VEGETABLE OIL-BASED FUELS, ADDITIVES AND COPRODUCTS
Location: Bio-oils Research Unit
Title: Preparation of fatty acid methyl esters from Osage orange (Maclura pomifera) oil and evaluation as biodiesel
Submitted to: Energy and Fuels
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 17, 2011
Publication Date: March 17, 2011
Citation: Moser, B.R., Eller, F.J., Tisserat, B., Gravett, A. 2011. Preparation of fatty acid methyl esters from Osage orange (Maclura pomifera) oil and evaluation as biodiesel. Energy and Fuels. 25:1869-1877.
Interpretive Summary: This research reveals that Osage orange oil is acceptable as an alternative feedstock for biodiesel production. The objective of this study was to produce biodiesel from Osage orange oil and evaluate its fuel properties, taking into consideration important biodiesel fuel standards. Osage orange biodiesel was also blended with petroleum diesel. Overall, the fuel properties of Osage orange biodiesel and its blends with petrodiesel were comparable to that of soybean-based biodiesel and its blends, thus indicating the acceptability of Osage orange-based biodiesel. These results will be important to biodiesel producers, distributors and end-users (customers) because a new biodiesel fuel was described that exhibits favorable fuel properties. 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.
Fatty acid methyl esters were prepared in high yield by transesterification of Osage orange (Maclura pomifera) oil. Extracted using supercritical CO2, the crude oil was initially treated with mineral acid and methanol to lower its content of free fatty acids, thus rendering it amenable to homogeneous, alkali-catalyzed methanolysis. The principle component identified in Osage orange methyl esters (OOME) was methyl linoleate at 76.4%, with methyl esters of oleic (11.9%), palmitic (7.0%) and stearic (2.4%) acids comprising most of the remaining content. As a result of the high content of methyl linoleate, OOME exhibited cetane number (44.9) and induction period (IP; 2.4 h) values below the ranges specified in the biodiesel standards ASTM D6751 and EN 14214. Addition of 500 ppm tert-butylhydroquinone (TBHQ) resulted in a higher IP (6.4 h) compliant with the biodiesel standards. Furthermore, the high content of methyl linoleate resulted in an iodine value (IV; 144 g I2/100 g) in excess of the maximum limit specified in EN 14214. The acid value (AV), glycerol content, kinematic viscosity, moisture content, phosphorous content, and sulfur content of OOME were within the limits prescribed in ASTM D6751 and EN 14214. In addition, data collected for density, lubricity and energy content was typical for biodiesel fuels. The cold flow properties of OOME were superior to those reported for several other biodiesel fuels. Also investigated were B5 and B20 blends of OOME in petrodiesel, which yielded AVs, kinematic viscosities, moisture contents, sulfur contents, lubricities, and densities within the limits prescribed in the petrodiesel standards. Addition of 500 ppm TBHQ to the blends resulted in IPs above the minimum thresholds specified in ASTM D7467 and EN 590. In summary, Osage orange appears to be a low-cost, non-food, high oil-producing feedstock suitable for production of biodiesel.