Direct effect of solvent viscosity on the physical mass transfer for wavy film flow in a packed column

The interphase mass transfer plays a critical role in determining the height of packed column used in the absorption process. In a recent experiment (Song, D. Ind. Eng. Chem. Res. 2018, 57, 718), the direct impact of viscosity (mu(L)) on the physical mass transfer coefficient (k(L)) was observed to be higher in a packed column as compared to the wetted wall column. We offer a plausible mechanism involving the wavy film and eddy enhanced mass transfer in a packed column to explain the underlying physics via analytical and numerical studies. The analytically derived mass transfer coefficient matches well with experimental observation in a packed column. The countercurrent flow simulations in a packed column with both uniform and wavy films also confirm this behavior. The predicted k(L) shows steep variation with mu(L) for a wavy film than a uniform film and further confirms the proposed theory. A similar relation (K-L similar to mu(-0.38)(L)) for a wavy film is also observed in theoretical, experimental, and numerical studies.