Dispersion conditions and drop size distributions in stirred micellar multiphase systems

Micellar multiphase systems can be applied to enable reactions like the hydroformylation of long-chained olefins. These liquid/liquid systems combine advantages of homogenous catalysis like high and specific yield or mild reaction conditions with a fast phase separation process. In previous studies highest yields were observed in systems under three phase operation conditions whereby the reaction rate was a function of stirrer speed. Hence, dispersion conditions and drop size distributions need to be taken into consideration. In this study, micellar three phase systems were analysed using an endoscope measurement technique and image analysis in a stirred tank. A methodical approach to identify the respective phases and to clarify the dispersion conditions was found. The mean Sauter diameters were quantified as a function of the system composition. By applying abrupt changes of the stirrer frequency, the dynamic behaviour and coalescence effects were investigated. (C) 2015 Elsevier B.V. All rights reserved.