Solubility of Binary and Ternary Systems Containing Vanillin and Vanillic Acid in Supercritical Carbon Dioxide

Experimental solubility data of binary and ternary systems containing vanillin and vanillic acid in supercritical carbon dioxide were carried out in equipment based on the static-synthetic method. Compositions of dissolved solids were determined online via high-performance liquid chromatography with a diode array detector. The carbon dioxide + vanillin, carbon dioxide + vanillic acid, and carbon dioxide + vanillin + vanillic acid systems were studied at (315.00, 324.90, and 334.71) K, (314.91, 324.91, and 334.71) K, and (314.13, 323.67, and 333.17) K, respectively. For all systems the measurements were carried out at pressure range between 8.00 and 30.00 MPa. For binary systems the maximum solubilities were 5.215 × 10^-3 and 2.911 × 10^-5 in mole fraction for vanillin and vanillic acid, respectively. For ternary systems the maximum solubilities were 4.669 × 10^-3 and 2.213 × 10^-5 for vanillin and vanillic acid, respectively. The expanded uncertainties (k = 2) for the measured properties are estimated to be U(P) = 0.04 MPa, U(T) = 0.04 K, and U_r(y) = 0.0286 mole fraction. Méndez-Santiago and Teja, Bartle et al., Kumar and Johnston, and Chrastil models were used to correlate the experimental data. The results from the correlation confirmed the consistency of the reported data.