"Biomass" seems to be a very well known and widely pronounced word during these days when the topics of "global warming", "green energy" "waste management" "renewable energy" etc are being widely discussed. Although the terminology is very well known, there are lots of aspects to know about it.
Basically biomass means some kind of partially degraded or waste and mostly biological matters. Biomass includes waste matters which can be used to produce energy. This also includes biological matters which are sometimes used to produce fibers or chemicals. This may include wood, garbage, decomposed dead animals, forest residues, domestic wastes etc.
Biomass may be misinterpreted as fossil fuels because both originate from biological matters and both are sources of energy. But in actual, biomass is different from fossil fuels. Although, both of them originate from biological matters, fossil fuels takes millions of years to attain the stage where it can serve as a source of energy whereas biomass don't. Again, biological matters have to first decompose to attain the stage of fossil fuel, whereas in case of biomass it is not so. It can be said that biomass forms the origin of fossil fuels.
Since it is not convenient to use biomass as direct source of energy, hence is converted to liquid biofuels or gaseous biogases to be used as a useful fuel, which can conveniently stored, transported or used. A number of processes for such conversion are available.
Just like any other fuel, use of biomass fuel also emits pollutants in the environment. Biomass seems to be nothing different from other fuels in respect to the pollution caused while in use. If we see the origination and life cycle of biomass, is seems that even though it emits pollutants like other fuels, in some other way it also compensates the same up to certain extent. Biomass is mainly composed of wood and other forest residues. Trees and green forests intakes carbon dioxide and emits oxygen, which is good for environment, in reducing greenhouse effect, and so for human being. When the forest dies it forms biomass which is again a useful thing for human being. Again, biomass is also composed of waste materials up to certain fraction. This also helps human civilization, in managing waste matters.
Organized plans may be put up in future for cultivation of planned forest areas which would provide the source for biomass. Although it sounds pretty ambitious and extremely good there are hurdles associated with it. Big trees take many years to grow up sufficiently to be used as a biomass. Other options with fast growing or hybrid species or small trees may be thought of. Hope, in future some advancement will eradicate these problems and will make biomass a reliable source of energy.