Table of Contents
ISRN Biotechnology
Volume 2013, Article ID 942810, 13 pages
Research Article

Effect of Extruder Screw Speed, Temperature, and Enzyme Levels on Sugar Recovery from Different Biomasses

Department of Agricultural Biosystems Engineering, South Dakota State University, 1400 North Campus Drive, Brookings, SD 57007, USA

Received 25 April 2012; Accepted 23 May 2012

Academic Editors: A. P. Kouzmenko and A. Maggio

Copyright © 2013 Chinnadurai Karunanithy 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.


Biofuels from biomass have the potential to reduce the dependency on fossil fuels. An efficient pretreatment method is required to accomplish the target of the Energy Act 2005. Extrusion could be a viable continuous pretreatment method to be explored. The objectives of the current study were to investigate the influence of screw speed and barrel temperature on sugar recovery from the selected warm season grasses and to select a suitable enzyme combination and dose for enzymatic hydrolysis. The ground, moisture-balanced biomasses were pretreated using a single screw extruder at various screw speeds (100, 150, and 200 rpm) and barrel temperatures (50, 75, 100, 150, and 200°C). Cellulase or multienzyme with β-glucosidase was varied from 1 : 1 to 1 : 4 during enzymatic hydrolysis to accomplish the second objective. Screw speed, barrel temperature, and their interaction had a significant influence on sugar recovery from the selected biomasses. A maximum of 28.2, 66.2, and 49.2% of combined sugar recoverywasachieved for switchgrass, big bluestem, prairie cord grass when pretreated at a screw speed of 200, 200, and 150 rpm and at a barrel temperature of 75, 150, and 100°C, respectively, using cellulase and β-glucosidase at a ratio of 1 :  4. Extrusion pretreatment of these biomasses used only 28–37% of the rated extruder power.