This paper was presented at the Biodiesel Exposicion Technica in Rosario Argentina in July 2007. It covers the basics of biodiesel stability issues and mechanical, operational and chemical solutions to protect biodiesel stability.

1. The Importance of Biodiesel Oxidation Stability by Phil Bureman Senior Regional Account Manager Nalco Company Olathe, Kansas USA [email_address]

2. Where Is Olathe, Kansas, USA? The Cowboy Boot was invented in Olathe!

5. Transesterification of Triglycerides Why is biodiesel unstable? Why is stability important? Managing biodiesel stability The type of fatty acid (R, R ’ , R ’’ ) making up the triglyceride will vary with the feedstock CH 3 -OH Triglyceride (soy oil) Methanol + Catalyst Mixed Methyl Esters (FAME or Biodiesel) + Glycerin R’-CH 2 R-CH R’’-CH 2 CH 2 -OH CH-OH CH 2 -OH O R-O-CH 3 O R’-O-CH 3 O R’’-O-CH 3

6. Different Feed Stocks Contain Different of Triglycerides Why is biodiesel unstable? Why is stability important? Managing biodiesel stability Stearic Fatty Acid Palmitic Fatty Acid CH 2 Linoleic Fatty Acid CH 2 Linoleic Fatty Acid Linoleic Fatty Acid CH 2 Oleic Fatty Acid CH 2 The type of fatty acids in the feedstock affects the stability of the biodiesel Stearic Fatty Acid Palmitic Fatty Acid CH 2 Oleic Fatty Acid CH 2 C H C H C H Palmitic Fatty Acid Palmitic Fatty Acid CH 2 Stearic Fatty Acid CH 2 C H

7. Methyl Ester Make Up Determines Stability Why biodiesel Is unstable? Why is stability important? Managing biodiesel stability Methyl Ester Name # of Carbons # of Unsaturated Bonds Relative Oxidation Stability Palmitate 16 Zero High Stearate 18 Zero High Palmitoleate 16 1 Medium Oleate 18 1 Medium Linoleate 18 2 Low Linolenate 18 3 Low

9. Biodiesel Stability Why biodiesel Is unstable? Why is stability important? Managing biodiesel stability

10. Biodiesel Stability Why biodiesel Is unstable? Why is stability important? Managing biodiesel stability European Spec USA Spec

27. Mechanical Solutions Why biodiesel Is unstable? Why is stability important? Managing biodiesel stability Biodiesel will clean petro diesel “gunk” from used fuel systems Fuel filters from Dodge pickup truck with ~ 32,000 km, burning it’s first B33 w ULSD From km 320 to km 640 New From km 130 to km 320 From km 1 to km 130 What else can you do? ( Photo courtesy of Tri-City Energy Biodiesel)

40. Biodiesel ….. It’s Time Has Come Gracias!