Biogas is the gas produced by the biological breakdown of organic matter in the absence of oxygen. Organic matter is the dead plants & animal material.
The methane gas is the component of biogas and is an extremely good fuel.
How it is produced ::
A landfill is a carefully designed structure built into or on top of the ground in which garbage is isolated from the surrounding environment (groundwater, air, rain).
Organic waste is put into and compacted into a landfill, air is gradually squeezed out of the landfill due to the weight of the mass of accumulated matheril landfills are upto 100 meters deep therefore there is little oxygen left (anaerobic situation) and little moisture. Under these conditions, bacteria decompose the organic matters contained in the landfill, producing biogas.