Article pubs.acs.org/EF
Quantitation of Aging Products Formed in Biodiesel during the Rancimat Accelerated Oxidation Test Stephanie Flitsch,† Philipp Marco Neu,† Sigurd Schober,† Norbert Kienzl,‡ Jörg Ullmann,§ and Martin Mittelbach*,† †
Institute of Chemistry, NAWI Graz, University of Graz, Heinrichstraße 28, 8010 Graz, Austria BIOENERGY 2020+ GmbH, Inffeldgasse 21b, 8010 Graz, Austria § Robert Bosch GmbH, Postfach 30 02 20, 70442 Stuttgart, Germany ‡
ABSTRACT: Biodiesel (rapeseed oil methyl ester) was aged in a Rancimat device at a temperature of 110 °C and an air flow of 10 L/h. Time-resolved analyses applying gas chromatography−flame ionization detection, gas chromatography−mass spectrometry, and ion-exchange chromatography on the formation of aging products were performed. Formic and acetic acid, fatty acids with chain lengths from 5 to 18 carbon atoms, fatty acid methyl esters, and epoxides were quantified. After 12 h of aging, the concentrations of formic and acetic acid were 5600 ± 80 and 1360 ± 80 mg/kg, respectively. Fatty acid concentrations were in the range of
