(329c) Multiphase Flow Investigations in a Structured Packings Unit

Multiphase
flow investigations in the structured packings unit

Rajesh K. Singh¹,
Janine E. Galvin² and Xin Sun¹

¹Pacific Northwest National
Laboratory, Richland, WA 99352, USA

²National Energy Technology Laboratory, Albany,
Oregon 97321, USA

Post combustion carbon capture by solvent absorption has gained a
significant commercial interest. The solvent absorption is carried out through
counter-current gas liquid flow in a structured packed column.   The local hydrodynamics in the packing, in
particular wetting of sheets is a key factor dictating overall efficiency of
the column. The CFD modelling of such system is a complex problem due to a wide
range of length scales.  In this context,
multiphase flow simulation for wetting of sheets in the representative
elementary unit (REU) of the structured packing can explain fundamental
insights into meso-scale flow phenomenon.
Specifically, Volume of Fluid (VOF) flow simulations are carried out over a
wide range of parameters influencing the wetting dynamics such as solvent
properties, contact angle, liquid load, etc. A scaling analysis for interfacial areas was
performed based on simulation results since interfacial area actively
participates in the transport phenomenon. Accordingly, a phenomenological
correlation for interfacial area in terms of Kapitza
number (Ka) is also proposed. The Kapitza number only
depends on fluid properties and it decreases with increased solvent viscosity.
The interfacial area decreases with increasing Ka number
for a given contact angle and liquid load. Effects of contact angle are also
extensively investigated at different Kapitza numbers and liquid loads. As
expected, interfacial area decreases with increasing contact angle. Further, influence
of liquid load at different contact angles and Kapitza number has also been
explored.