Abstract
The transesterification reactions of olive oil with methanol in supercritical water were conducted by means of batch type bomb reactor to produce fatty acid methyl ester as a biodiesel fuel. In the present study, we determined the optimum operation parameter such as reaction pressure, temperature, time and the methanol/olive oil molar ratio. The increase of the yield of fatty acid methyl ester at higher density(pressure) conditions revealed the transesterification reaction occurred by ionic reaction mechanism. The most important variables affecting methyl ester yield during the transesterification reaction are the molar ratio of methanol to olive oil, reaction temperature and reaction time. At a low temperature conditions, the transesterification reactions were less slower than that in the supercritical conditions. The time evaluation of the transesterificationreaction at the optimum operation condition (400°C,40 MPa,and the methanol/oil ratio is 3.)indicates the preferable operation time is 20 min to obtain the maximum yield of fatty acid methyl ester. The longer reaction time induces thermal decomposition of fatty acid methyl ester.
