Biomass Characteristics - Biomass Gasification, Pyrolysis and Torrefaction - page 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 2 OH

OH

H

H

H

OH

O C C C

H

O

OH OH

C C O C C

C

H H

H

H

C

O C C

C O

O

OH

O

C

C C

H

H H

H

OH

H

CH 2 OH

CH 2 OH

FIGURE 3.7 Molecular structure of cellulose.