Biomass energy
Energy produced by burning biomass it is known as biomass energy. When biomass is burnt, it releases stored chemical energy, which has accumulated in it through the process of photosynthesis.
When plants are burnt, CO2 gas is released that is recaptured by other plants for photosynthesis process. Therefore there is no gain of CO2 in the nature. There are several ways for using biomass for the generation of electricity.
1. Direct fired 2. Gasification 3. Anaerobic digestion.
1. Direct fired: biomass is burnt to produce steam which is used for turning of turbine and generation of electricity by a generator.
2. Gasification: In these process high temps is used to convert biomass into gas in an environment lacking oxygen. Gas is used to turn turbine and electricity is generated.
3. Anaerobic digestion: in this process organic matter is decomposed by bacteria in an oxygen-starved environment. Methane gas (CH4 ) is produce which is burnt to produce steam to run generator. Biogas is mixture ofCH4, CO2, H2S and hydrogen gas.
Advantages:
1. It is inexhaustible source of energy.
2. It reduces municipal, agricultural and industrial waste.
3. It contributes no new CO2 into the atmosphere.
Disadvantagers:
1. It is expensive to collect, harvest and store raw material.
2. It is more expensive than conventional fossil fuel.
3. If biomass is burnt improperly it may contribute in green house gases.