Utilization of immobilized lipase for transesterification of tubang bakod (Jatropha curcas) seed oil

Abstract

This study deals with the production of biodiesel from Jatropha curcas seed oil via enzymatic transesterification. The process was carried out using lipase enzyme as the biocatalyst and seed oil from the Jatropha species as the substrate. Lipase enzyme was immobilized using sodium alginate matrix dripped into calcium chloride solution to form calcium alginate beads. Transesterification processes were held using 5%, 10% and 15% enzyme loading. The amount of lipase with the highest yield was repeatedly used for three runs to evaluate its effectiveness and stability. The highest yield among the fresh lipase runs and the recycling trials were submitted to laboratory analyses for the determination of physicochemical properties. Results of the experiments revealed that the process which was carried out using 15% enzyme loading produced the highest amount of biodiesel with an average percentage yield of 78.29. In the recycling trials, it was found out that the highest percentage biodiesel yield was 70.49% which was obtained in the first recycling of lipase. Analysis of Variance were applied to such and the statistical results showed that varying amounts of enzyme loading and recycling trials have significant effect on the percentage biodiesel yield. Meanwhile, the physicochemical properties such as density, acid number, kinematic viscosity, flash point and water content were determined and compared to the Philippine National Standards for Methyl Ester (PNS 2020:2003) using individual t-tests. Statistical results showed that there is a significant difference between the properties of the produced biodiesel using fresh and recycled lipase with that of the values set by the PNS.