Among these methods, an extrusion process is a
novel and promising physical pretreatment method for biomass
conversion to ethanol production. In extrusion, materials are subjected
to heating, mixing and shearing, resulting in physical and
chemical modifications during the passage thorough the extruder.
Screw speed and barrel temperature are believed to disrupt the
lignocellulosic structure causing defibrillation and shortening of
the fibers for increasing accessibility of carbohydrates to enzymatic
attack (Karunanithy et al., 2008).