Vapor–Liquid Equilibria of Binary Associating Fluids Using a Cubic Equation of State with Limited Data

The vapor–liquid equilibria of binary associating fluids containing alcohols are described using a cubic equation of state, van der Waals mixing rules, and a binary interaction parameter. The binary interaction parameter is a linear function of composition. The binary interaction parameter is also a strong function of temperature. The temperature dependency was derived by combining van der Waals mixing rules with G E mixing rules followed by approaching infinite dilution limiting condition. Employing pure component parameters with literature values of infinite dilution activity coefficients, the vapor–liquid equilibria of systems containing alcohols were predicted satisfactorily. In the absence of experimental or estimated infinite dilution activity coefficients, the model can be coupled with the nonrandom two-liquid activity coefficient model to accurately correlate experimental vapor–liquid equilibrium data.