Improvement of the oxidation stability of biodiesel using natural antioxidants

Ethical reference number: 2019FEREC-STD-78

The oxidation stability of biodiesel has come to the forefront of studies mainly because of the presence of unsaturated fatty acids derivatives in biodiesel that are readily oxidised, thus resulting in the formation of oxidation products such as peroxides and hydro-peroxides. These products increase biodiesel's acidity, thus forming corrosive acids that can cause engine and fuel pump wear. Furthermore, the process generates undesirable product deposits, such as polymers responsible for obstructing fuel filters and injection systems. These drawbacks have hindered wide use of biodiesel in engine and fuel injection equipment, thus impeding the biodiesel market expansion. To solve this problem, synthetic and natural antioxidants have been introduced as additives to biodiesel. Although synthetic antioxidants are effective at improving oxidation stability, concerns regarding their biosafety have led to a research interest in natural antioxidants. The latter has shown great potential to improve the oxidation stability of biodiesel. In the present study, we investigate the effect of natural antioxidants (vitamins A, C and E) concentrations used separately and in pairs on the oxidative stability of waste cooking oil biodiesel. Studies on the influence of the aforementioned antioxidants on the oxidation stability of waste cooking oil biodiesel are relatively scarce in the literature.