Assessing the performance of non-associating SAFT-type equations of state to reproduce vapor pressure, liquid density, enthalpy of vaporization, and liquid heat capacity data of 1800 pure fluids

The performance of the PC-SAFT and I-PC-SAFT EoS in correlating Psat$$ {P}<^>{sat} $$, vliqsat$$ {v}_{liq}<^>{sat} $$, Delta vapH$$ {\Delta}_{vap}H $$, cP,liqsat$$ {c}_{P, liq}<^>{sat} $$, and critical coordinates of 1800 pure compounds that consist of 1252 non-self-associating and 548 self-associating compounds is evaluated. The PC-SAFT equation is able to reproduce Psat$$ {P}<^>{sat} $$ and vliqsat$$ {v}_{liq}<^>{sat} $$ data with a deviation close to 1%, which meets highest standards. The counterpart is however a large deviation on the critical pressure. The I-PC-SAFT EoS exactly reproduces the critical pressure and temperature and accurately correlates Psat$$ {P}<^>{sat} $$. Its weak point is a larger liquid density deviation. The key conclusion of this article is however the absence of correlation between the strength of association and the accuracy with which the experimental data were correlated. Regardless of the EoS, poor results are obtained for more than 15% of the non-self-associating compounds but 60% of the self-associating compounds are accurately correlated although no association term was included in the considered EoS.

Automated summary

This article evaluates the performance of PC-SAFT and I-PC-SAFT EoS on a large number of compounds. PC-SAFT is able to accurately reproduce Psat and vliqsat data, but has a large deviation on critical pressure. I-PC-SAFT accurately reproduces critical pressure and temperature, and correlates Psat accurately, but has a larger deviation on liquid density. The key conclusion is the absence of correlation between the strength of association and the accuracy of data correlation.