Investigation of mass transfer coefficients in irregular packed liquidliquid extraction columns in the presence of various nanoparticles

In the present study, the effect of various nanofluids on mass transfer coefficients in an irregular packed liquid-liquid extraction column was investigated. The chemical system of toluene–acetic acid–water was used. 10 nm SiO2, TiO2 and ZrO2 nanoparticles with various concentrations were dispersed in tolueneacid acetic to provide nanofluids. The influence of concentration and hydrophobicity/hydrophilicity of nanoparticle on mass transfer coefficient was discussed. The experimental results show that the mass transfer coefficient enhancement depends on the kind and the concentration of nanoparticles. The maximum enhancement of 35%, 245% and 207% was achieved for 0.05 vol% of SiO2, TiO2 and ZrO2 nanofluids, respectively. A new conceptual model was proposed for prediction of the effective diffusivity as a function of nanoparticle concentration, drop size and drop Reynolds number.