Thermodynamic Properties of o-Xylene, m-Xylene, p-Xylene, and Ethylbenzene Yong Zhou, Jiangtao Wu, and Eric W. Lemmon Citation: Journal of Physical and Chemical Reference Data 41, 023103 (2012); doi: 10.1063/1.3703506 View online: http://dx.doi.org/10.1063/1.3703506 View Table of Contents: http://scitation.aip.org/content/aip/journal/jpcrd/41/2?ver=pdfcov Published by the AIP Publishing Articles you may be interested in Reference Correlations of the Thermal Conductivity of o-Xylene, m-Xylene, p-Xylene, and Ethylbenzene from the Triple Point to 700 K and Moderate Pressures J. Phys. Chem. Ref. Data 43, 043104 (2014); 10.1063/1.4901166 Ab initio calculation of lattice dynamics and thermodynamic properties of beryllium J. Appl. Phys. 111, 053503 (2012); 10.1063/1.3688344 Assessing the thermodynamic signatures of hydrophobic hydration for several common water models J. Chem. Phys. 132, 124504 (2010); 10.1063/1.3366718 A Reference Equation of State for the Thermodynamic Properties of Ethane for Temperatures from the Melting Line to 675 K and Pressures up to 900 MPa J. Phys. Chem. Ref. Data 35, 205 (2006); 10.1063/1.1859286 An International Standard Formulation for the Thermodynamic Properties of 1,1,1-Trifluoroethane (HFC-143a) for Temperatures From 161 to 450 K and Pressures to 50 MPa J. Phys. Chem. Ref. Data 29, 521 (2000); 10.1063/1.1318909 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions. Download to IP: 129.6.153.224 On: Tue, 12 Apr 2016 20:24:06 Thermodynamic Properties of o-Xylene, m-Xylene, p-Xylene, and Ethylbenzene Yong Zhou (周永) MOE Key Laboratory of Thermo-Fluid Science and Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, People’s Republic of China, and Thermophysical Properties Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA Jiangtao Wu (吴江涛) MOE Key Laboratory of Thermo-Fluid Science and Engineering, Xi’an Jiaotong University, Xi’an Shaanxi 710049, People’s Republic of China Eric W. Lemmona) Thermophysical Properties Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA (Received 9 December 2011; accepted 26 March 2012; published online 4 May 2012) Equations of state for the xylene isomers (o-xylene, m-xylene, and p-xylene) and ethyl- benzene have been developed with the use of the Helmholtz energy as the fundamental property with independent variables of density and temperature. The general uncertainties of the equations of state are 0.5% in vapor pressure above the normal boiling point, and increase as the temperature decreases due to a lack of experimental data. The uncertainties in density range from 0.1% in the liquid region to 1.0% elsewhere (the critical and vapor- phase regions). The uncertainties in properties related to energy (such as heat capacity and sound speed) are estimated to be 1.0%. In the critical region, the uncertainties are higher for all properties. The behavior of the equations of state is reasonable within the region of validity and at higher and lower temperatures and pressures. Detailed analyses between the equations and experimental data are reported. VC 2012 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved.[http://dx.doi.org/10.1063/1.3703506] Key words: equation of state; ethylbenzene; m-xylene; o-xylene; p-xylene; xylene isomers. CONTENTS List of Tables 1. Introduction................................ 3 1. Identifications and fundamental constants of 1.1. Characteristics of xylene isomers and o-xylene, m-xylene, p-xylene, and ethylbenzene........................... 3 ethylbenzene . .................... 4 1.2. Equation of state ....................... 3 2. Summary of critical parameters for o-xylene, 1.3. Critical parameters of xylene isomers and m-xylene, p-xylene, and ethylbenzene . 4 ethylbenzene........................... 3 3. Coefficients and exponents of the ideal-gas 2. Equation of State ........................... 4 heat-capacity equations . .................... 6 2.1. Equation of state for o-xylene............ 7 4. Coefficients of the ideal-gas Helmholtz energy 2.2. Equation of state for m-xylene . ........ 11 equation . .................... 6 2.3. Equation of state for p-xylene............ 14 5. Coefficients and exponents of the equations of 2.4. Equation of state for ethylbenzene ........ 18 state . .................... 6 3. Extrapolation............................... 22 6. Coefficients of the equations of state . 7 4. Conclusions................................ 24 7. The range of validity of the equations . 7 5. References................................. 24 8. Summary of experimental data for o-xylene . 8 9. Summary of experimental data for m-xylene . 12 a) Author to whom correspondence should be addressed; Electronic mail: 10. Summary of experimental data for p-xylene . 15 [email protected]; Fax: (303) 497-5044. VC 2012 by the U.S. Secretary of Commerce on behalf of the United States. 11. Summary of experimental data for All rights reserved. ethylbenzene . .................... 18 0047-2689/2012/41(2)/023103/26/$47.00023103-1 J. Phys. Chem. Ref. Data, Vol. 41, No. 2, 2012 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions. Download to IP: 129.6.153.224 On: Tue, 12 Apr 2016 20:24:06 023103-2 ZHOU, WU, AND LEMMON List of Figures 20. Comparisons of isobaric heat capacities calculated with the equation of state to 1. The chemical structure of o-xylene, m-xylene, experimental data for p-xylene . 18 p-xylene, and ethylbenzene . ............... 3 21. Comparisons of vapor pressures calculated 2. Comparisons of vapor pressures calculated with the equation of state to experimental with the equation of state to experimental data data for ethylbenzene . .................... 20 for o-xylene. .............................. 9 22. Comparisons of saturated liquid densities 3. Comparisons of saturated liquid densities calculated with the equation of state to calculated with the equation of state to experimental data for ethylbenzene. 20 experimental data for o-xylene .............. 9 23. Comparisons of densities calculated with the 4. Comparisons of densities calculated with the equation of state to experimental data for equation of state to experimental data for ethylbenzene . .................... 21 o-xylene.................................. 10 24. Comparisons of saturated liquid sound speeds 5. Comparisons of sound speeds calculated with calculated with the equation of state to the equation of state to experimental data for experimental data for ethylbenzene. 21 o-xylene.................................. 10 25. Comparisons of saturation heat capacities 6. Comparisons of second virial coefficients calculated with the equation of state to calculated with the equation of state to experimental data for ethylbenzene. 21 experimental data for o-xylene .............. 10 26. Comparisons of isobaric heat capacities 7. Calculations of (Z–1)= along isotherms calculated with the equation of state to versus density for o-xylene . ............... 10 experimental data for ethylbenzene. 21 8. Comparisons of saturation heat capacities 27. Isochoric heat capacity versus temperature calculated with the equation of state to diagram plotted with the equation of state of experimental data for o-xylene .............. 11 o-xylene. .................... 22 9. Comparisons of isobaric heat capacities 28. Isobaric heat capacity versus temperature calculated with the equation of state to diagram plotted with the equation of state of experimental data for o-xylene .............. 11 p-xylene. .................... 22 10. Comparisons of vapor pressures calculated 29. Temperature versus density diagram plotted with the equation of state to experimental with the equation of state of m-xylene. 22 data for m-xylene .......................... 13 30. Sound speed versus temperature diagram 11. Comparisons of saturated liquid densities plotted with the equation of state of o-xylene. 23 calculated with the equation of state to 31. Gruneisen coefficient versus density diagram experimental data for m-xylene .............. 13 plotted with the equation of state of p-xylene. 23 12. Comparisons of densities calculated with the 32. Pressure versus density diagram plotted with equation of state to experimental data for the equation of state of p-xylene. 23 m-xylene ................................. 14 33. Characteristic curves of the equation of state 13. Comparisons of saturation heat capacities as a function of reduced temperature and calculated with the equation of state to reduced pressure plotted with the equation of experimental data for m-xylene .............. 14 state of ethylbenzene . .................... 23 14. Comparisons of isobaric heat capacities calculated with the equation of state to experimental data for m-xylene .............. 14 15. Comparisons of vapor pressures calculated List of Symbols with the equation of state to experimental data for p-xylene .......................... 16 a ¼ specific Helmholtz energy 16. Comparisons of saturated liquid densities ai, ni, ti ¼ coefficient calculated with the equation of state to B ¼ second virial coefficient experimental data for p-xylene .............. 17 cp ¼ specific isobaric heat capacity 17. Comparisons of densities calculated with cv ¼ specific isochoric heat capacity the equation of state to experimental data cr ¼ specific saturation heat capacity for p-xylene. .............................