New data and correlations for the custody transfer of natural gas liquids

Book · Wed Nov 01 04:00:00 EST 1995

OSTI ID:124620

Ely, J F ^[1]; Haynes, W M; Holcomb, C D; Magee, J W ^[2]

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1. Colorado School of Mines, Golden, CO (United States)
2. National Institute of Standards and Technology, Boulder, CO (United States)

This report presents new experimental density measurements and density prediction models for natural gas liquids. Experimentally, vibrating tube densimeters have been used to measure coexisting densities for ethane, propane, n-butane, isopentane, n-pentane and isohexane and for binary mixtures of ethane + propane, propane + n-butane, and n-butane + n-pentane. The density measurements were combined with simultaneous VLE measurements using a vapor and liquid recirculation phase-equilibrium apparatus at temperatures from 240 K to either 410 K or the critical temperature of the system. Also, an isochoric gas expansion technique has been used to carry out (p,{rho},T) measurements on two binary mixtures of ethane + propane with ethane mole fractions of 0.35 and 0.65 and one binary mixture of propane + n-butane with a propane mol fraction of 0.61. 6--10 isochores were obtained for each mixture at temperatures from approximately 200--400 K at pressures to 34.5 MPa. Single phase isothermal measurements were also performed in the VLE apparatus with the same samples as used for the isochoric measurements. These measurements were used to extend the bubble-point curve data to the compressed liquid region in order to carry out comparisons with the single-phase isochoric data. The expanded uncertainty of the liquid density measurements is approximately 0.10%. A new model for the temperature correction factor used in calculating volume correction factors for natural gas liquids from the relative density and temperature has been developed using the new data obtained in this study. The correlation is based on a two-fluid corresponding states principle and only requires the relative density at 60 F as input. In addition, new models for the calculation of volume correction factors for pressure effects and temperature effects given either composition or relative density have been developed. Comparisons of the new models with existing standards are presented. 89 refs., 16 figs., 6 tabs.

• OSTI ID: 124620
• Report Number(s): CONF-9503132--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
CALCULATION METHODS
CORRECTIONS
DENSITY
EXPERIMENTAL DATA
MATHEMATICAL MODELS
METERING
NATURAL GAS LIQUIDS
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES