Detailed Chemical Kinetic Modeling of Diesel Combustion with Oxygenated Fuels

The influence of the addition of oxygenated hydrocarbons to diesel fuels has been studied, using a detailed chemical kinetic model. Resulting changes in ignition and soot precursor production have been examined. N-heptane was used as a representative diesel fuel, and methanol, ethanol, dimethyl ether, dimethoxymethane and methyl butanoate were used as oxygenated fuel additives. It was found that addition of oxygenated hydrocarbons reduced the production of soot precursors. When the overall oxygen content in the fuel reached approximately 30-40 % by mass, production of soot precursors fell effectively to zero, in agreement with experimental studies. The kinetic factors responsible for these observations are discussed.