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Keywords Biomass · Depolymerization · Catalytic activity · Sustainable · Bio-oil
upgrading · Platform chemicals
1 Introduction
Biomass has the potential to produce value-added chemicals and has the potential to
become an alternative to fossil fuels. It is a stored solar energy in the form of
chemical bonds of carbon-hydrogen by photosynthesis or the metabolic activity of
the organism. The reason for the search for an alternate form of energy is the
depletion of fossil fuel reserves, as well as the emission of greenhouse gases and its
impact on the environment due to the consumption of fossil fuels. The potential of
biomass can be gauged from the fact that it is recognized as the fourth largest source
of energy. The other sources being crude oil, coal, and natural gas [1].
Utilization of biomass as a fuel source is sustainable that will help to balance out
the net emission of CO 2 by the interplay between photosynthesis and biorefinery.
Biomass is mainly obtained from lignocellulose, lipid, and starchy crops. There are
various methods for conversion of biomass, viz., catalytic processes like biochemical
(fermentation and enzymatic hydrolysis) and thermochemical (combustion,
pyrolysis, and gasification) processes, transesterification, and isomerization, etc.
[2]. These processes make use of both homogeneous and heterogeneous catalysts
with relative advantages and disadvantages. The choice of conversion process
depends on factors such as type of feedstock, the volume of biomass, targeted
chemicals, reactor type, etc.
1.1 Biomass Resources
A complex linkage exists between biomass for energy and materials, biomass for
food production, biomass for energy use, water requirement, and their impact on
biodiversity and climate change. Figure 1 illustrates the complexity by showing key
relationships and assumptions. Biomass feedstock can be classified into three
groups, viz., (1) agricultural waste, municipal solid waste, and forest residue, (2)
surplus forestry, and (3) biomass produced via cropping system. Altogether, the
three categories could produce 500 EJ/year of energy. As far as category one is
concerned, the biomass supply is almost inevitable. However, conventional uses of
biomass can affect its availability for energy applications. Approximately 100 EJ/
year of energy is estimated from this source, i.e., biomass residue [3]. The second
source, surplus forestry, indicates the possible growth of surplus forests that can
account for 60–100 EJ/year of energy worldwide. The availability depends on
sustainable forest management principles [3]. The third category includes the
R. Bhoi et al.
Keywords Biomass · Depolymerization · Catalytic activity · Sustainable · Bio-oil
upgrading · Platform chemicals
1 Introduction
Biomass has the potential to produce value-added chemicals and has the potential to
become an alternative to fossil fuels. It is a stored solar energy in the form of
chemical bonds of carbon-hydrogen by photosynthesis or the metabolic activity of
the organism. The reason for the search for an alternate form of energy is the
depletion of fossil fuel reserves, as well as the emission of greenhouse gases and its
impact on the environment due to the consumption of fossil fuels. The potential of
biomass can be gauged from the fact that it is recognized as the fourth largest source
of energy. The other sources being crude oil, coal, and natural gas [1].
Utilization of biomass as a fuel source is sustainable that will help to balance out
the net emission of CO 2 by the interplay between photosynthesis and biorefinery.
Biomass is mainly obtained from lignocellulose, lipid, and starchy crops. There are
various methods for conversion of biomass, viz., catalytic processes like biochemical
(fermentation and enzymatic hydrolysis) and thermochemical (combustion,
pyrolysis, and gasification) processes, transesterification, and isomerization, etc.
[2]. These processes make use of both homogeneous and heterogeneous catalysts
with relative advantages and disadvantages. The choice of conversion process
depends on factors such as type of feedstock, the volume of biomass, targeted
chemicals, reactor type, etc.
1.1 Biomass Resources
A complex linkage exists between biomass for energy and materials, biomass for
food production, biomass for energy use, water requirement, and their impact on
biodiversity and climate change. Figure 1 illustrates the complexity by showing key
relationships and assumptions. Biomass feedstock can be classified into three
groups, viz., (1) agricultural waste, municipal solid waste, and forest residue, (2)
surplus forestry, and (3) biomass produced via cropping system. Altogether, the
three categories could produce 500 EJ/year of energy. As far as category one is
concerned, the biomass supply is almost inevitable. However, conventional uses of
biomass can affect its availability for energy applications. Approximately 100 EJ/
year of energy is estimated from this source, i.e., biomass residue [3]. The second
source, surplus forestry, indicates the possible growth of surplus forests that can
account for 60–100 EJ/year of energy worldwide. The availability depends on
sustainable forest management principles [3]. The third category includes the
R. Bhoi et al.