Transesterification of coconut oil for FAME production using ultrasound

To overcome energy crisis, the vegetable oils-derived biofuel can be chosen as an alternative to petroleum-based diesel. The transesterification of coconut oil in methanol with K/γ-Al₂O₃ catalyst using ultrasound-assisted to produce fatty acid methyl ester (FAME) as one of type biofuel was studied. The reaction occurred in batch reactor at a 9: 1 molar ratio of methanol to coconut oil. The following reaction conditions were used in the catalytic test: concentration of catalyst to oil of 0.5, 1.0, 1.5, 2.0, and 2.5%, the reaction time of 10, 20, 30, 60, 90, 120, and 150 s, and the frequency ultrasonication of 20 and 40 KHz. At first, the preparation of K/γ-Al₂O₃ catalyst was done and followed by transesterification process. After reaction, the phase separation and purification from impurities were done. Finally, FAME was analized based on this parameters, i.e., yield, density, viscosity, and flash point. FAME yield of 93.76% was obtained at the frequency ultrasonication of 40 kHz with K/γ-Al₂O₃ catalyst concentration to oil of 2.5 wt.% for 150 s. It's the best conditions for FAME production by transesterification of coconut oil using ultrasound-assisted.