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

Abstract

Knowing the thermodynamic state of complex mixtures-liquid, gas, supercritical or two-phase-is essential to industrial chemical processes. Traditionally, phase diagrams are compiled piecemeal from individual measurements in a pressure-volume-temperature cell performed in series, where each point is subject to a long fluid equilibrium time. Herein, 1000 microfluidic chambers, each isolated by a liquid piston and set to a different pressure and temperature combination, provide the complete pressure-temperature phase diagram of a hydrocarbon mixture at once, including the thermodynamic phase envelope. Measurements closely match modeled values, with a standard deviation of 0.13 MPa between measurement and model for the dew and bubble point lines, and a difference of 0.04 MPa and 0.25 °C between measurement and model for the critical point.

Rapid Characterization of Multiple-Contact Miscibility: Toward a Slim-Tube on a Chip

“…We illustrate the performance of the channel for a room temperature and pressure ternary fluid system that is analogous to the true gas–oil system. The inferred MME is within 1% of that derived from existing thermodynamic measurements and can be determined within 2 h. We anticipate that the channel design is immediately transferable to a high-pressure and high-temperature microfluidic system using established fluorescence-based visualization methods , and etched-glass or hybrid silicon–glass ,,,− fabrication techniques. The hybrid silicon−glass provides finer geometry and higher pressure tolerance than etched glass.…”

“…The channel design demonstrated here for an ethanol–water–hexanol system would need to be replicated using materials that are appropriate for crude oil and gas at high pressure and temperature. This is already well-established in etched-glass or hybrid silicon–glass ,,,− fabrication techniques and fluorescence-based visualization methods. , The development of miscibility in a multicomponent system through a condensing or vaporizing gas drive is identical to that in a ternary system . Thus, the device operation would be identical for establishing the MME in a condensing gas drive, with crude oil injected as the first phase and becoming trapped in the pockets by an enriched-gas displacing phase.…”

Minireview of Microscopic CO2 Interactions with Fluids and Minerals in Shale: Advances and Outlook

“…Isolating confined fluid mixtures in nanometer pores/channels from connected microchannels is needed. The isolation technique has been developed in the microfluidics 43 and is readily applicable in nanofluidics in the near future.…”

Droplet Interfacial Tensions and Phase Transitions Measured in Microfluidic Channels

“…Other studies have employed co-flow-based systems in which the position of the interface determines the phase equilibrium (54,55). An innovative device design utilized a 2D array of cells with temperature and pressure gradients to visualize the thermodynamic phase diagram in the two-phase region (56,57). Massive arrays of droplets have also been used to gather statistically significant data in a short amount of time (44,58,59).…”