Influence of Nano Alumina Oxide Addition on the Performance of Diesel Engine Fueled with Nonedible Oil Biodiesel-Butanol Blends

Biodiesel and butanol are best-suited liquid fuels to fuel compression ignition engines. This experimental study is to investigate the effects of nano alumina on the performance of a variable compression ratio engine fueled with biodiesel-butanol blends. The experiment was conducted in two stages: Arriving at an optimal blend of biodiesel and butanol from the property testing of the blends followed by fueling the optimal blend containing 50% biodiesel and 50% butanol with nano alumina in four proportions (25, 50, 75, and 100 ppm) variable compression ratio engine. The compression ratio was varied as 16:1, 19:1, and 20.5:1. The compression ratio of the engine was varied by the increase and decrease of the clearance volume as the engine used was a variable compression ratio engine. Nano alumina was blended with biodiesel-butanol blend by ultasonication. The results of the property testing showed that the addition of butanol into biodiesel reduced the kinematic viscosity, cetane number, flash point, energy content, and an increase in oxygen content and heat of vaporization. The addition of nano alumina into biodiesel-butanol blend improved the energy content and cetane number significantly. The significance in the addition of nano alumina is that it is a combustion enhancer and due to its micro explosion and catalytic action, an increase in the rate of oxidation was improved. The engine results were compared with the characteristics of diesel fuel. The engine test results showed that the optimal blend with 100 ppm of nano alumina produced brake thermal efficiency, incylinder peak pressure, peak heat release rate, and ignition delay closer to that of diesel at compression ratio 19:1. However, the increase of compression ratio beyond this produced adverse results. The emissions of oxides of nitrogen and smoke from the engine fueled with the optimal blend and 100 ppm nano alumina were also found closer to that of diesel.