Biomass is carbon based and is composed of a mixture of organic molecules containing hydrogen, usually including atoms of oxygen, often nitrogen and also small quantities of other atoms, including alkali, alkaline earth and heavy metals.
These metals are often found in functional molecules such as the porphyries which include chlorophyll which contains magnesium.
Biomass is fed into a furnace where it is burned. The heat is used to boil water in the boiler, and the energy in the steam is used to turn turbines and generators.
Biomass can also be tapped right at the landfill with burning waster products. When garbage decomposes, it gives off methane gas. Pipelines are put into the landfills and the methane gas can be collected. It is then used in power plants to make electricity.
Also used to produce ethanol, a liquid alcohol fuel. Ethanol can be used in special types of cars that are made for using alcohol fuel instead of gasoline.
The alcohol can also be combined with gasoline. This reduces our dependence on oil
Biomass contains stored energy from the sun. Plants absorb the sun's energy in a process called photosynthesis. The chemical energy in plants gets passed on to animals and people that eat them.
Or we can say: Plants use and store carbon dioxide (CO2) when they grow. CO2 stored in the plant is released when the plant material is burned or decays. By replanting the crops, the new plants can use the CO2 produced by the burned plants. So using biomass and replanting helps close the carbon dioxide cycle.
It is also a renewable energy because plants to make biomass can be grown over and over
 Ethanol (bioethanol) is extracted by distilling plants which a high sugar content (sugar beet, sugarcane) or high starch content (wheat, potatoes, corn, etc.). ethyl alcohol is obtained by fermentation of the sugar or starch.
Generating energy from biomass is also called as conversion of biomass.
Various processes are employed to obtain energy from biomass. Three of them are:
biomass is used as fuel to heat water to obtain high-pressure steam. The steam is fed to a turbine linked to an alternator, which produces electricity.
The low-pressure stream given off by the turbine may be used to supply heat to district heating networks as well as in various industrial processes: sugarcane distillation, paper-making, esterification, etc.
when waste energy is also made use of in a power plant, this is called cogeneration.
Gasification is a partial oxidation process whereby a carbon source such as coal, natural gas or biomass, is broken down into carbon monoxide (CO) and hydrogen (H 2 ), plus carbon dioxide (CO 2 ) and possibly hydrocarbon molecules such as methane (CH 4 ).
Heating water in central heating, district heating or process heating applications
Steam for electricity generation or motive force
As part of systems producing electricity or motive force
Transport using an internal combustion engine.
Types of gasification: Low temperature & high temperature gasification
Pyrolysis is the precursor to gasification, and takes place as part of both gasification and combustion. It consists of thermal decomposition in the absence of oxygen. It is essentially based on a long established process, being the basis of charcoal burning.
Biomass energy densification for transport or storage
The wide use of biomass may significantly contribute to developing rural areas, as opposed to urban areas, because it will create sustainable activities that make use of unexplored agricultural resources and also provide access to electricity in isolated areas where the power supply is not always reliable.
Producing energy using biomass also allows for diversifying sources of income in the agricultural sector, where competition is fierce.
The traditional income generated by the production of electrical power will contribute to ensuring greater economic stability for agricultural producers.
When biomass materials are not the byproducts of an existing industry (bagassse produced by sugar factories, sawdust by forestry operations), using them as biofuel results in an increase in prices;
the cost of collecting the dead wood and branches from felled trees in forests and transforming then into wood pellets is Euro 40 to Euro 50 per metric ton, whereas the cost of sawmill waste is Euro 20 / metric ton.
In these countries, subsides are needed to make biomass a competitive energy. However, in contrast to other sources, biomass has a low environmental and social impact, which lower its cost over the long term.