Some Aspects of a Fluid Phase Equilibria and UNIFAC Model

= Adjustable parameter in the UNIFAC equation = Pure-component constant. 

C = Combinatorial part of the activity coefficient Q = UNIFAC equation R = Residual part of the activity coefficient 

The UNIFAC model defines functional groups, which make up the stractures of compounds. Each frmctional group makes a rrrtique contribution to the compound property. The interaction parameters obtained for a small number of groups using thermodynamically consistent data can be used for mrrlti-component systems. 

The UNIFAC (the universal qrrasi-cherrrical function group activity coefficient) is one of the best methods in estimating activity coefficient that has been established to date (Fredenslrmd et al., 1975 Fredenslrmd et al., 1977 Magnussen et al., 1981) has been successfully applied for the prediction of several LLE systems. This model depends on interaction parameters between each pair of components in the systerrr, which can be obtained by between each of the main groups. 

In this work, LLE data for water + formic acid + crunene at temperatures ranging from 298.2 to 313.2 K were measrrred, and UNIFAC model were used to estirrrate these data. The values for the interaction parameters were obtained for this equihbrittm model. The effect of formic acid addition on solubihty of water in cumene (organic phase) was also irrvestigated at different temperatures 298.2, 303.2, 308.2, arrd 313.2 K. 

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Some Aspects of a Fluid Phase Equilibria and UNIFAC Model... 

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