Abstract
The experimental results presented in the paper were obtained within a research program investigating the effect of different oxygenated fuels on exhaust emissions from diesel passenger cars. The objective of this study was to select the most promising oxygenate compounds as blending components in diesel fuel for further practical application. There were 11 different oxygenates tested at a concentration of 5% v/v. The oxygenates represented 3 chemical groups: maleates, carbonates and glycol ethers. The test were conducted on a Euro 4 passenger car equipped with a direct injection Common Rail turbocharged diesel engine, representing the latest technology in production at the start of the research program. The New European Driving Cycle (NEDC) was selected as a representative test for this study. The tests proved that oxygenated diesel fuels have a significant influence on exhaust emissions. First and foremost oxygenated compounds reduced PM emissions effectively, far more effectively than their percentage concentration in fuel. The more oxygen fuel contained the higher the reduction in PM emissions was observed, in principle regardless of the oxygenate type. CO and HC emissions were also reduced in case of some oxygenated fuels. Oxygenated fuels produced, in general, a little increase in NOx emissions, however the increase was always lower than 10%, and significantly lower than reduction in PM emissions. Oxygenated fuels had no significant influence on CO2 emissions.
Keywords: Exhaust emissions, Diesel engines, Diesel fuels, Oxygenated fuels