no contribution to the greenhouse effect. The consumption of
carbon dioxide by biomass from the environment is in equal
amounts for both combustion and growth purposes. Additionally, there is reduction in emission of carbon dioxide
overall owing to the fact that biomass as fuel is neutral of
carbon dioxide (Demirbaş 2005). In the year 2017, Alptekin
et al. reported that production of biodiesel by triacylglycerol
trans esterification causes discharge of lesser pollutants like
aromatic compounds, sulphur, carbon dioxide and carbon
monoxide in comparison to the diesel (Alptekin 2017). The
organic wastes generally consist of inexpensive and ideal
particulates necessary for production of microbial oil.
Moreover, organic waste’s chemical composition causes an
effect on production of lipids. This chapter discusses various
examples of bioconversion of organic waste into biodiesel. It
also highlights microorganisms of diverse organic waste for
economical production of biodiesel based on microbial
lipids. Biodiesel is a renewable source of energy which
meets the worldwide demands of energy for transportation
(Hill et al. 2006; Ragauskas et al. 2006). For the production
of biodiesel, the technology is not a hurdle rather the raw
materials generally used is the limitation (Koonin 2006). The
general raw materials include edible vegetable oil like sunflower, palm, soybean, rapeseed, etc. which cannot be
exploited blindly for production of biodiesel as it also meets
the food requirements (Tilman et al. 2009). Furthermore, the
feedstock cost is an economical hurdle for the production of
biodiesel (Demirbas 2011). Hence, for reducing the cost of
production of biodiesel there is the requirement of
cost-effective feedstock. For this purpose, certain renewable
sources of feedstock for biodiesel production are required
like Jatropha curcas and microalgae (Huang et al. 2010; Lu
et al. 2009). For fulfilling the energy requirements, it is not
wise to affect the surrounding and society, rather necessary
to use alternate sources of feedstock which will be economically sound, environmental friendly and also feasible
technically (Lang et al. 2001) like black soldier fly also
known as Hermetia illucens which are capable of converting
the organic waste into value-added products without compromising with the food sources (Craig et al. 1994). This
chapter discusses biodiesel production guided by insects and
microbes and various other examples of biodiesel production
from organic wastes.
2 Biomass of Waste
In general, biomass consists of natural renewable resources,
proteins, lignin, and hemicellulose, large amounts of cellulose, lignocellulosic materials and precious materials.
Mostly, the materials of biomass exist as residues of wood
which are left behind after any forest activities, food wastes
and municipal solid waste (Oliveira and Franca 2009). On an
average, the energy of biomass is generated from landfill
gases and agricultural waste (5%), municipal solid waste
(24%) and wood waste (64%) (Demirbas and Demirbas
2007; Balat 2009). Basically, biomass wood structure is
composed of three types of polymers, which are lignin,
hemicellulose and cellulose present in bark, foliage and
trunk. The quantity of constituent existing in wood varies
from species to species, and there is a unique variation
between soft and hardwood. Generally, hardwood consists
of nearly 2–8% extractives, hemicellulose (25–35%), lignin
(16–24%) and cellulose (43–47%). Similarly, softwood
consists of extractives (1–5%), hemicellulose (25–29%),
lignin (25–31%) and cellulose (40–44%) (Balat and
Demirbas 2009). In Table-1, there is the display of different
residues and their respective wastes and percentage of
composition of lignin, hemicellulose and cellulose in the
biomass. Cellulose comes in the category of homopolysaccharide made up of units of b-D- glucopyranose joined by
glycosidic bonding. The primary limitation was to depend
on biowaste as the only source for fuel even though biomass
exhibits distinct characteristics. The presence of high quantities of ash and moisture in biowaste fuels leads to combustion and ignition problems (Demirbaş 2005). Biomasses
which are highly rich in moisture are suitable for processes
like fermentation which involve reactions which are mediated biochemically. Similarly, biomasses which contain
lesser amounts of moisture are preferred for cost-effective
processes like gasification or pyrolysis, combustion (Oliveira
and Franca 2009). In comparison to coal, biowaste is different in many ways including physical, inorganic, organic
characteristics and energy content. Compared to coal, biowaste in general contains lesser amounts of carbon, iron,
aluminium and higher amounts of potassium, silica, oxygen,
and moisture, lower friability, density and heating value.
Agricultural residues disposal methods cause environmental
issues widely. For example, wheat and rice straw when burnt
in an open field lead to pollution (Demirbas 2008). Treatment of solid waste generated due to agricultural activities
anaerobically has attracted attention in recent years. Generation of methane, during organic matter digestion anaerobically, is dependent on the kind and amount of material
included in the system. Agricultural leftovers like molasses,
green leaves, plant stalks, seeds, fruit, fruit shells, nutshells
and straws are resources of renewable energy. Rice straw is a
potential source for production of approximately two hundred five billion litres of bioethanol every year which is the
highest quantity produced from one feedstock of biomass. In
Fig. 1, there is the illustration of the composition of waste
produced globally (Karimi et al. 2006).
386
T. Sahoo et al.
carbon dioxide by biomass from the environment is in equal
amounts for both combustion and growth purposes. Additionally, there is reduction in emission of carbon dioxide
overall owing to the fact that biomass as fuel is neutral of
carbon dioxide (Demirbaş 2005). In the year 2017, Alptekin
et al. reported that production of biodiesel by triacylglycerol
trans esterification causes discharge of lesser pollutants like
aromatic compounds, sulphur, carbon dioxide and carbon
monoxide in comparison to the diesel (Alptekin 2017). The
organic wastes generally consist of inexpensive and ideal
particulates necessary for production of microbial oil.
Moreover, organic waste’s chemical composition causes an
effect on production of lipids. This chapter discusses various
examples of bioconversion of organic waste into biodiesel. It
also highlights microorganisms of diverse organic waste for
economical production of biodiesel based on microbial
lipids. Biodiesel is a renewable source of energy which
meets the worldwide demands of energy for transportation
(Hill et al. 2006; Ragauskas et al. 2006). For the production
of biodiesel, the technology is not a hurdle rather the raw
materials generally used is the limitation (Koonin 2006). The
general raw materials include edible vegetable oil like sunflower, palm, soybean, rapeseed, etc. which cannot be
exploited blindly for production of biodiesel as it also meets
the food requirements (Tilman et al. 2009). Furthermore, the
feedstock cost is an economical hurdle for the production of
biodiesel (Demirbas 2011). Hence, for reducing the cost of
production of biodiesel there is the requirement of
cost-effective feedstock. For this purpose, certain renewable
sources of feedstock for biodiesel production are required
like Jatropha curcas and microalgae (Huang et al. 2010; Lu
et al. 2009). For fulfilling the energy requirements, it is not
wise to affect the surrounding and society, rather necessary
to use alternate sources of feedstock which will be economically sound, environmental friendly and also feasible
technically (Lang et al. 2001) like black soldier fly also
known as Hermetia illucens which are capable of converting
the organic waste into value-added products without compromising with the food sources (Craig et al. 1994). This
chapter discusses biodiesel production guided by insects and
microbes and various other examples of biodiesel production
from organic wastes.
2 Biomass of Waste
In general, biomass consists of natural renewable resources,
proteins, lignin, and hemicellulose, large amounts of cellulose, lignocellulosic materials and precious materials.
Mostly, the materials of biomass exist as residues of wood
which are left behind after any forest activities, food wastes
and municipal solid waste (Oliveira and Franca 2009). On an
average, the energy of biomass is generated from landfill
gases and agricultural waste (5%), municipal solid waste
(24%) and wood waste (64%) (Demirbas and Demirbas
2007; Balat 2009). Basically, biomass wood structure is
composed of three types of polymers, which are lignin,
hemicellulose and cellulose present in bark, foliage and
trunk. The quantity of constituent existing in wood varies
from species to species, and there is a unique variation
between soft and hardwood. Generally, hardwood consists
of nearly 2–8% extractives, hemicellulose (25–35%), lignin
(16–24%) and cellulose (43–47%). Similarly, softwood
consists of extractives (1–5%), hemicellulose (25–29%),
lignin (25–31%) and cellulose (40–44%) (Balat and
Demirbas 2009). In Table-1, there is the display of different
residues and their respective wastes and percentage of
composition of lignin, hemicellulose and cellulose in the
biomass. Cellulose comes in the category of homopolysaccharide made up of units of b-D- glucopyranose joined by
glycosidic bonding. The primary limitation was to depend
on biowaste as the only source for fuel even though biomass
exhibits distinct characteristics. The presence of high quantities of ash and moisture in biowaste fuels leads to combustion and ignition problems (Demirbaş 2005). Biomasses
which are highly rich in moisture are suitable for processes
like fermentation which involve reactions which are mediated biochemically. Similarly, biomasses which contain
lesser amounts of moisture are preferred for cost-effective
processes like gasification or pyrolysis, combustion (Oliveira
and Franca 2009). In comparison to coal, biowaste is different in many ways including physical, inorganic, organic
characteristics and energy content. Compared to coal, biowaste in general contains lesser amounts of carbon, iron,
aluminium and higher amounts of potassium, silica, oxygen,
and moisture, lower friability, density and heating value.
Agricultural residues disposal methods cause environmental
issues widely. For example, wheat and rice straw when burnt
in an open field lead to pollution (Demirbas 2008). Treatment of solid waste generated due to agricultural activities
anaerobically has attracted attention in recent years. Generation of methane, during organic matter digestion anaerobically, is dependent on the kind and amount of material
included in the system. Agricultural leftovers like molasses,
green leaves, plant stalks, seeds, fruit, fruit shells, nutshells
and straws are resources of renewable energy. Rice straw is a
potential source for production of approximately two hundred five billion litres of bioethanol every year which is the
highest quantity produced from one feedstock of biomass. In
Fig. 1, there is the illustration of the composition of waste
produced globally (Karimi et al. 2006).
386
T. Sahoo et al.