Over the last few decades, researchers have developed a number of empirical and theoretical models for the correlation and prediction of the thermophysical properties of pure fluids and mixtures treated as pseudo-pure fluids In this paper, a survey of all the state-of-the-art formulations of thermophysical properties is presented The most-accurate thermodynamic properties are obtained from multiparameter Helmholtz-energy-explicit-type formulations For the transport properties, a wider range of methods has been employed, including the extended corresponding states method All of the thermophysical property correlations described here have been implemented into CoolProp, an open-source thermophysical property library This library is written in C++, with wrappers available for the majority of programming languages and platforms of technical interest As of publication, 110 pure and pseudo-pure fluids are included in the library, as well as properties of 40 incompressible fluids and humid air The source code for the CoolProp library is included as an electronic annex

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Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp.

A new equation of state for the thermodynamic properties of natural gases, similar gases, and other mixtures, the GERG-2008 equation of state, is presented in this work. This equation is an expanded version of the GERG-2004 equation. GERG-2008 is explicit in the Helmholtz free energy as a function of density, temperature, and composition. The equation is based on 21 natural gas components: methane, nitrogen, carbon dioxide, ethane, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, hydrogen, oxygen, carbon monoxide, water, hydrogen sulfide, helium, and argon. Over the entire composition range, GERG-2008 covers the gas phase, liquid phase, supercritical region, and vapor–liquid equilibrium states for mixtures of these components. The normal range of validity of GERG-2008 includes temperatures from (90 to 450) K and pressures up to 35 MPa where the most accurate experimental data of the thermal and caloric properties are represented to within their accura...

The GERG-2008 Wide-Range Equation of State for Natural Gases and Other Mixtures: An Expansion of GERG-2004

[1] Methane gas hydrates, crystalline inclusion compounds formed from methane and water, are found in marine continental margin and permafrost sediments worldwide. This article reviews the current understanding of phenomena involved in gas hydrate formation and the physical properties of hydrate-bearing sediments. Formation phenomena include pore-scale habit, solubility, spatial variability, and host sediment aggregate properties. Physical properties include thermal properties, permeability, electrical conductivity and permittivity, small-strain elastic P and S wave velocities, shear strength, and volume changes resulting from hydrate dissociation. The magnitudes and interdependencies of these properties are critically important for predicting and quantifying macroscale responses of hydrate-bearing sediments to changes in mechanical, thermal, or chemical boundary conditions. These predictions are vital for mitigating borehole, local, and regional slope stability hazards; optimizing recovery techniques for extracting methane from hydrate-bearing sediments or sequestering carbon dioxide in gas hydrate; and evaluating the role of gas hydrate in the global carbon cycle.

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Physical properties of hydrate-bearing sediments

https://www.sfu.ca/~mbahrami/ENSC%20461/Project/Some%20papers%20for%20CO2%20Ref/Fundamental%20process%20and%20system%20design%20issues%20in%20CO2%20vapor%20compression%20systems.pdf

Fundamental process and system design issues in CO2 vapor compression systems

In a preceding project, functional forms for “short” Helmholtz energy equations of state for typical nonpolar and weakly polar fluids and for typical polar fluids were developed using simultaneous optimization. In this work, the coefficients of these short forms for the equations of state have been fitted for the fluids acetone, carbon monoxide, carbonyl sulfide, decane, hydrogen sulfide, 2-methylbutane (isopentane), 2,2-dimethylpropane (neopentane), 2-methylpentane (isohexane), krypton, nitrous oxide, nonane, sulfur dioxide, toluene, xenon, hexafluoroethane (R-116), 1,1-dichloro-1-fluoroethane (R-141b), 1-chloro-1,1-difluoroethane (R-142b), octafluoropropane (R-218), 1,1,1,3,3-pentafluoropropane (R-245fa), and fluoromethane (R-41). The 12 coefficients of the equations of state were fitted to substance specific data sets. The results show that simultaneously optimized functional forms can be applied to other fluids out of the same class of fluids for which they were optimized without significant loss of a...

Short Fundamental Equations of State for 20 Industrial Fluids

A vibrating-wire instrument for simultaneous measurement of the density and viscosity of liquids under conditions of high pressure is described. The instrument is capable of operation at temperatures between 298.15 and 473.15 K at pressures up to 200 MPa. Calibration was performed by means of measurements in vacuum, air, and toluene at 298.15 K. For n-dodecane measurements were made along eight isotherms between 298.15 and 473.15 K at pressures up to 200 MPa while for n-octadecane measurements were measured along seven isotherms between 323.15 and 473.15 K at pressures up to 90 MPa. The estimated uncertainty of the results is 2% in viscosity and 0.2% in density. Comparisons with literature data are presented.

The Viscosity and Density of n-Dodecane and n-Octadecane at Pressures up to 200 MPa and Temperatures up to 473 K

The speed of sound and derived thermodynamic properties of methane at temperatures between 275 K and 375 K and pressures up to 10 MPa

Measurements of the speed of sound u for n-hexane and n-hexadecane at temperatures of 298.3, 323.15, 348.15, and 373.15 K and at pressures up to 100 MPa are reported. The speeds of sound, the temperatures, and the pressures are subject to an uncertainty of ±0.1%, ±0.01 K, and ±0.2 MPa, respectively. These measurements were undertaken using a new apparatus which has been constructed for measurement of the speed of sound in liquids and supercritical fluids at pressures up to 200 MPa and at temperatures between 248 and 473 K. The technique is based on a pulse-echo method with a single transducer placed between two plane parallel reflectors. The speed of sound is obtained from the difference between the round-trip transit times in the two paths. It is expected that both the precision and the accuracy of the method can be further improved.

Speed of Sound of n-Hexane and n-Hexadecane at Temperatures Between 298 and 373 K and Pressures up to 100 MPa

The speed of sound in nitrogen has been measured in the temperature range 80 to 373 K and in the density range 10 to 200 mol/m 3 using a spherical resonator. Values of the second acoustic virial coefficient have been determined from the results with an imprecision of no worse than 0.11 cm 3 /mol. This estimation of imprecision includes all known sources of systematic and random errors at the level of one standard deviation. The results are compared with values calculated from two recently proposed intermolecular potential-energy functions for this system both of which were based partially on second virial coefficient data. Although neither of these functions proved able to predict the acoustic virial coefficients to within the high precision of the present measurements, the potential of Ling and Rigby (Mol. Phys. 51 (1984) 855) gives results that deviate by less than 1 cm 3 /mol. We have also obtained very precise values of the dynamic perfect-gas heat capacity of nitrogen from the zero-density limit of the sound speed measured in the frequency range 3 − 22 kHz . These resolve the effects of centrifugal distortion and are in good agreement with statistical mechanical calculations which include that effect. We report new calibration measurements in argon over the temperature range 90 to 373 K from which the mean radius of the resonator was determined as a function of temperature. In addition, these results provide values of the second acoustic virial coefficient for argon which deviate from those calculated from the interatomic potential energy function for this system by only 0.8 cm 3 /mol at 90 K and by less than 0.1 cm 3 /mol above 300 K. Ordinary ( p, V, T ) second virial coefficients have been calculated from the acoustic results for both gases. These are believed to be of superior accuracy to directly measured values at low temperatures.

J.P.M. Trusler

Papers

The Viscosity and Density of n-Dodecane and n-Octadecane at Pressures up to 200 MPa and Temperatures up to 473 K

The speed of sound and derived thermodynamic properties of methane at temperatures between 275 K and 375 K and pressures up to 10 MPa

Speed of Sound of n-Hexane and n-Hexadecane at Temperatures Between 298 and 373 K and Pressures up to 100 MPa

Second acoustic virial coefficients of nitrogen between 80 and 373 K

The speed of sound in gaseous argon at temperatures between 110 K and 450 K and at pressures up to 19 MPa