Evaluation of PC-SAFT on the Saturation Pressure Prediction of Different Mixture System at High Temperatures and Pressures

Abstract

Perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state (EOS) has been used to predict saturation pressure of five different mixing systems which are n-alkane mixture, CH4-CO2-H2O mixture, CO2-dimethyl carbonate (DMC), C3H8-pentafluoroethane (PFE) and methanol-methyl propionate (MTP) under high temperatures and pressures conditions. The data for those five types of mixing systems are cited from previous research. For the n-alkane mixture, PC-SAFT prediction is compared with experimental data. The mixture composition is 30%-70% CH4-C6H14, 50%-50% CH4-C6H14 and 70%-30% CH4-C6H14, respectively. The average absolute relative deviation (AARD) for each mixture is 1.51%, 2.68% and 4.87%. As for 20%-80% CO2-H2O and 4%-16%-80% CH4-CO2-H2O mixture, the AARD is 1.27% and 4.14%, respectively. The AARDs of PC-SAFT prediction on different CO2-DMC mixture are 0.78%, 0.72% and 0.91%, and the overall AARDs between PC-SAFT prediction and experimental data for C3H8-PFE and methanol-MTP mixtures are 6.76% and 5.5%, respectively. Compared with Peng-Robinson (PR) EOS used in original work, PC-SAFT EOS successfully predict the bubble point pressure for common substances used in chemical industry.