BIODIESEL FROM OITICICA OIL (Licania rigida, Benth): PRODUCTION, THERMOGRAVIMETRIC, AND OXIDATIVE STABILITY STUDIES

Oiticica is a feedstock with energetic potential for biofuel due to the presence of high oil content in its almond (54-60%). In this work, biodiesel from oiticica was produced by methyl transesterification using alkaline catalysts. Fatty acid methyl ester (FAME) obtained at 32 °C, with 1.5% of KOH and 2h of reaction time was higher (92%) than that with NaOH (85%). At the temperature of 50 °C, no difference between the catalysts was found, both resulting in a conversion of 91%. The best acid index was obtained with 1% of NaOH (0.40 mg KOH g-1 oil at 50 °C) and the best value of viscosity (9.61 mm2 s-1) with 1.5% of KOH at 50 °C. Oiticica oil and biodiesels exhibited high viscosities due the predominance of unsaturated compounds. Thermogravimetric analysis demonstrated to be a feasible technique, when compared to chromatography, in terms of time of analysis, conversion of the esters, and reagent consumption. All the biodiesels presented an oxidation temperature of 90 °C via Pressure Differential Scanning Calorimetry (PDSC).