Phase behavior of binary mixture for the isoalkyl acetate in supercritical carbon dioxide

• Phase behaviors for the CO2 + isoalkyl acetate systems were measured by static method.
• (P, x) isotherms of these systems are obtained at 313.2–393.2 K and pressure to 18.24 MPa.
• Experimental results of three systems are correlated using Peng–Robinson equation of state.

Pressure–composition isotherms of phase equilibria for the CO2 + isoalkyl acetate systems are investigated in the static method at five temperatures of (313.2, 333.2, 353.2, 373.2 and 393.2) K and pressures up to 18.24 MPa. The CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems have continuous critical mixture (locus) curves that exhibit maximums in pressure–temperature space between the critical temperatures of CO2 and isoalkyl acetate (isobutyl acetate, isopentyl acetate and isooctyl acetate). The solubility of isobutyl acetate, isopentyl acetate and isooctyl acetate for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems increases as the temperature increases at constant pressure. The CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems exhibit type-I phase behavior. The experimental results for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems are correlated with Peng–Robinson equation of state using a mixing rule including two adjustable parameters.

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