Fractionation of fatty esters and acylglycerols by CO2 liquid-liquid extraction

G. SOTO; G. MABE; P. HEGEL; S. PEREDA; E. BRIGNOLE

Cartagena

Conferencia; III Iberoamerican Conference on Supercritical Fluids; 2013

Universidad del Valle

Oleochemistry is gaining importance due to its wide range of applications in the energy, food and pharmaceutical industries. The production of biodiesel or fatty acid methyl esters (FAMEs) is of great interest due to their use in diesel engines, blended with petroleum fuels. Also, acylglycerols (ACs) are employed in the food and pharmaceutical industries as emulsifiers. Alternative technologies have been proposed in the last decade to improve the conventional process of biodiesel production from unrefined oils and fats. One process of high interest is non-catalytic continuous supercritical methanolysis (scMeOH), which can process raw materials with high free fatty acids (FFA) and water contents. The vegetable oil is treated with an excess of alcohol (40:1 methanol to oil molar ratio) at 593 K and 150 bar to achieve complete conversion. However, working under milder conditions, ACs could also be obtained (543 K to 573 K). In this work, a method for the fractionation of FAMEs + ACs mixtures with liquid CO2 was studied. A CO2 liquid-liquid extraction technique was implemented to fractionate the products obtained in a scMeOH process. Working at 298 K and 64 bars, a 98 wt% of FAMEs was obtained in the extract phase and almost pure acylglycerols in the raffinate phase.