Phase equilibria of methyl esters in supercritical propane

• Phase equilibrium data for propane/methyl decanoate to propane/methyl docosanoate.
• Increase in temperature leads to linear increase in phase transition pressure.
• Increase in molecular mass leads to increase in phase transition pressure.
• Higher solubility of methyl esters in propane than in CO2 or ethane.

High pressure phase equilibria measurements using a static synthetic view cell for methyl decanoate, methyl dodecanoate, methyl hexadecanoate, methyl octadecaonate and methyl docosanoate in supercritical propane were conducted between 376.6 and 412.4 K at methyl ester mass fractions between 0.0178 and 0.660. The data show a linear increase in phase transition pressure with an increase in temperature at constant composition and, within the experimental range, total solubility was achieved below 8.1 MPa for all systems. Comparing the various data sets, an increase in phase transition pressure with increasing hydrocarbon backbone is noted, indicating that propane is able to fractionate a mixture of methyl esters.

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