Mixing rules Wong Sandler

The first of the Wong/Sandler mixing rules relates the difference in mixture quantities b a.nda/RT to the corresponding differences (identified by subscripts) for the pure species ... 

The second Wong/Sandler mixing rule relates ratios of a/RT to b ... 

The pressure range of about 60-360 bar and temperature range from 35-70 °C are involved. Table 3 reports the results of the solubility calculations with 18 selected models. An important point must be emphasized, the Wong-Sandler mixing rule coupled with the UNIQUAC model generated a serious instability such that it was impossible to converge. Table 4 illustrates the variation of solid solubility and mixture density for a typical binary mixture. 

Wong-Sandler mixing rule is extremely sensitive to the initial parameters estimation, such that with the UNIQUAC method it was not capable to converge in most of the mixtures ... 

The original version of the Wong-Sandler mixing rule (Wong and Sandler 1992) uses the last equality of eqn. (4.3.1) as one of the restrictions on the parameters together with the combining rule... 

Figure 4.3.3. VLE correlation of the carbon dioxide and propane binary system at 277,310, and 344 K with the Wbng-Sandler (WS) mixing rule combined with the van Laar excess free-energy model and the PRSV equation of state. The van Laar model parameters used are f/j0 = AJ2/A21 = 0,7897/0,7928, and the Wong-Sandler mixing rule parameter k 2 = 0.3565. (Points are experimental data from the DECHEMA Chemistry Data Series, Gmehting and Onken, Vol. 6, p, 589 data files for this system on the accompanying disk are C02C3277.DAT, CO2C33I0.DAT and C02C3344.DAT.)...

Figure 4.3.4. VLE correlation (solid lines) of the 2-propanol and water binary system at 353 K with the Wong-Sandler (WS) mixing rule combined with the NRTL excess free-energy model and the PRSV equation of state. The dashed lines are calculated with a = 0.2529, ri2/T2i =0,1562/2,7548, and with the Wong-Sandler mixing rule parameter k 2 = 0.2529 obtained by fitting the experimental data. The solid lines represents results calculated with a =0.2893 and T 2/t2i =0.1509/1.8051 obtained from the DECHEMA Chemistry Series at 303 K (Gmehling and Onken 1977, Vol.l, Pt. 1, p.

In the Wong-Sandler mixing rule the EOS parameters for a homogeneous liquid or vapor mixture is computed from... 

The fugacity coefficient expression for species i in a mixture for the Wong-Sandler mixing rule is... 

D.5. Program WS Binary VLE from Wong-Sandler Mixing Rule... 

WS BINAHV VIE CALCULATIONS WITH THE WONG-SANDLER MIXING RULE... 

WS THE WONG-SANDLER MIXING RULE FOR BINARY VLE CALCULATIONS methanol - water at 373 K EXCESS ENERGY MODEL = VAN LAAR K12-. 2001... 

D.6. Program WSUNF Binary VLE Predictions Using the Wong-Sandler Mixing Rule Combined with the UNIFAC Excess Free-Energy Model... 

The program WSUNF is used to predict VLE by means of the PRSV EOS coupled with the Wong-Sandler mixing rule and the UNIFAC group contribution method... 

If no experimental data arc available, bubble pressures and vapor mole fractions are calculated at liquid mole fractions Xi = 0 to 1 at intervals of 0.1. In this mode no data are entered to, or accessed from, the disk. Instead, the user provides critical temperature, critical pressure, acentric factor, and the PRSV k parameter for each pure component in addition the Wong-Sandler mixing-rule parameter k 2 and a temperature. The program then returns isothermal bubble pressure and vapor mole fraction predictions at the temperature entered. 

Example D.6.A Use of the Wong-Sandler Mixing Rule and UNIFAC for Binary VLE Predictions Using an Existing Data File... 

E.2. Program WSMMAIN Multicomponent VLE Calculations with Wong—Sandler Mixing Rules... 

WSM MOLTICOMPONEHT VLE WITH THE WONG—SANDLER MIXING RULE INPUT FILE NAME testl.wsn... 

Press RETURN to continue. The following parameter matrix for the kjj parameter of the Wong-Sandler mixing rule appears ... 

Huang, H Sandler, S. I., and Orbey, H., 1994. Vapor-liquid equilibria of some hydrogen plus hydrocarbon systems with the Wong-Sandler mixing rule. Fluid Phase Eq., 96 143-153. 

Q term used in Wong-Sandler mixing rule (Appendix B)... 

Equation (7.10-11) is easily derived, is generic, and applies to any mixing rule. This will be used as the starting point. With the Wong-Sandler mixing rule Note that derivatives must be taken with respect to mole numbers. 

These equations are usually referred to as the Wong-Sandler mixing rules (Problem 9.32). 

Derive the expression for the partial molar volume of a species in a mixture that obeys the Peng-Robinson equation of state and the Wong-Sandler mixing rules. 

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