Page 30 - Biofuels for a More Sustainable Future

24 Biofuels for a More Sustainable Future

and Malaysia (EC et al., 2015). In 2015 almost all biodiesel in China was
produced from waste cooking oil (WCO), whether in India from WCO,
animal fats, and other oils (Beckman et al., 2018, pp. 259–260).
Second-generation biofuels are produced from lignocellulosic biomass
and waste-based materials, for example, agricultural and forest residues,
municipal solid wastes (UNCTAD, 2016). The lignocellulosic biomass is
considered advanced feedstock; instead of using sugar or starch fractions
of plants, the lignocellulosic conversion process utilizes entirely the lignocel-
lulosic material contained in residues and waste. The lignocellulosic biomass
is composed of polysaccharides that are converted into sugars through
hydrolysis and/or chemical processes and then fermented into ethanol
(Timilsina and Shrestha, 2010).
Although the residues and nonfood biomass conversion technologies
have been available since the beginning of the 21st century, no industrial
production of second-generation bioethanol was attainable until 2008. By
that time, there were only 15–20 companies, located mainly in the United
States, involved in pilot-scale plants using different biotechnological and
thermochemical biomass conversion processes (Timilsina and Shrestha,
2010). Second-generation bioethanol production technologies are more
complex and expensive than the first-generation ones; however, they are
considered more sustainable since there is no need for dedicated crops, thus
undermining indirect land use change (iLUC) and related social and envi-
ronmental issues (see session 3 for further discussion). The production of
second-generation biofuels from lignocellulosic biomass has increased sig-
nificantly since 2012, although the overall volumes remain below the pro-
duction capacity and the environmental needs. The United States produced
only 2 million liters, China reached 3 million liters of ethanol from maize
cobs for use in blends with petrol, and the EU had only some demonstration
plants available by that time (EC et al., 2015).
The algae-based biofuels, also called third generation biofuels, are fuels
produced with algae-based biomass. The latter can be cultivated specifically
for biofuel production or are collected from polluted aquifers, generating
little pressure on arable land (Timilsina and Shrestha, 2010). The utilization
ofmicroalgaeforbiofuelsproductionisbasedonthelipidcontentofthemicro-
organisms (reaching 60% to 70%) and has high productivity (7.4g/L/day)
(EC et al., 2015). The conversion of algae biomass into biofuels follows the
transesterification process of lipids as for the biodiesel production.
Although biofuels production from algae biomass is at an early stage, thus
uncertainties and costs of production are high, the potential yields for algae