Internal combustion engines (ICEs) represent one of the largest sources of emissions leading to air pollution in the united states. Emissions from ICEs pose a large issue due to human health and environmental effects, but they can be controlled. This dissertation is an investigation into the pollutants emitted from ICEs for a range of applications and the usefulness of available emission control strategies different fuel sources. The range of ICEs includes small off-road diesel engines, light duty gasoline and diesel engines, heavy duty diesel and alternative fuel engines, and large marine engines. The control technologies included gasoline particulate filters (GPFs), selective catalytic reduction (SCR), and diesel particulate filters (DPFs), and the alternative fuels included hydrogenated vegetable oil (HVO), biodiesel HVO fuel blends, natural gas (NG), liquefied petroleum gas (LPG), diesel-electric hybrids, marine gas oil (MGO) and ultra-low sulfur heavy fuel oil (ULSHFO). As renewable fuel sources gain more attention for their ability to reduce the overall greenhouse gas impacts of ICEs, it is important to fully understand the emissions of new renewable fuel sources. This dissertation provides an investigation into the fuel impacts and engine impacts of a second-generation biofuel, HVO, and fuel blends of HVO and biodiesel in light duty and heavy-duty diesel engines. This dissertation also investigates the toxicity of pollutants from heavy duty diesel engines utilizing HVO and HVO biodiesel fuel blends.
Laboratory testing follows standardized and repeatable procedures that allow emissions of different models of vehicles to be compared to each other. In real-world driving however, there are many variables that can affect emissions which cannot be reproduced in a laboratory, so it is important to investigate and understand the emissions during real world driving. This dissertation provides an investigation into emissions formations of light duty gasoline direct injection (GDI) engines and heavy-duty vehicles during real world driving
Off-road engines represent one of the largest sources of PM and NOx in California and nationwide. This dissertation investigated large ocean-going vessels (OGVs) utilizing two fuels and the feasibility of applying new stringent standards to small off-road diesel engines (SORDEs). The results of the SORDE study suggest that it is now feasible to apply more stringent emissions controls for the SORDE category of mobile sources.