Thermodynamic equations of state from molecular solvation

Obtaining Thermodynamic Properties and Fluid Phase Equilibria without Experimental Measurements

“…These results show that the atomic radii (Table 1) used in establishing the solvation cavity are adequate for describing the volume parameter b. The larger deviations (underestimation) found for larger compounds could be attributed to the ignorance of conformation flexibility in current calculations (e.g., long chain alkanes are modeled as linear but they could be folded in reality) and/or the ignorance of molecular shape effects in the PR EOS (the cavity term in PR EOS is valid for spherical molecules (Lin, 2006)). The deviations in T c are less than 120 K, except for carbon monoxide and methacrylic acid, marked by A and B, respectively, in Figure 6.…”

Towards the development of theoretically correct liquid activity coefficient models

“…According to equation (40), the function f i is closely related to the activity coefficient of species i, or conversely, the coordination number is affected by the bulk phase nonideality, i.e.,…”

“…These models were developed based on a very different approach (by consideration of the free energy involved to remove an interacting surface pair from the solution) and assumptions [40]. The approach suggested here allows for the understanding of fundamental assumptions made in these models from a local composition perspective.…”

Solvation and chemical engineering thermodynamics

“…With the enhancement of accuracy and efficiency in computational solvation theory, modeling phase equilibria from first principles is becoming practical. For example, Lin andSandler (1999a,b, 2002a,b) and Nanu and co-workers determined the infinite dilution activity coefficient and Henry's law constant from a group contribution solvation (GCS) model. Klamt (Banerjee and Khanna, 2006;Klamt, 1995, followed by Lin and Sandler (2002a,b) and by Grensemann and Gmehling (2005), developed a liquid activity coefficient model, Conductor-like Screening Model for Real Solvent (COSMO-RS), for vapor-liquid equilibrium predictions.…”

“…The COSMO-type models have also been combined with an equation of state model for high-pressure vapor-liquid or liquid-liquid predictions (Constantinescu et al, 2005;Shimoyama et al, 2006). There have also been attempts to develop equations of state from solvation models (Lin, 2006;Panayiotou, 2003a,b).…”