MODELING OF THE PHASE-BEHAVIOR OF MIXTURES IN THE CRITICAL REGION USING THE AUGMENTED PENG-ROBINSON EQUATION OF STATE

The Peng-Robinson equation extended to the PVT property representation in the critical point neighbourhood (PRA equation) was used to calcul ate binary pressure-composition and pressure-density diagrams. The mod ified excess function at constant packing fraction model was used to t ake into consideration binary interactions. In the case of binary syst ems exhibiting the mixture critical point, calculation results were sa tisfactory and substantially improved with respect to those obtained u sing the volume corrected Peng-Robinson (PRC) equation.