of the effects of the presence of a transferring solute (not of the mass transfer flux itself) on the dispersion’s steady state and dynamic behavior was the main objective. For this, we imposed forced step variations in the operating conditions − agitation intensity and continuous and dispersed-phase flowrates.