Abstract:
The objective of this research is to study the immobilization of lipase from Candida rugosa onto fine powder of Scirpus grossus L.f. fiber cross-linked by glutaraldehyde for catalyzing biodiesel synthesis. The morphology obtained from Scanning Electron Microscopy (SEM) indicated that the fiber was found to be the most suitable material as a support due to its large quantity of hollow tube for lipase adsorption. The different techniques of lipase immobilization using fine powder of Scirpus grossus L.f. conducted in this research showed that the best technique was to first activate Scirpus grossus L.f. with 2% of 3-aminoproplytriethoxysilane in distilled water and react with glutaraldehyde. The product obtained was then followed by lipase immobilization. The efficiency of lipase immobilization using the above technique was 84.2%. In addition, the immobilized lipase could catalyze hydrolysis-esterification reaction between palm oil and bioethanol at 50oC for biodiesel synthesis. The convesions of free fatty acid and ethyl ester were 43.9% and 32.2%, respectively. The lipase immobilization using the different concentration of glutaraldehyde at 0.2, 0.5, and 0.8% was found that obtained immobilized lipase with 0.2% glutaraldehyde was the most suitable for using as a catalyst for hydrolysisesterification reaction. The efficiency of the lipase immobilization was 76.7%. The conversions of free fatty acid and ethyl ester were 52.6% and 49.6%, respectively. In addition, it could be reused 6 times.