Table III. Liquid Phase Compositions and Molar Volumes for P-diketone/C02 Systems |

In Eq. (128), the superscript V stands for the vapor phase v2 is the partial molar volume of component 2 in the liquid phase y is the (unsym-metric) activity coefficient and Hffl is Henry s constant for solute 2 in solvent 1 at the (arbitrary) reference pressure Pr, all at the system temperature T. Simultaneous solution of Eqs. (126) and (128) gives the solubility (x2) of the gaseous component as a function of pressure P and solvent composition [Pg.198]

In this section the experimental liquid phase compositions and liquid molar volumes determined for the P-diketone/C02 systems studied will be presented coupled with the modeling results using the Peng-Robinson EOS with van der Waals-1 mixing rules. Table II lists the estimated critical constants, Tc and Pc, and the acentric factor, co, needed for modeling these systems. [Pg.249]

Fri] Thermodynamic calculation Recalculation of molar volumes of solid and liquid phases and their variation with composition and temperature [Pg.104]

In their correlation, Chao and Seader use the original Redlich-Kwong equation of state for vapor-phase fugacities. For the liquid phase, they use the symmetric convention of normalization for y and partial molar volumes which are independent of composition, depending only on temperature. For the variation of y with temperature and composition, Chao and Seader use the equation of Scatchard and Hildebrand for a multicomponent solution [Pg.173]

It is difficult to measure partial molar volumes, and, unfortunately, many experimental studies of high-pressure vapor-liquid equilibria report no volumetric data at all more often than not, experimental measurements are confined to total pressure, temperature, and phase compositions. Even in those cases where liquid densities are measured along the saturation curve, there is a fundamental difficulty in calculating partial molar volumes as indicated by [Pg.160]

The designations L = V or Li = L2 mean that the two phases in question are critically identical. They possess the same values for density, composition, molar volume, viscosity, and all other physical properties, and the boundary between the phases disappears (Fig. 1). Two phases can also become critically identical in the presence of a third phase, giving rise to the so-called K and L points. A K point arises when a low-density liquid (Li) becomes critically identical to a vapor in the presence of a high-density liquid (L2). [Pg.2067]

Here Vo is the characteristic volume of a drop chosen to be equal to Vmax v is the molar volume Dj is the binary coeflRcient of diffusion Jj is the molar flux M is the molecular mass the lower indexes I and G denote parameters belonging, respectively, to the liquid and the gaseous phase 0 and m denote the values taken at the initial moment of time and averaged over composition B denotes the values taken at the interface. [Pg.687]

In addition to deciding on the method of normalization of activity coefficients, it is necessary to undertake two additional tasks first, a method is required for estimating partial molar volumes in the liquid phase, and second, a model must be chosen for the liquid mixture in order to relate y to x. Partial molar volumes were discussed in Section IV. This section gives brief attention to two models which give the effect of composition on liquid-phase thermodynamic properties. [Pg.173]

The difficulties encountered in the Chao-Seader correlation can, at least in part, be overcome by the somewhat different formulation recently developed by Chueh (C2, C3). In Chueh s equations, the partial molar volumes in the liquid phase are functions of composition and temperature, as indicated in Section IV further, the unsymmetric convention is used for the normalization of activity coefficients, thereby avoiding all arbitrary extrapolations to find the properties of hypothetical states finally, a flexible two-parameter model is used for describing the effect of composition and temperature on liquid-phase activity coefficients. The flexibility of the model necessarily requires some binary data over a range of composition and temperature to obtain the desired accuracy, especially in the critical region, more binary data are required for Chueh s method than for that of Chao and Seader (Cl). Fortunately, reliable data for high-pressure equilibria are now available for a variety of binary mixtures of nonpolar fluids, mostly hydrocarbons. Chueh s method, therefore, is primarily applicable to equilibrium problems encountered in the petroleum, natural-gas, and related industries. [Pg.176]

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