Abstract
The most common catalysts for biodiesel production are homogeneous catalysts such as NaOH and KOH. In the present study, a comparison was performed in the different base and acid catalysts (NaOH, KOH, Na2CO3, K2CO3, H2SO4 and CH3COOH) for methanolysis and ethanolysis of triolein by means of ultrasonic cavitation. All experiments were carried out under the same experimental condition in a batch ultrasonic reactor at 25°C, where the molar ratio of alcohol to triolein and catalyst concentration were 6:1 and 1 wt%, respectively. The biodiesel conversion was near 100% for all base catalysts. However, it was found that the conversion was very low in the case of acid catalyst (H2SO4) and no conversion was observed in the case of CH3COOH. It was found that the catalytic activity for methanolysis and ethanolysis of triolein was in the order of CH3COOH (no conversion) ‹ H2SO4 ‹ K2CO3 ‹ Na2CO3 ‹ KOH = NaOH under the ultrasonic irradiation condition.
