Kinetic modeling of the glycerolysis reaction for soybean oils in supercritical carbon dioxide media

Production of MAG by glycerolysis is important for food, pharmaceutical, and cosmetic industries. Conducting glycerolysis in supercritical carbon dioxide (SC‐CO2) media has advantages over conventional alkali‐catalyzed glycerolysis. However, kinetic data are lacking for such conversions in the presence of SC‐CO2. The objectives of this study were to estimate the rate constants and elucidate the mechanism for the glycerolysis of soybean oil in SC‐CO2 using previously reported data. The data were taken from experiments using soybean oil, glycerol (glycerol/oil molar ratios of 15–25) and water (3–8% w/w) in SC‐CO2 at 20.7–62.1 MPa and 250°C for a 4 h period. Rate constants for the parallel glycerolysis and hydrolysis reactions were estimated for each processing parameter (glycerol/oil, water content, pressure) by minimizing the summed squared error between the values calculated from the experimental data and those obtained from the kinetic model. The results suggested that water and pressure had an effect on rate constants but the glycerol/oil ratio did not. Findings provide the kinetic modeling data necessary for the optimization of supercritical processes involving glycerolysis reactions for the production of MAG from vegetable oils.