Non-Alcohol Route of Biodiesel Synthesis from Used Cooking Oil Using Immobilized Biocatalyst in Packed Bed Reactor

Abstract

Immobilized Candida rugosa lipase acts as a biocatalyst for interesterification of used cooking oil with methyl acetate in a packed bed reactor. Reactants and products are analyzed using HPLC, and the effect of residence time and operational stability are also investigated. The results indicate that this biocatalyst can convert 71.5% fatty acid from triglyceride in used palm oil for 5.5 h of residence time. Stability test results show that the immobilized biocatalyst retains good activity for 50 hours without appreciable loss in substrate conversion. The largest conversion obtained from this study was 87.09%, achieved during the stability testing under optimum operating conditions. Furthermore, the kinetic models based on the Ping Pong Bi Bi mechanism are applied to the experimental data to describe the reaction behavior. The fitted results show that the Model C gave the smallest error and fairly described the reaction behavior.