An old single cylinder Petter AA1 and a new four cylinder Ford 1.61 engines were operated over a wide range of steady state conditions using kerosene and diesel fuels. The two engines exhibited different trends in forming the particulate emissions. For both fuels the particulate emissions were dominated by the carbon for the old engine, and by the SOF for the new engine where the latter was characterized by its low level of emissions. The engine operating conditions also influenced the emissions of the different particulate fractions. Generally, the old engine had higher unburnt lube oil emissions as well as high survival of diesel n-alkanes and PAH in the emissions. However, in the case of kerosene and the new engine when operated both with kerosene and diesel fuel, the pyrosynthesis of these compounds was evident. Sulphates in the particulates, which originated mainly in the fuel, were shown to incorporate low levels of background from the engine deposits and the lubricating oil.
DIESEL PARTICULATE EMISSIONS are function of many factors; including engine design, fuel properties and engine operating conditions. It is difficult to assign any of the fuel physical or chemical properties as the only factor that could be responsible for the formation of the particulate or gaseous emissions, since they are all inter-correlated. However, it has been shown that the fuel sulphur (1, 2, 3, 4) and the fuel PAH (5, 6, 7) has a direct influence on the emissions through the recurrence of these fuel components in the particulate emissions. Engine operating modes also play a significant role in generating gaseous and particulate emissions in diesel engine combustion (1, 2, 8).
In the present work two IDI engines were operated using diesel fuel no.2 and kerosene, and the particulates generated at different engine operating conditions were characterized.