EVALUATION OF CAPACITANCE DENSITOMETRY FOR LNG MIXTURES WITH LOW NITROGEN COMPOSITION
Densities of typical LNG mixtures under saturation and subcooled conditions were calculated using a computer program which uses the method of corresponding states. The dielectric constant for each mixture was determined from the Clausius-Mosotti relationship assuming the excess CM function is zero. Examination of the resulting density-dielectric constant plots shows that for fixed nitrogen composition a nearly linear relationship exists between saturation density and dielectric constant under isobaric or isothermal conditions, independent of the hydrocarbon mixture. The results show, however, that the effect of the nitrogen composition on this linear relationship may be taken into account partially by a measurement of the mixture temperature. For the range of mixtures of this study it is possible to determine density to + or - 0.3% independent of knowledge of the hydrocarbon composition from an exact measurement of dielectric constant and temperature. Further improvements can be made if the fraction of nitrogen is known.
- Sponsored in part by Maritime Administration, Washington, D.C. Pub. in Ind. Eng. Chem. Process Des. Dev., v16, n3 p330-336 1977.
National Bureau of Standards14th Between E Street and Constitution Avenue, NW
Washington, DC United States 20234
Maritime Administration1200 New Jersey Avenue, SE
Washington, DC United States 20590
- Giarratano, P J
- Collier, R S
- Publication Date: 1977
- Pagination: 7 p.
- TRT Terms: Chemical composition; Density; Dielectric properties; Hydrocarbons; Ignition systems; Ions; Liquefied natural gas; Mixtures; Natural gas; Nitrogen; Numerical analysis; Solutions (Chemistry)
- Old TRIS Terms: Charged particles; Density mass/volume; Lng ignition; Lng properties data; Solutions
- Subject Areas: Marine Transportation; Safety and Human Factors;
- Accession Number: 00168788
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: Final Rpt.
- Files: TRIS, USDOT
- Created Date: Dec 27 1978 12:00AM