Estimation and Correlation of Phase Equilibrium of CO₂–Hydrocarbon Systems with PRMHV2-UNIFAC and PRMHV2-NRTL Models

Abstract

In this work, the Peng–Robinson (PR) equation of state (EoS) and MHV2 mixing rule that were combined with UNIFAC and NRTL G E models were used to predict vapor–liquid phase equilibrium (VLE) data for CO2–hydrocarbon systems. These systems included 12 binary systems and three ternary systems. The PRMHV2-UNIFAC model was used to calculate the bubble pressure, and the average absolute relative deviations (AARD %) were 17.49–32.20% for 12 binary systems. For the PRMHV2-NRTL model, the binary interaction parameters of the NRTL model dependent on temperature were regressed based on the binary VLE data. These new interaction parameters were used to estimate CO2–hydrocarbon VLE data for binary and ternary systems. The bubble pressure was predicted by the PRMHV2-NRTL model, and the AARD % values were 1.52–9.44% for binary systems, which were lower than the value of the PRMHV2-UNIFAC model. The PRMHV2-UNIFAC and PRMHV2-NRTL models were also used to calculate the liquid phase mole fraction of CO2–hydrocarbon ternary systems, and the average absolute deviations (AAD %) were less than 20.70 and 8.54%, respectively.

Vapor–Liquid Equilibrium Data Measurement of CO2 + Diisopropyl Ether, CO2 + Methyl tert-Butyl Ether, and CO2 + 1,2-Dimethoxy Ethane Binary Systems at 253.15 K

“…In this work, SRK, PR, and PC-SAFT models are selected to correlate the obtained VLE data. By minimizing the objective function, p cal (calculated pressure) and y 1 cal (calculated mole fraction of CO 2 in the vapor phase) are calculated and obtained . To investigate the degree of deviation between different experimental and calculated values, we have calculated the relative deviations (RD p ) of p cal and p exp (experimental pressure) shown in Figures – , and the relative deviations (RD y 1 ) of y 1 cal and y 1exp (experimental mole fraction of CO 2 in the vapor phase) shown in Figures – .…”

“…By minimizing the objective function, p cal (calculated pressure) and y 1 cal (calculated mole fraction of CO 2 in the vapor phase) are calculated and obtained. 34 To investigate the degree of deviation between different experimental and calculated values, we have calculated the relative deviations (RD p ) of p cal and p exp (experimental pressure) shown in Figures 5−7, and the relative deviations (RD y1 ) of y 1 cal and y 1exp (experimental mole fraction of CO 2 in the vapor phase) shown in Figures 8−10. The overall deviation of different models is reflected by the average absolute relative deviation of pressure (AARD p ) and the average absolute relative deviation of the mole fraction of CO 2 in the vapor phase (AARD y1 ), which can be found in Table 6.…”

Experimental determination and modelling of high-pressure phase behavior for the binary system CO2 + cyclooctane

“…Phase equilibrium data of mixtures containing carbon dioxide are therefore still needed to design and improve industrial operations as well as to estimate the parameters of thermodynamic models [8][9][10].…”