Wd. Monnery et al., GAUSSIAN-LIKE VOLUME SHIFTS FOR THE PENG-ROBINSON EQUATION OF STATE, Industrial & engineering chemistry research, 37(5), 1998, pp. 1663-1672
The original form of the Peng-Robinson (PR) cubic equation of state do
es not predict liquid densities that are accurate enough to be used fo
r process calculations. Liquid densities predicted by the PR equation
have been improved by incorporating a Gaussian-like volume translation
which is a strong function of temperature near the critical point but
becomes a constant value away from the critical point, without any di
scontinuities in the critical region. This simple method provides liqu
id densities for 283 nonpolar, polar, and hydrogen-bonding fluids with
an overall average absolute deviation of 0.70%, which compares favora
bly with existing volume translation and dedicated liquid density calc
ulation methods.