Page 111 - AWSAR 2.0

construction, power generation, agriculture, and manufacturing applications. Carbon dioxide (CO2) emissions from diesel engines are relatively lower compared with gasoline engines. Fuel economy
improves with diesel-fueled
engines compared with
gasoline engines that save
about 20% or more fuel. In most
of the developing countries, the
consumption of diesel is higher
than that of gasoline. However,
the engines fueled with diesel
need to be modified because
of their higher nitrogen oxides
(NOx) and particulate matter
(PM) emissions. The emission
regulations have become
stringent for NOx and particulate
emissions to preserve the
environment. This has been continuously forcing the transportation sector to mitigate the problem of higher emissions from the combustion of diesel fuels. The manufacturing companies of diesel-fueled vehicles have been continuously working on the improvement of hardware or transformation in engine parts and parameters for better performance with fewer tailpipe emissions. The companies implemented exhaust gas recirculation, variable combustion chamber geometries, multi injection, etc., to reduce the exhaust emissions. On the contrary, the oil firms have been continuously working to introduce better diesel surrogates or renewable fuels aimed to improve the performance and lower emissions. Enhancing the efficiency of the energy release with lower pollutant emissions requires automobile manufacturers and oil companies to make an effort to determine the ideal solution with allied research programs.
Fuels used in various combustion engines necessitate a deep understanding of the fuel components before being used as a feedstock
Dr Paramvir Singh || 87
with present engine technology. Diesel is a complex mixture of hydrocarbons, which usually contains n-alkanes, iso-alkanes, cyclo- alkanes, and aromatics. Due to the higher
degree of saturation, aromatics are the main contributors towards the PM emissions from the burning of diesel. Earlier, surrogate fuels were prepared through a combination of various alkanes to minimize the pollutants from diesel fuel combustion. However, some authors in their recent studies reported that alkane blends alone did not provide the actual picture of fuel combustion. Hence, aromatics should be a part of the surrogate fuels. Aromatics have gained
attention due to their higher content (10%–30% by mass) in diesel fuels and high tendency to emit soot particles during combustion.
Therefore, the study of the aromatics content in the fuel and its structure has a great significance to various engine applications. A comprehensive study with a total of 13 different aromatics was performed to investigate the impact of their structure and content on diesel engine characteristics. Diesel and de- aromatized higher chain alkanes were used as fuel surrogates in the ternary mixture. Detailed spray investigations were carried out to investigate the spray behavior of these blends at higher pressures of 200 bars from a three- hole nozzle of a CI engine.
The blending content (5%–10%–15%) of aromatics in base fuel significantly impacts the properties of blends. The spray pattern of the aromatic blended fuel affects the engine performance and emission profile. The higher spray cone angle leads to fuel impingement on the combustion chamber walls, resulting in increased unburned carbon and carbon
The reliance on fossil-based fuels is not enough to meet the forthcoming energy demands due to their insufficient availability throughout the world. The higher regulated and unregulated emissions from the burning of the fossil-based fuels for energy are a major concern.