Volumetric properties for { x1CO 2+ x2CH 4+ (1 − x1− x2)N 2} at the pressures (19.94, 39.94, 59.93, and 99.93) MPa and temperatures (323.15, 373.15, 473.15, and 573.15) K

Abstract

The densities for { x 1CO 2+ x 2CH 4+ (1 − x 1− x 2)N 2} were measured at the pressures (19.94, 39.94, 59.93, 99.93) MPa and temperatures (323.15, 373.15, 473.15, 573.15) K using a custom-designed, high pressure, high-temperature vibrating-tube densimeter. Excess molar volumes V m Ewere calculated from the experimental results. Although V m Eis generally positive, negative deviations are observed in ternary mixtures with compositions close to those of binary mixtures that exhibit negative deviations. V m Egenerally decreases as pressure increases from 20 MPa to 100 MPa. V m Eis typically less than ±4 per cent of the total volume of the mixture. V m Eincreases substantially as ( p, T) conditions approach the critical point of CO 2. Predictions of V m Efor ternary mixtures may be made from experimental results for the binary subsystems. Comparisons with experimental results indicate that these methods are reasonably accurate for estimating the volumetric properties of ternary gas mixtures.