Location: Bio-oils ResearchTitle: Synthesis and analysis of an alkenone-free biodiesel from Isochrysis sp.) Author
|Knothe, Gerhard - Gary|
Submitted to: Energy and Fuels
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/13/2014
Publication Date: 4/24/2014
Citation: O'Neil, G.W., Knothe, G.H., Williams, J.R., Burlow, N.P., Culler, A.R., Corliss, J.M., Carmichael, C.A., Reddy, C.M. 2014. Synthesis and analysis of an alkenone-free biodiesel from Isochrysis sp. Energy and Fuels. 28(4):2677-2683. Interpretive Summary: Biodiesel is a renewable alternative to diesel fuel obtained from petroleum. Besides feesdstocks such as vegetable oils, (for example soybean, sunflower, rapeseed or palm oils), animal fats and used cooking oils, algae have become a biodiesel source of interest. As a result of problems associated with growth and harvesting of algae, very little biodiesel has been produced from algal feedstock with the amounts not even sufficing for experimental cetane number determination. In this work, however, the first experimental fuel properties of an algal biodiesel are reported. The species of algae from which the biodiesel was derived is termed Isochrysis. The high amounts of components specific to biodiesel from this kind of algae entail some differences in properties compared to biodiesel from other feedstocks. Overall, this work is unique in presenting the first experimental fuel property determination of algal biodiesel and is important for providing future direction for research and development in this area.
Technical Abstract: Some marine microalgae, such as Isochrysis sp., produce high-melting (~70 ºC) lipids known as long-chain alkenones that detrimentally affect biodiesel fuel quality. A method has been developed for the production of an alkenone-free Isochrysis biodiesel. This material was prepared on sufficient scale to allow for extensive analysis according to ASTM standards. Results revealed that while cold flow improved by removal of these high-melting components and lubricity along with glycerol content were below maximum levels prescribed in the standards, other properties dependent on fatty acid methyl ester (FAME) structure and composition such as oxidative stability failed to meet ASTM specifications. Both the cetane number and kinematic viscosity were lower than what would be calculated based on FAME content. This has been explained in part by 6-8% non-FAME contaminants in the tested samples.