Phase Equilibria for the Recovery of Monoglycerides from Fatty Esters using Near Critical CO2+Propane Mixtures

P. HEGEL; A. VELEZ; S. PEREDA; G. MABE; E. BRIGNOLE

Saint Petersburg

Simposio; 25th European Symposium on Applied Thermodynamics; 2011

Saint Petersburg State University

The production of biodiesel or  fatty esters from lipids with non-catalytic Supercritical Methanol (SC-MeOH) has gained interest in the last decade because it allows the processing of waste vegetable oils, crude oils and fats, with  high concentration of fatty acids and water[1]. Monoglycerides (Mg), diglycerides (Dg), and glycerol are the main by-products that can be obtained in the transesterification process when there is a partial reaction of transesterification. Acylglycerols constitute a very common food emulsifiers and they have been used as surface active agents in many industrial cleaning products. Mixtures of CO2+C3 have a good selectivity for the separation of  Fatty Esters (FE)  from glycerides because it is possible to obtain liquid-liquid equilibria at different operating conditions of temperature, pressure and solvent concentration. Solvent mixtures of carbon dioxide + propane (CO2+C3) were previously studied to analyze the extraction and separation of vegetable oils with dense gases [2,3].  The aim of this work is to study the phase equilibria of the transesterification reaction products, with CO2 + propane mixtures,  in order to design a  feasible reaction and separation process for the production of  fatty esters and monoglycerides. This technology would have direct application, for example, in  the separation steps of the biodiesel obtained from low cost vegetable oils.