Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Unphysical critical curves of binary mixtures predicted with GERG models

Published

Author(s)

Ian H. Bell, Ulrich K. Deiters

Abstract

When applied to asymmetric binary mixtures (e.g., methane + pentane or heavier alkanes, hydrogen-containing mixtures), the GERG equation of state (GERG-2004 or GERG-2008) predicts critical curves with physically unreasonable temperature maxima above the critical temperature of the heavier component. These maxima are associated with physically impossible vapor–liquid equilibria. The phenomenon is probably caused by corrections for critical anomalies that were built into the empirical pure-fluid equations of state forming the foundation of the GERG model. These corrections ensure that the model represents thermodynamic data of pure fluids quite well even close to their critical points. For mixtures, however, the corrections can cause artifacts.
Citation
International Journal of Thermophysics
Volume
41

Keywords

critical points, mixtures, thermodynamics

Citation

Bell, I. and Deiters, U. (2020), Unphysical critical curves of binary mixtures predicted with GERG models, International Journal of Thermophysics, [online], https://doi.org/10.1007/s10765-020-02743-3 (Accessed August 7, 2022)
Created October 18, 2020, Updated October 20, 2020