Characteristics of ultrafine particle from a compressionignition engine fueled with low sulfur diesel

Number size distributions (NSDs, 10―487 nm) and composition of nanoparticle emitted from an engine fueled with ordinary diesel (OD) and low sulfur diesel (LSD) fuel were comparatively studied. The results indicate that, compared with the OD, the LSD was found to slightly decrease the mass concentration, and significantly reduce the number concentration of the total particles (10―487 nm), and the reduction of number increased with the speed and load of engine. The NSD for the two fuels showed a similar bimodal structure under all test engine conditions. Under the same engine conditions, the nucleation mode for LSD fuel was significantly lower than that of ordinary diesel. However, the accumulation mode for the two fuels showed little difference. The elements composition of exhaust particles included C, O, Cl, S, Si, Ca, Na, Al and K. The S element was not detected in LSD fuel case. The main component of soluble organic fraction (SOF) of exhaust particles for the two fuels included saturated alkane (C15―C26), ester and polycyclic aromatic hydrocarbons (PAHs). However, PAHs were not found in LSD fuel case.