Experimental Investigation of the Effect of Adding Hydrous Ethanol on Diesel Engine Performance

The combustion characteristics of biodiesel fuel could be improved by supplementing a fraction of another biofuel as a fuel for internal combustion engines. This promise would improve energy conversion efficiency, reduce emissions, and improve environmental air quality. This study investigates the effect of adding a hydrous ethanol fraction to biodiesel-diesel fuel blends for diesel engines. Experimental work has been conducted to evaluate the engine performance under different operating conditions, including varying fuel blends and engine speeds. Each fuel blend was tested on a 418-cc single-cylinder, 4-stroke vertical engine with an air-cooled system. Hydrous ethanol was added to biodiesel-diesel blends at 30%, 35%, and 40% biodiesel concentrations, up to 10% v/v, to reduce the commercial diesel fuel content. The fuel code represents the fraction of the fuel blends as BxEx (x index refers to the percentage of biodiesel and ethanol). The results show that with 30% and 35% biodiesel concentrations, the average torque increased by 19.49%, and the average power grew by 19.76% when ethanol was present, particularly within the 1500–3000 rpm range. Moreover, the engine thermal efficiency improved by 13.66%, while the average of specific fuel consumption reduced by 15.47%. The study shows that using oxygenated fuel in a diesel engine improves combustion stability, leading to increased cylinder pressure with less fuel input energy.