LAUSR

Abstract In the current work, butanol-diesel-water microemulsions were formulated to replace up to 40% (v/v) of diesel without the use of any surfactant. These microemulsions had properties such as heating value, density, kinematic viscosity, cloud point, and copper strip corrosion rating within the standard specifications of diesel fuel oil. The microemulsions are sustainable alternatives to diesel that do not require any engine modifications. Effects of composition on the combustion characteristics of microemulsions inside the engine were also studied, which revealed that the ME80 fuels had a maximum of 8.7% reduction in fuel consumption when compared to neat diesel, ME70 fuels had equivalent fuel consumption, and ME60 fuels showed approximately 7% increase in the fuel consumption. ME80 and ME70 fuels had 6–11% reduction in energy consumption and 2.6–21.8% increase in thermal efficiency compared to those for neat diesel. The microemulsions also led to a significant reduction in almost all the emissions. The carbon monoxide emissions were reduced by upto 57% at higher loads, hydrocarbon emissions by 5.2–66.1%, and particulate matter emissions by 0.4–71.3% for these microemulsions. The NOx emissions were also 9.0–41.7% lower for ME70 and ME60 fuels. These microemulsions were sustainable, efficient, and economical compared to diesel, and hence could be used as a potential less-polluting and sustainable replacement of diesel.