Multicomponent phase equilibrium measurements and modeling for the allylic epoxidation of trans-2-hexen-1-ol to (2R,3R)-(+)-3-propyloxiranemethanol in high-pressure carbon dioxide

High-pressure gases can be attractive substitutes for hazardous organic solvents. In particular, our interest is the use of subcritical liquid or supercritical carbon dioxide as a replacement solvent for reactions. In considering carbon dioxide as a replacement solvent, a key factor is the solubility of the reaction mixture in the new solvent. We present solubility data and modeling for the reactants and products in the allylic epoxidation of trans-2-hexen-1-ol to (2R,3R)-(+)-3-propyloxiranemethanol in high pressure carbon dioxide. We show that it is possible to use the Peng–Robinson equation of state to model both the liquid and gas phases. We demonstrate that the use of the nonzero binary interaction coefficients between each compound and carbon dioxide dramatically improves the modeling results. This knowledge should prove useful to those who are considering carbon dioxide as a substitute solvent for complex chemical mixtures that are encountered in multistep chemical syntheses.