Study on droplet behaviour and mass transfer from nanofluid particles in liquid liquid extraction

Abstract

In the present study, experiments were conducted to study the motion of nanofluid drops moving through an immiscible quiescent liquid for the liquid-liquid extraction process. An extensive set of data in terms of terminal velocity and mass transfer coefficient were generated using three different systems (Chlorobenzene, Tetrachloroethylene, and Nitrobenzene) with the addition of propionc acid in case of mass transfer studies. To elucidate the effect of the addition of nanoparticles on hydrodynamic and mass transfer parameters, four nanoparticles (SiO2, Al2O3, ZnO, and MWCNTs) have been taken. It was observed that with the addition of nanoparticles into the system, the terminal velocity and mass transfer coefficient increases up to an optimum concentration of nanoparticles, beyond which it started to decrease. Based on the observed data, the existing models for pure systems were extended to predict the terminal velocity and mass transfer coefficient in terms of nanoparticle volume fraction (and#632;), the time scale for Brownian motion ( bd and#61556; ), the time scale for nano convection diffusion ( cd and#61556; ) and the time scale for mass diffusion ( md and#61556; ). The proposed correlation for terminal velocity and drag coefficient predicts the experimental data well to within a reasonable accuracy of ±8% with MRQE and %ARE of 0.038 and 2.99%, respectively for terminal velocity and 0.081 and 6.28%, respectively for the drag coefficient. The proposed correlation for mass transfer coefficient predicts the experimental data well to within a reasonable accuracy of ±15% with MRQE and %ARE of 0.074 and 6.29, respectively for mass transfer coefficient. newline