Comparison of Novozym 435 and Amberlyst 15 as Heterogeneous Catalyst for Production of Biodiesel from Palm Fatty Acid Distillate

Palm fatty acid distillate (PFAD), a byproduct from the palm oil refinery process, has recently been utilized as an alternative feedstock for biodiesel (BD) production via homogeneous acid-catalyzed esterification. This process suffers from catalyst recovery, wastewater treatment, and BD purification. To minimize the problem, heterogeneous catalysts, Novozym 435 (immobilized Candida antarctica lipase B) and Amberlyst 15 (acidic styrene-divinylbenzene sulfonated ion-exchange resin), are tested and their catalytic activities under various reaction conditions are compared. Novozym 435 acts fast and its optimal specific activity (g BD/h/g catalyst) is 50-fold higher than that of Amberlyst 15. The maximum BD yields obtained using Novozym 435 and Amberlyst 15 are 95 and 97%, respectively. Both catalysts are recycled more than 15 cycles without losing their activities. The results suggest that both Novozym 435 and Amberlyst 15 can be effectively used for BD production from PFAD.