Oxidation kinetics of biodiesel from soybean mixed with synthetic antioxidants BHA, BHT and TBHQ: Determination of activation energy

• Peroxide Index (PI) in biodiesel were determined by Accelerated Oven Method.
• By PI data, reaction order, rate constant, and activation energy were determined.
• Simplex-centroid was applied to formulate the proportion of antioxidants in biodiesel.

Antioxidants are additives for the prevention of the degradation of biofuels. This study evaluated the oxidative stability of B100 biodiesel from soybean oil with the addition of three synthetic antioxidants, butylhydroxyanisole (BHA), tertbutyl-hydroquinone (TBHQ) and butylated hydroxytoluene (BHT), either pure or mixed, according to the simplex–centroid mixture design. The obtained kinetic parameters indicated that the addition of the three pure antioxidants and a ternary mixture of the antioxidants resulted in an induction period that was greater than that of the control sample. Furthermore, based on the induction period (ip), the antioxidant BHT was the most efficient in preventing the oxidation of the B100 biodiesel used.