In the southern town of Houégbo, Swiss foundation for sustainable development ReBin, together with German social start-up (B)energy, built a 1.3-hectare facility were every week six tonnes of organic waste is processed under oxygen-free conditions, turned into 200 cubic metres of a flammable mixture of carbon dioxide and methane, packed and then used to fuel the kitchens of about 100 households.

“The process is rather simple and works like a human body. You feed the digester with organic waste, animal excrement (such as chicken droppings). For one tonne of waste, you need 1000 liters of water (it’s a 50/50 ratio). In order not to use clean water, we have developed a fish farming activity so we could use the enriched water coming from the ponds. It also provides fresh fish to local people. Biogas is then naturally produced and stocked in big bags before we can distribute it,” ReBin’s founder, Mark Giannelli, told MINING.com.

The input for the underground, dome-like digester is brought into the facility by the villagers, who can fill their bags for free when they bring 20 kilos of waste or receive about $1.14 in cash. If they don’t bring any garbage, they can fill a bag that lasts for four hours for about $0.71; they also pay approximately $0.18 to cover micro-credits that allow them to own their bags and stoves. Local craftsmen fabricate the latter.

The inspiration

In order for it to be a safe process, the “big bags” that contain a little bit over 1 cubic metre of gas need to be tight and the outside temperature needs to be above 20°C, something that is not difficult to achieve in warm countries such as Benin.

Gianelli said he was inspired to bring the project to that specific place after a scouting trip through a few West African countries. Once he landed in the continent’s fourth-biggest exporter of pineapples and took a glance at the mountains of pineapple skins that were being discarded, he saw an opportunity.

“West Africa represents more than 50 per cent of the challenges that we must solve through the 17 Sustainable Development Goals,” the executive explained. “Benin, because it is a stable and peaceful democracy, opened to the changes.”

ReBin’s centre launched in June and since then has processed more than 20 tonnes of waste, saving about 164 tonnes of wood from being used to make charcoal. “The idea was to replace wood and charcoal that are usually transported on the back of women and children through long distances. Results: deforestation and millions of death each year because of the house fires,” Gianelli said.

According to the World Health Organization, close to 500,000 people die in Sub-Saharan Africa every year by smoke inhalation from domestic fires. Worldwide, total deaths from the same cause amount to 2 million, as some 3 billion people rely on stoves and open fires for cooking and heating.

For ReBin’s founder, such devastating outcomes can be avoided by fueling daily life with alternative sources of energy. “We have set an example of ‘nothing is lost, everything is transformed.’ There is no waste on this Planet, only misplaced resources!” he said.