Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Interface light-scattering on a methane-decane system in the near-critical region at 37.8 deg.C (100 deg.F)

Strand, Knut Arne, Bjorkvik, Bard J.A.
Fluid Phase Equilib. 2019, 485, 168-182
ABSTRACT
A near-critical binary model fluid system consisting of approximately equal amounts of methane and n-decane by weight, is studied by use of interface light-scattering. The main objective has been - in the near-critical region - to obtain a high-accuracy data set for the interfacial tension. The system is studied at constant temperature 37.8 deg.C (100 deg.F) in the pressure range (34.5-36.2) MPa. The upper pressure is only 0.0014 MPa below the critical pressure of the system. In the pressure range studied, the interfacial tension decreased four decades from 1.6 * 10-1 mN m-1 to 1.4 * 10-5 mN m-1. The lower value is two orders of magnitude lower than measured for any binary hydrocarbon fluid system hitherto. In part of the pressure range also values for the density difference between liquid and gas and the sum of liquid and gas viscosities are determined from the same light scattering data. For interfacial tension and density difference the critical scaling exponents are determined to be respectively 1.304 +- 0.010 and 0.376 +- 0.016.
Compounds
# Formula Name
1 CH4 methane
2 C10H22 decane
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • Interfacial tension, N/m ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Gas
  • Surface laser light scattering (SLLS)
  • 18
  • POMD
  • 1
  • 2
  • Critical temperature, K ; Liquid
  • Mole fraction - 1; Liquid
  • Liquid
  • Gas
  • Light Scattering
  • 1
  • POMD
  • 1
  • 2
  • Critical pressure, kPa ; Liquid
  • Mole fraction - 1; Liquid
  • Liquid
  • Gas
  • Light Scattering
  • 1