PVT measurements of carbon dioxide + nitrogen and an equation of state development for natural and hydrocarbon gases

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7032372

Brugge, H B

Densities of five mixtures of carbon dioxide + nitrogen (0.10560, 0.25147, 0.50365, 0.71105, 0.90921) and pure nitrogen were measured at 300 and 320 K at pressures to 10 MPa using the Burnett technique. Second and third virial coefficients and densities were derived for each mixture from the measurements. Cross second and third virial coefficients were determined at each temperature. Several methods for calculating cross third virial coefficients are compared with the experimental values. The methods considered are: ideal solution, geometric mean, the Orbey and Vera correlation, Lennard-Jones, the MHEMHS model, and an algebraic determination using two mixture third virial coefficients. A continuously weighed pycnometer has been used to measure densities of the mixtures in the dense gas and liquid regions at temperatures from 225 to 450 K at pressures to 70 MPa. A procedure has been developed which uses this apparatus to detect phase transitions. Saturation densities and pressures are reported for those isotherms where phase transitions occur. A flexible foil gravity mixer is described which has been developed to assist in the preparation of gas mixtures of accurately known composition without contaminating the mixtures. A new automated temperature measurement and control scheme is described which has been implemented on both the Burnett apparatus and the pycnometer. A new equation of state has been developed for hydrocarbon gases based upon the truncated virial equation. The new equation can be applied to natural gases containing hydrocarbons, nitrogen and carbon dioxide by treating the hydrocarbon fraction of the mixture as a single component and using simple combining rules to calculate the cross virial coefficients without introducing additional parameters.

• Research Organization: Texas A and M Univ., College Station, TX (USA)
• OSTI ID: 7032372
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
033000* -- Natural Gas-- Properties & Composition
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
COMPRESSIBILITY
CONTROL
DENSIMETERS
DENSITY
DISPERSIONS
ELEMENTS
EQUATIONS
EQUATIONS OF STATE
FLUIDS
GASES
HYDROCARBONS
MEASURING INSTRUMENTS
MECHANICAL PROPERTIES
MIXERS
MIXTURES
NITROGEN
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
PYCNOMETERS
SATURATION
TEMPERATURE CONTROL
TEMPERATURE DEPENDENCE
TEMPERATURE MEASUREMENT