The Effect of System Type

In support of the local composition models contention that only binary parameters are needed for multicomponent predictions, the nine four- and five-component systems are predicted as well as - actually better than -the rest. 

As expected, the degree of nonideality effects the obtained accuracy systems containing hydrocarbons only give the best results, while those containing water, the poorest. This also explains the better prediction results for the four- and five-component systems, mostly hydrocarbon ones. 

Evaluate the performance of the UNIQUAC model in the prediction of the vapor-liquid equilibrium behavior for the system carbon tetrachloride(l)-benzene(2)-i-propyl alcohol(3) at 1.013 bar by comparing your results to the experimental data presented in Table 13.E.12 (Hala et al, 1968, pp.493-494).The required UNIQUAC binary parameters are included in the same Table and were obtained by regressing the corresponding VLE data at 343.15 K for the 1-2 and 1-3 binaries (Hirata et al, 1975) and at 760 mm Hg for the 2-3 one (see Example 13.10). 

The results, obtained with the Program VLEGPHI of Appendix E, are presented in the same Table. Notice the good quality of the predicted values with overall average absolute deviations of P = 1.6% 4yi = 0.004 Ay2 = 0.007. 

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