Characterization of Fuel and After-Treatment Device Effects on Diesel Emissions

Research Report 76,

Dr. Susan Bagley and colleagues at Michigan Technological University conducted a laboratory study to characterize the physical and chemical composition, and the mutagenicity of emissions from a heavy-duty 1988 diesel engine equipped with a ceramic particle trap. This engine was operated with low-sulfur fuel at a constant speed under two different load conditions. They also studied the effects of an oxidation catalytic converter on emissions from a heavy-duty 1991 diesel engine using a low-sulfur fuel. A unique aspect of this study was that the investigators determined the number and size of particles within the two typical classes of diesel particulate matter: the small, primary particles (nuclei mode) and the larger particle agglomerates (accumulation mode).