Phase equilibrium modelling of triglycerides with near critical solvents

The Group Contribution Equation of State (GC-EOS) is applied to calculate vapor–liquid and liquid–liquid equilibria of supercritical alkane–vegetable oil mixtures. A new functional group is defined, in order to represent the triglyceride nucleus of vegetable oil molecules. Pure group and binary interaction parameters for this group are given. The size of the high molecular weight triglyceride component is characterized by fitting its critical hard sphere diameter to infinite dilution activity coefficient data of hydrocarbons in the triglyceride.