Abstract
The use of emulsion fuel in the engine has been reported as an effective solution to reduce the harmful emission. This experimental study examined the effects of nano-emulsion biodiesel fuel on engine efficiency, gas emission parameters and combustion parameters of a single-cylinder air-cooled diesel engine. Nano-emulsion fuel made of 5% waste cooking oil biodiesel and 5% distilled water were used to test the performance of the diesel engine. This fuel was produced using ultrasonic waves by stabilizing 5% by volume tween 80 and spans 80 surfactants in HLB8 (Hydrophilic-Lipophilic Balance). Performance parameters and pollutants emission of a diesel engine using nano-emulsion fuel were compared with emulsion fuel. This test was performed on four different engine loads (25%, 50%, 75%, and 100%) at different speeds of 1700, 2000, 2300, and 2600 rpm. Power, torque, cylinder pressure levels, and emissions including soot opacity, carbon monoxide (CO), unburned hydrocarbon (UHC), carbon dioxide (CO2), and nitrogen oxides (NOX) were measured. The test results show that diesel engine power and torque using nano-emulsion fuel improved by about 4.84% and 4.65% compared to emulsion fuel, respectively. The use of nano-emulsion fuel significantly decreased CO (~11%), UHCs (~6%), NOx (~9%) and soot opacity (~10%) emission. However, a small rise in CO2 (~7%) emission was observed. The combustion result shows that nano-emulsion fuel creates more cylinder pressure (CP) than emulsion fuel during combustion. The highest CP was recorded at 10° crank angle after the top dead centre with diesel fuel. Finally, nano-emulsion fuel can be a satisfactory alternative to diesel fuel in a diesel engine without having to change the engine.