Diesel engine behavior using coconut oil methyl esters and its blends

Abstract

Diesel engines are renowned for its reliable performance. However, it continues to be a major polluter in terms of nitrogen oxides and smoke. Many researches are working on the adaptability of vegetable oil methyl ester (biodiesel) for lowering emissions of smoke, hydrocarbons, and carbon monoxide. This may be performed by delivering more amount of oxygen available within the cylinder. Also, it is possible to do this by increasing the oxygen content of the intake air or by using oxygenated fuels (biodiesel), although certain biodiesels increase nitrogen oxide emissions. The biodiesel investigated in this study is coconut oil methyl ester (COME), and the outcomes of its blend are compared to diesel fuel operation. Transesterification was used to produce the fuel from coconut oil. COME's fatty acid composition and fuel characteristics were determined. COME is composed of around 90% saturated fatty acids. Apart from neat COME operation, the trials were carried out for various COME and diesel fuel blends of 20%, and 30%, COME in the fuel blend. The laboratory results reveal that neat COME and its blend operation resulted in decreased brake thermal efficiency, increase in NOx, and decrease in smoke and hydrocarbon emissions. However, it is concluded that COME and its blend can be used as an alternative fuel for compression ignition engines with a sacrifice of thermal efficiency.