Carbon-based materials as heterogeneous antioxidants for biodiesel: efficiency and synergy with soluble antioxidants

Antioxidants are compounds widely used in several areas as fuels, foods, and cosmetics among others. In this work, we analyze the use of biochar produced from Jatropha curcas seeds as an antioxidant. The biochar presented low antioxidant activity, although the antioxidant capacity of traditional antioxidants and modified biochar has a particular synergy. The oxidation stability of biodiesel can be improved more than fivefold in comparison with that using only a traditional antioxidant. This interaction presents an excellent synergy that allows oxidation stability to be increased to relatively high levels without requiring an increase in the antioxidant concentration. At the end of the experiment the biochar is easily separated by simple filtration and can be reused. We expect that these results would allow a better use of this toxic biomass improving the sustainability of biodiesel storage.