Supercritical CO2 fractionation of crude palm oil

Crude palm oil was fractionated using supercritical CO2 (SC–CO2) in a semi batch apparatus. The fractionation conditions studied were at 40, 50 and 60°C and at 110, 140 and 200 bars, respectively. System pressure was found to be more significant rather than temperature for increasing the solubility of palm oil triglycerides in SC–CO2. The solubility of crude palm in SC–CO2 was generally low for triglycerides rich in the saturated and lower molecular weight fatty acids, i.e. C12:0, C14:0 and C16:0. These fatty acids were fractionated first followed by the heavier and mainly unsaturated fatty acids, i.e. C18:1, C18:3 and C20:0. The initial extracted fractions were white to yellow in colour and solid like. The later fractions however were more intense in colour and semi-liquid. It was difficult to extract β-carotene from the palm oil in the fractions even at high pressures because it is concentrated in the raffinate. The del Valle-Aguilera correlation was found to over estimated solubility of crude palm oil in supercritical CO2.