Multistage counter-current solvent extraction in a flat membrane microcontactor

Co-current, multistage counter-current and in situ counter-current extraction is demonstrated in a membrane microcontactor, by extracting benzyl alcohol from n-heptane with water as extractant, without the need for active pressure control or additional pumps in between stages. An analytical model to describe the concentration profile as a function of the residence time is presented for the different configurations. From the obtained experimental results the Sherwood number is determined for a channel filled with diamond shaped pillars having an aspect ratio of 3. This allows to calculate the local mass transfer coefficients and to determine the mass transfer kinetics. The obtained model can be used for the prediction of purity levels and allows to optimize the set-up configuration.