High-pressure vapor−liquid equilibria for the binary carbon dioxide + 3-petanol system were measured
at 313.2 K. The phase equilibrium apparatus used in this work was of the circulation type in which the
coexisting phases were recirculated, on-line sampled, and analyzed. The critical pressure and corresponding
mole fraction of carbon dioxide at 313.2 K were found to be 8.22 MPa and 0.974, respectively, for this
binary system. The phase equilibria for the ternary carbon dioxide + 3-pentanol + water system were
also measured at 313.2 K and pressures of 2.00, 4.00, 6.00, 8.00, and 8.25 MPa. This ternary system
showed the liquid−liquid−vapor (LLV) phase behavior over the range of pressure up to the critical pressure
of 8.25 MPa. The binary equilibrium data were all reasonably well-correlated with the Redlich−Kwong,
Soave−Redlich−Kwong, Peng−Robinson, and Patel−Teja equations of state incorporated with the eight
different mixing rules: the van der Waals, Panagiotopoulos−Reid, and six modified Huron−Vidal mixing
rules with UNIQUAC parameters. For the prediction of high-pressure phase equilibria for the systems
containing carbon dioxide and alcohols, the SRK-MHV2 might reproduce many features of the measured
behavior although further tests are needed with other systems.