Converting biomass
Anaerobic digestion
Anaerobic digestion occurs when bacteria breaks down organic material. This occurs in a situation where there is no oxygen present. This process produces a mixture of two gases - methane and carbon dioxide - that is called biogas.
Biogas can be produced in landfill where the organic material breaks down over time. Pipes are pushed into the landfill allowing the methane to be collected.
Animal waste, including human waste, can be mixed with water and placed in an airtight container called a digester. Bacteria break down the waste and methane is produced.
The methane can be used as fuel to produce electricity.
For further details on this process, refer to the landfill power generation section.
Briquetting & pelletising
In this process biomass is compressed into briquettes or pellets at high temperatures and pressures. This reduces the volume of the biomass making it easier to store and transport. The briquettes or pellets can be used in the same way coal is used to produce electricity.
Direct combustion & cogeneration
Burning biomass is the main way in which it is used to produce energy. Biomass such as wood chips, bagasse and MSW can be burnt to produce steam that will turn steam turbines.
