Phase Equilibria for Production and Fractionation of Mono, Di and Triacetin with Supercritical CO2

M. FORTUNATTI; F. A. SANCHEZ; P. HEGEL; S. PEREDA

Essen

Congreso; 15th European Meeting on Supercritical Fluids (EMSF 2016); 2016

The world production of biodiesel has greatly increased the availability of glycerol as a cheap raw material for the synthesis of a variety of chemicals. Among many other products, the glycerol acetates (mono, di and triacetin) have application as fuel additives, solvents or raw materials for other chemical products. Also it is possible the direct production of glycerol acetates mixture when methyl acetate is used instead of methanol in the transesterification of tryglicerides. Experimental studies of synthesis and fractionation of these components using liquid and supercritical CO2 have been carried out recently, in a lab scale (1,2). On the other hand, phase equilibria modeling and high pressure experimental data for triacetin+CO2 have been studied by Hegel et al (3). Also, Soto et al. (4) measured phase equilibria of the supercritical transesterification reaction products: mono and diacylglycerides and fatty esters with CO2. In both studies the high pressure phase equilibria modeling was made with the Group Contribution with Association equation of state (GCA-EOS). The synthesis of glycerol acetates and their fractionation with liquid and supercritical CO2 calls for phase equilibrium experimental data of binary and multicomponent mixtures to validate and/or tune the GCA-EoS predictions to different phase scenarios. The model is highly needed for the rigorous simulation and optimization of both, the reaction media and fractionation units. Moreover, with this tool we perform a phase equilibrium engineering to identify promising operating conditions to carry out the reaction and fractionation processes.(1) M. Rezayat, H. Ghaziaskar, Continuous synthesis of glycerol acetates in supercritical carbon dioxide using Amberlyst 15, Green Chem., 2009, 11, 710-715. (2) M. Rezayat, H. Ghaziaskar, Continuos extraction of glycerol acetates from their mixture using supercritical carbon dioxide, J.of Supercritical Fluids, 2011, 55, 937-943.(3) P. Hegel, G. Mabe, M. Zabaly, S.Pereda, E.A.Brignole, Liquid-liquid-supercritical fluid equilibria for systems containing carbon dioxide, propane and triglycerides, J.Chem.Eng.Data 2009, 54, 2085-2089.(4) G. Soto, P. Hegel, S. Pereda, Supercritical production and fractionation of fatty esters and acylglycerols, J. of Supercritical Fluids 2014, 93, 74-81.