Transesterification of crude palm kernel oil and crude coconut oil by different solid catalysts

This work reports on the preliminary results of using several acidic and basic solids, such as ZrO2, ZnO, SO42−/SnO2, SO42−/ZrO2, KNO3/KL zeolite and KNO3/ZrO2 as heterogeneous catalysts for crude palm kernel oil (PKO) and crude coconut oil (CCO) transesterification with methanol. It was found that ZnO and SO42−/ZrO2 exhibited the highest activity for both PKO and CCO transesterification. In the case of SO42−/ZrO2, only 1 wt.% of this acidic solid was needed to catalyze the reaction, and resulted in fatty acid methyl esters content higher than 90%. Moreover, a study of the catalyst's recyclability indicated that the spent SO42−/ZrO cannot be directly reused for the transesterification. However, this spent catalyst can be easily regenerated and the same activity can be obtained.