Performance and Emission of Palm Oil Methyl Ester Biodiesel with Various Additives in Direct Injection Diesel Engine

Abstract

Biodiesel can be used as an alternative fuel for the diesel engine and have a good combustion characteristic because of their longchain hydrocarbon structure. However, biodiesel possesses few disadvantages such as lower heating value, higher viscosity, higher density and will contribute to several engine problems such as low atomization during injection and carbon deposit formation. There are many types of additives on the market but the extent of the additives on engine performance is unknown and only several researches has been done in studying the performance, emissions and fuel consumption of 100% palm oil methyl ester (B100 biodiesel). In this study, there is five type of B100 biodiesel. The objectives of this research are to identify individual composition in each biodiesel samples, such as the identification of additives and fatty acids methyl esters using gas chromatography (GC-FID). The experimental measurements of density, viscosity and calorific value of B100 biodiesel were conducted. The results showed that a blend of biodiesel with diethyl ether and n-butanol has the closest calorific value to fuel diesel followed by the combination additives of ethanol, butanol and methyl pyrrolidone. Engine performance and emission were also investigated by determining the BSFC, BTE and CO, HC, and NOx gas emissions by simulation using CONVERGE CFD software based on single-cylinder, direct injection YANMAR TF90 diesel engine parameters. Performance results show that the combination of diethyl ether and n-butanol as an additive with crude palm oil will give a higher brake power and lower NOx and brake specific fuel consumption among all samples. The emission studies revealed that the addition of n-butanol additive can reduce carbon monoxides (CO), nitrogen oxides (NOx), particulate matter (PM) emission while diethyl ether can improve the spray characteristics when it blends with B100 biodiesel due to its low density and viscosity.