Ultralow Sulfur Diesel and Rapeseed Methyl Ester Fuel Impact on Performance, Emitted Regulated, Unregulated, and Nanoparticle Pollutants

Abstract

The operation of engines using rapeseed methyl ester (RME) and ultralow sulfur diesel (ULSD) was tested for the combustion properties, emitted regulated, unregulated exhaust pollutants, and the size of nanoparticles. The combustion analysis showed higher apparent heat release rate and shorter ignition delay period during RME combustion than during ULSD combustion. The ULSD engine has a combustion chamber maximum pressure relatively higher than that of RME. This study showed that the heat release rate of ULSD is always higher than that of RME while more fuel consumption occurred from the combustion of biodiesel in comparison with diesel. When the engine is running on RME, HC and NOx formation increased at high loads up to 15% and 13%, respectively; meanwhile, CO concentrations reduced by 30.9% for the same conditions. Most of the particulate matter (PM) emitted from a diesel engine has a particle size from 5 to 100 nm, while the particle size from ULSD ranged from 5 to 40 nm. Overloading the engine caused a decrease in the sizes of emitted PM for both fuels. The smoke number for RME was less than that for ULSD by 33.9% at high loads. For high engine load, the cumulative concentration number for the nucleation mode decreased, while it increased for the accumulation mode. Furthermore, measurements of formaldehyde, ethane, methane, acetylene, ethylene, propylene, and isocyanic acid emissions showed the presence of these harmful substances at very low concentrations (8 ppm) for both fuels.

Reducing Soot Nanoparticles and NOX Emissions in CRDI Diesel Engine by Incorporating TiO2 Nano-Additives into Biodiesel Blends and Using High Rate of EGR

“…It can be said that the BTE increased with a high load compared with medium and low engine loads for all the fuels studied. It is well known that biodiesel produces a higher BTE compared to diesel fuel due to the oxygen bonds in biodiesel that enhance thermal efficiency [40,41]. Figure 4 illustrates that the BTE increased by 2.8% when adding TiO2 nanoparticles to the castor oil compared to the neat fuels (without nano-additives).…”

Reducing the Effect of High Sulfur Content in Diesel Fuel on NOx Emissions and PM Characteristics Using a PPCI Mode Engine and Gasoline–Diesel Blends

“…Therefore, part of the sulfur content is oxidized to form SO 2 , while other parts enter into the formation of other compounds such as aromatics and PM. 62 Therefore, SO 2 concentrations are reduced in this range. The engine working with high loads or high engine speeds generates great heat inside the combustion chamber, which contributes to higher oxidation of fuel.…”

“…At medium loads and speeds, the temperature of the combustion chamber increases and the oxidation of all molecules is also improved. Therefore, part of the sulfur content is oxidized to form SO 2 , while other parts enter into the formation of other compounds such as aromatics and PM . Therefore, SO 2 concentrations are reduced in this range.…”

“…Although the results of H 2 S concentrations did not reach dangerous levels, these emissions in closed areas (such as tunnels and garages) may pose a great risk to health due to the accumulation of these concentrations and upon reaching critical levels. 62 , 64 From the above results, the use of GD50 by converting conventional diesel engines to operate with PPCI mode can be considered an important first stage in reducing exhaust pollutants. Certainly, the Iraqi state should work on improving aging oil refineries to produce ultralow-sulfur diesel fuel.…”