EVALUATION OF OXIDATION STABILITY OF SUNFLOWER OIL BIODIESEL WITH ANTIOXIDANTS

Biodiesel can contain unsaturated fatty acids, which are susceptible to oxidation, being able to change into polymerized compounds. In this work biodiesel was characterized according to physical-chemistry parameters and the antioxidant activity of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ) added to biofuel was analyzed. Biodiesel was submitted to accelerate oxidation in the Schaal oven test, and peroxide value was analyzed. The absorptivity values at 232 nm and 270 nm and oxidative stability in Rancimat (R) were determined. It was observed that TBHQ presented superior antioxidant activity than BHT and BHA.