High-pressure phase equilibrium data for the carbon dioxide + methyl esters homologous series and SAFT-VR Mie modelling

Abstract

High-pressure phase transition data measured using a visual static synthetic method are presented for various CO2 + saturated fatty acid methyl ester systems in the range 308–358 K and up to 27.5 MPa. The newly measured data cover methyl esters between methyl decanoate and methyl docosanoate in the liquid-like, mixture critical and vapour-like regions, and complement previously published data. The systems studied do not suggest three-phase behaviour, liquid-liquid immiscibility or temperature inversions in the temperature range considered. An increase in temperature and molecular mass of the methyl ester leads to an increase in the phase transition pressure. The SAFT-VR Mie equation of state was able to correlate the data well with decreasing performance at higher methyl ester molecular masses and lower temperatures.