Diesel Combustion of Coconut Oil Methyl Ester with 1-Butanol

In order to reduce smoke emissions from coconut oil methyl ester (CME), the fuel properties, ignitability, combustion characteristics, and exhaust emissions of CME with 1-butanol (CME/1-butanol=60/40 mass %) were investigated using a single cylinder DI diesel engine. CME/1-butanol has a pour point of -12.5°C, which is lower than that of CME. Three other blends tested were rapeseed oil methyl ester (RME)/1-butanol, palm oil methyl ester (PME)/1-butanol, gas oil/1-butanol, where 1-butanol content represents 40 mass%. Thermal efficiency of CME/1-butanol is almost the same as that of gas oil. Although CME/1-butanol has longer ignition delay and higher HC and CO emissions, especially at low load conditions, the smoke emission of CME/1-butanol is lowest among the test blends due to its higher oxygen content. From the experimental results obtained, CME/1-butanol can be considered as a promising alternative diesel fuel.