High-Pressure Equilibrium Data in Systems Containing Supercritical Carbon Dioxide, Limonene, and Citral

This paper presents experimental equilibrium data for both CO2 + limonene and CO2 + citral systems at a constant temperature of 315 K and at pressures varying between (3 and 10) MPa. Experimental data on the ternary system CO2 + limonene + citral are also presented. The experiments were performed at 315 K and at two different pressure values: (8.4 and 9.0) MPa. The experimental results obtained were correlated by means of the Peng−Robinson equation of state and by applying mixing rules characterized by two different interaction parameters specific to each binary subsystem present in the ternary system. The data obtained show that limonene is characterized by higher solubility in carbon dioxide than citral. It is therefore possible to obtain an enrichment of citral through the extraction of limonene by means of supercritical carbon dioxide starting from a mixture of limonene and citral.