Mass transfer coefficients in liquid–liquid extraction

The paper concerns with mass transfer in liquid–liquid extraction, considering that the experimental determination of the individual mass transfer coefficients during liquid–liquid extraction is still considered to be a difficult problem. In this work, the liquid–liquid extraction using a ternary system, water–acetone–carbon tetrachloride, was studied. The investigations were performed in an improved Lewis cell, in continuous and batch operation modes. The immiscible components (water–carbon tetrachloride) were mixed separately, while the acetone transfer was carried out in the two directions through an interface with a constant area of the surface, created between the two phases. The specific fluxes, the driving forces and the individual and overall mass transfer coefficients were determined by measuring the inflow and outflow acetone concentrations in the two phases, together with the equilibrium data. The values of the individual mass transfer coefficients in each phase were correlated and expressed in the form of criterial equation, as Sh=bRepScm.