The Influence of Oxygenated Diesel Fuels on a Diesel Vehicle PM/NO _x Emission Trade-Off 2009-01-2696

Research on the influence of oxygenated diesel fuels on the PM/NO_x emission trade-off was carried out with use of 11 different synthetic oxygenated compounds, representing 3 chemical groups (glycol ethers, maleates, carbonates). Each of oxygenates were evaluated as a fuel additive at a concentration of 5% v/v in the same base diesel fuel. The tests were conducted on a passenger car equipped with a common rail turbocharged diesel engine over the European cycle NEDC and US FTP-75 cycle. All the tested oxygenates caused a reduction in PM emissions and most of them caused a certain increase in NO_x emissions. The changes in emissions depended on the oxygenate type and cycle. In general, the favorable and unfavorable influence of oxygenated compounds was more intensive during the NEDC, which is a softer and less transient cycle than the FTP-75. The most favorable changes in the PM/NO_x emission trade-off were obtained for maleates and carbonates. Diethyl maleate, dimethyl carbonate and diethyl carbonate have been selected as the most promising oxygenate compounds as blending components in diesel fuel for further advanced testing and possible practical application.