Effects of Biodiesel, Biodiesel Blends, and a Synthetic Diesel on Emissions from Light Heavy-Duty Diesel Vehicles

Abstract

Over the past several years, there has been increased interest in reformulated and alternative diesel fuels to control emissions and provide energy independence. In the following study, a California diesel fuel was compared with neat biodiesel, an 80% California diesel/20% biodiesel blend, and a synthetic diesel fuel to examine the effects on emissions. Chassis dynamometer tests were performed on four light heavy-duty diesel trucks using each of the four fuels. The results of this study showed that biodiesel, the biodiesel blends, and the synthetic diesel produced generally lower THC and CO emissions than California diesel. NO x emissions were comparable over most of the fuel/vehicle combinations, with slightly higher NO x emissions found for the two noncatalyst vehicles on 100% biodiesel. Particulate emissions were slightly higher for two test vehicles and significantly higher for a third test vehicle on the biodiesel fuels. Chemical analyses showed elemental and organic carbon to be the primary constituents of the diesel particulate, accounting for 73−80% of the total mass for the four vehicles. Neat biodiesel had the highest organic carbon fractions for each of the test vehicles. PAH emissions for all fuel combinations were relatively low, probably due to the low fuel PAH levels.

Effects of Biodiesel Blends and Arco EC-Diesel on Emissions from Light Heavy-Duty Diesel Vehicles

“…This is consistent with the results of our previous study on light heavy-duty diesel vehicles that showed a tendency for higher PM emissions with the soy-based biodiesel blends (8).…”

“…This work is a follow-up of CE-CERT's previous biodiesel project (8) and also provides ties to CE-CERTs on-going work in testing Hertz equipment rental trucks as part of the ARCO EC-D demonstration program (9).…”

“…For this work, a comparison was made between CARB diesel, a 100% biodiesel, an 80/20 (CARB/biodiesel) blend and a synthetic diesel for emissions performance (8). Chassis dynamometer tests were performed on four light heavy-duty diesel vehicles using each of the four fuels.…”

In-Use Measurement of Activity, Energy Use, and Emissions of a Plug-in Hybrid Electric Vehicle

“…If errors were identified, they were either corrected or the affected data were not used for data analysis. The procedure includes identifying and correcting problems associated with the ECU data, such as missing or invalid values of manifold absolute pressure (MAP), engine RPM, and intake air temperature (IAT) and associated with the gas analyzers of the PEMS, such as large discrepancies in simultaneous exhaust gas concentration measurements for a given pollutant when comparing the two gas analyzers, "freezing" of the analyzers (failure to update data), occurrence of negative values of emissions that are statistically significantly different from zero, 11 and air leakage into the sampling system based on assessment of the observed air-to-fuel ratio. The latter tends to occur in episodic transient situations when the engine shuts down or turns on during vehicle operation, during which there may be residual infiltrated air in the tailpipe.…”

“…1 The heating value of gasoline is approximately 125,000 BTU/gallon, and its density is 2,790 g/gallon. 11 Thus, each kWh of electricity obtained from the grid corresponds to the potential energy contained in 226 grams of gasoline. On this basis, a gasoline-equivalent fuel economy can be estimated even when the vehicle is operating in part on electricity stored in the plug-in battery from the electrical grid.…”