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International audience; The phase behavior of the CO2 (1) + 2,3-dimethylbutane (2) binary mixture has been experimentally studied between 293 and 373 K. Saturation pressures, ranging from 14.0 to 112.2 bar, were visually measured using a high-pressure cell at carbon dioxide mole fractions between 0.20 and 0.93.78 experimental points have been measured: 67 bubble points and 11 dew points. Experimental results reveal that the vapor-liquid critical locus is a continuous curve between the two pure compounds, meaning that the studied binary system exhibits a type I or II phase behavior in the classification scheme of Van Konynenburg and Scott. The experimental data can be very satisfactorily represented by the Peng-Robinson equation of state with mixing rules that embed a temperature-dependent binary interaction parameter.

International audience

The measurement of densities (ρ) of the pure component diethylene glycol monoethyl ether (2-(2-ethoxyethoxy)ethanol) has been carried out using a vibrating-tube densimeter (Anton Paar DMA HPM) alon...

Density and speed of sound of methane + n-heptane binary mixtures were measured at a temperature equal to 303.15 K and at pressures ranging from 10 MPa to 70 MPa. The measurements were performed in pure n-heptane and eight different mixtures with methane molar percentage ranging from 20 % to 95 %. Speed of sound data was obtained by a pulse-echo technique working at 3 MHz whereas density data were acquired from a vibrating U-tube densimeter. Isothermal and isentropic compressibilities were derived from both measurements in the same conditions. Finally, partial molar volumes, excess molar volume, excess isothermal compressibility as well as excess speed of sound and excess isentropic compressibility were estimated at the same conditions and the relative excess properties were represented as a function of methane content. From these measurements, it was observed that the large difference in compressibility of pure components provoked significant deviations to ideal behavior with relative excess values that can reach − 20 %, − 100 % and 200 % of the ideal properties for molar volume, isothermal compressibility and speed of sound, respectively. Moreover, a small clustering effect at high dilution of n-heptane at 30 MPa was brought forth to light by evaluating the partial molar volumes.

In this work, high-pressure viscosity measurements for seven compositions of the binary mixture (x) HFE-7500 + (1 – x) diisopropyl ether were carried out. A set of 163 points have been measured cov...

Density and speed of sound of carbon dioxide + n-dodecane binary mixtures were measured at pressures from 10 to 70 MPa and at two temperatures around the critical temperature of carbon dioxide (303...

Speeds of sound for the binary system HFE-7500 + Diisopropyl ether have been measured at pressures up to 100 MPa and within a temperature interval from (293.15 to 353.15) K. High pressure density measurements were carried out by using a U-tube densimeter up to 140 MPa and at temperatures from (293.15 to 393.15) K. Additionally, the density and the isentropic compressibility were evaluated from integration of speed of sound data in the pressure range from (0.1 to 100) MPa and in the temperature interval from (293.15 to 353.15) K. This work also reports a correlation for both the density and the speed of sound within their estimated uncertainties to evaluate the volume and its derivatives with respect to pressure and temperature.

This work reports experimental density data (1073 points) for the mixtures methyl nonafluorobutyl ether (HFE-7100) + 2-propanol along isotherms ranging from 298.15 to 393.15 K and at pressures from 0.1 to 140 MPa. To perform the measurements we used an Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.7 kg m−3. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, we derived the isobaric thermal expansivity and the isothermal compressibility from the Tait-like equation.

Measurements of density and speed of sound were carried out in the binary mixture comprising n-heptane with dissolved carbon dioxide at two temperatures near critical temperature (303 and 313 K) and at pressure from 10 to 70 MPa. The measurements were performed for five sample mixtures ranging from 20 to 88.5 % CO2 mol fraction. The density measurements were performed using an ANTON-PAAR vibrating U-tube densimeter whereas speed of sound measurements were based on a pulse echo technique working at 3 MHZ. Derived properties such as the isothermal and isentropic compressibilities were determined from these measurements. Finally, excess volume, excess compressibilities as well as excess speed of sound were estimated and represented as a function of CO2 content. By comparing the excess volume to the excess isothermal compressibilities and the excess speed of sound, it appeared that excess curves for derivative properties highlight large deviation from ideality in such binary system.

A computation method was developed for estimating the compressibility and its uncertainty from density measurements carried out from atmospheric pressure to 100 MPa. For that purpose, first the abi...

ACL; International audience; Accurate knowledge of physical and acoustical properties is of importance in many fields of science and engineering. In this work, density and speed of sound measurements of diisopropyl ether (DIPE) are reported. The speed of sound has been measured up to 100 MPa and in the temperature range (293.15–353.15) K by using an apparatus based on a pulse echo technique working in transmission mode, and a correlation for this property was proposed. By using a procedure which rests on the Newton-Laplace relationships, density and its derivatives were determined. To show the reliability of this method, high pressure density measurements were carried out up to 140 MPa and within the temperature interval (293.15–393.15) K with an Anton Paar densitometer. © 2017 Elsevier B.V.

ACL; International audience; Speed of sound measurements were carried out in liquid tris(2-ethylhexyl) trimellitate (TOTM) at pressures up to 200 MPa along isotherms ranging from (293.15 to 373.15) K in order to report data of density and its derivatives. The measurements were performed with a pulse echo technique working at 3 MHz. Additional density and heat capacity measurements were carried out at atmospheric pressure in order to initiate the estimation procedure of volumetric properties from speed of sound integration. Results were compared with density measurements performed with a U-tube densimeter at pressures up to 140 MPa on the same sample. Finally, an equation that correlates density and its derivatives within their estimated uncertainties is given. © 2017 American Chemical Society.

ACL; International audience; The speed of sound of hydrofluoroether fluid HFE-7500 has been measured at pressures up to 100 MPa along isotherms ranging from (293.15 to 353.15) K. The measurements were carried out using a pulse echo technique operating at 3 MHz. Additional high pressure density data were measured up to 140 MPa with temperatures from (293.15 to 393.15) K in order to evaluate isentropic compressibility using speed of sound measurements. A correlation was then proposed to describe both density and speed of sound within their estimated uncertainties and used to evaluate the density and its derivatives. © 2017 Elsevier Ltd

International audience; This work reports new experimental density data (960 points) for 1-propanol and for binary mixturesof dibutyl ether + 1-propanol, +2-propanol and +1-hexanol over the full composition range (5 composi-tions; 0.15 ≤ dibutyl ether mole fraction x ≤ 0.85), between 293.15 and 353.15 K (every 20 K), and for 15pressures from 0.1 MPa up to 140 MPa (every 10 MPa).An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5 kg m−3was usedto perform these measurements. The experimental density data were fitted with a Tait-like equationwith low standard deviations. Excess volumes have been calculated from the experimental data andfitted by the Redlich-Kister equation. In addition, the isobaric thermal expansivity and the isothermalcompressibility have been derived from the Tait-like equation.

International audience; This work reports new experimental density data (445 points) for binary mixtures of (dibutyl ether + 1-butanol) over the composition range (five compositions; 0.15 ≤ dibutyl ether mole fraction x ≤ 0.85), from (293.15 to 393.15) K (every 20 K), and for 15 pressures from (0.1 to 140) MPa (every 10 MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5 kg * m-3 was used to perform these measurements. The experimental density data were fitted with a Tait-like equation with low standard deviations. Excess volumes have been calculated from the experimental data and fitted by the Redlich-Kister equation. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

This work reports new density data (178 points) of 1-butanol at twelve temperatures between 293.15 and 403.15K (every 10K), and fifteen pressures from 0.1 up to 140MPa (every 10MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5kgm-3 was used to perform these measurements. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation. © 2010 Elsevier B.V.

This work reports new density data (180 points) of 1-pentanol at twelve temperatures between 293.15 and 403.15 K, and pressures up to 140 MPa (every 10 MPa). A new Anton Paar vibrating-tube densimeter, calibrated with an uncertainty of ±0.5 kg m−3 was used to perform these measurements. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

International audience; This paper presents new reference correlations for both the density and viscosity of squalane at high pressure. These correlations are based on critically evaluated experimental data taken from the literature. In the case of the density, the correlation, based on the Tait equation, is valid from 273 to 473 K at pressures to 200 MPa. At 0.1 MPa, it has an average absolute deviation of 0.03%, a bias of 0.01%, and an expanded uncertainty (at the 95% confidence level) of 0.06%. Over the whole range of pressures, the density correlation has an average absolute deviation of 0.05%, a bias of 0.004%, and an expanded uncertainty (at the 95% confidence level) of 0.18%. In the case of the viscosity, two correlations are presented, one a function of density and temperature, based on the Assael-Dymond model, and the other a function of temperature and pressure, based on a modified Vogel-Fulcher- Tammann equation. The former is slightly superior to the latter at high temperatures (above 410 K), whereas the reverse is true at low temperatures, where the viscosity is strongly temperature dependent. In the temperature range from 320 to 473 K at pressures to 200 MPa, the first correlation has an average absolute deviation of 1.41%, a bias of 0.09%, and an expanded uncertainty (at the 95% confidence level) of 3%. Below 320 K, deviations from the present scheme rise to a maximum of 20%. In the temperature range from 278 to 473 K at pressures to 200 MPa, the second viscosity correlation has an average absolute deviation of 1.7%, a bias of 0.04%, and an expanded uncertainty (at the 95% confidence level) of 4.75%.

Squalane is being recommended as a secondary reference material for viscometry at moderate to high pressure and at moderate viscosity. As part of this work, a correlation has been developed for atmospheric pressure (Comunas et al., 2013) [12]. Here we report new experimental high pressure viscosities for squalane (176 data points obtained for temperatures (293.15 to 363.15) K, at pressures up to 350 MPa with a maximum viscosity of 745 mPa · s). These have been determined with four different falling-body viscometers as well as a quartz crystal resonator viscometer. A preliminary high pressure viscosity correlation for squalane is proposed, based on our new data. At pressures up to 350 MPa, this correlation provides an absolute average deviation of 1.5% with a maximum absolute deviation of 8.9%. Comparison is made between the different instruments. In addition, we have also considered the validity of a thermodynamic scaling model. © 2013 Elsevier Ltd. All rights reserved.

International audience; Three recent physically based models (Lennard-Jones, free volume, thermodynamic scaling) for representing the viscosity of sulfur hexafluoride (SF6) are discussed together with two models (friction theory and Enskog 2r) that have been recently applied to this fluid. The experimental database employed for adjustment (1562 data points) considers a large temperature (225.18 to 473.15 K) and pressure intervals (0.0264 to 51.21 MPa). The absolute average deviation is 3.8% for the Lennard-Jones model (one parameter), 1.7% for the free volume model (three parameters) and 1.5% for the thermodynamic scaling model (six parameters). Thus, it is shown that when physically based approaches are employed, a limited number of parameters is sufficient to represent accurately the shear viscosity of SF6. Furthermore it has been confirmed, using the thermodynamic scaling approach, that the repulsive steepness of the SF6 interaction potential is higher than usually found for fluids composed by non polar spherical molecule.

International audience; This work reports new density data (175 points) of 2-propanol at 12 temperatures between 293.15 and 403.15 K (every 10 K), and 15 pressures from 0.1 to 140 MPa (every 10 MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5 kg*m -3 was used to perform these measurements. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

International audience; This work reports new density data (180 points) of 1-hexanol at twelve different temperatures between 293.15 and 403.15K (every 10K), and fifteen different pressures from 0.1 to 140MPa (every 10MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5kgm -3 was used to perform these measurements. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility were derived from the Tait-like equation.

International audience; This work reports new density data (90 points) of 1-butoxybutane (also known as dibutyl ether, DBE) at six temperatures between (293.15 and 393.15) K (every 20 K) and 15 pressures from (0.1 to 140) MPa (every 10 MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ± 0.5 kg*m-3, was used to perform these measurements. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

International audience; The viscosity of the binary system 1-propanol + toluene has been measured with a falling-body viscometer for seven compositions as well as for the pure alcohol in the temperature range (293.15 to 353.15) K and up to 100 MPa with an experimental uncertainty of ± 2 %. At 0.1 MPa, the viscosity has been measured with a classical capillary viscometer (Ubbelohde) with an uncertainty of ± 1 %. A total of 216 experimental data points are reported. The viscosity behavior of this binary system is interpreted as the results of changes in the free volume and the breaking or weakening of hydrogen bonds. These data have been used to study the performance of two compositional models and a free-volume model.