Effect of n-Butanol Blends on Engine Performance and Exhaust Emission of Compression Ignition Engine Fuelled with Diesel-Palm Oil Methyl Ester (B20)

Abstract

The study aims to evaluate the performance and emission characteristic in a compression ignition engine of conventional diesel fuel-biodiesel blends with different percentage of fuel additive n-butanol. The experiment was operated at a constant engine load (50% throttle condition) with different engine speed (2700, 3100, 3500 rpm). A blend of biodiesel and diesel fuel known as B20 (20% palm oil methyl ester and 80% diesel in volume) was prepared, and then n-butanol was added to B20 at a volume of 5ml, 10ml and 15ml (denote as B20+Bu5, B20+Bu10 and B20+Bu15, respectively) and the tested fuel samples were compared with diesel fuel and diesel-biodiesel (B20). The experimental results show that when the proportion of n-butanol was increased in B20 blends, kinematic viscosity was larger while calorific value was smaller than those of the neat diesel. Although n-butanol have some negative impacts on engine performance parameters, its generally positively affect exhaust emission parameters compared to diesel fuel. According to engine performance and exhaust emission test result of n-butanol fuel blends with B20 blends, average values of brake thermal efficiency (10.19%, 7.58% and 4.29%), carbon monoxide (21.75%, 17.06% and 11.28%), hydrocarbon (18.51%, 15.68% and 12.13%) are lower, while brake specific fuel consumption (BSFC) (27.48%, 45.37% and 59.20%) are higher and carbon dioxide (CO2) and oxides of nitrogen (NOx) are comparable than those of diesel fuel.