Table of Contents
Journal of Catalysts
Volume 2014, Article ID 868535, 7 pages
http://dx.doi.org/10.1155/2014/868535
Research Article

Silk-Cocoon Matrix Immobilized Lipase Catalyzed Transesterification of Sunflower Oil for Production of Biodiesel

1Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar, Assam 788010, India
2Centre for Energy, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
3Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
4Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India

Received 23 September 2013; Revised 2 January 2014; Accepted 3 January 2014; Published 10 February 2014

Academic Editor: Vijay Bokade

Copyright © 2014 Sushovan Chatterjee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Biodiesel from sunflower oil using lipase chemically immobilized on silk-cocoon matrix in a packed-bed bioreactor was investigated. The immobilization was demonstrated by field-emission scanning electron microscopy and activity study. The lipase loading was 738.74 U (~0.01 g lipase powder)/g-lipase-immobilized matrix. The (Michaelis-Menten constant) of the free and the immobilized lipase was 451.26 μM and 257.26 μM, respectively. Low value of the immobilized lipase is attributed to the hydrophobic nature of the matrix that facilitated the substrate diffusion to the enzyme surface. The biodiesel yield of 81.62% was obtained at 48 hours reaction time, 6 : 1 methanol : oil ratio (v/v), and 30°C. The immobilized lipase showed high operational stability at 30°C. The substrate conversion was only marginally decreased till third cycle (each of 48 hours duration) of the reaction since less than even 5% of the original activity was decreased in each of the second and third cycle. The findings demonstrated the potential of the silk-cocoon as lipase immobilization matrix for industrial production of biodiesel.