Improved vapor pressure prediction from PR + COSMOSAC EOS using normal boiling temperature

Abstract

AbstractWe evaluate the predictive power of the PR + COSMOSAC Equation of State (EOS) for vapor pressure using a large dataset of 19,081 compounds. The PR + COSMOSAC EOS uses results of quantum mechanical solvation calculations to determine the energy and molecular volume parameters in the Peng‐Robinson EOS and thus does not require experimental critical temperature (Tc), pressure (Pc), and acentric factor (ω) as in the conventional approach. The prediction accuracy (average absolute relative deviation) is 141%, about seven times that of the PR EOS. A new approach is developed to improve the prediction accuracy from PR + COSMOSAC EOS by incorporating experimental normal boiling temperature. The prediction accuracy improves to 58%, about three times that of the PR EOS. The PR + COSMOSAC EOS is an effective method for vapor pressure prediction when no or just some experimental data is available.