Nitrogen stripping of isopropyl-alcohol and toluene in a falling film micro reactor : gas side mass transfer experiments and modeling at isothermal conditions

A falling film micro reactor has been investigated as a contactor for a separation process in order to be implemented in fine chemical and pharmaceutical production. Nitrogen stripping of a pure solvent was performed allowing straightforward mass transfer measurements due to the absence of resistance in the liquid side.

Two mass transfer models were developed in this study, a semi-analytical one based on the mass balance equations combined with an existing Sherwood correlation for laminar flow in micro channels and a numerical model solving the hydrodynamics and mass transport equations. Very good agreement was found between the two models, which were then compared with experimental data. The experimental values of stripping efficiency agree with the calculated ones with an error of ±15% showing good modelling prediction. The calculated gas side mass transfer coefficients of the investigated micro contactor are in the range of 0.007–0.01 m s−1.