  Computational countercurrent flow investigation in the structured packed
column is a multiscale problem. Multiphase flow studies using volume of fluid
(VOF) method in the representative elementary unit (REU) of the packed column
can insight into the local hydrodynamics such as interfacial area, film
thickness, etc. The interfacial area dictates the mass transfer in absorption
process and thereby overall efficiency of column. Impacts of solvent's physical
properties, liquid loads and static contact angle (SCA) on the interfacial area
were examined earlier. In the present study, the dynamic contact angle (DCA)
was used to explore the impact of contact angle hysteresis on the interfacial
area. DCA has more pronounced impact on the interfacial area (10%) for aqueous
solvent of 0.10M Sodium hydroxide (NaOH). The interfacial area shows undulation
and does not achieve the pseudo-steady state. In contrary, the interfacial area
gets a net pseudo-steady value for the aqueous solvent having 40%
monoethanolamine (MEA) by weight. The wetting hysteresis was also explored via
simulations conducted with initially dry and wetted sheets. For 0.10M NaOH
aqueous solvent, the initially wetted sheets lead to slightly higher value of
the interfacial area (10%) as compared to the initially dry sheets at the same
liquid load and DCA. As expected, wetting hysteresis reduces with increasing
liquid loads. On the other hand, wetting hysteresis is not significant for 40%
MEA aqueous solvent which might be lower surface tension and higher viscosity.
Overall, the effect of the dynamic contact angle is not pronounced as compared
to those found in a flat surface.
