The Impact of Ethanol Fuel Blends on PM Emissions from a Light-Duty GDI Vehicle

Abstract

This study explores the influence of ethanol on particulate matter (PM) emissions from gasoline direct injection (GDI) vehicles, a technology introduced to improve fuel economy and lower CO 2 emissions, but facing challenges to meet next-generation emissions standards. Because PM formation in GDI engines is sensitive to a number of operating parameters, two engine calibrations are examined to gauge the robustness of the results. As the ethanol level in gasoline increases from 0% to 20%, there is possibly a small (<20%) benefit in PM mass and particle number emissions, but this is within test variability. When the ethanol content increases to >30%, there is a statistically significant 30%-45% reduction in PM mass and number emissions observed for both engine calibrations. Particle size is unaffected by ethanol level. PM composition is primarily elemental carbon; the organic fraction increases from ∼5% for E0 to 15% for E45 fuel. Engine-out hydrocarbon and NO x emissions exhibit 10-20% decreases, consistent with oxygenated fuel additives. These results are discussed in the context of the changing commercial fuel and engine technology landscapes.

Particulate Matter and Gaseous Emission of Hydrous Ethanol Gasoline Blends Fuel in a Port Injection Gasoline Engine

“…When the engine is working at the same load, a significant reduction of the PN distribution of the particles can be observed for the ethanol blends equated to gasoline (HE0). The results here are consistent with the PN distribution results reported in previous publications [43][44][45][46][47][48][49]62]. There are many causes leading to a decrease of the PN in the ethanol blends; compared with gasoline fuel, hydrous ethanol and anhydrous ethanol have no aromatic content, a higher laminar flame propagation speed, and a higher percentage of oxygen content.…”

“…A number of researchers [43][44][45][46][47][48][49] have made a significant reduction in engine-out PM emissions from gasoline engines by using anhydrous ethanol. Price et al [43] reported that anhydrous ethanol blends E85 and E30 showed the lowest PM emissions, followed by methanol blends M85 and M30 for lean fuel-air mixtures.…”

Real-Time Black Carbon Emission Factor Measurements from Light Duty Vehicles

“…Interestingly, steady-state EFBC's for the SULEV GDI were substantially larger than for the other LEVs equipped with standard multi-port fuel injection, consistent with previous studies. 28 As expected, EFBC for the diesel vehicle, which was not equipped with a diesel particle filter, was substantially larger than the GDI, ULEV, and LEV vehicles.…”

Size distribution, chemical composition and oxidation reactivity of particulate matter from gasoline direct injection (GDI) engine fueled with ethanol-gasoline fuel

“…However, for GDI engines, the results are divergent [16e19]. For example, some researchers [16,17] have found that adding ethanol to gasoline reduces the GDI engine PM emission. The experiments conducted by Zhang et al [17] were at low speed and high load condition (2000 rpm, 210 Nm), it was found that the E10 and E20 fuels reduced PN emissions from GDI engine.…”