a modification of peng-robinson equation is described wherein in the parameter b is expressed as a linear function of temperature. the modified equation is then applied to a series of light hydrocarbons and refrigerants, and predicted values for vapor pressure, saturated vapor volume, saturated liquid volume and the heat of evaporation are compared with the corresponding experimental data. cons...

Through this study, the ability of a modified Peng-Robinson (MPR) equation of state in predicting the surface tension of n-alkanes based on the density functional theory approach was investigated and compared with other studies. The interfacial layer thickness and the density profile were calculated simultaneously at different temperatures from triple point to near critical point using the modi...

A modification of Peng-Robinson equation is described wherein in the parameter b is expressed as a linear function of temperature. The modified equation is then applied to a series of light hydrocarbons and refrigerants, and predicted values for vapor pressure, saturated vapor volume, saturated liquid volume and the heat of evaporation are compared with the corresponding experimental data. ...

an extended peng-robinson equation of state (epr-eos) is used to model the vapor-liquid equilibrium (vle) in systems containing (water + nacl + co2), (water + methanol + nacl + co2), (water + na2so4 + co2) and (water + nh4cl + co2). the binary and ternary interaction parameters between salt and solvent are adjusted to experimental mean solvent activity of salts (nacl and na2so4). for the system...

Densities, structural effects and viscosities of binary nonelectrolyte systems including nitrobenzene + 2-propanol, 2-butanol and 2-pentanol at temperatures (293.15 to 323.15) K and normal atmospheric pressure were measured using an Anton-Paar SVM 3000 stabinger viscometer. Excess molar volumes  and viscosity deviations Δη were calculated and correlated by the Redlich-Kister equation to estimat...

Modeling of the relationship between the pressure and yield of biomaterials is an essential issue in supercritical fluid extraction. In this paper, neural networks are proposed for modeling of supercritical fluid extraction. First a three-layer neural network with a fast learning algorithm is used, and its performance is compared to a conventional model of the Peng-Robinson equation of state. A...

The peng-Robinson (PR), a cubic equation of state (EoS), is extended to polymers by using a single set of energy (A1, A2, A3) and co-volume (b) parameters per polymer fitted to experimental volume data. Excellent results for the volumetric behavior of the 11 polymer up to 2000 bar pressure are obtained. The EoS is applied to the correlation and prediction of Henry constants in polymer solutions...

in this paper, a simplified formulation for compositional reservoir simulator is presented. these types of simulators are used when inter-phase mass transfer depends on phase composition as well as pressure. the procedure for solving compositional model equations is completely described. for equilibrium calculation, property estimation peng robinson equation of state is used. this equation was ...