Measurement and correlation of the (p, ρ, T) behavior of liquid propylene glycol at temperatures from (272.7 to 393.0) K and pressures up to 91.4 MPa

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Highlights

  • Density measurements on liquid propylene glycol were conducted utilizing a vibrating-tube densimeter.

  • Measurements were conducted at temperatures from (272.7 to 393.0) K and pressures up to 91.4 MPa.

  • The combined expanded uncertainty (k = 2) in density was estimated to be 1.78 kg·m−3.

  • A correlation equation for calculating liquid-phase densities of liquid propylene glycol was established.

  • The experimental data could be used to develop a fundamental EOS for propylene glycol.

Abstract

The (p, ρ, T) behavior of propylene glycol was investigated in the homogeneous liquid phase over the temperature range from (272.7 to 393.0) K at pressures from (5.0 to 91.4) MPa. A commercially-available high-pressure vibrating-tube densimeter was utilized to perform the measurements. The measuring system was calibrated by using water and helium as reference fluids, and the calibrated system was validated by measurements of argon and propane. Prior to the measurements, the propylene glycol sample with a purity of 98.8 mol-% was degassed by several freeze-pump-thaw cycles. Considering the measurement uncertainties in temperature, pressure and oscillation period, and uncertainties resulting from instrument calibration and sample impurities, the combined expanded uncertainty (k = 2) in density was estimated to be 1.78 kg·m−3. Using the new experimental data, a correlation equation for the (p, ρ, T) behavior of propylene glycol was established; in the investigated (p, T) range, the combined expanded uncertainty (k = 2) is also 1.78 kg·m−3. The agreement of the carefully selected experimental data from literature and the correlation equation is within the uncertainty of the equation.

Introduction

Propylene glycol (IUPAC name: propane-1,2-diol) is an important industrial substance across a variety of applications. It is generally used as an emulsifier and is an ingredient in antifreeze, cosmetics and pharmaceuticals [1]. Additionally, propylene glycol is commonly utilized as a pressure transmitting fluid [2]. Although propylene glycol has a large and diverse portfolio of applications, there is currently no fundamental equation of state (EOS) available to accurately calculate thermodynamic properties of this fluid over a wide range of temperature and pressure.

A literature review of the available experimental (p, ρ, T) data and vapour pressures ps for propylene glycol is summarized in Table 1, Table 2, respectively, and is illustrated in Fig. 1; here, the vapour-liquid phase boundary was calculated with the Wagner-type equation [3]:lnpspC=TCT·i=14ai·1-TTCbiwhere TC = 676.40 K, pC = 6.3455 MPa, al = 2.60958, a2 = –37.8647, a3 = 32.84467, a4 = –15.2156, bl = 1.0, b2 = 1.5, b3 = 2.0, and b4 = 4.0. The critical point data (TC and pC) were acquired from literature [4], [5], and the parameters ai were obtained by correlating the available experimental data to Eq. (1) with fixed parameters bi. An obvious lack of experimental (p, ρ, T) data was observed. Therefore, the main purpose of this work is to extend the current experimental (p, ρ, T) data situation for propylene glycol.

Measurements were conducted with a commercially-available high-pressure vibrating-tube densimeter (VTD) in the homogeneous liquid phase over the temperature range from (272.7 to 393.0) K at pressures from (5.0 to 91.4) MPa. The measured (p, T) state points are depicted in Fig. 1. While the development of a fundamental EOS is outside the scope of the current work, a simpler correlation equation for liquid densities of propylene glycol is introduced here.

Section snippets

Apparatus description

The current measuring system was set up to enable density measurements between T = (263.15 and 393.15) K and from vacuum up to pressures of 100 MPa. A schematic diagram of the measuring system is shown in Fig. 2. The VTD (Anton Paar, Austria, type: DMA HPM), with its inlet and outlet tubes, is connected to a sample manifold, which also includes a pressure transducer (WIKA, Germany, type: P-30) and a rupture disc. The VTD is thermostated by a circulation thermostat (Huber, Germany, type:

Calibration

To determine the apparatus parameters A(p,T) and B(p,T) in Eq. (2), mathematical models and calibration measurements with reference fluids are necessary. There are various models available in the literature [7], [8], [9], [10]. To investigate the influence of the selected model on the results of the density determination and to estimate the uncertainty attributed from the model, two models were utilized in this work.

May et al. [7], [11] presented a physically-based model as:A=ρ00τ002·(1+βτ·p)(1+

Conclusion

The (p, ρ, T) behavior of propylene glycol was investigated over the temperature range from T = (272.7 to 393.0) K at pressures from (5.0 to 91.4) MPa utilizing a commercially-available high-pressure vibrating-tube densimeter. This work extends the current data situation for propylene glycol with respect to temperature and pressure range. The influence of the model for the vibrating-tube densimeter on the results of the density measurements was investigated, and the uncertainty in density

Notes

The authors declare no competing financial interest.

Acknowledgements

This work was financially supported through funds of the faculty of mechanical engineering at Ruhr-Universität Bochum (RUB). We thank our colleague Dr. Monika Thol of the thermodynamics group at RUB who has motivated the measurements presented here and who was always available for fruitful discussions. Also, we appreciate our laboratory engineer Malte Heine for his support in setting up the high-pressure measuring system in a short time and our colleague Christian Scholz for conducting part of

References (182)

  • L.Y. Garcia-Chavez et al.

    J. Chem. Thermodyn.

    (2012)
  • W. Wagner

    Cryogenics

    (1973)
  • C. Bouchot et al.

    Fluid Phase Equilib.

    (2001)
  • C.D. Holcomb et al.

    Fluid Phase Equilib.

    (1998)
  • Y.A. Sanmamed et al.

    Fluid Phase Equilib.

    (2007)
  • E.M. Živković et al.

    Fluid Phase Equilib.

    (2014)
  • G. Schilling et al.

    J. Chem. Thermodyn.

    (2008)
  • D.I. Sagdeev et al.

    Fluid Phase Equilib.

    (2017)
  • M. Atilhan et al.

    J. Chem. Thermodyn.

    (2013)
  • H. Geyer et al.

    J. Chem. Thermodyn.

    (2001)
  • A. Arce et al.

    Fluid Phase Equilib.

    (2003)
  • D.M. Bajić et al.

    J. Chem. Thermodyn.

    (2013)
  • J. Basiri Parsa et al.

    J. Mol. Liq.

    (2009)
  • H. Geyer et al.

    J. Chem. Thermodyn.

    (2000)
  • U.R. Kapadi et al.

    Fluid Phase Equilib.

    (2001)
  • M.L. Kijevčanin et al.

    J. Chem. Thermodyn.

    (2013)
  • T. Kimura et al.

    Thermochim. Acta

    (2006)
  • S.K. Kushare et al.

    J. Chem. Thermodyn.

    (2008)
  • H. Lee

    J. Chem. Thermodyn.

    (1990)
  • D.M. Makarov et al.

    J. Mol. Liq.

    (2016)
  • A. Marchetti et al.

    J. Mol. Liq.

    (2000)
  • M. Moosavi et al.

    Thermochim. Acta

    (2013)
  • A.K. Nain

    J. Chem. Thermodyn.

    (2007)
  • A.K. Nain et al.

    J. Chem. Thermodyn.

    (1998)
  • J.D. Olson et al.

    Fluid Phase Equilib.

    (1992)
  • A. Pal et al.

    Fluid Phase Equilib.

    (2016)
  • J.B. Parsa et al.

    J. Chem. Thermodyn.

    (2008)
  • H. Piekarski et al.

    J. Mol. Liq.

    (2005)
  • A. Pietrzak et al.

    Fluid Phase Equilib.

    (2015)
  • B. Guignon et al.

    J. Chem. Eng. Data

    (2010)
  • W.V. Steele et al.

    J. Chem. Eng. Data

    (2002)
  • D.M. VonNiederhausern et al.

    J. Chem. Eng. Data

    (2000)
  • W. Wagner et al.

    J. Phys. Chem. Ref. Data

    (2002)
  • E.F. May et al.

    Rev. Sci. Instrum.

    (2014)
  • S.L. Outcalt et al.

    Ind. Eng. Chem. Res.

    (2007)
  • E.F. May et al.

    Rev. Sci. Instrum.

    (2015)
  • D.O. Ortiz Vega
  • C. Tegeler et al.

    J. Phys. Chem. Ref. Data

    (1999)
  • E.W. Lemmon et al.

    J. Chem. Eng. Data

    (2009)
  • International Organization for Standardization, Uncertainty of measurement – Part 3: guide to the expression of...
  • CRC Handbook of Chemistry and Physics, 99th ed., CRC Press, Boca Raton,...
  • E.W. Lemmon et al.

    NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties – REFPROP

    (2013)
  • O. Fandiño et al.

    J. Chem. Eng. Data

    (2005)
  • P.W. Bridgman

    Proc. Am. Acad. Arts Sci.

    (1932)
  • E. Zorębski et al.

    J. Chem. Eng. Data

    (2008)
  • A. Bagheri et al.

    J. Solution Chem.

    (2013)
  • L.P. Barbetova et al.

    Oniitekhim

    (1982)
  • R. Belda Maximino

    Phys. Chem. Liq.

    (2009)
  • J.M. Canosa et al.

    J. Therm. Anal. Calorim.

    (1998)
  • E. Cepeda et al.

    Anal. Quim. Ser. A.

    (1984)
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