| Abstract
| - Particulate and gaseous exhaust emission phasesfrom running 10 diesel fuels on two makes of heavy-duty diesel engines were analyzed with respect to63 chemical descriptors. Measurements for one of thefuels were also made in the presence of an exhaustaftertreatment device. The variables included 28polycyclic aromatic compounds (PAC), regulated pollutants (CO, HC, NOx, particles), and 19 otherorganicand inorganic exhaust emission components. Principalcomponents analysis (PCA) was applied for thestatistical exploration of the obtained data. Inaddition,relationships between chemical (12 variables) andphysical (12 variables) parameters of the fuels to theexhaust emissions were derived using partial leastsquares (PLS) regression. Both PCA and PLS modelswere derived for the engine makes separately. ThePCA showed that the most descriptive exhaustemission factors from these diesel fuels includedfluoranthene as a representative of PAC, the regulatedpollutants, sulfates, methylated pyrenes, and monoaromatics. Exhaust emissions were significantlydecreased in the presence of an exhaust aftertreatmentdevice. Both engine makes exhibited similar patternsof exhaust emissions. Discrepancies were observedfor the exhaust emissions of CO2 andoil-derivedsoluble organic fractions, owing to differences in enginedesign. The PLS analysis showed a good correlationof exhaust emission of the regulated pollutants andPAC with the contents of PAC in the fuels and thefuel aromaticity. Also, the emission of solublesulfatewas directly related to the contents of sulfur in thefuels. In conclusion, the PCA clearly indicates thatemissions of PAC, particulates, and sulfates are themost descriptive exhaust emission factors. Theseexhaust emissions can, as shown from the PLSanalysis, be much reduced by a decrease of aromatics,PAC, and sulfur in the fuels.
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