A microfluidic approach for investigating multicomponent system thermodynamics at high pressures and temperatures

Abstract

In this work, we present a novel microfluidic-based approach for investigating the thermodynamics of multicomponent systems at high pressures and temperatures, such as determining miscibility diagrams and critical coordinates of complex mixtures. The developed method is primarily based on (i) bubble and dew point detection through optical characterization and (ii) the use of a so-called dynamic stop-flow measurement mode for fast screening of the diagram parameters, mainly P, T and composition. Our strategy was validated through the studies of model binary CO2-alkane mixtures. The obtained results were then compared to PREOS-calculated and literature data. We later applied this strategy for determining ternary and quaternary mixtures critical coordinates. This approach has equal accuracy compared to conventional high-pressure optical cell methods but allows for a much faster phase diagram determination, taking advantage of improved heat and mass transfers on the microscale and of the dynamic stop-flow approach.

The Full Pressure–Temperature Phase Envelope of a Mixture in 1000 Microfluidic Chambers

“…Recently, specialized microfluidic approaches have been applied to measure isolated phase properties, including the dew point, bubble point, and liquid‐to‐vapor ratios . These methods each use direct visual observation to determine the formation of droplets or bubbles within a confined planar surface or microfluidic channel and benefit from short equilibrium times, reduced sample volume requirements and precise control over pressure and temperature offered by microfluidic systems .…”

Monitoring phase transition of aqueous biomass model substrates by high‐pressure and high‐temperature microfluidics

“…Before studying APR with a similar configuration, we first aim to evaluate the phase transition of model APR reaction mixtures. A number of microfluidic set-ups have specifically been described for studying phase transitions and for degassing processes [14][15][16][17][18][19]. Some microfluidic devices contain a constriction in the microchannel, behind which vortices are created.…”

Influence of surface modifications and channel structure for microflows of supercritical carbon dioxide and water

“…Recently, Marre et al have demonstrated how a simple glass/silicon chip can be used for many applications, e.g. a pressure-volumetemperature cell for scCO 2 [8], quantum dot synthesis using supercritical hexane [9], and supercritical water oxidation [10].…”