2012 : TRANSESTERIFICATION OF VEGETABLES OIL USING SUBAND SUPERCRITICAL METHANOL
Prof. Dr. Ir. Achmad Roesyadi M.Sc
A benign process, non catalytic transesterification in sub and supercritical methanol method was used to prepare biodiesel from vegetables oil. The experiment was carried out in batch type reactor (8.8 ml capacity, stainless steel, AKICO, JAPAN) by changing the reaction condition such as reaction temperature (from 210 C in subcritical condition to 290 C in supercritical state with of 20 C interval), molar ratio oil to methanol (1: 12-1: 42) and time of reaction (10-90 min). The fatty acid methyl esters (FAMEs) content was analyzed by gas chromatography-flame ionization detector (GCFID). Such analysis can be used to determine the biodiesel yield of the transesterification. The results showed that the yield of biodiesel increases gradually with the increasing of reaction time at subcritical state (210-230oC). However, it was drastically increased at the supercritical state (270-290oC). Similarly, the yield of biodiesel sharply increased with increasing the ratio molar of soy oilmethanol up to 1: 24. The maximum yield 86 and 88% were achieved at 290oC, 90 min of reaction time and molar ratio of oil to methanol 1: 24, for soybean oil and palm oil, respectively.