Kinetics of Jatropha oil methanolysis

The effect of temperature, methanol to oil molar ratio and catalyst concentration on Jatropha oil methanolysis were studied in the range from 40 to 60 °C, 3 to 12 and 0.2 to 1 wt% (NaOH), respectively. 100% Conversion of Jatropha oil and 97% yield to fatty acid methyl esters (FAME) were obtained after 60 min of reaction at 60 °C, methanol to oil molar ratio 6:1 and 0.6 wt% of NaOH. Catalyst concentration increment between 0.2 wt% and 0.6 wt% had a positive effect on the reaction rate and on the yield to FAME. Furthermore, catalyst concentrations of 0.2 wt% did not show catalytic activity at all the temperatures tested. A second order kinetic model that includes the three consecutive reversible reactions involved in triacylglycerol methanolysis and the effect of temperature and catalyst concentration on reaction rate describes adequately Jatropha oil methanolysis, as validated by the Fisher-Snedecor test of unbiased variances. A set of eighteen parameters: six kinetic constants, six activation energies and six parameters related to the catalyst concentration were determined using a Dual Population Evolutionary Algorithm (DPEA). Finally, the kinetic model parameters of Jatropha oil and palm oil methanolysis were compared. Parameters obtained were similar in both reactions.