Impact of gasoline composition on particulate matter emissions from a direct-injection gasoline engine: Applicability of the particulate matter index

Abstract

The new fuel property “particulate matter (PM) index” suggested by Aikawa et al. in their previous report, which reflects particulate matter emission potential of gasoline, has been shown to have a significant correlation with PM in port fuel injection engine. However, the particulate matter index applicability to direct-injection gasoline engines has not been well verified. The purpose of this study is to confirm the particulate matter index applicability to direct-injection gasoline engines. Results verified good correlation between particulate matter index and particulate matter emissions of a direct-injection gasoline engine, just as with the port fuel injection engine. The verification of particulate number emissions of the direct-injection gasoline engine on the US FTP-75 cycle indicated a high correlation with the particulate matter index. In particular, a significantly high correlation (R2 = 0.9644) was observed in the FTP-75 cold-start phase (Phase 1) in which the fuel influences are considered most evident. The filter PM (PM mass) was simultaneously measured, and its correlation with PM index was verified. The correlation with PM mass was slightly lower than with particulate number, but it also had a good correlation with PM index. This indicated that the PM index will apply well to DI gasoline engines.

A Review of Particulate Number (PN) Emissions from Gasoline Direct Injection (GDI) Engines and Their Control Techniques

“…There is a strong link between PM emissions from GDI engines and the composition and properties of the gasoline. These effects are in general dominated by the aromatic content of the fuel, but other fuel components and properties notably olefin content, oxygenate content, sulphur content, fuel volatility, enthalpy of vaporization and boiling points of individual components have significant effects on PM emissions [1,69,84,85,[115][116][117][118][119][120][121][122][123][124][125][126][127].…”

“…Fuel volatility has a noticeable impact on PN emissions, [119][120][121]128] as a fuel with a lower vapour pressure will be slower to evaporate on injection, and produce a less well prepared mixture leading to higher PN emissions. In extreme cases, fuel with very low volatility will impact on the piston or walls and burn as a pool fire, leading to a significant increase in PN emissions.…”

“…Numerous attempts have been made to link fuel composition and particulate emissions [119][120][121][122]125,126]. All of these indices take a similar form generally linking some measure of aromatic content and vapour pressure, and have shown that there is an excellent correlation between fuel composition and PN emissions, although the detail depends on the parameters used, and the details of the engine and operating point.…”

Recent progress in particle matter emissions and control strategies of gasoline direct injection engines

“…(a) 微粒数目与喷射时刻的关系; (b) 微粒浓度-粒径分布规律 Figure 2 (Color online) Effect of fuel injection timing on PM emissions [16] . (a) PN as a function of SOI; (b) particle size spectra for different SOI [18] . (a) PFI汽油机; (b) GDI汽油机…”

Effects of the Particulate Matter Index and Particulate Evaluation Index of the Primary Reference Fuel on Particulate Emissions from Gasoline Direct Injection Vehicles

“…where Wt is the weight fraction of an identified constituent molecule within a fuel sample, DBE is double bond equivalence and achieved by detailed hydrocarbon analysis (DHA) from American society for testing and materials (ASTM) standard D6729, n is the total number of compounds in the fuel, and V.P (443 K) is the vapor pressure at 443 K. The significant paper took into account V.P at 443 K of the gasoline range and DBE of all compounds in gasoline. The result was obtained by the DHA method [14][15][16]. PEI was developed by Chapman et al from General Motors and has an excellent correlation R 2 = 0.93 with PMI, which focuses more on just aromatics instead of the whole spectrum of molecules [17].…”