Separation of liquid–liquid dispersion in a batch settler: CFD‐PBM simulations incorporating interfacial coalescence

Abstract

Several commercially important chemical processes involve liquid-liquid phase separation. In the present work, we have developed a multi-fluid Eulerian CFD model using OpenFOAM that incorporates binary and interfacial coalescence processes. We simulated separation of kerosene dispersed in water in a batch settler and validated the predictions using the measurements of time-evolution of coalescing and settling interfaces, local dispersed-phase volume fraction (α O) and drop size distribution (DSD). Simulations are performed to understand the contributions of binary and interfacial coalescence processes to the phase separation process. While the timeevolution of coalescing and settling fronts can be predicted reasonably well using the two-fluid model with empirically-corrected drag models, local α O and DSD could not be predicted. We have shown that the comprehensive multi-fluid Eulerian model, which incorporates binary and interfacial coalescence, predicts the time-evolution of the coalescing and settling fronts, local α O and the DSD in an excellent agreement with the measurements.

CFD-PBE Simulation of Flow Dynamics and Mass Transfer in Two-Stage Countercurrent Mixer-Settler

“…In order to evaluate the influence of flow field on the mass transfer in a liquid–liquid extraction column, a CFD-PBE simulation was proposed by Gourdon et al Since then, CFD-PBE simulation has become a standard tool to predict the performances of industrial-scale extractors. The binary coalescent interface in the settler was applied to CFD-PBE simulations to predict the time evolution of the settling interface, volume fraction, and DSD of the dispersed phase. − Meanwhile, coalescence and breakage models of droplets were employed to describe the variation of DSD and extraction behavior in a single stage mixer . In addition, the effect of mixing on coalescence and breakage of droplets in the mixer were also investigated numerically and experimentally. , Although CFD-PBE simulation was used to predict the spatial and temporal distribution of droplets in single-stage extractors, the effect of volume fraction and DSD on mass transfer parameter, namely volumetric mass transfer coefficient ( k L α) has not been clearly identified.…”