Biomass energy or bio energy is the energy from organic matter. It has been used for thousands of years. Wood is still the world’s largest biomass energy resource but many other sources of biomass can now be used, including plants, residues from agriculture or forestry, animal waste and the organic component of municipal and industrial wastes. The fumes from landfills are used as a biomass energy source.
Of all the renewable sources of energy, biomass is unique in that it is effectively stored solar energy. It is the only renewable source of carbon and can be processed into convenient solid, liquid and gaseous fuels. All biomass ultimately decomposes to its elementary molecules with the release of heat. As with fossil fuel, burning biomass does release carbon into the atmosphere but when biomass crops are grown to replace the biomass resource the equivalent amount of carbon is removed from the atmosphere by photosynthesis.
Biomass resources are plentiful and varied throughout the world. They are primarily food crops, forestry by-products, energy crops and wastes. Biomass sources can be classified into two main categories, plants and waste and within these into a series of sub divisions. The main source are as follows:
Agricultural crops and residues
Sugar industry wastes
Forestry crops and residues
Municipal solid waste (MSW)
Biomass can be used in two fundamental manners – Directly (e.g. burning wood for heating and cooking) and Indirectly (by conversion into a liquid or gaseous fuel, e.g. ethanol from sugar crops, biodiesel from vegetable oils or biogas from landfills and animal waste). Direct use is often termed “traditional” use and Indirect use is often termed “modern” or “commercial” biomass use because it involves more advanced processes, such as gasification and electricity generation.
In 2002, renewable energy sources accounted for 14.2% of the world Total Primary Energy Supply (TPES). As a primary energy source biomass is a significant resource, representing almost 80% of the total supply of renewable energy. Primary biomass energy currently represents approximately 14% of world Final Energy Consumption, a higher share than that of coal (12%) and comparable to the shares of gas (15%) and electricity (14%).