UC Riverside

This dissertation provides investigation and evaluation of different types of renewable and alternative fuels impact on reducing emissions of critical pollutants on light-duty vehicles and heavy-duty and off-road equipment and marine related emissions. It is important to understand fuel impact on emissions characteristics and marine related emissions to be able to facilitate policy making. This dissertation assessed the potential of increasing ethanol content in California reformulated gasoline (CaRFG) by investigating the exhaust emissions from a fleet of 20 light-duty vehicles. A baseline CaRFG E10 (10% ethanol by volume) fuel was splash blended with denatured ethanol to create a E15 fuel. Each vehicle/fuel combination were exercised over triplicate Federal Test Procedure (FTP) cycles on a chassis dynamometer. Emissions measurement included nitrogen oxides (NOx), total hydrocarbons (THC), non-methane hydrocarbons (NMHC), carbon monoxide (CO), particulate matter (PM) and solid particle number (SPN), greenhouse gases (GHG) and volatile organic compounds (VOCs). Life cycle GHG emissions and ozone forming potential analysis were also performed. The dissertation also discussed gaseous and particulate emissions from natural gas and diesel-powered yard tractors tested on different driving cycles, some being representative of typical yard tractor operation. The natural gas yard tractors were operated with fuel blends of varying compositions, including a renewable natural gas (RNG) fuel. Emissions measurement included NOx, THC, CO, PM, SPN, GHG. Life cycle GHG emissions analysis was performed. This thesis also quantified emissions and performance effects, using an engine dynamometer, with RD fuel and RD/BD fuel blend relative to a petroleum-derived conventional ultra-low sulfur diesel (conventional CARB ULSD) reference fuel. This study was conducted using an agricultural engine without selective catalytic reduction (SCR) exhaust treatment and without a diesel particulate filter (DPF). The emissions measured included NOx, THC, CO, GHG, as well as particulate emissions and fuel economy. Overall, we have seen reductions in NOx, THC, CO, GHG and particulate emissions for RD and RD/BD with a slight increase for fuel economy for RD and RD/BD compared with ULSD. Marine vessels, including ocean going vessels (OGVs) and commercial harbor crafts (CHCs), contribute significantly to air pollution in California, especially nearby and downwind from seaports. One of the major pollutants in OGVs and CHCs exhaust are PM with an aerodynamic diameter less than 2.5 µm (PM2.5). NOx is also of particular concern as it will lead to the formation of ground level ozone. Nearer shore, Federal and California regulations is determined to reduce the emissions impact of ships and CHCs. In order to better understand marine related emissions, this thesis discussed barge-based capture and control systems (CCS) as an option to meet the requirement of this regulation and mitigate the harmful pollutants from OGVs. Moreover, emissions measurement for Tier 2, Tier 3 and Tier 4 CHCs were also performed focused on NOx, CO and CO2 emissions to understand the effectiveness of SCR system in Tier 4 CHCs.