There are two basic methods of igniting fuel in an internal combustion engine (ICE):  diesel cycle and spark-ignited (SI) or Otto cycle.  In a diesel engine, the fuel/air mixture is compressed until it reaches the ignition point while the combustion of the fuel in a SI engine is initiated by an electric arc.  The diesel cycle is leaner combustion while SI combustion is typically closer to stoichiometric.  The fuel composition used in these two combustion platforms is also very different.  Diesel fuel is comprised of a higher molecular weight species cut from the crude oil barrel than the Otto cycle fuel (gasoline), and the fuel typically contains between 10 and 35 percent aromatics and less than 2 percent olefins with the balance of paraffins.  Gasoline fuel typically contains less than 35 percent aromatics and about 10 percent olefins with the balance of paraffins, and the fuel is a lower molecular weight cut from the barrel.  While the method of initiating combustion is different, both ICE platforms produce particles which are comprised of solid carbonaceous particles, fuel and lubricating oil (both partially burned and unburned), sulfate, and ash.  This paper compares the differences in particle size, particle number, and mass between diesel and Otto cycle based modern ICE.<br/><br/>

Comparison of particulate from diesel and spark-ignited engines

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.