Liquid density of HFE-7000 and HFE-7100 from T = (283 to 363) K at pressures up to 100 MPa

doi:10.1016/j.jct.2014.05.017

The Journal of Chemical Thermodynamics

Volume 77, October 2014, Pages 131-136

https://doi.org/10.1016/j.jct.2014.05.017 Get rights and content

Highlights

•
Density were reported for HFE-7000 at T from (283 to 363) K and p up to 100 MPa.
•
Density were reported for HFE-7100 at T from (283 to 363) K and p up to 100 MPa.
•
Modified Tait equations were correlated with the experimental data.
•
The isobaric thermal expansivity of HFE-7000 and HFE-7100 were calculated.
•
The isothermal compressibility of HFE-7000 and HFE-7100 were calculated.

Abstract

In this paper, liquid densities for HFE-7000 (1-methoxyheptafluoropropane) and HFE-7100 (methoxy-nonafluorobutane) are reported in the temperature range from (283 to 363) K and pressures up to 100 MPa. The measurements were conducted with a high pressure vibrating-tube densimeter with combined expanded uncertainties (k = 2) of 16 mK in temperature, 0.062 MPa (p < 60 MPa) and 0.192 MPa (60 MPa < p < 100 MPa) in pressure, and 0.6 kg · m⁻³ in density. The experimental densities were correlated to the modified Tait equation with an absolute average percentage deviation of 0.019% and 0.034% for HFE-7000 and HFE-7100, separately. In addition, the isothermal compressibility and isobaric thermal expansivity have been derived from these density data.

Graphical abstract

Compressed density data of HFE-7000 (a) and HFE-7100 (b).

Introduction

During the last decade, intensive efforts have been devoted to identify replacements to the traditional fluoro-chems compounds which have been proven to deplete the ozone layer and enhance greenhouse effect. Hydrofluoroether fluids (HFEs) are being proposed as environmentally friendly alternatives to other halogenated compounds because of their nearly zero ozone depletion, relatively low global warming potential, short atmospheric lifetimes and low toxicity [1], [2]. They have been used in various industrial applications as refrigerants, cleaning solvents of electronic components, foaming agent, heat transfer fluids and so on [3].

In spite of the widespread application of HFEs, there is still much to learn about their thermophysical properties. For HFE-7000 and HFE-7100, very limited experimental data has been published. Table 1 gives an overview of the literature which presents the liquid density data for HFE-7000 and HFE-7100. The corresponding temperature and pressure region and the number of data points are also provided.

For HFE-7000, Ohta et al. [4] presented the saturated-liquid and compressed-liquid densities from T = (250 to 370) K and pressures up to 3 MPa. Klomfar [7] investigated the compressed liquid density in the temperature range of (209 to 353) K and pressures up to 40 MPa. Additionally, references [1], [5], [6] reported the liquid density of HFE-7000 at normal temperatures and pressures. For HFE-7100, Pineiro et al. [9] measured the liquid density between T = (283.15 and 313.15) K at pressures up to 40 MPa. Minamihounoki et al. [8], [10], [11] only reported the density of HFE-7100 in the normal pressures and temperatures. Shiflett et al. [12] presented the liquid density data as a linear equation which was valid in the temperature range of (283 to 333) K and pressures at 0.1 MPa.

In previous work, our group has conducted compressed-liquid densities of HFE-7200 (1-Ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane) and HFE-7500 (3-ethoxyperfluoro(2-methylhexane)) in a wide range of temperatures and pressure [13]. As a continuous research, in this work, measurements of compressed-liquid densities were carried out for HFE-7000 and HFE-7100 over the temperature range from (283 to 363) K with pressures up to 100 MPa using a vibrating-tube densimeter system. The experimental data were correlated to a modified Tait equation, with which the isothermal compressibility and isobaric thermal expansivity have also been calculated.

Section snippets

Samples

HFE-7000 and HFE-7100 were supplied by the 3M Company (mass purity > 0.995). HFE-7100 consists of two inseparable isomers (nonafluoro-iso-butylmethyether and nonafluoro-n-butylmethylether) with essentially identical properties. These isomers are considered to be azeotrope and azeotropic mixtures are equivalently handled with pure substance. In this work, HFE-7100 was used as the sample supplied without out any separation of the isomers. The water contents of HFE-7000 and HFE-7100 were tested with

Density

The compressed liquid densities of HFE-7000 and HFE-7100 were measured between T = (283 to 363) K with pressures up to 100 MPa. As the vibrating tube could be only used to measure the liquid density, the vapor pressure of HFE-7000 and HFE-7100 were estimated with equations in reference [12] to select the initial pressure along each isotherms. A total of 138 and 141 data points are reported for HFE-7000 and HFE-7100, separately. The uncertainties of each experimental data point were calculated with

Conclusion

In present work, a total of 279 compressed liquid densities of HFE-7000 and HFE-7100 along nine isotherms between T = (283 and 363) K with pressures up to 100 MPa were presented. The maximum expanded uncertainty with a level of confidence of 0.95 (k = 2) of HFE-7000 and HFE-7100 are 0.04% and 0.03%, respectively. The experimental data were fitted with a modified Tait equation with low standard deviations. And the isobaric thermal expansivity, α_p, and the isothermal compressibility, κ_T_, were derived

Acknowledgment

The authors acknowledge the financial support of the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20100201120014), Natural Science Foundation of Jiangsu Province, China (No. SBK201122327) and Natural Science Foundation of Changchun Normal University (Grant 2014).

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Liquid density of HFE-7000 and HFE-7100 from T = (283 to 363) K at pressures up to 100 MPa

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Samples

Density

Conclusion

Acknowledgment

J. Fluorine Chem.

J. Chem. Thermodyn.

J. Chem. Thermodyn.

J. Chem. Thermodyn.

Fluid Phase Equilib.

J. Hazard. Mater. A

Ind. Eng. Chem. Res.

J. Chem. Eng. Data

J. Chem. Eng. Data