| Abstract
| - The perturbed-chain SAFT (PC−SAFT) equation of state is applied to pure associatingcomponents as well as to vapor−liquid and liquid−liquid equilibria of binary mixtures ofassociating substances. For these substances, the PC−SAFT equation of state requires five pure-component parameters, two of which characterize the association. The pure-componentparameters were identified for 18 associating substances by correlating vapor pressure and liquiddensity data. A comparison to an earlier version of SAFT confirms the good results for puresubstances. When only one associating compound is present in a mixture, the PC−SAFT equationof state does not require mixing rules for the association term. Using one binary interactionparameter kij for the dispersion term only, the model was applied to azeotropic and nonazeotropicvapor−liquid equilibria at low and at high pressures, as well as to liquid−liquid equilibria. Simplemixing and combining rules were adopted for mixtures with more than one associating compound,introducing no additional binary interaction parameter. The simultaneous description of liquid−liquid and vapor−liquid equilibrium was also possible with a single kij parameter.
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