Page 81 - 00. Complete Version - Progress Report IPEN 2014-2016

Application of Ionizing Radiations | Progress Report 81

Energy Production

Radiation effect on structure and
composition of sugarcane bagasse

Ash Solubles Beta cellulose Alpha celulose Lignin Hemicellulose

100

80
Compositional Fraction (%) 60

40

20

0
Untreated 5 kGy 10 kGy 20 kGy 50 kGy 70 kGy 100 kGy 150 kGy

The structural and chemical modifications pro- the changes observed in the cellulose suggest
duced by ionizing radiation in the sugarcane some effects on the lignin structure, since the
bagasse are very important matter to be in- cellulose is protected by lignin and hemicel-
cluded in the second generation energy pro- luloses. The obtained results show that radia-
duction and it depends on the combination tion interacts initially on the surface of hemi-
of pretreatment technologies to transform celluloses liberating the arabinose, and then
these modifications into bioethanol produc- acts on the xylose polymers. The main byprod-
tion growth. The industrial application of elec- uct liberated is acetic acid originated from the
tron beam accelerator on the second gener- deacetylation of hemicelluloses; the removal
ation process is a challenging task and very of this acetyl group enhances the accessibili-
feasible since the equipment could take part ty of the enzyme to the cellulose and can in-
in the first generation installation. The radia- crease the enzymatic hydrolysis. This sequence
tion processing promotes an increase in the of radiation interaction probably happens due
soluble portion that is related to hemicellu- to the location of xylose in the backbone of
lose and cellulose cleavage, and cellulose with arabinoxylan, while arabinose is located in
high molecular weight (alpha) presented a to- the branches of the macromolecules where
tal reduction. It is important to point out that the glycosidic bonds are easier to hydrolyze.