ABSTRACT
Pretreatment is the first step enabling reduce the recalcitrance of lignocellulosic biomass so that enzymatic hydrolysis of polysascharides like cellulose takes place more rapidly and gives greater yields (Sun & Cheng, 2002; Harmsen et al., 2002). It can be achieved by reduction of the particulate size, increase surface area and porosity, redistribute the main components of lignocellulosic biomass, release and depolymerize hemicellulose, decrease the crystallinity of cellulose, and modify lignin structure (Galbe & Zacchi, 2002; Mosier et al., 2005). To avoid the formation of degradation products that inhibit enzymatic hydrolysis and fermentation, pretreatment processes need to be optimized. Furthermore, capital and energy costs should be lowered as much as possible (Jaiswal & Ravindran, 2015).
