(245c) Characterization of Microfluidic CO2 Absorption in Water By Computational Fluid Dynamics

Characterization of Microfluidic CO₂ Absorption
in Water by Computational Fluid Dynamics

Chongwei
Xiao*, Hariganesh Bheema

Texas
A&M University-Kingsville

Chongwei.Xiao@tamuk.edu

Advanced
eco-friendly and efficient processed are needed to decrease post-combustion
carbon dioxide (CO₂) released to the atmosphere. However,
low mass transfer between gas and liquid phases hinders the development of new
chemical absorption process. By a mean of process intensification,
microfluidic reactors provide high surface to volume ratio and greatly increase
gas-liquid mass transfer, which makes new processes for gas-liquid reactions
possible. This intensified process also ensures instant thermal stability
across the reactor and rapid heat transfer between the reactant, which greatly
benefits reactions with strong heat effect. A few
recent experimental and simulation works on CO₂-water system in
micro-channels showed good potential of this new process. More studies of microfluidic
CO₂-water process verified by experimental work are needed.

The characteristics of multiphase CO₂ absorption in micro-channels were
numerical studied by Eulerian Volume of Fluid (VOF) approach. The hydrodynamic parameters of CO₂-H₂O
in microchannel were investigated by the factors of channel dimension, inlet
configuration, fluid flowrate, surface tension, and wall wettability. The
reactor performance affected by design parameters was investigated. The
microstructures of semi-cylinder with hydraulic diameter of 0.667 mm and
various inlet configurations including T- and Y- junctions were studied. The
multiphase flow in micro-channels was dominated by Taylor flow and annual flow
depending on relative gas-liquid velocities. The effect of the angle at which
the two inlet channels join and the influence of the static contact angle (SCA)
on the flow regime was observed and found to be in a good agreement with
experimental data. The parameters that influence flow patterns and corresponding
transition were also found to affect Taylor bubble sizes. The two-phase flow
pattern and the pressure drop through the microchannel were simulated and are
compared with published experimental data. This work provides a theoretic
support for the design of new CO₂ absorption processes.