Oxygenated fuels for clean heavy-duty diesel engines

Abstract: For diesel engines, changing the fuel composition is an alternative route towards achieving lower emission levels. The potential of oxygenated fuels to significantly reduce particulate matter emissions has already been demonstrated earlier. In this study, this research has been extrapolated towards lower emission levels. Exhaust gas recirculation (EGR) was applied to a modern EURO-3-type HD diesel engine. Tests were done at different engine working points, with EGR-levels and start of fuel delivery timings set to give NOx emissions between 3.5 and 2.0 g/kWh with regular diesel fuel. Fourteen blends of a low-sulphur diesel fuel respectively of a gas-to-liquid synthetic diesel fuel with different oxygenates were tested. The corresponding fuel matrix covers a range of fuel oxygen mass fractions up to 15%. Results are presented and the impact of fuel oxygen mass fraction and Cetane Number are analysed and compared with results from previous research.