Simultaneous determination of phase equilibria compositions and phase molar densities of hydrocarbon + CO{sub 2} systems

Journal Article · Wed Jan 01 04:00:00 EST 1997 · Journal of Chemical and Engineering Data

DOI:https://doi.org/10.1021/je9602273· OSTI ID:438911

Barrufet, M A; Rahman, S ^[1]

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1. Texas A and M Univ., College Station, TX (United States). Dept. of Petroleum Engineering

Carbon dioxide-hydrocarbon systems frequently occur in the petroleum industry either in CO{sub 2} flooding for enhanced oil recovery or in downstream separation processes. This paper presents new phase equilibria compositions and density data for (1) a quaternary mixture of propane + pentane + octane + CO{sub 2} at temperatures from 310 K to 394 K and pressures from 3 MPa to 6.374 MPa. Additionally, liquid densities for a ternary mixture of propane + pentane + octane at four temperatures and gas CO{sub 2} densities are included for comparison with literature values. A single mixture load can be used to measure simultaneously phase equilibria compositions and densities at various pressures and temperatures. This can be accomplished using a uniquely designed pressure/volume/temperature-vapor/liquid/liquid equilibrium apparatus (PVT-VLLE) connected to a uniquely designed system for infinitesimal sampling to a gas chromatograph (GC) at high pressures and temperatures. Carbon dioxide density compares well with the published data of Vargaftik and the predicted densities by DDMIX. Saturated liquid hydrocarbon densities are within 0.5% of the densities predicted by the modified Rackett equation. For liquid mixtures containing CO{sub 2}, the deviations from the Rackett Equation are within {+-}1%. Therefore the authors conclude that this methodology is suitable for determining volumetric and phase equilibria properties of multiphase systems with sufficient accuracy for most engineering applications.

• OSTI ID: 438911
• Journal Information: Journal of Chemical and Engineering Data, Journal Name: Journal of Chemical and Engineering Data Journal Issue: 1 Vol. 42; ISSN JCEAAX; ISSN 0021-9568
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CARBON DIOXIDE
DENSITY
EQUATIONS OF STATE
EQUILIBRIUM
MEASURING METHODS
OCTANE
PENTANE
PETROLEUM PRODUCTS
PHASE STUDIES
PROPANE
THERMODYNAMIC PROPERTIES