Impact of doping alumina nanoparticles on spray characteristics of diesel-biodiesel fuel blends

Abstract

Diesel vehicles are amongst the major root cause of environmental degradation. Therefore, finding an alternative liquid fuel is only a probable solution according to future perspectives. The harmful exhaust emissions emitted by diesel engines due to poor combustion characteristics are increasing the level of Green House Gases (GHG) and Climate change into the atmosphere. Alternative fuels especially biodiesel is considered the most viable future substitute for running the CI engines. The biodegradable, toxic-free nature of biodiesel and improved physio-chemical properties as compared to diesel can effortlessly replace diesel fuel without undergoing any engine modification. However, the poor spray characteristics such as Sauter mean diameter (SMD) and Specific surface area (SSA) of biodiesel droplet are some severe hurdles which hamper its acceptance in the worldwide market. Fuel spray and atomization plays a crucial role in defining the combustion, performance and emission characteristics of diesel engines. Fuel reformulation approach, i.e., doping of nanoadditives with the diesel, biodiesel and their blends is the most potent approach which can considerably resolve these flaws. In this work, efforts had been devoted to utilizing the catalytic advantages of metal oxide (alumina) nanoparticles (np’s) to improve the spray characteristics of the diesel engine. Nanoparticles provide a higher surface area to the fuel blends and thereby helps in adequate fuel-air mixing. Three different test fuel blends, diesel-biodiesel (D80:B20), diesel-biodiesel-20 and 30 ppm of alumina np’s (D80:B20:Al20), (D80:B20:Al30) were prepared and compared with commercial diesel (D100). The high concentration spray characteristics of test fuel blends were investigated using a Malvern Spraytec device. The study reveals that the doping of alumina np’s improves the specific surface area of the diesel-biodiesel blends and among all the test fuel, D80:B20:Al30 showed best fuel spray and atomization properties. Hence, the study confirms that alumina np’s can be successfully used as fuel additives for CI engines.