(A) drop population balance model for mass transfer in liquid-liquid dispersion systems

Abstract

For calculation of mass transfer rate in a liquid-liquid extraction system the solution of the trivariate drop population balance model was obtained by computer simulation, in which probability density of the drop population was expressed in terms of drop volume, solute content in the drop, and drop age. The Coulalogou``s drop interaction model was employed for describing the drop phenomena, and a moving boundary diffusion model was used for mass transfer calculation. In the simulation the quiescence interval method, differentiation of the constant stirred tank contactor, and ten random number were introduced. The numerical solution of the moving boundary diffusion equation was obtained, and a modified solution which gave the same results as the numerical solution was also obtained by inserting a factor into the analytic solution of the fixed boundary diffusion model. The calculated results of the model are in good agreement with reported data and experimental data in this study. The effect of drop collision on the effective diffusivity was fully discussed, and concluded that the effective diffusivity was depended mainly on the dispersed phase hold-up in the region that the rigid body assumption was valid.