Azeotrope-Breaking Potential of Binary Mixtures in Phase Equilibria Modeling

Abstract

Global phase diagrams (GPD) of binary mixtures in phase equilibria modeling are analyzed. The mapping of the global equilibrium surface in the parameter space of the equation of state (EoS) model provides the most comprehensive system of criteria for predicting binary mixture phase behavior. One may obtain the relationships for azeotropic boundaries from the global phase diagram [A (azeotrope) and H (heteroazeotrope)] regions. Analytical expressions to predict azeotrope and double azeotrope phenomena in terms of critical parameters of pure components were derived using global phase diagram. The problem estimations of phase behavior modeling under the uncertainty are formulated applying the Pareto-optimum parameter and different (crisp and fuzzy) convolution schemes. The Paretooptimum parameters in the Redlich-Kwong equation of state used different conflicting data sets (simultaneous description of the phase equilibria and critical line data in binary mixtures, thermodynamically consistent description of the inhomogeneous data). Ionic liquids (ILs) are one of prospective new working media for different environmentally friendly technologies. Practically undetectable vapor pressure is considered the ILs as ideal solvents replacing conventional solvents in the frame of a “green chemistry.” Combination of ionic liquids with conventional natural and synthetic refrigerants promotes the increasing efficiency of absorption processes due to nonvolatile ionic liquids (absorbents).