Sufficient oxidation and cold stability are essential for the safe use of fatty acid methyl esters (FAME), also known as biodiesel.

The additives used must not have any negative interactions with the FAME itself or the base diesel fuel and its additives.

Only two antioxidants and one flow improver were able to pass the German biodiesel quality management association’s (AGQM's) challenging no-harm tests in 2023 and be included on the no-harm lists.

Biodiesel is often stabilized with additives to ensure safe storage and use at low temperatures in winter.

In cooperation with the mineral oil industry, AGQM has developed the no-harm tests to examine the additization of biodiesel with antioxidants and flow improvers for possible negative interactions with FAME, the fossil diesel fuel and various additives.

In addition to the standard requirements in the test programs for pure biodiesel, a series of other specific tests such as interaction, filtration and engine-oil compatibility tests as well as the XUD-9 engine test are carried out in a diesel fuel with 10 percent biodiesel content (B10).

Depending on the additive type, special tests such as the relative efficiency to BHT for antioxidants and the foam, emulsion and corrosion test for flow improvers complete the demanding test programs, which AGQM said are unique worldwide.

In this year’s test round, three additives were able to pass all the demanding tests.

The antioxidants Spec-Aid BIO9401 and Spec-Aid BIO9402 (both VEOLIA Water Technologies and Solutions Belgium B.V.) and the flow improver Bio WinterFlowTM 902 (Innospec Ltd.) were included in the respective no-harm lists.

Further information on the no-harm test as well as the no-harm list with all successfully tested products can be found on the AGQM homepage.

Information on the next no-harm test round for the testing of oxidation stabilizers is available on request at info@agqm-biodiesel.de.

AGQM is an organization founded by leading companies of the German biodiesel industry.

As a technical association, AGQM predominantly deals with all issues concerning the quality management of biodiesel and its byproducts.