Mass transfer in structured packing: A wetted-wall study
A short wetted-wall column was used to measure and correlate gas-phase mass transfer coefficients for various pure components evaporating counter current into an air stream. Mass transfer coefficients were also measured for binary mixtures. Both a smooth and a complex surface, similar to the surface of the structured packing Mellapak, were used in the study. The gas-phase mass transfer coefficients for the smooth surface were correlated with Shg = 0.0044RegScg0.5We10.111. The results for the complex surface were correlated with Shg = 0.0036Reg0.76Scg0.5 Re10.41Bo-0.13. Mass transfer coefficients for binary mixtures were compared with these gas-phase mass transfer coefficients. Enhanced mass transfer was observed for systems with large differences in pure-component surface tensions. This was not the case for binary systems with small differences in the pure-component surface tensions. Negligible liquid-side resistance to mass transfer was found in all systems in this study. High-viscosity liquids deviated from the proposed correlations.