Abstract
This study investigates the effects of oxygenated alcohol fuels blended with diesel on exhaust emissions, carbon particle morphology and nanostructure in a single-cylinder direct injection diesel engine. Blends incorporating n-pentanol, diethylene-glycol diethyl-ether (DE), diethylene-glycol dimethyl-ether (DM) and dimethyl carbonate (DMC) at varying concentrations were tested across different engine loads. These oxygenates, characterized by diverse chain lengths and ether functionalities, enhance fuel oxygenation, promoting more full combustion and altering soot formation mechanisms. Experimental results demonstrate significant reductions in brake specific fuel consumption (BSFC) compared to baseline diesel operation. The improved BSFC, particularly evident in DE and DM blends under high-load conditions, stems from superior fuel properties such as higher cetane numbers, better atomization and enhanced airfuel mixing. Heat release rate analysis reveals shorter combustion durations and higher peak pressures, indicative of advanced ignition and efficient energy release. Emissions performance shows marked decreases in carbon monoxide (CO) and hydrocarbon (HC) levels across all blends, attributed to the oxygen content facilitating oxidation of unburnt fuel residues. Combustion efficiency gains lead to elevated NOx formation from higher flame temperatures, though overall energy utilization improves substantially. These findings establish foundational guidelines for oxygenated diesel blend formulations, emphasizing BSFC optimization and combustion enhancements to advance cleaner engine designs for future regulatory compliance.
Keywords: Diesel Engine, Diethylene Glycol Diethyl Ether, Diethylene Glycol Dimethyl Ether, Dimethyl Carbonate, Emissions.