Effects of fuel properties on exhaust emissions from diesel engines

Exhaust emissions from a vehicle diesel engine with different property fuels were studied, and the emissions include exhaust smoke, particulate matter (PM), nitrogen oxide (NO_x), unburned hydrocarbon (HC), carbon monoxide (CO) and sulfur dioxide (SO₂). Engine bench test and simulated New European Driving Cycle (NEDC) test cycle were operated on the engine with five kinds of fuel, and the fuels have different sulfur content, aromatic content and cetane number. The results show that exhaust smoke, HC, CO and SO₂ emissions decrease with fuel sulfur content decreasing, and the PM emission under the simulated NEDC test cycle decreases remarkably, while NO_x emissions was not affected obviously. With fuel aromatic content decreasing, emissions including exhaust smoke, PM, NO_x, HC and CO descend distinctly. With cetane number ascending, the exhaust smoke, PM and HC emissions decline evidently, while NO_x and CO emissions have very small changes.