PVT measurements of carbon dioxide + methane mixtures and an equation of state development

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7080165

Hwang, C A

A mixture apparatus has been constructed for preparing mixtures of accurately known composition using a gravimetric method and has been used to prepare mixtures needed in this study. Two experimental techniques have been used to measure accurately the densities of carbon dioxide + methane mixtures over wide ranges of temperature and pressure. A continuously weighed pycnometer which can provide one density measurement about every twenty minutes in an isothermal run has been used to measure densities of four carbon dioxide + methane mixtures from 225 to 350 K up to 35 MPa. The Burnett apparatus can provide the bets low density measurements and the best determinations of the virial coefficients; it has been used to obtain the densities and virial coefficients for four carbon dioxide + methane and pure methane at 300 and 320 K up to 10 MPa. The ac.curacy of the density measurements using the pycnometer is 0.1 kg/m{sup 3} or 01%, whichever is greater, and that of the Burnett apparatus is 0.023%. An innovative approach to the reference system of an EOS has been developed. It consists of three parts: (1) the choice of a proper pair potential and its division into reference and perturbation potentials; (2) the method used to calculate the effective hard-sphere diameter; and (3) different forms for the hard-body equations. The authors have investigated step-ramp and Born (exponential) pair potentials, and Carnahan-Starling and random closest packing basis hard-body equations. The random closet packing basis hard-body equation plus Born pair potential provides the best representation of the experimental saturated liquid densities and vapor pressures of argon.

• Research Organization: Texas A and M Univ., College Station, TX (USA)
• OSTI ID: 7080165
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
ACCURACY
ALKANES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DENSIMETERS
DENSITY
DISPERSIONS
EQUATIONS
EVALUATION
HYDROCARBONS
MEASURING INSTRUMENTS
METHANE
MIXTURES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
PYCNOMETERS
SATURATION
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
VAPOR PRESSURE