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290 Refining Biomass Residues for Sustainable Energy and Bioproducts

Figure 13.10 Utilization of postharvest rice crop residues for production of biofuels.

cellulose (36.20%), hemicellulose (19%), and lignin (9.90%) (Nigam et al., 2009).
The cellulose and hemicellulose are polysaccharides, and lignin is a polyphenolic
polymer.

13.7.1.2 Pretreatment

These polymers of cellulose, hemicellulose, and lignins start to degrade at tempera-

ture above 180 C. The pretreatment is essential for the separation of lignin and
hemicellulose. Pretreatment is a prerequisite for hydrolysis as it increases the effi-
ciency of enzymatic hydrolysis (Chen et al., 2007). The biological pretreatment of
lignocellulosic biomass by Phanerochaete chrysosporium is essential to enhance
enzymatic hydrolysis (Zeng et al., 2011).

13.7.1.3 Hydrolysis
The hydrolysis of the pretreated lignocellulosic biomass is required for the conver-
sion of polymers such as cellulose, hemicellulose and lignin into monomers. With
hydrolysis, the lignocelluloses are converted to monomers such as reducing sugars.
The produced monomers include pentose and hexose sugars such as xylose, arabi-
nose, mannose, galactose, glucose, and aromatics alcohols. The cellulose