Study of the liquid-liquid equilibria aiming at deodorizing bioglycerol through solvent extraction

Abstract

For competing with the consolidated and traditional petrochemical industry, the oleochemical industry has been searching for superior applications for its most important co-product, bioglycerol. After the transesterification reaction and separation of the biodiesel fraction, the glycerol fraction contains several impurities, such as methanol, salts, matter organic non-glycerol (MONG) and moisture, which must be removed to a greater or lesser degree during purification steps. In fact, the range of applications of bioglycerol (from the production of biodiesel) is directly related to its purity degree in terms of 1,2,3 propanetriol (or glycerol). In this sense, this master's project aims at investigating the feasibility of applying solvent extraction as a step in the process of bioglycerol purification for the removal of odoriferous compounds, which are formed by the oxidation of fatty compounds. Experimental data of liquid-liquid equilibria (ELL) will be determined for 3 ternary model systems formed by glycerol + solvent (gamma-valerolactone, GVL) + odoriferous compound (valeric acid or valeraldehyde) at 50 ºC and (glycerol/water at 50% molar) +solvent (gamma-valerolactone) + odoriferous compound (valeric acid or valeraldehyde) at 25 ºC. The binodal curve will be measured by the cloud point method and the quantification of the tie-lines by indirect method. The density and refractive index of the equilibrium phases will also be measured experimentally. The ELL experimental data will be correlated by the NRTL and UNIQUAC models. The predictive capacity of the UNIFAC method will also be investigated. It is of note that this project is part of the scope of the FAPESP Thematic Project 2014/21252-0 entitled "Phase Equilibria and Processes for the Production of Biofuels and Bioproducts" valid from 01/02/2017 to 01/31/2022, for which the advisor of this project is an Associate Researcher.