diminishing of glaciers, global warming, climate change, rising sea level and decline
of biodiversity.
This has led to the development of renewable fuels: biofuels which are sustainable, effective and are economical natural energy source with lesser carbon dioxide
emissions. They are one of the most important sustainable fuels which limit gas
emissions, improve air quality and also provide a regular income to the farmers.
2.2 Biofuels: Definition, Classification and Characterization
Biofuels are predominantly produced through modern technologies from biomass
(biological raw material) and convert them to solid, liquid or gaseous fuels. Biomass
is the fourth largest renewable energy resource in the world which is natural and
inexpensive, and has been used to produce biofuels. The EIA (U.S. Energy Information Administration) explains the word biomass is primarily used for the production of liquid and gas biofuel which are particularly used as transportation fuels.
Biofuels are considered as a source of renewable energy as these biofuels are
produced from biomass which can be regenerated at a faster rate.
Microbial biotechnology approach and microorganisms are being used to produce
different types of biofuels such as biohydrogen, bioethanol, biogas, biodiesel, etc.
from different types of raw material such as lignocellulosic biomass, carbohydrates,
oil crops, vegetables, etc.
2.2.1 Characteristics of Biofuels
1. Source of renewable energy
2. Cost-effective
3. Eco-friendly and as an alternative to petroleum fuels and non-renewable energy
resources
4. Considered as carbon neutral
5. Sustainable
6. Non-toxic
2.2.1.1 Classification of Biofuels According to Generations
First-generation biofuels are produced from crops, sugars, waste oils or fats
employing traditional technology. These are converted into biodiesel (made from
vegetable oil after pressing), bioethanol (produced from grains with high sugar)
using trans-esterification or fermentation by yeast. The most commonly used firstgeneration biofuels are biodiesel, bioalcohols (bioethanol, biobutanol), biogas,
biochar, and syngas.
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N. Jaiswal et al.
of biodiversity.
This has led to the development of renewable fuels: biofuels which are sustainable, effective and are economical natural energy source with lesser carbon dioxide
emissions. They are one of the most important sustainable fuels which limit gas
emissions, improve air quality and also provide a regular income to the farmers.
2.2 Biofuels: Definition, Classification and Characterization
Biofuels are predominantly produced through modern technologies from biomass
(biological raw material) and convert them to solid, liquid or gaseous fuels. Biomass
is the fourth largest renewable energy resource in the world which is natural and
inexpensive, and has been used to produce biofuels. The EIA (U.S. Energy Information Administration) explains the word biomass is primarily used for the production of liquid and gas biofuel which are particularly used as transportation fuels.
Biofuels are considered as a source of renewable energy as these biofuels are
produced from biomass which can be regenerated at a faster rate.
Microbial biotechnology approach and microorganisms are being used to produce
different types of biofuels such as biohydrogen, bioethanol, biogas, biodiesel, etc.
from different types of raw material such as lignocellulosic biomass, carbohydrates,
oil crops, vegetables, etc.
2.2.1 Characteristics of Biofuels
1. Source of renewable energy
2. Cost-effective
3. Eco-friendly and as an alternative to petroleum fuels and non-renewable energy
resources
4. Considered as carbon neutral
5. Sustainable
6. Non-toxic
2.2.1.1 Classification of Biofuels According to Generations
First-generation biofuels are produced from crops, sugars, waste oils or fats
employing traditional technology. These are converted into biodiesel (made from
vegetable oil after pressing), bioethanol (produced from grains with high sugar)
using trans-esterification or fermentation by yeast. The most commonly used firstgeneration biofuels are biodiesel, bioalcohols (bioethanol, biobutanol), biogas,
biochar, and syngas.
36
N. Jaiswal et al.