6.5
Value-Added Biochemicals Production via Sustainable
Biorefinery Approach
More than 90% of chemicals available in the commercial markets are derived from
fossil fuels (Fernando et al. 2006). The conventional chemical industries are recently
shifting the raw materials from fossil fuels to greener feedstocks. The reasons for this
change are rapid depleting of reserves and frequent price hike, and environmental
issues. Biomass feedstock has the potential to address chemical requirements from
society. Agro-residues contain cellulose, hemicellulose, and lignin. The appropriate
technology can be chosen to disintegrate these three components and used as raw
materials to produce different platform chemicals or value-added biochemicals.
Generally, platform chemicals can be processed to produce a variety of higher
value-added products. The valorization of these components of agro-residues are
discussed below.
6.5.1 Valorization of Cellulose
Cellulose is a useful component available in the lignocellulosic materials, and it has
the potential for fuels or biochemicals production. Annual production and consumption of cellulose are ca. 75 billion tonnes (Kirk-Othmer 2001), and its demand is
increasing every year. It consists of long linear fibrils of β-(1,4)-glucopyranoside
chains and its degree of polymerization in the range of 800–10,000 units (KirkOthmer 2001). Cellulose made of polysaccharides is composed of C 5 and C 6 sugars
that can be used as carbon sources after different pretreatment processes (Sun and
Cheng 2002; Moncada et al. 2013). In the lignocellulose biomass, cellulose is tightly
embedded with the other two components viz., hemicellulose and lignin. Generally,
the cellulose is insoluble in water due to a highly crystalline nature. Application of
the hydrolysis process for monomer sugars production from cellulose is a more
difficult and challenging task than that of hemicellulose. The cellulose can be
separated from the residues and used to produce different platform chemicals such
as sorbitol, xylitol, succinic acid, lactic acid, furfural, 5 HMF, and Itaconic acid.
Details of optimized process conditions and biochemicals yield for cellulose and
hemicellulose substrates obtained from different agro-residues are presented in
Table 6.2.
6.5.2 Valorization of Hemicellulose
Hemicellulose can have a variety of C 5 , C 6 sugars, and also sugar acids (Saha 2003)
and highly soluble in water. Cellulose and hemicellulose made of polysaccharides.
After biomass pretreatment, these polysaccharides are used as a carbon source for
further process (Sun and Cheng 2002; Moncada et al. 2013). Different routes used to
converting C 5 /C 6 sugars into various chemicals and aromatic furfurals and furfural
are presented in Table 6.2.
110
D. Ramesh et al.
Value-Added Biochemicals Production via Sustainable
Biorefinery Approach
More than 90% of chemicals available in the commercial markets are derived from
fossil fuels (Fernando et al. 2006). The conventional chemical industries are recently
shifting the raw materials from fossil fuels to greener feedstocks. The reasons for this
change are rapid depleting of reserves and frequent price hike, and environmental
issues. Biomass feedstock has the potential to address chemical requirements from
society. Agro-residues contain cellulose, hemicellulose, and lignin. The appropriate
technology can be chosen to disintegrate these three components and used as raw
materials to produce different platform chemicals or value-added biochemicals.
Generally, platform chemicals can be processed to produce a variety of higher
value-added products. The valorization of these components of agro-residues are
discussed below.
6.5.1 Valorization of Cellulose
Cellulose is a useful component available in the lignocellulosic materials, and it has
the potential for fuels or biochemicals production. Annual production and consumption of cellulose are ca. 75 billion tonnes (Kirk-Othmer 2001), and its demand is
increasing every year. It consists of long linear fibrils of β-(1,4)-glucopyranoside
chains and its degree of polymerization in the range of 800–10,000 units (KirkOthmer 2001). Cellulose made of polysaccharides is composed of C 5 and C 6 sugars
that can be used as carbon sources after different pretreatment processes (Sun and
Cheng 2002; Moncada et al. 2013). In the lignocellulose biomass, cellulose is tightly
embedded with the other two components viz., hemicellulose and lignin. Generally,
the cellulose is insoluble in water due to a highly crystalline nature. Application of
the hydrolysis process for monomer sugars production from cellulose is a more
difficult and challenging task than that of hemicellulose. The cellulose can be
separated from the residues and used to produce different platform chemicals such
as sorbitol, xylitol, succinic acid, lactic acid, furfural, 5 HMF, and Itaconic acid.
Details of optimized process conditions and biochemicals yield for cellulose and
hemicellulose substrates obtained from different agro-residues are presented in
Table 6.2.
6.5.2 Valorization of Hemicellulose
Hemicellulose can have a variety of C 5 , C 6 sugars, and also sugar acids (Saha 2003)
and highly soluble in water. Cellulose and hemicellulose made of polysaccharides.
After biomass pretreatment, these polysaccharides are used as a carbon source for
further process (Sun and Cheng 2002; Moncada et al. 2013). Different routes used to
converting C 5 /C 6 sugars into various chemicals and aromatic furfurals and furfural
are presented in Table 6.2.
110
D. Ramesh et al.