AN EQUATION OF STATE FOR ASSOCIATING SYSTEMS

The thermodynamic framework proposed by Hu et al. ( 1984) for generating the Helmholtz free energy functions for associating systems is rectified. A generic Cubic equation of state is incorporated with the infinite linear association model and the monomer-dimer association model as well as two different sets of mixing rules to result in four different forms of equations of state. The Peng-Robinson equation of state is accordingly reformulated and the applicability of one of the reformulated equations is tested by using the selected equation to correlate the vapor pressures and liquid densities of water and selected alcohols. The values calculated by means of the reformulated Peng-Robinson equation are in good agreement with the experimental data reported in the literature.