Keywords: biodiesel, magnesium methoxide, transesterification, kinetics, crude soybean oil, methanol, biofuels, apparent activation energy
Kinetics of transesterification crude soybean oil to biodiesel catalysed by magnesium methoxide
The apparent activation energy of transesterification of soybean oil with methanol was investigated by the use of magnesium methoxide as solid base catalyst. The effect of variations in reaction time and temperature (50-65°C) on the macro reaction rate were studied while the molar ratio of methanol to oil (9 : 1) and the mass ration of catalyst to oil (8 wt%) were held. The experimental data were curve-fitted by using Origin software, and the relationship of FAME concentration with the reaction time was given, and the apparent activation energy was calculated. The total apparent activation energy was 46.3878 kJ mol−1 and k0 was 5.9112 × 105 L mol−1 min−1. And the apparent activation energies of each fatty acid composition were 36.16, 39.54, 54.23, 43.50 and 32.15 kJ mol−1 for the palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, respectively.