Bio-gas is produced naturally through a process of anaerobic decomposition from waste / bio-mass sources like agriculture residue, cattle dung, sugarcane press mud, municipal solid waste, sewage treatment plant waste, etc. After purification, it is compressed and called Compressed Bio-Gas(CBG), which has pure methane content of over 95%.
Compressed Bio-Gas is exactly similar to the commercially available natural gas in its composition and energy potential. With calorific value (~52,000 KJ/kg) and other properties similar to CNG, Compressed Bio-Gas can be used as an alternative, renewable automotive fuel. Given the abundance of biomass in the country, Compressed Bio-Gas has the potential to replace CNG in automotive, industrial and commercial uses in the coming years.
The National Policy on Biofuels 2018 emphasises active promotion of advanced bio-fuels, including CBG. The Government of India had launched the GOBAR-DHAN (Galvanising Organic Bio-Agro Resources) scheme earlier this year to convert cattle dung and solid waste in farms to CBG and compost.
There are multiple benefits from converting agricultural residue, cattle dung and municipal solid waste into CBG on a commercial scale:
1 . Responsible waste management, reduction in carbon emissions and pollution
2 . Additional revenue source for farmers
3 . Boost to entrepreneurship, rural economy and employment
4 . Support to national commitments in achieving climate change goals
5 . Reduction in import of natural gas and crude oil
6 . Buffer against crude oil/gas price fluctuations
The potential for Compressed Bio-Gas production from various sources in India is estimated at about 62 million tonnes per annum.
Compressed Bio-Gas can be produced from various bio-mass/waste sources, including agricultural residue, municipal solid waste, sugarcane press mud, distillery spent wash, cattle dung and sewage treatment plant waste. The other waste streams, i.e, rotten potatoes from cold storages, rotten vegetables, dairy plants, chicken/poultry litter, food waste, horticulture waste, forestry residues and treated organic waste from industrial effluent treatment plants (ETPs) can be used to generate biogas.