Phase equilibria for the two-component systems of allyl acetoacetate, methyl acetoacetate and ethyl acetoacetate under high-pressure CO2

Abstract

The phase behavior study of allyl acetoacetate, methyl acetoacetate, and ethyl acetoacetate in supercritical CO2 (S-CO2) is important for several industrial processes. This study investigated the binary mixture solubility curves of the three systems (allyl acetoacetate, methyl acetoacetate, and ethyl acetoacetate) at five temperature sets (313.2–393.2 K) and pressures (3.09 ≤ p ≤ 20.78 MPa). In S-CO2, the three systems exhibited a critical mixture curves and the maximum point in pressure–temperature (p-T) diagram was obtained between critical point of allyl acetoacetate/methyl acetoacetate/ethyl acetoacetate and that of CO2. These characteristics of the critical mixture plot fall under the category of type-I behavior. The experimental solubility curves and critical mixture curves of above three systems are correlated using Peng-Robinson equation of state with van der Waals mixing rules using two interaction parameters. The calculated root mean square relative deviation % (RMSD %) of the allyl acetoacetate + S-CO2, methyl acetoacetate + S-CO2, and ethyl acetoacetate + S-CO2 systems for five temperature sets ranges from (1.29% − 3.63%), (1.47% − 8.95%) and (2.17% − 3.87%), respectively.