monomers in lignin (Pauly and Keegstra 2010). The composition in terms of main
components of the most important lignocellulosic feedstocks is shown in Table 1.4.
Woody biomass contains more cellulose and lignin, whereas grass biomass has
higher content of hemicellulose (mainly xylan), extractives, and ashes.
Cellulose is a polysaccharide consisting of a linear chain of D-glucose units.
Hemicellulose has a backbone composed of 1, 4-linked β-D-hexosyl residues and
may contain pentoses, hexoses, and/or uronic acids. Other sugars, such as rhamnose
and fucose, may also be present, and the hydroxyl groups of sugars can be partially
substituted with acetyl groups (Gírio et al. 2010). Unlike cellulose, hemicellulose
composition varies depending on cell tissue and plant species (Chundawat et al.
2011). In fact it can be noted that:
– The principal hemicellulose of hardwoods is an O-acetyl-4-Omethylglucuronoxylans.
– The main hemicellulose of soft woods is an O-acetylgalactoglucomannan.
Table 1.2 Feedstock for biodiesel production (Leung et al. 2010)
Type of oil Species
Fatty acids
composition (wt. %)
Kinematic viscosity
(cst. at 40
C)
Acid value
(mg KOH/g)
Edible oil
Soybean
C16:0, C18:1, C18:2
32.9
0.2
Rapeseed
C16:0, C18:0, C18:1,
C18:2
35.1
2.92
Sunflower
C16:0, C18:0, C18:1,
C18:2
32.6
–
Palm
C16:0, C18:0, C18:1,
C18:2
39.6
a
0.1
Corn
C16:0, C18:0, C18:1,
C18:2, C18:3
34.9
a
–
Canola
C16:0, C18:0, C18:1,
C18:2, C18:3
38.2
0.4
Nonedible
oil
Jatropha
curcas
C16:0, C16:1, C18:0,
C18:1, C18:2
29.4
28
Other
Used
cooking
oil
Depends on fresh
cooking oil
44.7
2.5
a Kinematic viscosity at 38
C, mm
2
/s
Table 1.3 Starch content in energy crops used for 1st generation bioethanol (Zabed et al. 2017)
Crop
Scientific name
Starch content (%)
a
Corn
Zea mays
70–72
Sorghum
Sorghum bicolor
68–70.7
Wheat
Triticum aestivum
65.3–76
Rice
Oryza sativa
87.5
Oat
Avena sativa
65.6
Potato
Solanum tuberosum
73
a Dry weight
6
P. Bartocci et al.
components of the most important lignocellulosic feedstocks is shown in Table 1.4.
Woody biomass contains more cellulose and lignin, whereas grass biomass has
higher content of hemicellulose (mainly xylan), extractives, and ashes.
Cellulose is a polysaccharide consisting of a linear chain of D-glucose units.
Hemicellulose has a backbone composed of 1, 4-linked β-D-hexosyl residues and
may contain pentoses, hexoses, and/or uronic acids. Other sugars, such as rhamnose
and fucose, may also be present, and the hydroxyl groups of sugars can be partially
substituted with acetyl groups (Gírio et al. 2010). Unlike cellulose, hemicellulose
composition varies depending on cell tissue and plant species (Chundawat et al.
2011). In fact it can be noted that:
– The principal hemicellulose of hardwoods is an O-acetyl-4-Omethylglucuronoxylans.
– The main hemicellulose of soft woods is an O-acetylgalactoglucomannan.
Table 1.2 Feedstock for biodiesel production (Leung et al. 2010)
Type of oil Species
Fatty acids
composition (wt. %)
Kinematic viscosity
(cst. at 40
C)
Acid value
(mg KOH/g)
Edible oil
Soybean
C16:0, C18:1, C18:2
32.9
0.2
Rapeseed
C16:0, C18:0, C18:1,
C18:2
35.1
2.92
Sunflower
C16:0, C18:0, C18:1,
C18:2
32.6
–
Palm
C16:0, C18:0, C18:1,
C18:2
39.6
a
0.1
Corn
C16:0, C18:0, C18:1,
C18:2, C18:3
34.9
a
–
Canola
C16:0, C18:0, C18:1,
C18:2, C18:3
38.2
0.4
Nonedible
oil
Jatropha
curcas
C16:0, C16:1, C18:0,
C18:1, C18:2
29.4
28
Other
Used
cooking
oil
Depends on fresh
cooking oil
44.7
2.5
a Kinematic viscosity at 38
C, mm
2
/s
Table 1.3 Starch content in energy crops used for 1st generation bioethanol (Zabed et al. 2017)
Crop
Scientific name
Starch content (%)
a
Corn
Zea mays
70–72
Sorghum
Sorghum bicolor
68–70.7
Wheat
Triticum aestivum
65.3–76
Rice
Oryza sativa
87.5
Oat
Avena sativa
65.6
Potato
Solanum tuberosum
73
a Dry weight
6
P. Bartocci et al.