Population balance modelling of droplets in an oscillatory baffled reactor - Using direct measurements of breakage rate constants

Population balance modelling (PBM) is a useful tool for design and prediction in a range of processes that involve dispersed phases, particulates or micro-organisms. In the Inverse Problem approach, constants related to the rates of evolution and/or interaction of the individual components are optimized so as to match the experimentally observed distribution curves. However, the significance of these results may be slight, or several solutions may be possible. In this paper, a method is presented to circumvent this problem, and is applied to the breakage and coalescence of oil droplets in a continuous oscillatory baffled reactor (OBR). Direct observation of droplet breakage using a high-speed camera should enable breakage rate constants to be obtained independently from the Inverse Problem approach, and thus obtain more reliable coalescence rate constants. An analysis of the droplet size distributions (DSDs) is also combined with direct observation with the high-speed camera to allow the development of a breakage model specific to the OBR. It is expected that this method should yield parameters useful for prediction of steady-state DSDs, and hence enhance the accuracy of design, scale-up, and prediction of operation. © 2003 Society of Chemical Industry.