Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/1996
Publication Date: N/A
Technical Abstract: Glycerolysis of soybean oil was conducted in a supercritical carbon dioxide (SC-CO2) atmosphere to produce monoglycerides in a stirred autoclave at 150-250 deg C, over a pressure range of 20.7-62.1 MPa, at glycerol/oil molar ratios between 15-25, and water concentrations of 0-8% (added as wt. % of glycerol). Mono- (MG), di- (DG), triglyceride (TG), and free fatty acid (FFA) composition of the reaction mixture as a function of time was analyzed using supercritical fluid chromatography. At 250 deg C, MG formation decreased (p<0.05) with pressure and increased with glycerol/oil ratio and water concentration. A maximum MG content of 49.2% was achieved at 250 deg C, 20.7 MPa, a glycerol/oil ratio of 25 and 4% water after 4 h. These conditions also resulted in the formation of 14% FFA. Conversion of TG into DG and MG followed pseudo-first order reaction kinetics after a lag period of 50-110 min. The reaction rate constant was 0.015 min **-1 for the condition of maximum MG formation. Conduction glycerolysis in SC-CO2 atmosphere offers advantages compared to conventional alkali catalysis.