Biomass includes wood, fast growing plants, cultivated algae, animal remains, etc. It is a source of energy from, ultimately, the sun, and is renewable when properly used.
The biomass can be used directly as fuel. About half of the world’s population still relies on biomass as the main source of energy. The problem is that in many places the wood is burning and destroying forests at a faster rate than they are replenished, so we are causing serious environmental damage: deforestation, loss of biodiversity, desertification, degradation of water sources , etc.
Can also be used for preparing the biomass liquid fuels such as methanol or ethanol, which are then used in engines. The main problem of this process is that the yield is low, 30 to 40% of the energy contained in the source material is lost in the preparation of the alcohol.
Another possibility is to use biomass for biogas. This is done in the deposits that accumulate organic debris, crop residues and other materials that can decompose in a tank that is called digester. In this debris that deposit fermented by microorganisms and gases produced mixture can be stored or transported for use as fuel.
The use of biomass as fuel has the advantage that the combustion gases are produced in much smaller proportion of sulfur compounds that cause acid rain, than those from coal combustion. CO2 when burned added to the environment, but this effect can be counteracted with the sow or plant new forests that remove this gas from the atmosphere.
Today they are doing many experiments with different types of plants to take advantage of the best possible way this promising energy source.