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Biomass is all organic fossilized material, including plants and animals and their biproducts. It is a scientific term for living matter, but the word is also used to denote products derived from living organisms - wood from trees, harvested grasses, plant parts and residues such as twigs, stems and leaves, as well as aquatic plants and animal wastes. All the Earth's biomass exists in a thin surface layer called the biosphere. This represents only a tiny fraction of the total mass of the Earth, but in human terms it is an enormous store of energy - as fuel and as food. More importantly, it is a store which is being replenished continually. The source which supplies the energy is of course the Sun, and although only a tiny fraction of the solar energy reaching the Earth each year is converted into biomass, it is nevertheless equivalent to over five times total world energy consumption.
In bioenergy, this biomass is burnt to produce heat energy and electricity. Bioenergy is an alternative renewable energy source that has raised some environmental concerns. Biomass energy or "bioenergy" includes any solid, liquid or gaseous fuel, or any electric power or useful chemical product derived from organic matter, whether directly from plants or indirectly from plant-derived industrial, commercial, or urban wastes, or agricultural and forestry residues. Thus bioenergy can be derived from a wide range of raw materials and produced in a variety of ways. Because of the wide range of potential feedstocks and the variety of technologies to produce them and process them, bioenergy is usually considered as a series of many different feedstock / technology combinations.
In practice, we tend to use different terms for different end uses - e.g. electric power or transportation.
- Biopower are the biomass power systems that use biomass feedstocks instead of the usual fossil fuels (natural gas or coal) to produce electricity.
- Biofuel or Biomass Fuel is used mostly for liquid transportation fuels which substitute for petroleum products such as gasoline or diesel.
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