Reactive mass transfer in a membrane-based microcontactor

Influence of silica nanoparticles on mass transfer in a membrane-based micro-contactor

“…for an organic channel 7where d h represents the hydraulic channel diameter, D aq and D org are the diffusion coefficients of the solute in the aqueous and organic phase respectively, the three parameters a, b and c are functions of channel geometry/ow regime and L is the channel length. In eqn (6) and 7, the 1/3-power law of the Schmidt number is generally accepted 5,45 and this power is independent from ow and/or geometry characteristics. In previous studies a mass transfer model was developed (eqn (8) and (9)) for rectangular micro-channels and non-dispersive, membrane-based systems without considering chemical reactions.…”

Kinetics of Ge(IV) Extraction Using a Microstructured Membrane Contactor

“…As it was shown in previous studies , it is possible to isolate the reaction part of the coupled mass transfer with the developed model (Eqs. and ) by subtracting all the diffusional resistances from the overall mass transfer resistance.…”

“…As mentioned earlier, the boundary layer mass transfer coefficients k aq and k org have been extensively studied for laminar flow in hollow fiber membrane contactors [29,[32][33][34] and to some extent for rectangular microchannels [35]. In previous studies [25], such a correlation has been developed specifically for the microcontactor used in this study: (for the organic channel) (4) where d h represents the hydraulic microchannel diameter, D Ge(IV),aq and D Ge(IV),org the diffusion coefficients of germanium in the aqueous or organic phase , respectively, and L the channel length. Because both microchannels have exactly the same geometric dimensions and flow pattern, the parameters of the correlation for both channels are identical.…”

“…To neglect the apparatus specific hydrodynamics and diffusion resistances, the diffusional parts of the overall mass transfer are quantified by the model and subtracted from the experimentally obtained K w . Hence, this yields a mass transfer coefficient, which is only determined by chemical reaction [25,26]. The results of this analysis are summarized in Tables III and IV. The relative resistance to overall mass transfer indicates the solvent extraction regime.…”

“…The methodology of this work is not the elimination, but rather the model‐based quantification of diffusion resistances in a well‐defined environment followed by an isolated view of the reaction resistance in a second step . In the same way, Agarwal et al break down the overall mass transfer resistance of copper with Acorga M5640 in a hollow fiber module, where the boundary layer resistance of the tube side is approximated by the well‐known Lévêque equation and the boundary layer resistance of the shell side by other (adapted) correlations published elsewhere .…”