Biomass includes residues from forestry, purpose-grown agricultural crops, trees
and plant types, organic waste, agricultural residue, agro-industrial and
domestic origin waste [sewage and municipal solid waste]. On a worldwide
scale Biomass contributes about 12% to today's primary energy supply, rising
between 40% and 50% in most developing countries. Biomass fuel obtained from
purpose-grown energy crops as well as forests and agricultural waste are being
used in power plants and it is very competitive in price and quality with fossil
fuels. Applying biomass technology is both an environmental and human necessity,
whether on a local scale to get rid of slurries, waste and refuses, or on a
global scale to reduce carbon dioxide content in the atmosphere and hence
reduce global warming.
Bioamss resource | Potential annual supply in EJ |
Energy crop | 128 |
Dung | 25 |
Forestry residue | 14 |
Cereal residues | 13 |
Sugar cane residues | 12 |
Existing forest | 10 |
Urban refuses | 3 |
Total | 205
|
Table: 4 - World potential for biomass energy supplies in the year 2050.
Source: Johnsson et al., 1992.
There are five routes to obtain energy from biomass
Production of crops which yield starch, such
as sorghum, sugar such as sugar cane; cellulose such as Polar, Eucalyptus trees
or other wood-forming trees; and oil such as Sunflower, Euphorbia etc.
Solid waste, which can be burnt.
Manure which produces biogas in
digesters. The two common ones are the Indian floating top and Chinese covered
top.
Landfill: This is a very ancient
technique whereby all the municipal waste and refuse is accumulated in large
ditches, valleys or specifically excavated holes in the land and the bacteria,
decomposing waste, produces methane.
In 1990, there were over 240 landfill gas projects in operation worldwide, 90%
of them in developed countries, about one third of them in USA. The largest
one is in New York and produces 150,000/day. Germany has more than 70 projects,
while UK has 35 projects. The UK projects are saving more than 400,000 tones
of coal per year by using landfill energy and an electrical power generation
of 22MW is achieved from a few of them.
Alcohol production: Many countries now-a-days have alcohol production plants,
which utilise the alcohol directly in cars of partially mixed with petrol to
upgrade the octane level, or it may be used by power station to generate
electricity. Brazil is one of the leading countries in this technology where
13 x 106 tons of alcohol per year is produce which is sufficient to run 3
million cars per year.
Energy crops are being used globally. One of the most successful projects is
that of Ashdown Environmental Company to grow trees which take 8 years to
reach harvesting and use the solid arable coppice to generate 2.5 MW in
Cornwall, UK.
The cost of electricity is about double the conventional one, but it is
clean and does not contribute to the CO2 emission.
Energy from Waste in Kolar
The extremely varied nature of the biofuels is a matter of controversy because
of their present use and future potential. The tremendous potential of biomass
has not been tapped properly, leading to their degradation which of foremost
concern. Lack of adequate relevant information on different bioenergy resources
in regional planning framework hamper efforts to develop alternatives to achieve
multiple goals set by environmental objectives and the energy demand on the
resource. Bioenergy continue to contribute significantly to the total energy
consumption in most of the developing world. In domestic and rural industrial
sector, they play a critical role. In this context it is necessary that the
regional planning exercises formulate policies to develop sustainable bioenergy
systems consistent with the objectives of ecodevelopment and environmental
conservation.
Domestic activities such as cooking and water heating are the major thrust areas,
where energy consumption in the form of bioresource is more in rural areas.
Technological advancement, fortunately made way for cleaner energies such as
biogas, electricity from biomass even in remote rural region. Of all renewable,
non-conventional energy programs, biogas program in India is considered as a
successful one, but only 10% of the available potential is harnessed so far.
Biogas Status in Kolar
Biogas Usage: Biogas can be used for many purposes, mainly for cooking and
lighting in rural area. Biogas can be burned with a gas mantle or can be converted
to electricity, using a dual mode engine. The per capita requirement of gas
for cooking is in the range 0.34-0.43 m3/day (efficiency of a standard burner
is about 60%). The gas requirement to generate one unit of electricity (kWh)
is about 0.54 m3. The calorific value of m3 of gas is about 4713 kcals.
Biogas Potential in Kolar
Firewood is a primary energy source and much of the world still relies on
firewood for domestic and industrial energy need.