The truncated virial equation or the ideal gas equation is often used as the equation of state. In the latter case all fugacity coefficients are 1, so the simplest form of Eq. (19) is Eq. (20). [Pg.20]

Another commonly used equation of state is the virial equation. We discuss the calculation of fugacity from virial coefficients in Chapter 13, 13.5.1. [Pg.204]

Species Fugacity Calculation Using the Virial Equation of State [Pg.422]

Many times the virial equation truncated after the second virial coefficient is used in place of a more complicated equation of state to calculate the fugacity of the components in the vapor phase. [Pg.6]

The virial coefficients can be determined from studies of the pressure-volume-temperature relations of gases. A graphical method for determining the fugacity may be illustrated by the use of the equation of state [Pg.154]

Compute the fugacities of ethane and /t-butane in an equimolar mixture at 373.13 K and 1, 10. and 15 bar using the virial equation of state. [Pg.422]

Derive equations to calculate component fugacity coefficients in a binary mixture using the virial equation of state truncated after the second virial coefficient. The mixture second virial coefficient is given as [Pg.68]

Fugacity coefficients and hence activity coefficients can be calculated with the help of appropriate equations of state (see Section IV). This is possible, however, only for the gas phase (van der Waals equation, Redlich-Kwong equation, virial equation) for condensed phases no useful general equations of state are available. Experimental determination of activity coefficients in condensed phases is based on the study of equilibria. There are numerous methods, but only typical examples will be given. [Pg.36]

IF BINARY SYSTEM CONTAINS NO ORGANIC ACIDS. THE SECOND VIRTAL coefficients ARE USED IN A VOLUME EXPLICIT EQUATION OF STATE TO CALCULATE THE FUGACITY COEFFICIENTS. FOR ORGANIC ACIDS FUGACITY COEFFICIENTS ARE PREDICTED FROM THE CHEMICAL THEORY FOR NQN-IOEALITY WITH EQUILIBRIUM CONSTANTS OBTAINED from METASTABLE. BOUND. ANO CHEMICAL CONTRIBUTIONS TO THE SECOND VIRIAL COEFFICIENTS. [Pg.266]

The separation of the vapor and liquid fugacities and the activity coefficients in the fundamental equilibrium relationship allow great flexibility, and a multitude of choices, in the selection of the thermodynamic relationships or empirical equations for estimation of each of these quantities. For the vapor fugacity coefficient any of the equations of state mentioned earlier or some other, such as the virial equation, may be used. In the latter case, the virial coefficients may be determined experimentally or estimated using three- or four-parameter generalized correlations. [Pg.171]

In Eq. (77) p° is the standard pressure, p° = l atm quantity p

[Pg.28]

From the historical point of view and also from the number of applications in the literature, the common method is to use activity coefficients for the liquid phase, i.e., the polymer solution, and a separate equation-of-state for the solvent vapor phase, in many cases the truncated virial equation of state as for the data reduction of experimental measurements explained above. To this group of theories and models also free-volume models and lattice-fluid models will be added in this paper because they are usually applied within this approach. The approach where fugacity coefficients are calculated from one equation of state for both phases was applied to polymer solutions more recently, but it is the more promising method if one has to extrapolate over larger temperature and pressure ranges. [Pg.196]

For very accurate measurements the non-ideal behaviour of CO2 has to be taken into account, Le., fugadty has to be used instead of partial pressure. This is the case if the results are to be used to calculate other parameters of the CO2 system in seawater. The fugacity can be calculated from a knowledge of the virial expression of the equation of state for CO2. For the binary mixture C02-air the fugacity of CO2 (/(CO2)) is given by [Pg.156]

AG = 0, and the equilibrium pressure as ouqiut of the simulation. Then, a second set of runs (G-NPT) was performed with the same feed mixtures and the pressure fixed at the values obtained fiom the G-NVT runs. In this case < Fb) is an output of the simulation. Finally, a third set of runs (GCMC) was carried out to check the validity of our simulation technique. These runs consisted of standard multicomponent GCMC simulations with mixture fugacities calculated from the virial equation of state using the pressures and gas-phase compositions obtained in the G-NVT runs. [Pg.300]

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