Combustion and Emissions Performance of Low Sulfur, Ultra Low Sulfur and Biodiesel Blends in a DI Diesel Engine

Experiments were conducted with a commercially available six-cylinder, 4-valves per cylinder, turbocharged, direct injection (DI) diesel engine. The engine was operated with low sulfur diesel fuel, ultra low sulfur diesel fuel and two other blends, low sulfur diesel fuel with 20 wt.% biodiesel and ultra low sulfur diesel fuel with 20 wt.% biodiesel, to investigate the effect of the base fuels and their blends on combustion and emissions. Combustion analysis, particulate matter emissions and exhaust gas composition (CO, NO_X and total hydrocarbons) were determined at eight steady-state operating conditions according to the AVL 8-Mode test protocol. Combustion analysis showed at high load conditions a retarded start of injection, an earlier start of combustion and a lower premixed burn peak with ultra low sulfur diesel fuel. Mode averaged NO_X emissions decreased with ultra low sulfur diesel fuel and biodiesel blends compared to low sulfur diesel fuel. A 20% PM reduction was observed with ultra low sulfur (15 PPM) diesel fuel compared to low sulfur (325 PPM) diesel fuel.