Modeling of physical properties and vapor – liquid equilibrium of ethylene and ethylene mixtures with equations of state Academic Article uri icon


  • © 2018 Elsevier B.V. Ethylene (C2H4) is one of the most important compounds for the chemical and petrochemical industry, since it has found extensive use in the production of polymers, functionalized hydrocarbons and many other basic and intermediate products. As a result, significant amounts of ethylene are being transported, mainly through pipelines, from the site of production to the relevant industrial areas for exploitation and conversion to products of higher value. Accurate knowledge of the physical properties of the chemical systems involved, as well as the conditions for which two or more phases are formed, is a key aspect to the design and operation of a safe and optimal transportation process. In this work, the capability of three different Equations of State (EoS) in predicting the various physical properties (density, heat capacity, speed of sound, Joule-Thomson coefficient, and isothermal compressibility coefficient) of pure ethylene was assessed. The EoS considered include the Peng-Robinson (PR), the Perturbed Chain – Statistical Association Fluid Theory (PC-SAFT), and the SAFT with the Mie potential of variable range (SAFT-VR Mie) EoS, all of them in their original forms, with respect to the parameterization procedure. Furthermore, the vapor - liquid equilibrium (VLE) of pure ethylene and binary ethylene mixtures with hydrocarbons (CH4, C2H6, C3H6, C3H8, 1-C4H8) and gaseous components (H2, CO2) was calculated and the binary interaction parameters (BIPs) were regressed to optimize the performance of each EoS. Finally, the VLE of ternary mixtures with the components mentioned above and ethylene was predicted using the optimized BIPs. Most of the physical properties of pure C2H4 are predicted with relatively high accuracy by PC-SAFT and SAFT-VR Mie EoS, with none being clearly superior to the other. Both SAFT EoS are more accurate than PR in predicting the pure C2H4 physical properties overall. For phase equilibrium predictions, SAFT-VR Mie is overall the most accurate EoS, but when BIPs are used, the performance of all EoS is of comparable accuracy.

author list (cited authors)

  • Nikolaidis, I. K., Franco, L., Vechot, L. N., & Economou, I. G.

citation count

  • 8

publication date

  • August 2018