Method of increasing the oxidation stability of biodiesel

Abstract

The invention relates to a method of increasing the oxidation stability of biodiesel, which comprises adding a primary antioxidant having a melting point of less than or equal to 40° C. to the biodiesel to be stabilized in an amount of from 10 to 20 000 ppm (w/w), where the primary antioxidant comprises at least one compound having the structure where: R1, R2=hydrogen, a linear alkyl group having from 1 to 20 carbon atoms or where * is a carbon atom of the aromatic ring system, R3, R5=hydrogen, a linear alkyl group having from 1 to 20 carbon atoms, R4=hydrogen, a linear alkyl group having from 1 to 40 carbon atoms, where both the substituents of the type R1 and R2 and those of the type R3 and R5 are in each case identical or different.

Dependencies are inferred from the claim text.