Browse Topic: Cetane
This study explores the feasibility of using a sustainable lignin-based fuel, consisting of 44 % lignin, 50 % ethanol, and 6 % water, in conventional compression ignition (CI) marine engines. Through experimental evaluations on a modified small-bore CI engine, we identified the primary challenges associated with lignin-based fuel, including engine startup and shutdown issues due to solvent evaporation and lignin solidification inside the fuel system, and deposit formation on cylinder walls leading to piston ring seizure. To address these issues, we developed a fuel switching system transitioning from lignin-based fuel to cleaning fuel with 85 vol% of acetone, 10 vol% of water and 5 vol% of ignition improving additive, effectively preventing system clogs. Additionally, optimizing injection parameters, adopting a constant pressure delivery valve, and fine-tuning injection timing mitigated lignin deposit formation related to incomplete combustion or spray tip penetration to the cylinder
Cetane number (CN) is an important fuel property in designing high-performance fuels in recently diversifying compression ignition engines. We introduce graph neural networks (GNNs) that predict CNs of multicomponent surrogate mixtures when only 2D structures and mole fractions of molecules are given. It considers the influences of mixing multiple components and their chemical structures on CN, reproducing the non-linear blending behavior observed for certain mixtures. We trained the GNNs using the CNs of 1,143 mixtures, and reliable accuracy was achieved with mean absolute errors of 3.4-3.8 from the cross-validation. Lastly, we analyzed the chemical structural effects on non-linear blending behavior.
Butanol is a potential alternative fuel for diesel in compression ignition (CI) engines. Many of the physico-chemical properties of butanol such as low carbon-to-hydrogen (C/H) ratio compared to diesel, higher heating value, lower heat of vaporization and suitable density-viscosity values compared to ethanol and methanol makes it suitable as an alternative fuel. However, poor cetane number and miscibility are the limitations associated with butanol. The use of fuel additives as ignition improver could be beneficial in overcoming the issues associated with alcohols. In this work, an experimental investigation in a twin-cylinder CI engine was carried out to assess the effect of doped cetane improving additives (Diethyl ether (DEE), Diglyme (DEGME) and Ethyl diglyme (DEGEE)) for diesel-butanol blend (B15). Cylinder pressure trace, heat release rate (HRR), location of maximum in-cylinder pressure (Pmax) and maximum rate of heat release (HRRmax), engine performance (brake thermal efficiency
As the global economy grows, so does the demand for heavy-duty commercial vehicles, both on-road and off-road. Currently, these vehicles are powered almost entirely by diesel engines. There is an imminent need to reduce the greenhouse gases (GHG) from this growing sector, but alternatives to the internal combustion engine face many challenges and can increase GHG emissions. For example, through simple analysis, this work will show that a Class 8 long haul on-highway truck powered entirely by battery electrics and charged from the average US electrical grid, yields significantly higher CO2 emissions per ton-mile as compared to an engine using alternative fuels. Thus, the most pragmatic and impactful way to reduce GHG emissions in commercial vehicles is using low carbon alternative fuels, such as ethanol made from renewable sources. The challenge is that heavy-duty applications use non-premixed compression ignition engines for their performance characteristics and ethanol is a poor
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