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Bio-energy is obtained from biomass (any plant or
animal matter). Bio-energy in the form of heat or
electricity can be produced by using biomass directly
as a fuel or by converting it to biogas or liquid
bio-fuel. The main source of biomass include:
- Industrial and agricultural wastes and residues
such as sugar cane waste (bagasse), wood waste from
forestry operations,and residues from other short
rotation crops such as straw and husks.
- Organic waste from animal husbandry.
- Energy crops, such as sugar cane,corn and trees
grown in short rotation plantation.
The main processes of utilizing these biomass
sources include:
- Direct combustion, usually of solids,in boilers
or furnaces.
- Gasification via physical or chemical
conversion processes to a secondary gaseous fuel,
followed by combustion in a engine or turbine.
- Biological conversion via bacterial anaerobic
digestion to methanol rich biogas for use as a
gaseous fuel;
- Chemical or biochemical conversion to produce
methanol, ethanol or other liquid fuels.
A bio energy project can often be designed to
co-generate both heat and electricity. Such project
may also create a cost-effective solution to the
disposal of agriculture or industrial wastes that may
otherwise become potential environment problems, for
example UNIDO's sisal waste project in Tanzania.
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