In an effective ‘waste to wealth’ initiative, the Banas Dairy from Banaskantha District of Gujarat is converting cow dung into biogas and slurry. While the bio-gas is then purified into Bio CBG (compressed Biogas) and Bio CNG (compressed natural gas) for use as fuel in vehicles; the slurry is converted into organic manure for use in agricultural fields, thereby safeguarding the environment and at the same time promoting waste management.
Mr. Arun Baroka Additional Secretary, Swachh Bharat Mission- Grameen, Department of Drinking Water and Sanitation (DDWS) (Ministry of Jal Shakti), who visited the plant yesterday and studied the initiative is convinced that it can be replicated across the country.
Banas Dairy that had been registered as Banaskantha District Cooperative Milk Producers’ Union Limited way back in 1969 has been procuring milk from farmers residing in nearby villages in Dama Gram Panchayat of Deesa Taluk. Under the new initiative on Waste to Wealth, they set up a Biogas Plant in February 2020. Towards this, the dairy commenced procuring cow dung from the 254 dairy farmers at the rate of Rs.1 per kilogram.
The Bio-gas plant has the capacity to treat 40 tonnes of cow dung and potato waste each day. To collect the cow dung, each day, tractors are sent to homes of farmers, equipped with weighing scales.
Once the cow dung reaches the plant, it is mixed with water in the ratio of 1:1 and after 2-3 hours is fed into a digester or a closed tank where it remains for 35 days. The gas is stored in large balloon shaped tanks where the slurry is separated into solid and liquid parts. The solid part is now used for vermi-composting and the liquid part is recycled in the plant or directly sold to farmers for use in fields.
The raw gas is then compressed and after removing CO2, water vapour and H2S, the purified gas which contains 95-97 methane (CH4), can be used as fuel in automobiles.
As done in the case of milk, money is transferred to the bank accounts of farmers. For the farmers, selling their cow dung is an additional source of income, making this a win-win situation.
According to reports, the biogas produced from this plant, using German technology can supply CNG as fuel to 100 vehicles a day, providing more mileage.
The project is undoubtedly environment friendly given that in normal circumstances, methane a greenhouse gas which emanates from cow dung disperses into the atmosphere and contributes to global warming. Through this venture, methane gas is tapped and converted into fuel.