ARS | Publication request: Counter-current CO2 purification of partially deacylated sunflower oil

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract
Publication Acceptance Date: January 11, 2008
Publication Date: May 18, 2008
Citation: Eller, F.J., Taylor, S.L., Laszlo, J.A., Compton, D.L. 2008. Counter-current CO2 purification of partially deacylated sunflower oil [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 123 #4.

Technical Abstract: High oleic sunflower oil was partially deacylated by propanolysis to produce a mixture of diglycerides and triglycerides. To remove by-product fatty acid propyl esters (FAPEs) from this reaction mixture, a liquid carbon dioxide (L-CO2) counter-current fractionation method was developed. The fractionation column was 1.2 m and separations were done at 25 deg C and 11.0 MPa. Solvent to feed ratio (S:FR) (i.e., 7.5, 15, 30, and 60 g/g) and feed rate (FR) (i.e., 1, 2, 2.5, 3, and 4 mL/min) at constant S:FR of 15 were examined. Raffinate purity (i.e, glycerides) as well as extract purity (i.e., FAPEs) were both monitored. Percentage glycerides in both the raffinate and the extract increased with S:FR. The raffinate was ca. 83, 97, 100 and 100% glycerides at S:FRs of 7.5, 15, 30 and 60, respectively. The percentage glycerides in the extracts were ca. 3, 4, 8, and 17%, respectively. With a constant S:FR of 15, the raffinate purity peaked at ca. 99% glycerides with a FR of 2.5 mL/min and the extract at this FR contained ca. 96% FAPEs (i.e., ca. 4% glycerides). This demonstrates that L-CO2 effectively separates by-product FAPEs from product glycerides, giving a raffinate of over 99% glycerides and a very pure extract (i.e., 96% FAPEs). In addition, this continuous separation is done at a temperature which minimizes potential chemical changes to the product.