Microfluidics
Microfluidic devices handle fluids in channels tens to hundreds of micrometres wide, where flows are laminar and surface-to-volume ratios are high. Segmented gas-liquid flow in such channels creates well-defined interfaces whose evolution can be imaged directly, which makes microfluidics a fast, low-volume way to measure gas solubility, mass transfer and reaction in liquids.
Gas plug shrinkage as a CO2 solvent screen (2015)
Hallenbeck and coworkers formed pure CO2 plugs at a Y-junction of a glass serpentine microreactor and tracked a single plug with a 500 Hz camera, converting its volume loss into absorbed CO2 via the ideal gas law (Hallenbeck et al. 2015). The method ranked MEA and four potassium amino acid salts by loading and initial flux using less than a millilitre of solution, and the capacity ranking of lysinate versus MEA matched stirred-reactor breakthrough tests. Measured fluxes (about 0.25 to 0.52 mol m-2 s-1) far exceed wetted-wall values and the capacities were lower than equilibrium values, so absolute numbers are setup specific and the method is best used for relative ranking. Summary: hallenbeck2015.