The Effect of the Diesel Cetane Number on Exhaust Emissions Characteristics by Various Additives

This paper described the effect of the diesel cetane number on exhaust emissions characteristics according to various additives. In addition, the emission characteristics of test fuels blended with three additives (GTL, biodiesel and additive for improving CN) were analyzed and the potential for uses of these additives were evaluated in this study. To achieve this purpose, the test diesel vehicle with a two-thousand cubic centimeter displacement was used to analyze the emission characteristics according to the CN. Also, the NEDC (New European Driving Cycle) was applied as the test mode which is widely used as the test method for environmental certification of diesel vehicles. To analyze the characteristics of HAPs, the VOCs and PAHs were analyzed from the BTEX and the particulate matter, respectively. The analysis results revealed that the CO emissions show the largest reduction rate while the NOx+THC emissions are reduced at a low as the CN got higher. In the NEDC mode, the PM emissions in the EUDC mode were found to be at a lower level than those in the UDC mode. As for the VOCs and PAHs characteristics, the VOCs of the CN 58 show the lowest amounts. Also, the PAHs of diesel blended with GTL show the highest level, followed by those of diesel blended with biodiesel and diesel blended with cetane additive.