Applying nanofluid to a rotary disc contactor to investigate breakage phenomenon

Abstract

Five different nanofluids have been prepared by use of two‐step procedure, in which SiO2 nanoparticles with different volume fractions and hydrophobicities have been dispersed in butyl acetate as base fluid by applying ultrasonication method. Three different methods have been used to evaluate the nanofluids' stability: conventional sedimentation method, particle size analyser and UV‐Vis spectrophotometric. As a quite novel research, these nanofluids were applied to a Rotary Disc Contactor with 91 mm diameter and 12 rotating discs to investigate breakage probability and the first critical rotor speed. The effects of nanoparticles' volume fraction and hydrophobicity, as well as rotor speed, mother drop size and continuous phase height on the breakage phenomenon have been studied. © 2011 Canadian Society for Chemical Engineering

A critical review on the use of nanoparticles in liquid–liquid extraction

“…Rotary disc contactors have attracted significant attention for liquid-liquid extractions due to their low driving power, high throughput, and high efficiency per unit height[108].Molavi et al [109]. studied droplet breakage in a rotary disc contactor in the presence of nanoparticles.They dispersed SiO 2 nanoparticles with two different degrees of hydrophobicity in the dispersed phase (butyl acetate).…”

“…The authors attributed this phenomenon to the Brownian motion of nanoparticles inside each droplet, which increased internal mixing and facilitated breakage.On the other hand, they reported increasing the nanoparticle content caused increased interfacial tension, which consequently predominated over the increased circulation inside the droplets due to the Brownian motion of nanoparticles, resulting in a decrease in the breakage probability and an increase in the first critical rotor speed. In terms of the hydrophobicity of the nanoparticles, they demonstrated that drop breakage increases when nanoparticles with greater hydrophobicity are added, due to increased mixing in the drops caused by Brownian movement[109].Mixer-settlers are a widely used class of liquid-liquid contactors due to their reliable scale up, low maintenance, high stage efficiency, and operational flexibility and simplicity[110,111]. Raji-Asadabadi et al[112] studied the effect of SiO 2 nanoparticles on droplet size in a horizontal mixer-settler, and found that the addition of nanoparticles reduced the size of droplets.…”