PHASE-EQUILIBRIA FOR ENZYME-CATALYZED REACTIONS IN SUPERCRITICAL CARBON-DIOXIDE

A five-component system resulting from an enzyme-catalyzed transesterification consists of the four reactants ethyl acetate, ethanol, isoamyl acetate, isoamyl alcohol and the reaction solvent, supercritical carbon dioxide. VLE behaviour of the system is predicted applying the Soave-Redlich-Kwong equation of state with mixing rules proposed by Huron and Vidal. Model parameters are adjusted using only pure substance and binary sub-systems data. New VLE measurements are performed with a high pressure apparatus for validating the model. Comparison with experimental data shows the model is able to predict phase equilibria of the five-component system sufficiently well over a wide range. It may thus be used for designing a supercritical fluid extraction process for separating the reactants.