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Title: An Equation of State for the Thermodynamic Properties of Cyclohexane

An equation of state for cyclohexane has been developed using the Helmholtz energy as the fundamental property with independent variables of density and temperature. Multi-property fitting technology was used to fit the equation of state to data for pρT, heat capacities, sound speeds, virial coefficients, vapor pressures, and saturated densities. The equation of state was developed to conform to the Maxwell criteria for two-phase vapor-liquid equilibrium states, and is valid from the triple-point temperature to 700 K, with pressures up to 250 MPa and densities up to 10.3 mol dm{sup −3}. In general, the uncertainties (k = 2, indicating a level of confidence of 95%) in density for the equation of state are 0.1% (liquid and vapor) up to 500 K, and 0.2% above 500 K, with higher uncertainties within the critical region. Between 283 and 473 K with pressures lower than 30 MPa, the uncertainty is as low as 0.03% in density in the liquid phase. The uncertainties in the speed of sound are 0.2% between 283 and 323 K in the liquid, and 1% elsewhere. Other uncertainties are 0.05% in vapor pressure and 2% in heat capacities. The behavior of the equation of state is reasonable within the regionmore » of validity and at higher and lower temperatures and pressures. A detailed analysis has been performed in this article.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Honeywell Integrated Technology China Co. Ltd., 430 Li Bing Road, Zhangjiang Hi-Tech Park, Shanghai 201203 (China)
  2. Center for Applied Thermodynamic Studies, College of Engineering, University of Idaho, Moscow, Idaho 83844 (United States)
  3. Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305 (United States)
Publication Date:
OSTI Identifier:
22413360
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical and Chemical Reference Data; Journal Volume: 43; Journal Issue: 4; Other Information: (c) 2014 U.S. Government; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CYCLOHEXANE; DENSITY; EQUATIONS OF STATE; EQUILIBRIUM; LIQUIDS; SOUND WAVES; SPECIFIC HEAT; TRIPLE POINT; VAPOR PRESSURE; VAPORS; VELOCITY