Overview of Diesel Emission Control-Sulfur Effects Program 2000-01-1879

This paper describes the results of Phase 1 of the Diesel Emission Control - Sulfur Effects (DECSE) Program. The objective of the program is to determine the impact of fuel sulfur levels on emissions control systems that could be used to lower emissions of nitrogen oxides (NO_x) and particulate matter (PM) from vehicles with diesel engines. The DECSE program has now issued four interim reports for its first phase, with conclusions about the effect of diesel sulfur level on PM and total hydrocarbon (THC) emissions from the high-temperature lean-NO_x catalyst, the increase of engine-out sulfate emissions with higher sulfur fuel levels, the effect of sulfur content on NO_x adsorber conversion efficiencies, and the effect of fuel sulfur content on diesel oxidation catalysts, causing increased PM emissions above engine-out emissions under certain operating conditions. The fourth Phase 1 report covers the effect of diesel sulfur level on a catalyzed diesel particulate filter (CDPF) and a continuously regenerating diesel particulate filter (CR-DPF).