Liquid-liquid equilibria for the model systems composed by sunflower seed oil + aldehydes + anhydrous ethanol at 25 °C under atmospheric pressure

Author(s)

Perci Odilon Bonetti Homrich

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2015-06-03

Examining board members

Roberta Ceriani; Maria Regina Wolf Maciel; Cintia Bernardo Gonçalves

• Advisor: Roberta Ceriani

Abstract

Sunflower seed oil is the oilseed that represents the fourth major agricultural productivity destined to obtaining refined oils, possessing some advantages due to its high quantity of linoleic acid (polyunsaturated fatty acid) and nutraceutical compounds, promoting benefits to human health. In order to become edible, sunflower oil must be chemically refined for removing free fatty acids and minority compounds. Basically, chemical refining consists of four steps: degumming, deacidification, bleaching and deodorization. The deodorization step removes odoriferous compounds (mainly aldehydes), formed by the oil oxidation reaction, in addition to contaminants, such as pesticides, by a steam stripping under high temperatures (up to 265 °C) and very low pressures. These drastic process conditions result in the degradation and volatilization of nutraceutical compounds (mainly antioxidants), and favor the occurrence of oxidation and cis-trans isomerization reactions of the unsaturated fatty acids. In this context, this work investigated the possibility to pre-treat the sunflower oil with a solvent, removing the crude oil odors by liquid-liquid extraction, which would enable a posterior deodorization stage with milder operational conditions. To achieve this purpose, the liquid-liquid equilibrium data for model systems composed by sunflower seed oil + aldehydes + anhydrous ethanol at 25 °C were experimentally determined and the systems were quantified using three different methods. From the experimental data obtained, the distribution coefficient and the solvent selectivity parameters indicated that aldehydes extraction using ethanol as solvent was satisfactory, and the data correlation done by the thermodynamics methods NRTL and UNIQUAC showed that the NRTL model faithfully correlated the experimental data, presenting a global deviation that varied between 0.4447 and 0.7203 % (AU)

• FAPESP's process: 13/11868-1 - Liquid liquid equilibrium of model systems containing vegetable oil + aldehyde + anhydrous ethanol at 25 ºC
• Grantee: Perci Odilon Bonetti Homrich
• Support Opportunities: Scholarships in Brazil - Master