Modeling Phase Equilibria for Systems with Vegetable Oils

MANDAGARAN, BEATRIZ A.; CAMPANELLA, ENRIQUE A.

Algarve - Portugal

Congreso; VIII Iberoamerican Conference on Phase Equilibria and Fluid Properties for Process Design (EQUIFASE 2009); 2009

Universidad de Porto

Chemical processes involving vegetables oils are more important today due to the increasing use of vegetable oils as raw materials for fuels, lubricants, or intermediate chemicals production. Process design requires information of the phase and chemical equilibria. A problem is to characterize these complex mixtures. In this work the vegetable oil or its methyl esters has been represented by a pseudocomponent with the same molecular weight and unsaturated degree than the complex compound. Two types of calculations are presented: partition coefficient calculation and liquid-liquid equilibrium calculation. For the partition coefficient of carboxylic acids and pollutants between an aqueous and an organic phase (vegetable oil or fatty acid methyl ester (FAME)) calculations were done using NRTL [1] and compared with prediction from UNIFAC [2,3], linear free energy relationship model (LFER) [4] and octanol-water partition coefficient. For liquid-liquid equilibrium of FAME-alcohol-glycerol calculations were done with UNIQUAC [5] and compared with prediction from UNIFAC and LFER. Results show that it is possible to represent the vegetable oil or its fatty acid methyl ester with a pseudocomponent and to use traditional activity model to calculate or to predict phase equilibria involving vegetable oil or its methyl esters.