Our Work / Sanitation Technology
Public Toilet Linked
Biogas Plant
Sulabh International Social Service Organisation
Public Toilet Linked
About This Technology
Transforming Waste
into Wealth
Sulabh International Social Service Organisation’s public toilet-linked biogas plants represent an innovative and environmentally sustainable approach to sanitation and waste management. Developed under the leadership of Dr Bindeshwar Pathak, this technology converts human excreta from public toilets into valuable resources such as biogas (clean energy) and bio-fertiliser, transforming waste into wealth while improving public health and environmental conditions.
In this system, human excreta from Sulabh public toilets flows into an underground biogas digester, where it undergoes anaerobic fermentation by methanogenic bacteria, producing biogas that is safely stored and used as a renewable energy source.
Merits
Merit 01
Recycling and reuse of human excreta for biogas generation is an important way to get rid of health hazards from human excreta.
Merit 02
The Digester is built underground into which excreta from public toilets flows under gravity.
Merit 03
One cubic foot biogas is produced on an average from human excreta per person per day.
Merit 04
Biogas is utilised for cooking, lighting through mantle lamps, electricity generation and body warming during winter. Cooking is the most efficient use of biogas.
Engineering Details
Technical Specifications
Human excreta based biogas contains 65–66% methane, 32–34% carbon dioxide and, rest the hydrogen sulphide and other gases in traces + moisture.
Methane is the only combustible constituent, which is utilized in different forms of energy. Its calorific value is 24 MJ/cum or about 5000 Kcal/cum.
Biogas burners are available in a wide ranging capacity from 8 cft to 100 cft biogas consumption per hour. It burns with a blue flame without soot and odour. The biogas mantle lamp consumes 2–3 cft per hour having illumination capacity equivalent to 40 W electric bulbs at 220 volt. Motive power can be generated by using biogas in dual fuel internal combustion (IC) engine.
In the last 14–15 years, the IC engines have been mostly replaced by biogas engines, which do not need diesel as a support fuel. These are more dependable in terms of performance. The dual-fuel engines uncertainty about diesel consumption.
Recognition & Impact
Technical Validation
Sulabh International’s toilet-linked biogas plants have also received technical validation from national research institutions and support from the Ministry of Non-Conventional Energy Sources, highlighting their relevance as a decentralized sanitation and renewable-energy solution.
By integrating sanitation infrastructure with renewable energy generation, this decentralized model reduces environmental pollution, eliminates the need for manual handling of human waste, and promotes dignified, sustainable sanitation systems for communities.