Submitted to: Biomass and Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/28/2009
Publication Date: 3/22/2010
Citation: Moser, B.R., Vaughn, S.F. 2010. Coriander Seed Oil Methyl Esters as Biodiesel Fuel: Unique Fatty Acid Composition and Excellent Oxidative Stability. Biomass and Bioenergy. 34:550-558.
Interpretive Summary: This research reveals that coriander oil is acceptable as an alternative feedstock for biodiesel production. The objective of this study was to produce biodiesel from coriander oil and evaluate its fuel properties, taking into consideration important biodiesel fuel standards. Coriander biodiesel fuel was considerably more stable to unwanted oxidative degradation than soybean oil-based biodiesel. This result is significant because one of the technical disadvantages of biodiesel versus normal diesel fuel is poor oxidative stability. With coriander biodiesel, this disadvantage is eliminated without the need for antioxidant additives. 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.
Technical Abstract: Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid (FA) hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt %) acid. Most of the remaining FA profile consisted of 18 common carbon constituents such as linoleic (9Z,12Z-octadecadienoic; 13.0 wt %), oleic (9Z-octadecenoic; 7.6 wt %) and stearic (octadecanoic; 3.1 wt %) acids. A standard transesterification procedure with methanol and sodium methoxide catalyst was used to provide Coriandrum sativum oil methyl esters (CSME). Acid-catalyzed pretreatment was necessary beforehand to reduce the acid value (AV) of the oil from 2.66 to 0.47 mg KOH g-1. The derived cetane number, kinematic viscosity and oxidative stability (Rancimat method) of CSME was 53.3, 4.21 mm2 s-1 (40 deg C) and 14.6 h (110 deg C). The cold filter plugging and pour points were -15 deg C and -19 deg C, respectively. Other properties such as AV, free and total glycerol content, iodine value (IV), as well as sulfur and phosphorous contents were acceptable according to the biodiesel standards ASTM D6751 and EN 14214. Also reported are lubricity, heat of combustion, and Gardner color, along with a comparison of CSME to soybean oil methyl esters (SME). CSME exhibited higher oxidative stability, superior low temperature properties and lower IV than SME. In summary, CSME has excellent fuel properties as a result of its unique FA composition.