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Liquid-liquid equilibrium for the system of rice brain oil + commercial oleic acid + anhydrous ethanol + hexane

Wagner Luiz Priamo
Total Authors: 1
Document type: Master's Dissertation
Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
Defense date:
Examining board members:
Maria Regina Wolf Maciel; Marcos Lucio Corazza; Martin Aznar
Advisor: Eduardo Augusto Caldas Batista

Solvent extraction has the advantage of operating at lower temperatures and also can extract other desirable components from oilseeds when compared to mechanical extraction. Commercial hexane is the usual solvent to extract oil by leaching, but it is highly flammable and it can cause hazard to human health. Some studies have begun to investigate the change of this solvent. The refining processes of crude vegetable oils involve solvent stripping, degumming, bleaching, deacidification and deodorization. Vegetable oils can be deacidified by conventional processes, such as chemical and physical refining. Chemical refining is applicable for all raw materials; however, it can result in large losses of neutral oil. For high acidity oils, physical refining is also a possibility, but can cause undesirable alterations in color and stability to oxidation. An alternative is the deacidification by liquid-liquid extraction, process carried out at room temperature and atmospheric pressure and that causes lower loss of neutral oil. Biodiesel is a renewable energetic source and it is gaining acceptance and market. The most common way to produce biodiesel is by transesterification of triacylglycerols with methanol or ethanol, generating methyl or ethyl esters. The low solubility of triacylglycerols in alcohols presents the necessity of using some another solvent to create a system of one phase and to improve the diffusion of the reagents. The knowledge of the behavior of all these systems of crude vegetable oil / solvents at different temperatures configures the principal topic in mass transfer operations and catalysis. Taking, these points into account, this work aims to determine experimental data for liquid-liquid equilibrium of ternary systems containing refined rice brain oil / anhydrous ethanol / n-hexane and quaternary systems containing refined rice brain oil / commercial oleic acid / anhydrous ethanol / n-hexane, using Near Infrared Spectroscopy (NIR) for quantification of the components in each phase in equilibrium. For the quaternary systems, the increasing in the oleic acid composition in rice brain oil increases the solubility of the systems and decreases the biphasic region. For the ternary systems, the results showed that the increase in the temperature promotes a reduction of the two phase region, given by the increase of the mutual solubility of refined rice brain oil and anhydrous ethanol. In all systems higher deviations of mass balance for the commercial oleic acid and hexane were found, while for the other components, refined rice brain oil and anhydrous ethanol, the deviations were lower. According to the results obtained, we concluded that the Near Infrared Spectroscopy is highly accurate, with some advantage in relation to other analytical methods. The experimental data were correlated using the NRTL model, and for the systems at 298.3 K, the global deviation was 1.06 %; for the ternary system at 313.3 K, the global deviation was 0.26 % (AU)

FAPESP's process: 06/01864-5 - Determination of liquid-liquid equilibrium data for rice bran oil/fatty acid/ethanol/hexane systems
Grantee:Wagner Luiz Priamo
Support type: Scholarships in Brazil - Master