Biomass & Bioenergy, Vol.37, 31-41, 2012
Efficacy of fatty acid profile as a tool for screening feedstocks for biodiesel production
Fuel properties are largely dependent on the fatty acid (FA) composition of the feedstock from which biodiesel is prepared. Consequently, FA profile was employed as a screening tool for selection of feedstocks high in monounsaturated FAs for further evaluation as biodiesel. Those feedstocks included ailanthus (Ailanthus altissima L.), anise (Pimpinella anisum L.), arugula (Eruca vesicaria L.), cress (Lepidium sativum L.), cumin (Cuminum cyminum L.), Indian cress (Tropaeolum majus L.), shepherd's purse (Capsella bursa-pastoris L.) and upland cress (Barbarea verna (Mill.) Asch.). Other selection criteria included saturated FA content, iodine value (IV), content of FAs containing twenty or more carbons and content of trienoic FAs. Anise oil satisfied all selection criteria and was therefore selected for further investigation. Arugula, cumin and upland cress oils were selected as antagonists to the selection criteria. Preparation of FA methyl esters (FAMES, >= 92 wt % yield) following conventional alkaline-catalyzed methanolysis preceded fuel property determination. Of particular interest were oxidative stability and cold flow properties. Also measured were kinematic viscosity (40 C), IV, acid value, free and total glycerol content, sulfur and phosphorous content, cetane number, energy content and lubricity. FAMEs prepared from anise oil yielded properties compliant with biodiesel standards ASTM D6751 and EN 14214 whereas the antagonists failed at least one specification contained within the standards. As a result, FA profile was an efficient predictor of compliance with biodiesel standards and is therefore recommended as a screening tool for investigation of alternative feedstocks. Published by Elsevier Ltd.