hectare, and the production of ethanol from this biomass can reach 1400 to 2800
liters per hectare.
Some countries have the advantage of producing biofuels from waste, while
others cultivate biomass to have feedstock, that is, production of energy crops.
Brazil has excelled in both sources of biomass and presents a potential to produce
biofuels from the vegetal biomass.
2.4
Carbohydrate Content in Biomass
In its natural form, the lignocellulosic biomass is composed of organic compounds
which are considered to be a renewable kind of feedstock for producing inputs of
industrial interest and biofuels (Kamm 2012). Cellulose is a macromolecule insoluble in water, made up of glucose units connected by β-1,4 glycoside connections,
while hemicelluloses are a heteropolymer aggregate that includes several pentose
and hexose sugars connected by several kinds of glycoside links. Lignin is a
tridimensional macromolecule based on phenylpropane units (Melati et al. 2019),
protecting and difficulty polysaccharides solubilization. The mass composition of
these three components in the lignocellulosic biomass depends on the kind of plants
and regions, as it is possible to see in Table 2.2. However, the entire mass proportion
found in cellulose and hemicelluloses usually represents more than 60% (dry basis).
Thus, the sugars derived from lignocellulosic biomass would be the first chemical
products from this vegetal platform to be used by biorefineries of the next generation
(Zakzeski et al. 2010).
It is possible to classify the sources of lignocellulosic biomass into several
groups. They account for energy crops (the grasses that are perennial and other
energy crops grown exclusively for this purpose), water plants (e.g., water hyacinth),
wastes and biomasses from forests (soft- and hardwood, sawdust, pruning, and
residues from bark thinning), residues from agriculture (straws from cereals, stovers,
and bagasse), as well as organic fractions found in municipal solid wastes (MSW)
(Kumar et al. 2009; Limayem and Ricke 2012). These resources from biomass
appear to be the largest, most promising, and most abundant ones, considering that
it is possible to find them all over the world (Table 2.2). One of the uses possible for
the lignocellulosic biomass is as ethanol feedstock, and it practically does not need
any extra requirements or any interference on the production of food and fiber crops
(Sims et al. 2010). Roughly, 200 tonsÁyear
-1 of plant biomass are produced in the
world. Nearly 109 tons of the primary biomass continues to be potentially accessible
for the production of biofuels (Saini et al. 2015). There are predictions that claim that
around 442 billion liters of bioethanol could be produced a year through the use of
lignocellulosic biomass, if total crop waste and wasted crops were to be considered
(Kim and Dale 2004; Sarkar et al. 2012).
The United States alone generate 1368 million tons of biomass that can be used
for producing bioethanol. Of these, 428 million tons are derived from agriculture
waste. Forestry wastes, energy crops, grains and corn, municipal and industrial
wastes, and other kinds of waste contribute with 370, 377, 87, 58, and 48 million
tons, respectively (Saini et al. 2015).
42
F. L. Shimizu et al.
liters per hectare.
Some countries have the advantage of producing biofuels from waste, while
others cultivate biomass to have feedstock, that is, production of energy crops.
Brazil has excelled in both sources of biomass and presents a potential to produce
biofuels from the vegetal biomass.
2.4
Carbohydrate Content in Biomass
In its natural form, the lignocellulosic biomass is composed of organic compounds
which are considered to be a renewable kind of feedstock for producing inputs of
industrial interest and biofuels (Kamm 2012). Cellulose is a macromolecule insoluble in water, made up of glucose units connected by β-1,4 glycoside connections,
while hemicelluloses are a heteropolymer aggregate that includes several pentose
and hexose sugars connected by several kinds of glycoside links. Lignin is a
tridimensional macromolecule based on phenylpropane units (Melati et al. 2019),
protecting and difficulty polysaccharides solubilization. The mass composition of
these three components in the lignocellulosic biomass depends on the kind of plants
and regions, as it is possible to see in Table 2.2. However, the entire mass proportion
found in cellulose and hemicelluloses usually represents more than 60% (dry basis).
Thus, the sugars derived from lignocellulosic biomass would be the first chemical
products from this vegetal platform to be used by biorefineries of the next generation
(Zakzeski et al. 2010).
It is possible to classify the sources of lignocellulosic biomass into several
groups. They account for energy crops (the grasses that are perennial and other
energy crops grown exclusively for this purpose), water plants (e.g., water hyacinth),
wastes and biomasses from forests (soft- and hardwood, sawdust, pruning, and
residues from bark thinning), residues from agriculture (straws from cereals, stovers,
and bagasse), as well as organic fractions found in municipal solid wastes (MSW)
(Kumar et al. 2009; Limayem and Ricke 2012). These resources from biomass
appear to be the largest, most promising, and most abundant ones, considering that
it is possible to find them all over the world (Table 2.2). One of the uses possible for
the lignocellulosic biomass is as ethanol feedstock, and it practically does not need
any extra requirements or any interference on the production of food and fiber crops
(Sims et al. 2010). Roughly, 200 tonsÁyear
-1 of plant biomass are produced in the
world. Nearly 109 tons of the primary biomass continues to be potentially accessible
for the production of biofuels (Saini et al. 2015). There are predictions that claim that
around 442 billion liters of bioethanol could be produced a year through the use of
lignocellulosic biomass, if total crop waste and wasted crops were to be considered
(Kim and Dale 2004; Sarkar et al. 2012).
The United States alone generate 1368 million tons of biomass that can be used
for producing bioethanol. Of these, 428 million tons are derived from agriculture
waste. Forestry wastes, energy crops, grains and corn, municipal and industrial
wastes, and other kinds of waste contribute with 370, 377, 87, 58, and 48 million
tons, respectively (Saini et al. 2015).
42
F. L. Shimizu et al.