Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: February 20, 2003
Publication Date: May 20, 2003
Citation: KNOTHE, G.H. FUEL PROPERTIES AND THE STRUCTURE OF FATTY ESTERS. ANNUAL MEETING AND EXPO OF THE AMERICAN OIL CHEMISTS SOCIETY. 2003. Abstract p.81. Technical Abstract: Biodiesel fuel is being produced and used commercially in numerous countries around the world. To obtain biodiesel, the vegetable oil or animal fat is transesterified with an alcohol, usually methanol, to give the corresponding alkyl esters. The fatty acid profile of a biodiesel fuel is one of the major factors influencing its fuel properties. More specifically, structural features such as chain length and unsaturation of the fatty acids contained in the oil or fat from which the biodiesel fuel is derived are responsible for the fuel properties. The nature of the ester moiety can also influence fuel properties since alcohols other than methanol can be used in the transesterification reaction to give vegetable oil or animal fat alkyl esters. Among the most important fuel properties that are influenced by structural features of both moieties of fatty esters in biodiesel are cetane number, which relates to ignition quality and thus ultimately to exhaust emissions, cold flow, oxidative stability and viscosity. This work investigates and evaluates the influence of the various structural features on biodiesel fuel properties and suggests possible routes for improvement of those properties. An equation relating cetane number and ignition delay in an Ignition Quality Tester(TM) is presented. Viscosity data of various compounds found in petrodiesel and biodiesel fuels are compared.