Page 296 - Refining Biomass Residues for Sustainable Energy and Bioproducts

264 Refining Biomass Residues for Sustainable Energy and Bioproducts

generated in the sugar-producing countries worldwide. The variety of plant, growth
conditions, age of harvest decides the quantity of biomass. Initially, residues have
been dumped as waste, and the implementation of innovation in agro-industry
developments has been used as a feedstock for renewable energy in the country’s
energy matrix. Cane trash comprises mixture of fractions such as cellulose (40%),
polyoses (30%), and lignin (23%), and also possesses high calorific value. Due to
the low moisture content, it possesses high demand for energy production by means
of either cogeneration or biochemical conversion processes.

12.2.1 Bagasse as biorefinery
Bagasse is the pulpy left over trash collected upon extracting sugarcane juice.
Composition of bagasse is found to be 35% 45% cellulose, 25% 35% hemicellu-
lose, 11% 25% lignin, 3% 7% ash, and waxes in trace. The minimal changes in
the composition of bagasse are due to the factors such as plant age, climatic condi-
tions, and variety of the plant (Canilha et al., 2011; Zhang et al., 2013). Further
individual analysis of elements in bagasse consists a mixture of 45.5 wt.% C,
5.6 wt.% H, 45.2 wt.% O, and 0.3 wt.% N (Bilba et al., 2003). According to FAO,
present bagasse global production has reached 60 million tons (bone dry weight),
and the market value is increasing steadily in the world market. Due to the huge
amount of production of this biomass—bagasse, there is a great interest in develop-
ing it into a biorefinery concept (Rabelo et al., 2011). Biorefinery is an integrated
facility of biomass conversion process and technology to produce useful products
such as fuel, power, heat, and chemicals from biomass and, as such, is analogous to
petroleum refinery (Cherubini, 2010)(Table 12.2). Sugarcane bagasse is considered
to be a potential feedstock for the commercialization of biorefining technologies in
terms of lower feedstock price and accompanied economical risk. Cogeneration of
integrated electricity and heat source from sugarcane bagasse caters energy
demands of the future (Arshad and Ahmed, 2016). The conventional strategies
involved in the production of electricity from bagasse include (Fig. 12.2):
1. generation of steam upon combusting stalks and utilizing it over expanding it on a turbine
and
2. producing low-energy fuel gas by the process of gasification (Stanmore, 2010).
Bagasse is combusted to generate electricity that powers sugar mills. The power
generated is utilized during the production of sugar; excess energy is sent to the grid.
During off season, the whole power generated is consumed by the grid. Ethanol pro-
duction from bagasse is an alternative to traditional methods and is economically ben-
eficial (Rabelo et al., 2011). The presence of mixed inhomogeneous fibers and high
complexity act as a limiting factor for the bagasse refinery (Hernawan et al., 2017).
According to Sieria et al. (2015), the key step in the process pretreatment can be
physical, chemical, and biological that can be used individually or in combination
and will greatly impact in elevating the efficiency and lowering of costs in ethanol
production from biomass (Mosier et al., 2005; Wyman et al., 2005). The rise in
energy demand is significantly increasing annually over the past few decades due to