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

Abstract

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.

Impacts of dimethyl carbonate blends on gaseous and particulate emissions from a heavy-duty diesel engine

“…The use of DMC resulted in statistically significant increases in particle number emissions compared to CARB ULSD, ranging from 66% to 141%. Our results are in contrast with those seen in previous studies of DMC where particle number emissions showed reductions with higher concentrations of DMC in diesel fuel [21,25,33]. Zhang and Balasubramanian [25] found reductions in particle number emissions of 25.1% and 36.1% for 5% and 10% DMC blends, respectively, based on measurements with a fast mobility particle sizer (FMPS), while Cheung et al [21] also showed reductions in particle number on average of 21% and 37%, for 9.1-18.6% DMC blends, respectively.…”

“…This could be a plausible explanation for the higher concentrations of nucleation mode particles with the DMC blends, since DMC possesses a lower boiling point than typical diesel fuel and emits higher levels of nucleation mode particles. Previous studies have shown a shift of the geometric mean diameter of particles towards smaller sizes in comparison to diesel fuel, primarily due to the fuel-borne oxygen [23,33]. Increases in nucleation particles have also been seen in studies of DME [35].…”

“…DMC also has a lower viscosity and boiling point and a lower cetane number compared to diesel fuel. This may also lead to an increase in ignition delay together with an increase in the amount of fuel burned in the premixed combustion phase, since it was expected that the fuel atomized in smaller fuel droplets and at faster rates of vaporization and thus increasing the efficiency of fuel and air mixing prior to the start of combustion [16,19,25,[32][33][34]. These phenomena would reduce the amount of fuel burned in the diffusion mode and hence suppress the formation of soot and subsequently PM emissions.…”

Particle emissions from microalgae biodiesel combustion and their relative oxidative potential

“…As shown in Fig. 45 Others suggest that oxygen atoms in the ester molecule decompose into two separate reactive oxygen carriers, which then contribute to reductions in soot-precursors. To the contrary, although a number of studies showed consistent reductions in PM with increased biodiesel oxygen content, 18,39 both TPM and TPN increased for the 20% and 50% microalgal biodiesel blends in this study, which have a relatively higher oxygen content.…”

Organic Carbonate Production Utilizing Crude Glycerol Derived as By-Product of Biodiesel Production: A Review

“…Diesel engines are much more efficient than gasoline engines, however, they suffer from NOx and particulate emissions. Many studies have already been reported on the reduction of hydrocarbons, CO, NOx, and particulate emission from diesel engines because of the use of organic carbonates as oxygenate in the fuel [98][99][100].…”