Page 78 - Biomass Gasification, Pyrolysis And Torrefaction Practical Design and Theory

Chapter | 3 Biomass Characteristics 57

made up of many glucose molecules. This structure gives it high strength,
permitting it to provide the skeletal structure of most terrestrial biomass
(Klass, 1998, p. 82). Cellulose is primarily composed of D-glucose, which is
made of six carbons or hexose sugars (Figure 3.7).

Composition (%)

Lignin
Hemicellulose
Cellulose

S 1 S 2 S 3
Secondary wall
Compound middle lamella

Distance
FIGURE 3.6 Distribution of amounts of cellulose, hemicellulose, and lignin in cell walls and
their layers.

CH OH
OH 2 H
H H OH
O C C H C
OH O OH
C C O C C C
H H H
H
O C C C O C O
O OH
C C C H
H H
H OH
H CH 2 OH
OH
CH 2
FIGURE 3.7 Molecular structure of cellulose.