Liquid-vapor equilibriums of the helium-carbon dioxide system

Abstract

The liquid-vapor equilibria of the helium-carbon dioxide system were studied in a vapor-recirculation apparatus. Six isotherms were studied, from 21 9.9' to 289.9' K., with pressures up to 200 atm. The accuracy is believed to be within about & 5 % of the reported values.

Unified chromatography: Fundamentals, instrumentation and applications†

“…If it is possible for mobile phase components to enrich the stationary phase, could it be possible to achieve a separation applying only mobile phase in a column without stationary phase? To answer this question we evaluate the CO 2 /helium case discussed by Pacher , based on a diagram generated by Guereca, Barrick and Kordikowski . A very low concentration of helium is enough to break the system into two phases unless temperature is above 30°C and the pressure is below the CO 2 vapor pressure.…”

Determination of thermodynamic properties by supercritical fluid chromatography

“…Phase equilibrium data for helium-CO 2 system [124,125] indicate that, under the conditions prevailing in an HHPCO 2 tank, the equilibrium solubility of helium in the liquid phase may reach up to 5 mol%. Also, in the course of usage of HHPCO 2 tanks, it has become apparent that the assumption mentioned above is not valid.…”

Peer Reviewed: Unified Chromatography with CO2-Based Binary Mobile Phases

“…Such phase behavior is illustrated in Figure 4 for the helium-CO 2 system at several temperatures. In this example, the isotherms were generated from experimentally measured data (23,24). The critical points were extrapolated from experimental data reported by Kordikowski et al (25).…”

“…FIGURE 4. Full-phase diagram for helium-CO 2 system: red lines(23) and blue lines(24) are data from the literature; the black line is the vapor-liquid line for pure CO 2 ; and the green line indicates critical points(25).…”