The demand for acetoacetate-based compounds has risen significantly in recent years due to their unique physicochemical properties and wide-ranging industrial applications. The critical-point, dew-point, and bubble-point equilibria data for the 3-pentyl acetoacetate + carbon dioxide binary system in the temperature range of 313.2 K to 393.2 K and pressure limited to 20.06 MPa were measured. The mole fraction responses acquired in the range of (0.0433 to 0.7950). The pressure–temperature diagrams indicate that the critical locus of the mixture forms a continuous boundary connecting the critical points of carbon dioxide and pure 3-pentyl acetoacetate. The binary system 3-pentyl acetoacetate + carbon dioxide did not display 3-phases according to the vapor-liquid equilibria research at the test temperature. At a fixed temperature, the solubility of the system was found to increase with increasing mole fraction of 3-pentyl acetoacetate. The observed phase behavior corresponds to a Type-I system according to the classification of Van Konynenburg and Scott. Additionally, the experimentally measured bubble-point pressures were correlated using the PR EoS (Peng–Robinson equation of state) combined with vdW(van der Waals) one-fluid mixing rules. The binary interaction parameters (kᵢⱼ=0.005 and ηᵢⱼ=-0.025) were optimized and determined for the CO₂ + 3-pentyl acetoacetate system. The model predictions showed good agreement with the experimental data, yielding RMSD (root mean square deviation) values of 8.14%, 5.05%, 3.37%, 3.36%, and 2.90

The demand for acetoacetate-based compounds has risen significantly in recent years due to their unique physicochemical properties and wide-ranging industrial applications. The critical-point, dew-point, and bubble-point equilibria data for the 3-pentyl acetoacetate + carbon dioxide binary system in the temperature range of 313.2 K to 393.2 K and pressure limited to 20.06 MPa were measured. The mole fraction responses acquired in the range of (0.0433 to 0.7950). The pressure–temperature diagrams indicate that the critical locus of the mixture forms a continuous boundary connecting the critical points of carbon dioxide and pure 3-pentyl acetoacetate. The binary system 3-pentyl acetoacetate + carbon dioxide did not display 3-phases according to the vapor-liquid equilibria research at the test temperature. At a fixed temperature, the solubility of the system was found to increase with increasing mole fraction of 3-pentyl acetoacetate. The observed phase behavior corresponds to a Type-I system according to the classification of Van Konynenburg and Scott. Additionally, the experimentally measured bubble-point pressures were correlated using the PR EoS (Peng–Robinson equation of state) combined with vdW(van der Waals) one-fluid mixing rules. The binary interaction parameters (kᵢⱼ=0.005 and ηᵢⱼ=-0.025) were optimized and determined for the CO₂ + 3-pentyl acetoacetate system. The model predictions showed good agreement with the experimental data, yielding RMSD (root mean square deviation) values of 8.14%, 5.05%, 3.37%, 3.36%, and 2.90

High-pressure phase behavior Carbon dioxide 3-Pentyl acetoacetate Supercritical fluids