The performance of a two-phase liquid-liquid continuous flow stirred tank reactor (CFSTR) was evaluated experimentally by simultaneous determination of dispersed phase drop size distribution and extraction efficiency as a function of reactor operating conditions. The results provided a basis against which predictions made by a previously developed simulation technique (Bapat et al., 1984) were compared. The close agreement between the experimental and the simulation results validates the drop rate models and the simulation algorithm employed in this work.
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SCOPEMultiphase contacting is a commonly used operation in chemical process industries handling a wide range of substances in different forms and states of matter. Two-phase liquid-liquid contacting, which is a major multiphase operation, is frequently encountered in nuclear, hydrometallurgical, petrochemical, pharmaceutical, and food industries for extracting valuable substances. The optimum design and operation of such an extraction system require, in addition to the homogeneous reaction kinetics, a thorough understanding of the physical rate processes. The physical factors which influence the extractor performance are: (1) dispersed phase droplet processes (breakage and coalescence); (2) microscopic interphase transport processes; and (3) macroscopic flow patterns in the contacting equipment.The effect of these individual factors and their mutual interaction has not yet been quantitatively formulated by a comprehensive model. As a step in that direction, this work investigates the first two factors for a homogeneous liquid-liquid dispersion in a continuous flow stirred tank reactor (CFSTR). The dynamics of the dispersed phase drop interactions and the microscopic interphase mass transfer in the turbulent flow field were simulated to predict the behavior of the liquid extractor. The predictions are validated by comparison against the experimental data acquired from a cyclohexane/carbontetrachloride(dHiodine]-water(c) dispersion agitated in a one-liter CFSTR system capable of providing simultaneous determination of drop size distribution and extraction efficiency. The drop size distributions are obtained by in situ photomicrography. The mass transfer efficiencies are estimated by spectrophotometric iodine concentration measurements of the reactor dispersion phases separated by a specially developed instantaneous in situ membrane filtration technique.In the past, the population balance equation (PBE) that provides the mathematical apparatus for describing the particulate systems has been used successfully to obtain the dispersion state distributions ( Simulation of interphase transport in two-phase liquid-liquid dispersions has not been successfully attempted before the present work. The highly interactive droplet swarm in a turbulent environment has precluded any theoretical treatment of these processes. Experimental estimation of interphase mass transfer also encounters major difficulties due to turbulence in mechanically agitated stirred tanks. Because the...