Particulate Emission Characteristics of a Compression Ignition Engine Fueled with Diesel-DMC Blends

The effect of fuel composition on the combustion characteristics and particulate emissions of a compression-ignition engine fueled with Euro V diesel fuel blended with dimethyl carbonate (DMC) was investigated experimentally. Blended fuels containing 4.48%, 9.07%, 13.78%, and 18.6% by volume of DMC, corresponding to 3%, 6%, 9%, and 12% by mass of oxygen in the blended fuels, were investigated. By analyzing the measured in-cylinder pressure data and the derived heat release rate, it is observed that the addition of DMC increases the ignition delay and the amount of heat release in the premixed combustion duration, but shortens both the diffusive burning duration and the total combustion duration. On the emission side, the smoke opacity, the particulate mass concentration as well as the total number of particulates are all reduced, while the proportion of soluble organic fraction (SOF) in the particulate is increased, by using the blended fuels. The geometric mean diameter of the particles shifts towards smaller size in comparison with that of the diesel fuel. The particulate mass concentration, the total number of particles and SOF can be further reduced by the use of diesel oxidation catalyst (DOC), while the particles shift towards larger geometric mean diameter for each fuel, indicating that the DOC could reduce the finer particles.