The Effect of Biodiesel Fuels on Transient Emissions from Modern Diesel Engines, Part I Regulated Emissions and Performance 2000-01-1967

The use of biodiesel fuels derived from vegetable oils or animal fats as a substitute for conventional petroleum fuel in diesel engines has received increased attention. This interest is based on a number of properties of biodiesel including the fact that it is produced from a renewable resource, its biodegradability, and its potential beneficial effects on exhaust emissions. Transient exhaust emissions from three modern diesel engines were measured during this study, both with and without an oxidation catalyst. Emissions were characterized with neat biodiesel and with a blend of biodiesel and conventional diesel fuel. Regulated emissions and performance data are presented in this paper, while the results of a detailed chemical characterization of exhaust emissions are presented in a companion paper. The use of biodiesel resulted in lower emissions of unburned hydrocarbons, carbon monoxide, and particulate matter, with some increase in emissions of oxides of nitrogen on some engines. Biodiesel also appeared to enhance the ability of the catalytic converters to reduce particulate emissions. With its high oxygen content, neat biodiesel fuel generally resulted in a measurable loss of engine power and an increase in fuel consumption.