Investigating the effect of nanoparticles on the dispersed phase mass transfer coefficient in a rotary disc column

• Mass transfer and static hold-up are investigated in presence of SiO2 nanoparticles.
• A new equation is proposed for predicting mass transfer coefficient.
• Heat and mass transfer in presence of nanoparticles is taken into account.
• Mass transfer performance is improved 6–45% using nanoparticles.
• An effective diffusivity is proposed in a RDC column.

In this study, mass transfer performance and static holdup of dispersed phase in a liquid–liquid extraction column with rotating discs is investigated in presence of nanoparticles. The required nanofluid was prepared by dispersing SiO2 nanoparticles in kerosene, as the base fluid, using ultra sonication. The results show that the presence of nanoparticles increases static holdup of the dispersed phase. Moreover, the mass transfer performance was improved 6–45%. At higher rotor speeds, the effect of nanoparticles is reduced. Taking the heat and mass transfer analogy into account, an equation is presented for prediction of effective diffusivity and dispersed phase mass transfer coefficient in terms of nanoparticles content, Reynolds number and Schmidt number. Finally, the mass transfer coefficients obtained via the proposed equation of this work and the equations given by some other researchers have been compared with experimental data.