Page 26 - Lignocellulosic Biomass to Liquid Biofuels

6 Lignocellulosic Biomass to Liquid Biofuels

three-dimensional polymer of 4-propenyl phenol, 4-propenyl-2-methoxy
phenol, and 4-propenyl-2.5-dimethoxyl phenol [7].

1.3 Sources of lignocellulosic biomass
1.3.1 Annual and perennial energy grasses
Urbane grasses are well-thought-out as the most prominent sources of
cellulosic biomass. The major herbaceous energy crops that play a vital
role as the source of LCB are as follows: switchgrass, Miscanthus, canary
grass, giant reed, alfalfa (Medicago sativa), and Napier grass (Pennisetum pur-
pureum). Besides circumventing “food versus fuel” conflict, they are con-
sidered to have energetic, economic, and environmental advantages over
food crops for ethanol manufacturing [11,12].

1.3.2 Woody biomass
The forest trees, which are fast growing and have short rotation periods,
are major source of cellulosic biomass. Though forests are unequally dis-
tributed, they play a vital role on reducing the landslide, redundancy of
CO 2 into our atmosphere, and maintain an equilibrium condition
between human being and wild life. Meanwhile, every year approxi-
mately 370 million tons of LCB are producing from forest in the United
States [13]; other forest-rich countries are Canada, Russian, China, and
Brazil. The collected LCB from the abovementioned countries is the half
of the amount of whole world. Sources of woody biomass are as follows:
• Natural forest residues
• Forestry wastes: sawdust from sawmills, wood chips, and branches
from dead trees
• Tree bark
• Wood shavings
• Sawdust
• Low-grade lumber
• Rejected part from sawmills
• Rejected log from plywood mills
• Rejected trunk/log/branch from pulp mills

1.3.3 Nonwoody biomass
The lower lignin content biomasses are known as nonwoody biomass.
They contain comparatively low energy and bulky in size. However, this