Alternative binary blends and their synergistic effect on stability of soybean biodiesel

The primary antioxidant tert-butylhydroquinone (TBHQ) and an alternative additive, named 1,4-bis(ethylamino)-9,10-anthraquinone, were mixed to yield a potent blend able to be used in the field of biodiesel preservation. Physicochemical parameters such as peroxide value, total acid number, density and induction period were used to evaluate the effectiveness of the combination in stabilising soybean biodiesel during the accelerate storage period of degradation. The induction period values were also used to calculate the occurrence of synergistic effect, and it was observed a high percentage of synergism for the combined additives. The results showed that the presence of target alternative additive also enables lower the concentration of the primary antioxidant (TBHQ) in the blend. The cost-effective comparison was evaluated, and it was verified that the final cost of biodiesel can also be lowered, since the amount of additives (in the blend) required to meet the biodiesel specifications was reduced between 70 and 88%.