Shyh-Ming Chern
Tuning Cubic Equations of State for Supercritical Water Applications
954 - 959
2013
7
12
International Journal of Chemical and Molecular Engineering
https://publications.waset.org/pdf/9996719
https://publications.waset.org/vol/84
World Academy of Science, Engineering and Technology
Cubic equations of state (EoS), popular due to their simple mathematical form, ease of use, semitheoretical nature and reasonable accuracy, are normally fitted to vaporliquid equilibrium PvT data. As a result, they often show poor accuracy in the region near and above the critical point. In this study, the performance of the renowned PengRobinson (PR) and PatelTeja (PT) EoS’s around the critical area has been examined against the PvT data of water. Both of them display large deviations at critical point. For instance, PREoS exhibits discrepancies as high as 47 for the specific volume, 28 for the enthalpy departure and 43 for the entropy departure at critical point. It is shown that incorporating PvT data of the supercritical region into the retuning of a cubic EoS can improve its performance at and above the critical point dramatically. Adopting a retuned acentric factor of 0.5491 instead of its genuine value of 0.344 for water in PREoS and a new F of 0.8854 instead of its original value of 0.6898 for water in PTEoS reduces the discrepancies to about one third or less.
Open Science Index 84, 2013