In this work, we have calculated the Joule-Thomson inversion curve of two important associating fluids, namely water and methanol, from the SAFT equation of state. Comparisons with the available experimental data, for water and methanol indicate that this molecular based equation of state gives good prediction of the low temperature branch; but, unfortunately, due to lack of isenthalpic dat...

the compressibility factor of nonassociated chain molecules composed of hard convex core yukawa segments was derived with saft-vr and an extension of the barker-henderson perturbation theory for convex bodies. the temperature-dependent chain and dispersion compressibility factors were derived using the yukawa potential. the effects of temperature, packing fraction, and segment number on the com...

We developed an equation of state (EOS) by Ihm, Song, and Mason (ISM) for polar fluids. The model consists of four parameters, namely, the second virial coefficient, an effective van der Waals co-volume, a scaling factor, and the reduced dipole moment. The second virial coefficient is calculated from a correlation that uses the heat of vaporization, and the liquid density at the normal boiling ...

The SAFT-VR equation of state is extended to treat heteronuclear chain fluids, focusing, in particular, on symmetric and asymmetric diblock chains. The chain molecules studied are composed of segments of different size and/or energy of interaction. Both symmetric and asymmetric systems are considered. The theoretical predictions are compared with isothermal– isobaric and Gibbs ensemble Monte Ca...

A Helmholtz energy functional for inhomogeneous fluid phases based on the perturbed-chain polar statistical associating fluid theory (PCP-SAFT) equation of state is proposed. The model is supplemented with a capillary wave contribution to the surface tension to account for long-wavelength fluctuations of a vapor-liquid interface. The functional for the dispersive attraction is based on a nonloc...

The water solubility in fatty acid esters and biodiesels and the vapor–liquid equilibria (VLE) of fatty acid ester + methanol/ethanol systems, formed at biodiesel production and purification industrial units, were modeled in this work to complete the development and application of the soft-SAFT equation of state (EoS) to the design and optimization of biodiesel production plants. The soft-SAFT ...

The compressibility factor of nonassociated chain molecules composed of hard convex core Yukawa segments was derived with SAFT-VR and an extension of the Barker-Henderson perturbation theory for convex bodies. The temperature-dependent chain and dispersion compressibility factors were derived using the Yukawa potential. The effects of temperature, packing fraction, and segment number on the com...

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...

Varnish and sludge formation are considered as one of the most common problems in lubrication and hydraulic systems. In order to simulate the condition of sludge formation, base stock lubricant (Group 1 API) has been selected and exposed to heat in a laboratory setup. Sludge formation process accelerated in the laboratory scale and solid liquid equilibrium data were extracted. Then solid-liquid...

In this work we extend the crossover (CR) modification of the statistical-associating-fluid-theory (SAFT) equation of state (EOS), recently developed and applied for non-associating systems [Ind. Eng. Chem. Res. 38 (1999) 4993] to associating fluids. Unlike the previous crossover EOS that was based on the parametric linear model for the universal crossover function Y, the new CR SAFT EOS is bas...