be digested anaerobically. Other methods are also available such as thermal degradation and gasification method (Show et al. 2013).
2.4 Biofuel Types
Biofuels can be categorized into types such as biohydrogen, bioethanol,
biomethanol, biomethanol, and biodiesel. We have discussed few important biofuels
in this chapter.
2.4.1 Biohydrogen
Biohydrogen is a clean, environmentally safe, and low-cost-based fuel. It has much
more advantages compared to other fuels. Biohydrogen produces high energy which
enhances fuel efficiency. The biohydrogen production is still a developing sector in
biofuel research. Nowadays, biohydrogen generally produces through conventional
methods (Shaishav et al. 2013). There are various conventional methods such as
electrolysis as well as gasification of coal, but these methods have some disadvantages. The major disadvantages of these methods are requirement of high thermal
energy and generation of some hazardous by-products such as gases and wastewater
(Hsia and Chou 2014; Chang and Lin 2004). Electrolysis of water is an environmentally safe process, but it requires a large amount of electricity for hydrogen
generation. Hence, this process is only possible in the developed area where regular
electricity supply is possible (McKinlay and Harwood 2010). Hence, it is needful to
find out a cost-effective and eco-safe method for biohydrogen production. The
production of biohydrogen from microbial species is a very inexpensive and
eco-safe method (Dincer 2012). Biohydrogen is produced during photosynthetic
reaction in the plant, algae, or cyanobacteria. It is also produced via aerobic or
anaerobic fermentation process. There are several microbial species that are applicable and used for biohydrogen production (Manish and Banerjee 2008). Some wellknown examples of biohydrogen-producing organisms are Chlamydomonas
moewusii, Scenedesmus obliquus, Enterobacter aerogenes, and Rhodobacter
sphaeroides.
2.4.2 Bioethanol
Nowadays, bioethanol is used as an additive in petrol and diesel. Hence, it is
considered as an alternative of conventional fuels, and it has the ability to replace
the use of petroleum products in the future (Guo et al. 2015; Littlewood et al. 2014;
Saini et al. 2015). It is derived from several types of biomasses which are easily
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V. Singh et al.
2.4 Biofuel Types
Biofuels can be categorized into types such as biohydrogen, bioethanol,
biomethanol, biomethanol, and biodiesel. We have discussed few important biofuels
in this chapter.
2.4.1 Biohydrogen
Biohydrogen is a clean, environmentally safe, and low-cost-based fuel. It has much
more advantages compared to other fuels. Biohydrogen produces high energy which
enhances fuel efficiency. The biohydrogen production is still a developing sector in
biofuel research. Nowadays, biohydrogen generally produces through conventional
methods (Shaishav et al. 2013). There are various conventional methods such as
electrolysis as well as gasification of coal, but these methods have some disadvantages. The major disadvantages of these methods are requirement of high thermal
energy and generation of some hazardous by-products such as gases and wastewater
(Hsia and Chou 2014; Chang and Lin 2004). Electrolysis of water is an environmentally safe process, but it requires a large amount of electricity for hydrogen
generation. Hence, this process is only possible in the developed area where regular
electricity supply is possible (McKinlay and Harwood 2010). Hence, it is needful to
find out a cost-effective and eco-safe method for biohydrogen production. The
production of biohydrogen from microbial species is a very inexpensive and
eco-safe method (Dincer 2012). Biohydrogen is produced during photosynthetic
reaction in the plant, algae, or cyanobacteria. It is also produced via aerobic or
anaerobic fermentation process. There are several microbial species that are applicable and used for biohydrogen production (Manish and Banerjee 2008). Some wellknown examples of biohydrogen-producing organisms are Chlamydomonas
moewusii, Scenedesmus obliquus, Enterobacter aerogenes, and Rhodobacter
sphaeroides.
2.4.2 Bioethanol
Nowadays, bioethanol is used as an additive in petrol and diesel. Hence, it is
considered as an alternative of conventional fuels, and it has the ability to replace
the use of petroleum products in the future (Guo et al. 2015; Littlewood et al. 2014;
Saini et al. 2015). It is derived from several types of biomasses which are easily
40
V. Singh et al.