Biogas is an alternate source of renewable energy. A mixture of gases like methane plus carbon dioxide in a proportion of 60: 40 is produced from the organic matter and is popularly known as biogas. The gas is produced by the action of a mixed community of micro-organisms on organic matter through a process called an anaerobic digestion, in absence of oxygen.
Hence it is an ideal method to produce energy using a wide variety of agricultural, agro-industrial and domestic wastes as the raw materials. As a byproduct the slurry form biogas plant is enriched manure as it has a high content of oxygen, phosphorus and potassium.
Other merits are improvement in rural sanitation, reduction in eye diseases among rural women and easy smokeless and efficient cooking. It can also be used for lighting purposes and running small motors for lifting water and providing power to the cottage industries.
Nowadays, biogas plants are very common in countries like India and China. In India, biogas is mainly produced by using cow dung (Goober). It is very popular in our rural villages and is called as Goober-gas.
Government of India is trying to make it much popular in rural areas as an alternate source of energy for cooking and lighting through its various organisations like the Khadi and Village Industries Commission, Department of Non-Conventional Energy Resources and Council of Scientific and Industrial Research (C.S.I.R.) etc. Government has even announced as subsidy of 60 per cent of total cost.
There are different models of Gobar-gas plant depending upon the size and volume of the digester. A Goober-gas plant can be installed for an individual home or for the whole village or the community. For that, community biogases plants are there that provide energy for cooking and lighting for the whole community.
In India, so far 12.40 lakh biogas plants including 500 community goober-gas plants have been installed under National Programme on Biogas Development. It has saved 43.8 lakh tones of fuel wood annually; whole value in rupees is Rs. 175.6 cores. Besides that, about 71,000 latrine linked biogas plants have also been installed.
Gobar-gas has a bright future in coming years. One drawback in it is the daily feeding of cow dung to the plant. We have large cattle population, highest in the world. So it is not a difficult task. On the other hand, it can solve the energy crisis in our rural areas and can reduce load on fuel wood. It has, therefore, been postulated that with appropriate strategies and rural extension, small sized Goober-gas units can meet the cooking fuel requirement of about 16 to 22 million households by AD 2004-2005.