Estudo da estabilidade oxidativa do biodiesel de soja com aditivos

Abstract

Biodiesel is a biofuel obtained from a renewable biomass, amongst those are vegetable oils such as soy, castor bean, sunflower and others. Seen as an alternative to diesel oil due to being biodegradable and generating a smaller degree of pollution during its combustion, however it presents a smaller stability to oxidation, related to one of the parameters known as oxidative instability included in the European Standard EN 14214, exposure to air, light, and presence of metallic ions, as well as long periods of storage are factors that influence on its deterioration, reducing its quality and preventing its commercialization. This paper presents a study in the oxidative stability of soy biodiesel when added commercial additives. The antioxidants tested were 2,6 diter-butil-4-methylphenol (BHT), Di-sec-butil-p-fenilenodiamina (PDA) e Terc-butil-hydroquinone (TBHQ). These antioxidants were tested in concentrations varying between 250, 500, 750, 1000, 1250 and 1500ppm. With the goal of checking the effect of antioxidants over the biodiesel’s induction period. All samples were analyzed in accelerated oxidation tests (Rancimat). The antioxidant TBHQ, in this study, presented a superior action to the remaining additives, for the induction period achieved was at least twice the one obtained from the other additives. However certain samples obtained success when reaching the minimum induction period (8 hours) established by ANP standards.