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Equations of State for n-Hexadecane and n-Docosane

Published

Author(s)

Raffaela Romeo, Eric W. Lemmon

Abstract

Equations of state for n-hexadecane (C16H34) and n-docosane (C22H46) have been developed as functions of the Helmholtz energy with independent variables of temperature and density. The equations were developed based on experimental values of density, speed of sound, isobaric heat capacity, and vapor pressure. With these equations, all thermodynamic properties of n-hexadecane and n-docosane can be calculated. For n-hexadecane, the uncertainty in vapor pressure is 0.5 %. The uncertainty of the saturated liquid density is 0.05 % from the triple point up to 400 K, and 0.2 % at higher temperatures. The uncertainty in densities is within 0.5 %. The speed of sound and isobaric heat capacity can be calculated within 0.25 %. The uncertainties of the properties calculated with the equation for n-docosane are 5 % for vapor pressure, 0.1 % for saturated liquid density, 1 % for density, 0.5 % and 1 % for speed of sound at atmospheric pressure and higher pressures, respectively, and within 3 % for heat capacity.
Citation
International Journal of Thermophysics
Volume
43

Keywords

equations of state, n-hexadecane, n-docosane, Helmholtz energy, thermodynamic properties

Citation

Romeo, R. and Lemmon, E. (2022), Equations of State for n-Hexadecane and n-Docosane, International Journal of Thermophysics, [online], https://doi.org/10.1007/s10765-022-03059-0, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934414 (Accessed December 3, 2022)
Created August 5, 2022, Updated November 29, 2022