Improved biodiesel oxidative stability

2nd May, 2008

Global additive leader Eastman Chemical Company looks at the benefits of antioxidants and metal chelators

Biodiesel is susceptible to the same oxidative processes that cause rancidity in food oils, which can generate undesirable filter-plugging or metalcorroding by-products.

Several factors play a role in a biodiesel’s inherent oxidative stability. These include the origin of the feedstock, presence of contaminants, the production process, and exposure to light, heat and oxygen during the handling and storage.

Metal contamination is particularly problematic because the free radical process responsible for oxidation can be accelerated by the presence of metals.

The oxidative stability of biodiesel can be improved by the addition of antioxidants and the effect of metals can be reduced by the inclusion of chelators.

Eastman Chemical Company has over 50 years of expertise producing and marketing antioxidants for use in food. Recently Eastman began supporting the biodiesel industry by supplying Eastman BioExtend1 30 antioxidant solution. This product, formulated specifically for biodiesel, combines an antioxidant with a metal chelator in a solvent system.

Oxidative stability testing and standards Biodiesel is derived from natural, renewable resources, such as plant oils and animal fats which exist in nature as fatty acid triesters of glycerol. It is produced from the triglycerides by transesterification with alkaline methanol to produce the corresponding fatty acid methyl esters (FAME).

Both the oils or fats and the biodiesel derived from them are susceptible to oxidation.

Click here to subscribe to Biofuels International now!