Phase equilibria of free fatty acids enriched vegetable oils and carbon dioxide: Experimental data, distribution coefficients and separation factors

In present work, the oils were treated by saponification procedure to release fatty acids from triglycerides to obtain free fatty acids (FFA) enriched oils and glycerol. Phase equilibria data for systems FFA enriched rapeseed oil-CO2, FFA enriched corn germ oil-CO2 and FFA enriched borage oil-CO2 were determined at temperatures 35, 45, 65 and 85 C, and in pressure range from 100 to 550 Bar. Experiments using FFA enriched oils were performed using high-pressure variable-volume view cell, where phase inversions were also observed at temperatures 35 and 45 C. Samples from liquid and vapor phases were analyzed by gas chromatography for the content of free fatty acids, and based on obtained data; the distribution coefficients and the separation factors between FFA and glycerol were calculated.