Fe2O3/Chitosan coated superparamagnetic nanoparticles supporting lipase enzyme from Candida Antarctica for microwave assisted biodiesel production

Abstract

Biocatalysis has emerged as a green technology in chemical based catalysis. Immobilization of enzymes onto magnetized nanomaterials enhances downstream processing as it eases their separation from reaction mixture. Synthesis of the nanoparticles was performed in an aqueous solution of FeCl3.6H2O as precursor and NH3 as nucleating agent under microwave irradiation. The maghemite complex was cross-linked with glutaraldehyde to provide conducive environment for enzyme immobilization. Stability of produced immobilized lipases against different conditions were evaluated such as working temperatures from 27 °C to 85 °C and retained more than 64% of its activity at 85 °C. The immobilized lipase complex was able to withstand a wide range of acidic to alkaline environment from pH 5.5 to pH 9.5. The enzyme retains more than 59% of its activity after 14 days of storage and can be recycled for more than 7 cycles with remaining high activity at 93.7%. Developed enzyme was then subjected to microwave irradiation for transesterification of palm oil to produce biodiesel. Highest biodiesel recovery achieved from microwave assisted immobilized lipase catalysed transesterification of palm oil was 70.2%. The physical properties of produced biodiesel was evaluated and fulfilled the ASTM general requirement for fuels.