The influence of nanoparticles on hydrodynamic characteristics and mass transfer performance in a pulsed liquid-liquid extraction column

With respect to the influence of nanoparticles on mass transfer characteristics, limited number of studies available in the literature, deal primarily with gas-liquid systems. In this work, mass transfer performance and hydrodynamic characteristics including static and dynamic dispersed phase hold-ups of nanofluids have been investigated for pulsed liquid-liquid extraction column (PLLEC). The nanofluids used were prepared by dispersing SiO2 nanoparticles of 0.01, 0.05 and 0.1 volume percent with two different hydrophobicities in kerosene as base fluid using ultrasonication. UV-vis spectrophotometer was also used for evaluation of the nanofluids stability. The results were compared with conditions of no-nanoparticles in the dispersed phase and in the absence of mass transfer effect (no acetic acid as solute). Different pulsation intensities were maintained for the fixed mass flow rates of dispersed (Q(d)) and continuous (Q(c)) phases (with ratio Q(c)/Q(d) = 1.2) with mass transfer direction being made from the dispersed phase to the continuous one. The results indicate that in the presence of the nanofluids, static and dynamic dispersed phase hold-ups increased by 23-398%, and 23-257%, respectively, while mass transfer performance was enhanced by 4-60%. (C) 2011 Elsevier B.V. All rights reserved.