Avaliação das Propriedades de Óleos Vegetais Visando a Produção de Biodiesel

Abstract

Awareness of countries in search for alternative fuels to minimize the emission of pollutants has contributed to develop fuels from renewable biomass. Vvegetable oils appear as an excellent alternative to replace petroleum diesel, since the transesterification process easily results in biodiesel. The aim of this study is to establish the composition of methylester from Peanut, Andiroba, Babassu, Buriti, Crambe, Palm, Sesame, Linseed, Macaúba, Moringa, Oiticica, Pequi, Jatropha and Grape Seed by gas chromatography. Levels of acidity, peroxide, iodine and kinematic viscosity were also determined. Rheological behavior and the use of accelerated oxidation techniques in controlled temperature at different pressures were performed by using PetroOxy, CSDP and Rancimat equipments. Chromatographic analyses showed that the profile of the fatty acids in vegetable oils studied were consistent with values found in the literature. Kinematic viscosity data showed a good correlation with unsaturated fatty acid composition and size of chains. Rheological analysis assigned the Newtonian behavior for all oils, with constant viscosity at different shear rates. The values of thermal and oxidative stability, in Rancimat, were: higher than 24 for the Babassu, Buriti, Andiroba, Macaúba and Crambe; Jatropha (12.36 h), and Moringa (7.60 h). The values found in PetroOxy, were 6.48 h 3.05 h 4.49 h 6.35 h 4.09 h 4.57 h and 3.20 h, respectively. The oxidative induction time (OIT) in PDSC was greater than 10h for Babassu; Buriti (3.84 h), Moringa and Macaúba (1.73 h), Andiroba (1.19 h), Jatropha (0.49 h). Crambe was not tested in this equipment