Valorisation énergétique de la matière solide issue des eaux usées et des boues de vidanges de latrines et fosses septiques

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BENIN-PortoNovo©J. Etienne, FFEM
The projects aims to transform and value solid matter from wastewater and faecal sludge from latrines and septic tanks.

The sanitation sector in developing countries, especially in sub-Saharan Africa, does not work well, with over 85% of human waste generated in the world disposed of without undergoing any treatment at all (World Water Assessment Program 2009). Two million people each year mainly children die of water-borne diseases linked to poor hygiene conditions. Methane emissions from wastewater and untreated waste represent 18% of anthropogenic methane emissions worldwide and the uncontrolled disposal of human waste in waterways is responsible for a great deal of pollution in the aquatic environment.

The GreenHeat project from Waste Enterprisers (WE) is an innovative approach to contribute to sanitation services so badly needed among towns and cities in developing countries, which includes most towns and cities in sub-Saharan Africa. Among the most significant obstacles are the high operating costs of conventional waste-treatment approaches.
WE (Waste Enterprisers) is seeking to bring about change in the technical and financial standards that usually govern waste processing, by developing the first completely safe and truly profitable human waste management system.


The GreenHeat economic model was designed to be a human waste management solution at town/city scale. The sanitation service proposed by Waste Enterprisers (WE) and the sale of fuel benefits from low production costs with an increasing volume of processed waste and the attractiveness of the fuel among buying industry partners because of its wide availability on the market. Given the constant availability of input, GreenHeat is produced year-round. This constitutes a major difference with most traditional agricultural residue, which has irregular production flows requiring significant storage facilities. The GreenHeat model is suited to an urban environment and presents a widespread, transferable solution in many places where the input is available (towns and cities) and where there is energy-consuming industry.
The underlying principle of the Waste Enterprisers marketing plan is to renew strategic alliances with cement multinationals. Targeting this industry in particular can be justified through the geographical coverage and scale of this industry, its capacity for encouraging the expansion of this market being simultaneously a consumer of fuel, a major employer and an influential player in the economies in which it operates and the appeal of GreenHeat as a means to achieve its environmental objectives and of meeting its corporate social responsibility obligations.
The network and expertise of Waste Enterprisers are most firmly anchored in sub-Saharan Africa, which is the priority region for WE to develop its short to medium-term plans. Sub-Saharan Africa will have over 60 cities of over a million inhabitants by 2020, and 10 with over 5 million inhabitants. Once WE has become established in Africa, the company will seek out collaboration opportunities with partners whose expertise is employed in other territories, including Asia.


The results expected for each production centre are as follows:


  • The production of over 10,000 tonnes of renewable fuel (GreenHeat) per year, replacing the equivalent of 170,000 GJ of coal.
  • Prevention of the hazardous disposal of 200,000 t of human per month, which would otherwise be disposed of on land or in water with the absence of suitable processing centres.
  • Reduction of up to 22,000 t of CO2 equivalent greenhouse gases per year, avoiding carbon emissions linked to burning coal.


  • Safe sanitation for 500,000 extra inhabitants in Mombasa, Kenya.
  • The introduction of supply chain partnerships and schemes for the raw material in four townships by the end of the project, with low income populations being targeted as the main source of supplies.

20 jobs created at the plant, 75% of which are for low-skilled workers.

Project start date
Project end date
Project grant date
20 years
Duration of funding
financing tool
2 338 265 EUR
Amount of the program
500 000
Amount of FFEM funding
Ministère de l'Economie et des Finances
Institution responsible

Project manager – Dominique Richard