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...

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...

asphaltenes are the n-pentane or n-heptane insoluble fractions of crude oil that remain in solution under reservoir temperature and pressure conditions. they are destabilized and start to precipitate when the pressure, temperature and/or composition changes occur during primary production. the precipitated asphaltene particles will then grow in size and may start to deposit onto the production ...

A semi-empirical equation of state has been studied for modelling vapour-liquid data of pure substances. The specific molecular based equation of state is employed here as basis because of its mathematical simplicity. The semi-empirical extension has been accomplished to real fluids by correlating the density dependence of the attraction term to vapour liquid data of a reference fluid. The resu...

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...

The minimum miscibility pressure (MMP) is one of the crucial and substantial parameters in the gas injection projects for enhanced oil recovery (EOR). This parameter indicates the minimum pressure at constant temperature and composition conditions for reaching 100 percent of the oil production recovery which leads to a huge economic income. Therefore, an inaccurate prediction of the MMP may lea...

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. ...

based on the carnahan and starling hard sphere equation of compressibility, an equation of state has been derived. conditions that must be met by all equations of state are applied in order to obtain attractive term or non - ideal compressibility term of the equation. second virial coefficient and acentric factor arc used in the derivation of the equation of state. in this equation, compressibi...