Abstract:
The aim of this research is to study the immobilization of lipase from Candida rugosa on various renewable natural biopolymer supports for biodiesel synthesis. From the results of morphology and moisture content, the plant fiber from Cyperus papyrus L. was found to be the most suitable material for immobilizing lipase because of its large quantity and regular appropriate size of porosity, and also its low moisture conten of 9.1%. The three different types of immobilization techniques used were physical adsorption using heptane and phosphate buffer as media and covalent bonding with 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide(EDC) for the pulverized Cyperus papyrus L. of 0.25 mm. Results show that the technique of physical adsorption using heptane as media and covalent bonding provided percentage of immobilization 93.4 and 76.2, respectively. The activity of immobilized lipase of physical adsorption using heptane as media was reduced only to 11.2%,whereas,its activity using technique of catalyse transesterification between palm oil and methanol with 19.3% conversion of covalent bonding was extremely reduced to 66.6% comparing to the activity of free lipase. The immobilized lipase on the pulverized Cyperus papyrus L.can catalyse transesterification between palm oil and methanol with 19.3% conversion of alkylester which was similar to the free lipase and can catalyse hydrolysis-esterification reaction between palm oil and methanol with 48.8% conversion of alkylester with 1 time reusable. However, this immobilized lipase can catalyse hydrolysis-esterification reaction between palm oil and bioethanol with 51.3% conversion of alkylester with 2 time reusable.