Fractionation of fatty esters and acylglycerols by liquid CO2

N. COTABARREN; P. HEGEL; S. PEREDA

Alicante

Conferencia; X Iberoamerican Conference on Phase Equilibria and Fluid Properties for Process Design (EQUIFASE 2015); 2015

Acylglycerols have many applications as emulsifiers and surfactants[1]. Moreover, new applications are being developed for this byproducts in the food/beverage as well as pharmaceutical sector [1,2]. Fatty acid esters (FAE) and acylglycerols mixtures can be produced by a partial transesterification of vegetable oils with methanol or ethanol. In that respect, the non-catalytic supercritical alcoholysis is one the most studied alternative technologies that have been proposed to improve the conventional transesterification process [3]. In the supercritical alcohol transesterification it is possible to obtain a complete conversion of triglycerides with products containing FAE and a high concentration of ACs [4]. In addition, these reaction products require fractionation and supercritical CO2 extraction is a green technology that is gaining importance over conventional techniques to process natural substrates. In a previous work [4] it was shown through a phase equilibrium engineering analysis that FAE and ACs can be effectively fractionated using CO2 under liquid or supercritical state.In this work, FAE and AC mixtures obtained by supercritical ethanolysis were fractionated experimentally in a modified high pressure Soxhlet apparatus by liquid-liquid (L1-L2) crosscurrent extraction using liquid CO2. The condenser and heater temperatures were set at 278K and 403 K, respectively. This gives an operating pressure of around 43bars, which corresponds to an extraction temperature of near 283K. Finally, a thermodynamic and mass transfer models, combined with the experimental information, were applied to study the crosscurrent extraction process.