Influence of extended storage on fuel properties of methyl esters prepared from canola, palm, soybean, and sunflower oils

Authors: Moser, Bryan

Submitted to: Renewable Energy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2010
Publication Date: 1/1/2011
Citation: Moser, B.R. 2011. Influence of extended storage on fuel properties of methyl esters prepared from canola, palm, soybean, and sunflower oils. Renewable Energy. 36:1221-1226.

Interpretive Summary: This research reveals that the fuel properties of biodiesel change after extended storage. The objective of this study was to periodically measure important fuel properties of biodiesel such as oxidative stability over the course of one year. Understanding the oxidative stability of biodiesel is important, since one of its principle disadvantages versus petrodiesel is lower resistance to unwanted oxidative degradation. These results will be important to biodiesel producers, distributors and end-users (customers) because insight on the influence of extended storage on oxidative stability of biodiesel was determined. This research may ultimately improve market penetration, availability, and public perception of domestically produced agricultural fuels such as biodiesel, thus affording greater national independence from imported petroleum-based fuels.

Technical Abstract: Fatty acid methyl esters prepared from canola, palm, soybean, and sunflower oils by homogenous base-catalyzed methanolysis were stored for 12 months at three constant temperatures (-15, 22, and 40 deg C) and properties such as oxidative stability, acid value, kinematic viscosity, low temperature operability, and iodine value were periodically measured. Oxidative stability was significantly reduced upon extended storage and acid value as well as kinematic viscosity were increased by only small increments, with these effects more pronounced at elevated temperatures. Iodine value and low temperature operability were essentially unaffected by extended storage. Based on these findings, it is not recommended that acid value or kinematic viscosity be used as indicators of storage stability of biodiesel, nor is it recommended that iodine value be used as a predictor of oxidative stability or indicator of oxidative degradation.