Microbes in Production of Biogas

Ø Microbes produce many gases during their metabolism.

Ø The type of gas produced depends upon the substrate they grow on and the type of microbe.

Ø Anaerobic bacteria usually produce methane along with CO₂ and H₂. Such bacteria are called methanogens. Example – Methanobacterium.

Ø Methanogens are commonly found in anaerobic sludge (as in sewage treatment) and in the rumen of cattle. In the rumen of cattle, these bacteria help in cellulose digestion.

Ø Hence, excreta of cattle (gobar) are rich in methanogens. Biogas is also called gobar gas.

Biogas Plant − Components of biogas plant:

o Concrete tank− Here, slurry of dung is fed. It is a 10 − 15 feet deep tank.

o Floating cover− Placed on slurry; rises as the gas is produced

o utlet − It is connected to the pipe.

o Pipe − It supplies the biogas to nearby houses.

o Outlet for spent slurry − Spent slurry can be used as a fertiliser.

· Biogas plant is usually set up in rural areas since cow dung is available in abundance there.

· Biogas is used for cooking and lighting.

· Biogas technology in India is due to the efforts of:

o IARI (Indian Agricultural Research Institute)

o KVCI (Khadi and Village Industries Commission)