A group contribution molecular model of liquids and solutions

Abstract

A = a = = ideal gas state Subscripts c = critical property i, i, k = component identifications o = reference state A group contribution molecular model is developed for the thermocluding energy of vaporization, pVT relations, excess properties, and activity coefficients. The model is based on the cell theory in which the repulsive forces of molecules are expressed with a modified cell partition function derived from the Carnahan-Starling equation of state for hard spheres. The attractive forces are made u p of group pair interaction contributions. Group and interaction properties have been determined for methyl, methylene, hydroxyl, and carbonyl. Extensive comparisons are School of Chemical Engineering made of predictions of the model with data for pure liquids and their solu-Purdue University tions. West Lofayette, Indiana 47907 1. To develop a comprehensive theory of group contribution for the estimation of various thermodynamic

Temperature dependence of the excess molar volume of (dimethyl carbonate, or diethyl carbonate+ toluene) fromT= 278.15 K to 323.15 K

“…In previous papers (3,4) we have determined the characteristic parameters for carbonate and methyl, or methylene groups of the UNIFAC model (in the versions of Dang and Tassios, (5) Larsen et al (6) and Gmehling et al (7) ) and the Nitta-Chao (8) model. Our next step is to determine the carbonate-aromatic parameters for several group contribution models.…”

Thermodynamic properties of (a butyl ester + an -alkane). XIII. and for {}, where= 1 to 3 and= 1 to 7

“…A recent series of studies (1)(2)(3) dealing with binary systems of (an alkyl ester + an n-alkane) have shown that the results of modeling of the mixtures using the UNIFAC, (4,5) DISQUAC, (6) and Nitta et al (7) group-contribution models become less accurate with increasing length of the aliphatic chain R 1 or R 2 in esters of the type R 1 COOR 2 and a To whom correspondence should be addressed (E-mail: jortega@cicei.ulpgc.es). also with increasing molar mass of the n-alkane.…”

Excess volumes of (1,3-dichloropropane or 1,4-dichlorobutane + ann-alkan-2-one) at the temperatures 298.15 K and 308.15 K

“…For (an a,v-dichloroalkane+an n-alkane) both H E and V E decrease with the a,v-dichloroalkane size. (12,(17)(18)(19) Recently Garcı´a et al (19) determined interaction parameters which depend regularly on the distance between the Cl atoms for (a,v-dichloroalkane+alkane) in the framework of the Nitta-Chao (20) the application of the Nitta-Chao model to complete the analysis of the behaviour of these mixtures.…”