Passion fruit seed extract as an antioxidant additive for biodiesel; shelf life and consumption kinetics

One of the primary concerns in the use of biodiesel is its susceptibility towards radical-mediated oxidative reactions. The presence of unsaturated methyl esters renders biodiesel vulnerable to oxidation. It necessitates strategic interventions, which among a few others, includes the use of antioxidant additives. Natural antioxidants have multiple significant advantages over their synthetic counterparts. In the present study, the activity of methanolic passion fruit seed (PFS) extract as an antioxidant additive for waste cooking oil (soybean) biodiesel has been evaluated. The PFS extract contained a high proportion of phenolic compounds and exhibited excellent antiradical activity against model radical DPPH, which encouraged us to explore the case of unstable biodiesel further. At a concentration of 200 ppm, the PFS extract augmented the fuel's resistance towards oxidation to levels where it could comply with European and the Indian specifications for blend-stock biodiesel. The performance of PFS extract was comparable to that of synthetic antioxidants, including butylated hydroxyanisole and butylated hydroxytoluene. The present study substantiates the utility of plant extracts rich in phenolics as an antioxidant additive for biodiesel.

Automated summary

The study evaluated the activity of methanolic passion fruit seed extract as an antioxidant additive for biodiesel, showing high phenolic content and excellent antiradical activity. At 200 ppm concentration, the extract significantly increased the fuel's resistance to oxidation, meeting European and Indian specifications for blend-stock biodiesel. This study confirms the effectiveness of plant extracts rich in phenolics as an antioxidant additive for biodiesel.