Title: NOx emissions of biodiesel as an alternative diesel fuel

Authors: M. Canakci

Addresses: Department of Mechanical Education, Kocaeli University, 41380 Kocaeli, Turkey; Alternative Fuels R&D Center, Kocaeli University, 41040 Kocaeli, Turkey

Abstract: As an environmental friendly alternative fuel for compression-ignition (diesel) engines, fatty acid alkyl monoesters, commonly known as biodiesel, are produced from renewable feedstocks such as vegetable oils and animal fats. Without engine modification, when a diesel engine is fuelled with biodiesel, it provides significant reductions in particulate matter, carbon monoxide and unburned hydrocarbons compared with petroleum-based diesel fuel. In contrast to these reductions, many studies show that the use of biodiesel increases NOx emissions, while only a few papers have reported no changes or reduction in NOx emissions. Various arguments have been used in the literature to explain the increase in NOx emissions when biodiesel is used. This study discusses the combustion characteristics of biodiesel and its fuel properties which are effective in the NOx formation.

Keywords: biodiesel; combustion characteristics; fuel properties; NOx emissions; nitrogen oxide; alternative fuels; compression-ignition engines; diesel engines; biofuels; particulate matter; carbon monoxide; unburned hydrocarbon.

DOI: 10.1504/IJVD.2009.024975

International Journal of Vehicle Design, 2009 Vol.50 No.1/2/3/4, pp.213 - 228

Published online: 06 May 2009 *

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