Computer simulation and theory for free energies in dilute near‐critical solutions

Local density augmentation in attractive supercritical solutions: Inhomogeneous fluid approach

“…19,29 Both types of systems have been extensively studied theoretically. 7,14,[18][19][20][21][22][23][24][25][26][27][28][29] It has been shown that the local solvent density is enhanced in the vicinity of an attractive solute and depleted in the vicinity of a repulsive one. The former case is of particular importance since the vast majority of industrial and technological applications of SCFs involve attractive mixtures.…”

First‐order corrections to infinite dilution fugacity coefficients using computer simulation

“…The use of computer simulation techniques to study the thermodynamic behavior of dilute supercritical fluid solutions has become an important problem in the simulation field (Shing and Gubbins, 1981;Shing and Chung, 1987;Wu et al, 1990;Petsche and Debenedetti, 1991;Chialvo and Debenedetti, 1992;Li et al, 1993;Munoz and Chimowitz, 1993a,b;Munoz et al, 1995). These solutions are invariably extremely dilute, with solute mole fractions typically of the order low4, and the infinite dilution limit of solute properties are often the target quantities of the simulation results.…”

Henry's law and synergism in dilute near‐critical solutions: Theory and simulation

“…The theory used is based on the Kirkwood-Buff formalism with the Percus-Yevick closure used for the integral equation calculations. In recent comparisons with simulation results, including those very near the critical point of the system (Li et al, 1993), this theory has proven to be quite accurate and valuable for investigating the thermodynamic properties of dilute supercritical solutions (McGuigan and Monson, 1987, mation is prone to large errors because of the strong synergistic solvation effects that are characteristic of these solutions (Munoz and Chimowitz, 1993a,b).…”

“…In pursuing this point several simulations were done using the potential parameters of system I11 in Table 5 . The algorithm for these calculations was described in our recent article (Li et al, 1993). The first set of results were developed for 20 solute species in a 1,000 member ensemble using 5 x lo6 sampling steps.…”

“…This approximation is a convenient and often used method for estimating thermodynamic properties in dilute solutions, notwithstanding the assumptions involved in its use. In both theoretical and computer simulation studies in dilute supercritical mixtures, the infinite dilute reference state has often been used to represent solution properties Chung, 1987, 1988; Petsche and Debenedetti, 1989; Monson, 1987, 1990; Lee, 1988, 1989; Wu et al, 1990; Munoz and Chimowitz, 1992; Li et al, 1993;Tom and Debenedetti, 1993). In simulations the solute's infinite dilution property is usually estimated by using a single solute species in an ensemble of finite size and the resultant solute concentration is thus necessarily finite.…”