PinkMonkey Online Study Guide-Biology
CHAPTER 9 : BIOENERGY
Socio-economic development, standard of living, as well as the quality of life of any country largely and primarily depend on the availability and supply of energy. The availability and supply of energy come under great pressure because of increasing demands of the ever-increasing global population. This eventually leads to the problem of energy crisis. This is especially true for the developing countries like India.
At present, the main conventional source of energy used
all over the world is the ’fossil fuels’ (i.e. the huge deposits
of plant and animal remains accumulated during the geological past
and which serve as the main source of energy such as. petroleum
(oil), natural gas, coal, derivatives of coal, oil shale, tar sands,
etc.). However, fossil fuels are non-renewable and hence their deposits
will eventually be exhausted. Therefore, alternative energy sources
must be tapped and exploited to their full potential. Solar energy,
nuclear energy, energy from tides, energy from wind, and hydroelectric
energy are some of the alternative resources. However, one of the
major renewable alternative sources is the bioenergy obtained
"Bioenergy refers to the various
forms of energy (e.g. heat (fire), fuel, oil, biogas (methane), ethanol
(alcohol), methanol, charcoal, oil gas, etc. ) generated from the biomass
by using simple or complex biotechnological methods."
"Biomass refers to all the living organisms as well as their products and wastes."
"Biofuels are the combustible bodies of plants or combustible products derived from the biomass."
Biofuels are a renewable resource of energy. The primary source
of the energy stored in biomass is solar energy which is trapped by green
plants during photosynthesis and stored as potential energy in organic
Biofuels are obtained from the terrestrial biomass (
wood, forest litter etc.), aquatic biomass (algae and water weeds like
water hyacinth, Pistia, Salvinia, Azolla, etc. ), various
types of organic wastes (agricultural and industrial wastes, municipal
and domestic wastes like sewage, garbage, animal drug, wastes from slaughter
houses, etc. ). Plants that produce alcohol, oil and petroleum (petro-plants)
also are a source of biofuels.
Various methods and technologies which convert biomass into
bioenergy fuels fall into two main categories.
(1) The non-biological processes such as (a) direct
combustion (b) conversion of biomass into liquid fuels such as fuel oil
(e.g. by pyrolysis - a type of fertilization, liquefaction, etc. ) and
(2) The biological process or bioconversion
involves the conversion of biomass into bioenergy, fertilizer, food and
chemicals through the biological action of micro-organisms. One of the
important biofuels obtained through bio-conversion is natural gas,
a biogas (methane).