The effect of preheating Amberlyst-15 catalyst used for the biodiesel production reaction of Karanja
oil was studied. The preheated Amberlyst-15 samples were characterized for their surface area and
pore volume and by SEM, TGA and FTIR spectroscopy. A preheat temperature of 473 K was found to
optimum. At this temperature, the surface area had increased and the sulfonic acid groups of Amberlyst-15
were retained. At 473 K preheated Amberlyst-15 gradually deactivated with reuse from a biodiesel
yield of 85% to 27% in four runs at a reaction temperature of 393 K and methanol to oil ratio of 60:1.
For the power-law model, the reaction order was 0.65, the rate constant at 373 K was 0.027 h-1 and
activation energy was 86.98 kJ/mol.