Fuel Effects on Emissions from Heavy-Duty Diesel Engines – Results of Recent Research Programs 2001-24-0081

The main goal of the work presented here was to compile a review of the available literature on the effects of diesel fuel properties on emissions from heavy-duty diesel engines (HDDEs). Because of the large number of various studies that have been performed in this area, the present review is mainly based on the most comprehensive recent research programs: the European Programme on Emissions, Fuels and Engine Technologies (EPEFE), and the USA Programs EPA Heavy-Duty Engine Working Group (EPA-HDEWG) and Diesel Emission Control – Sulfur Effect (DECSE). Fuel properties that have been identified over the years as influencing emissions from HDDEs, and were considered in this work, are cetane number, density, aromatics (total and poly-), sulfur and oxygen contents and back-end distillation.

The impact of fuel sulfur content on emission control systems was reviewed, based mainly on the findings of the latest DECSE Program, which was concluded in 2000. These systems include diesel oxidation catalysts, lean-NO_x catalysts, NO_x adsorbers and diesel particulate filters (traps).

A comparison is presented between the regression models, developed in the framework of the EPEFE and EPA-HDEWG programs. Only limited data are available addressing oxygen effects on HDDE emissions. It is noted that there is still lack of data regarding the fuel effects on emissions of engines tested over the new European Transient Cycle.