Multivariate Analysis of Exhaust Emissions from Heavy-Duty Diesel Fuels

Abstract

Particulate and gaseous exhaust emission phases from running 10 diesel fuels on two makes of heavyduty diesel engines were analyzed with respect to 63 chemical descriptors. Measurements for one of the fuels were also made in the presence of an exhaust aftertreatment device. The variables included 28 polycyclic aromatic compounds (PAC), regulated pollutants (CO, HC, NO x , particles), and 19 other organic and inorganic exhaust emission components. Principal components analysis (PCA) was applied for the statistical exploration of the obtained data. In addition, relationships between chemical (12 variables) and physical (12 variables) parameters of the fuels to the exhaust emissions were derived using partial least squares (PLS) regression. Both PCA and PLS models were derived for the engine makes separately. The PCA showed that the most descriptive exhaust emission factors from these diesel fuels included fluoranthene as a representative of PAC, the regulated pollutants, sulfates, methylated pyrenes, and monoaromatics. Exhaust emissions were significantly decreased in the presence of an exhaust aftertreatment device. Both engine makes exhibited similar patterns of exhaust emissions. Discrepancies were observed for the exhaust emissions of CO 2 and oil-derived soluble organic fractions, owing to differences in engine design. The PLS analysis showed a good correlation of exhaust emission of the regulated pollutants and PAC with the contents of PAC in the fuels and the fuel aromaticity. Also, the emission of soluble sulfate was directly related to the contents of sulfur in the fuels. In conclusion, the PCA clearly indicates that emissions of PAC, particulates, and sulfates are the most descriptive exhaust emission factors. These exhaust emissions can, as shown from the PLS analysis, be much reduced by a decrease of aromatics, PAC, and sulfur in the fuels.

Source identification of polycyclic aromatic hydrocarbons in sediments of a creek around a flow station

“…Various methods are being applied in source identification and apportionment of PAHs. These include emission inventory modelling approaches, multivariate statistical methods and the use of diagnostic ratios (DRs) of selected PAHs (Li and Kamens 1993;Westerholm and Li 1994;Sjogren et al 1996;Wang et al 1999;Dvorska et al 2011). Source identification using DRs holds advantages due to the ease of application (Yunker et al 2002;Morillo et al 2008;Wang et al 2010;Dvorska et al 2011) and unlike inventory modelling approaches; DRs do not rely on emissions inventories which may not be available in most countries especially developing countries.…”

Urban rivers as conveyors of hydrocarbons to sediments of estuarine areas: Source characterization, flow rates and mass accumulation

“…Retene originates from soft woods (i.e. conifers) (Fine, 2001;Simoneit, 2002) but it has also been observed as a product from diesel combustion (Sjögren et al, 1996). The ratio Re/(Re + Ch) has been proposed by Yan et al (2005) to distinguish the different sources of Re.…”

Sources of Polycyclic Aromatic Hydrocarbons in an Environment Urbanised by Crude Oil Exploration

“…These include: emission inventory modelling approaches, multivariate statistical methods and the use of diagnostic ratios(DRs) of selected PAHs as reported by Dvorska et al (2011);Wang et al (1999); Sjogren et al (1996); Westerholm and Li, (1994). Applying DRs for PAHs sources prediction holds advantages due to the ease of application (Dvorska et al, 2011;Morillo et al, 2008;Yunker et al, 2002;Wang et al, 2010) and unlike inventory modelling approaches, DRs do not rely on emissions inventories which may not be available in most countries especially developing countries.…”