What is Bio-gas?
Bio-gas is one of the most commonly used renewable energy for various domestic and industrial applications. Biogas is the gas produced from biomass like plant, animal and human waste. Bio-gas is the mixture of 55-65% or methane and 30-40% of carbon dioxide. It also contains a number of impurities like hydrogen sulphide and some compounds of nitrogen.
The biogas burns very slowly and it has the calorific value of about 5000Kcal/kg. The biogas is being in number of parts of the world for cooking purposes, which greatly reduces pressure on the use of firewood and petroleum gases.
Sources of Biogas
The bio-gas is obtained from plant, animal and human waste, also called as biomass. The main source of biogas is wet cow dung, which is most commonly used for production of biogas. The other sources of biogas are: sewage, crop residue, vegetable wastes, waste wood, dry leaves of the plants, broken branches of trees, garbage, waste paper, poultry droppings, pig manures, algae, ocean kelp etc.
Advantages of the Biogas
1) Biogas is a clean gas and produces no pollution when it is burnt; hence it is being greatly promoted by a number of environmental organizations.
2) The biogas is obtained from the plant, animal and human wastes, which would have gone wasted in the atmosphere. The biogas obtained from such sources not only gives us extra energy source, but also helps keeping the environment clean by utilizing the waste in a productive manner.
3) The residual material that are left after substances which are used for obtaining the biogas can be used as the fertilizer. Thus they get mixed to the soil and there is no problem in their decomposition. Let me remind you here, that the residual materials left from the coal power plants are very difficult to decompose and are one of the major sources of environmental pollution.
Production of Biogas
Biogas is produced in small plants, which are called as biogas plants or bio-gas generators. The various chemical processes that can used for production of biogas in biogas plants are: digestion, Pyrolysis and hydrogasification. There are various models and designs of biogas plants depending on the type of biomass used for producing the gas and the quantity of the gas to be produced.