Performance Evaluation of Single-Cylinder Diesel Engine Using Different Microemulsions of N-Butyl Alcohol, Coconut Oil and Diesel Fuel

The use of n-butanol as surfactant allows the mixing of coconut oil and diesel fuel through microemulsification without any additional significant energy input compared with transesterification. This study evaluated the performance of a single-cylinder compression-ignition engine using different blends of n-butanol, coconut oil, and diesel. Four blends of fuel (D90-nB5-CO5, D80-nB10-CO10, D70-nB15-CO15, and D60-nB20-CO20) were formulated based on the available literature regarding the miscibility of the three fuel components. Each blend was evaluated at the engine's maximum rated output speed and maximum torque speed and compared with commercially available diesel (B5) through the varying load tests. Statistical analysis revealed that there were no significant differences in the power output, torque, fuel consumption, and oil and water temperatures between the blends and D100. Significant differences were observed among the blends at maximum output speed (6.18 kW) which were attributed to the higher oxygen content of blend D60. Significant differences were also observed between D100 (534.33 degrees C) and the blends (420.67 degrees C, 361.33 degrees C, 356.00 degrees C, and 435.67 degrees C) in terms of exhaust gas temperatures which were attributed to the higher latent heat of vaporization of n-butanol which contributed to a cool-burn effect. Therefore, blends of up to 40% of 1:1 ratio of n-butanol and coconut oil mixed with diesel fuel can perform at par with the commercially available diesel fuel.