Computational study of biodiesel–diesel fuel blends on emission characteristics for a light-duty diesel engine using OpenFOAM

Biofuel Pure Component Spray Characteristics at Engine-Relevant Conditions

“…Allen et al reported that coconut biodiesel exhibits an SMD comparable to that of diesel due to the presence of methyl laurate in its composition. The comparable droplet size along with higher oxygen content in biodiesel is reported to be the cause of lower soot in the case of coconut biodiesel . Kuti et al reported the longer liquid length of palm biodiesel is due to its higher boiling point and lower volatility.…”

“…SVOs are converted to biodiesel by the transesterification process to reduce viscosity and surface tension to levels near those of diesel. Biodiesel is widely used as a renewable substitute either neat or in the form of blends with diesel. − The engine studies reported comparable performance for biodiesel and diesel fuel, while an increase in NO x emissions and lower soot emissions with biodiesel is observed. − ,, The observed increase in NO x emissions is explained by various researchers using spray and combustion studies. ,− The increase in NO x emissions with biodiesel is related to atomization and the evaporation characteristics of the spray. NO x emissions also strongly depend on the chemical compositional features and the nature of the constituents of the biodiesel. − Myo et al studied the effect of chemical composition via engine experiments with methyl oleate and its blends with methyl palmitate, methyl laurate, methyl stearate, and methyl myristate.…”

“…reported lower NO x emissions with animal-derived biodiesel blends than with plant-derived soybean biodiesel blends due to the saturated nature of the fatty-acid ester constituents. The presence of saturated pure components in biodiesel composition is observed to produce lower NO x emissions. , The composition of biofuel, biodiesel, and SVO determines the physical properties of fuel, which govern spray atomization, evaporation, and A/F mixture formation, and it also affects the emission formation. − The NO x and soot emissions are effectively controlled using EGR and multiple-injection technology, which controls the A/F mixture formation . In view of the utility of biofuel, it is important to understand atomization and the A/F mixture formation of these fuels with advanced combustion control technologies.…”

Numerical Analysis of the Effects of Biodiesel Unsaturation Levels on Combustion and Emission Characteristics under Conventional and Diluted Air Conditions

“…Different oils or fats contain different proportions of saturated and unsaturated fatty acids, and the resulting biodiesel will have the same saturation profile as the feedstock from which it is derived from, as shown in Table . As such, many experimental and numerical studies have been conducted to examine the combustion and emission behaviors of different biodiesel fuels ,− under similar engine setups. Experimentally, Allen et al found that the increase of polyunsaturated content in biodiesel resulted in a longer ID period, when comparing the ID periods measured for coconut methyl ester (CME) against those of SME in a rapid compression machine.…”

“…Similarly, the behaviors of different biodiesel fuels such as jatropha, linseed, PME, and rapeseed under various diesel engine conditions were also studied, − where all works generally reached the conclusion that the soot and NO x levels of biodiesel are strongly correlated to the unsaturation levels. Meanwhile, there is only a handful of simulation works which have evaluated the effects of biodiesel unsaturation levels in diesel engine setups. − Mohamed Ismail et al and Wang et al numerically analyzed the combustion and emission behaviors according to the biodiesel unsaturation levels. In the former study, CME, SME, and PME were evaluated at an engine speed of 2000 rpm and load of 0.5–1.5 kW.…”