Mass transfer coefficients in a perforated rotating disc contactor (PRDC)

• The mass transfer performance is studied in a perforated rotating disc contactor.
• The operating variables are evaluated and found to be significant.
• Mass transfer coefficients are illustrated in terms of the axial diffusion model.
• An empirical correlation is derived for prediction of mass transfer coefficient.
• This correlation can be used to estimate the column height for different processes.

The volumetric overall mass transfer coefficients were investigated in a pilot scale perforated rotating disc contactor (PRDC) of 113 mm internal diameter, using axial diffusion model for two different liquid–liquid systems. The effects of operating parameters including the disc rotational speed and dispersed and continuous phase velocities on the mass transfer performance are investigated. The previous models for dispersed phase overall mass transfer coefficient were reviewed and compared with the experimental data. The results show that the previous correlations do not have enough accuracy for prediction of mass transfer performance in this extractor. Effective diffusivity is applied instead of molecular diffusivity in Gröber equation and enhancement factor is predicted from experimental data as a function of holdup of the dispersed phase, Reynolds number and Eötvös number. Good agreement between prediction and experiments was found for all operating conditions that were investigated.