Impact of Ethanol and Aromatic Hydrocarbons Content on Particulate Emissions from a Gasoline Vehicle 2019-24-0160
The impact of transport on global and local pollution have resulted in stricter emission limits. More specifically, increasing attention is being paid to particulate emissions at the exhaust gases in spark ignition engines. The particulate formation is mainly affected by: 1-fuel properties, 2-engine and fuel system characteristics and 3-Exhaust after-treatment system.
In order to estimate the influence of fuel characteristics on particulate emissions, several research works have proposed fuel indices that correlate some of the fuel physical and chemical properties with engine particulate emissions.
This work investigates the impact of fuel composition on particulate emissions and evaluates the Particulate Matter Index (PMI) proposed by Aikawa et. al, and other fuel indices, in terms of agreement with vehicle test bed results for a passenger car.
Vehicle tests were performed on New European Driving Cycle (NEDC) and Worldwide Harmonized Light Vehicles Test Cycle (WLTC) by using an E10 euro6 reference fuel and five different fuel blends with 10% to 20% of ethanol and 23% to 35% of aromatic hydrocarbons content by volume.
Results illustrate a good correlation between particulate emissions and aromatic hydrocarbons content, but little or no sensitivity of particulate emissions to ethanol content in the fuels.
The comparison of the fuel particulate matter indices and vehicle results revealed different sensitivities but good overall agreement, for all fuel blends. PMI, Simplified index 1 and 2 (sPMI 1, sPMI2) were found to represent well the effect of aromatics while the ethanol influence wasn’t captured by any fuel index. The effect of aromatic hydrocarbons composition on particulate emissions is also investigated by considering the same amount of global aromatic hydrocarbons but different aromatic composition: heavy aromatic hydrocarbons (C11)- and light aromatic hydrocarbons (C7-C9). It was found that particulate emissions show a high sensitivity to heavy aromatic hydrocarbons content.
These results highlight the importance of fuel quality and more specifically the role of heavy aromatic hydrocarbons for the reduction of particulate emissions.
Toni Tahtouh, Arij Ben Amara, Patricia Anselmi, Laurie Starck
IFP Energies Nouvelles, France
14th International Conference on Engines & Vehicles