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Prospects and technological advancement of cellulosic bioethanol ecofuel production 219

immobilization of cells technique is employed in a bioreactor system that has gained
noteworthy research interest in the last few decades [45]. This technology is found to
be more effective in the reduction of end-product inhibition, increase in the ethanol
yield, and process stability over suspended cell systems [46]. Recently, the focus
has been given for reducing the process steps in lignocellulosic ethanol production.
Integration of lignocellulosic pretreatment and hydrolysis steps with fermentation
offers the benefit of cellulose hydrolysis and sugar fermentation at the same time
[47, 48]. This integrated technology is known as simultaneous saccharification and
fermentation, and was observed to increase ethanol production efficiency compared
to separate hydrolysis and fermentation.

8.5 Current state of global bioethanol activities

8.5.1 Global bioethanol potential
In recent years, global bioethanol production has increased to help ensure the world’s
energy security and reduce greenhouse gas emissions. In 2017, global bioethanol pro-
duction reached 105.5 billion liters from 101 billion liters in 2016 [49]. However, the
production, consumption, and trade of bioethanol are influenced by feedstock growing
conditions, bioethanol policy, and import tariffs. To date, ethanol shares about 74% of
total biofuel consumption (143 billion liters) while in terms of energy, it accounts for
almost 65% of the total energy from biofuel. It is estimated that the ethanol market can
produce nearly $58 billion per year [50]. It is expected that almost 50% of the total
biofuel demand by 2030 can be met by utilizing only 10% of the global biomass res-
idue [50]. About 60% of the global bioethanol is produced from sugarcane-based bio-
3
mass. It was estimated that sugarcane contributed about 21 million m of global
ethanol production, whereas corn and grains shared approximately 60 million m 3
of global ethanol production in 2012 [51]. In 2017, the United States produced
95% of its ethanol from corn. Brazil produces ethanol mainly from sugarcane while
the United States, China, Canada, France, Germany, and Sweden produce from corn
and grains. The United States and Brazil are the leading bioethanol producing coun-
tries. In 2017, they together produced about 84% of global bioethanol production,
comprising approximately 57% from the United States and 27% from Brazil [49].
During that year, the United States produced about 60 billion liters of bioethanol
[52]. Fig. 8.6 shows the global bioethanol production. The United States consumes
almost 90% of its potential and exports the remaining bioethanol. Brazil is the
second-largest bioethanol producing country in the world with a production of 28.5
billion liters, followed by China (3.3 billion liters) and Canada (1.7 billion liters)
[49]. China’s bioethanol production is largely dependent on the contribution from
maize (70%), cassava (25%), and molasses (5%). Moreover, China imports a signif-
icant quantity of bioethanol from the United States. Thailand is the fifth-largest bio-
ethanol producer in the world with 1.5 billion liters, followed by Argentina (1.1 billion
liters) and France (1.0 billion liters) [49]. The European Union contributed 4.1 billion
liters of bioethanol to the world’s total production in 2017.