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Biodigesters Reduce Indoor Air Pollution in Burkina Faso

indoor air pollution in Burkina Faso

Indoor air pollution from burning biomass is one of the 10 most significant threats to public health worldwide. Burkina Faso is one of the 21 countries most affected by indoor pollution. The country’s government has rolled out the National Biogas Program as part of its green economy initiative to reduce indoor air pollution in Burkina Faso.

Globally, more than three billion people cook with wood or charcoal. Exposure to indoor smoke from burning biomass is linked to pneumonia in children and chronic respiratory diseases in adults.

About 86 percent of Burkina Faso’s energy comes from burning biomass like firewood and charcoal. In rural areas, this percentage is often even higher. Approximately 16,500 deaths per year can be attributed to indoor air pollution in Burkina Faso.

The National Biogas Program has the potential to reduce indoor air pollution in Burkina Faso. The government of Burkina Faso, led by President Roch Marc Christian Kabore, is working in tandem with Dutch NGO Hivos and Dutch development organization SNV to install 40,000 biodigesters by 2024. The government of Burkina Faso subsidizes the biodigesters so that the technology is more affordable for poor households. 

Biodigesters are enclosed structures that break down animal dung and food waste into methane gas. The biogas can be piped into a stove for cooking. The nutrient-rich compost left over can be used as fertilizer. So far, 8,000 biodigesters have been installed.

Each biodigester creates 3.62 tons of CO2eq emission reduction per year. Transitioning to biodigesters is particularly impactful for women and children, who often spend hours collecting biomass to burn and who are typically responsible for household cooking. Biodigesters protect this vulnerable group from the harmful health effects of indoor air pollution in Burkina Faso.

Approximately 85 percent of Burkina Faso’s population lives in rural areas and works in agriculture. For these agrarian households, biodigesters produce economic benefits. Farmers with biodigesters produce natural, high-quality fertilizer, eliminating the need to buy chemical fertilizer. One 6m3 biodigester produces 20 tons of compost per year. 

Fields fertilized with slurry from biodigesters produce greater yields. The slurry also increases the soil’s capacity to hold rainwater, which is particularly important during droughts. 

Additionally, some regions of Burkina Faso have experienced wood scarcity. Biodigesters protect owners from increasing wood fuel prices.

Biodigesters also create tangible environmental benefits. About 46 percent of Burkina Faso’s territory suffers from soil degradation. Harvesting wood for energy has created a deforestation rate of 105,000 hectares per year. Biodigesters replace wood-burning stoves and thus reduce the amount of wood that must be harvested for energy each year. 

The U.N.’s Clean Development Mechanism has issued the first carbon credits in Burkina Faso. The World Bank’s Carbon Initiative for Development (Ci-Dev) program is now purchasing carbon credits created by the biodigesters. Ci-Dev will purchase 540,000 certified emission reductions through 2024. This revenue stream is used to lower the price of biodigesters and to extend the warranty on the devices. With the numerous benefits of biodigesters, they are sure to have an impact not only on air pollution in Burkina Faso, but on may aspects of its people’s livs.

– Katherine Parks

Photo: Flickr

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Biodigesters: Sustainable Fuel from Manure

Biodigesters_Sustainable_Fuel_from_Manure
Farmers interested in sustainable agriculture have taken to doing something different with the manure they collect from their livestock. Normally, manure is piled into a mound in the corner of the farm to be used as fertilizer when needed or simply left to break down in its own time. Sustainable farms, however, are pouring the manure into plastic sheeting measuring about a meter wide and ten meters long. The end result resembles a large white sausage. This plastic encased manure is called a biodigester, and it’s not a new idea.

Biodigesters or anaerobic decomposition was first documented in the early 18th century. Breaking down waste through fermentation in a sealed container has been used since the early 20th century. It has only been in recent years, however, that small farmers have embraced the use of biodigesters.

The long plastic tube is the most common kind of biodigester. They consist of a few very simple parts. The main body is made of hardy plastic sheeting rolled into a tube with PVC pipes at both ends. One pipe is the waste entrance where farmers put manure into the biodigester. The other end is the fertilizer exit. The highest point of the biodigester has a third PVC pipe that usually leads into the house. This pipe collects and directs the natural gas from the fermented manure and sends it to places it can be used as an energy source, like a stove or a furnace. Everything that happens within the tube is technology-free. There are no mechanisms or added chemicals within the body of the biodigester.

Biodigesters perform several functions at once. As it breaks down, the manure separates into flammable natural gases, mostly methane, a liquid fertilizer called biol and solid waste. The high-methane environment inside the biodigester chokes out all of the aerobic bacteria normally found in manure, like e. Coli. This means that fertilizer fermented in biodigesters is sterile. This is a huge advantage over raw manure, which can spread bacteria and other contaminants to crops when used as fertilizer. Furthermore, studies have shown that the biol produced by this fermentation process increases plant health.

Theoretically, biodigesters can be used anywhere there is enough ground, rural or urban. They are mostly popular in developing countries. Currently, their use is widespread in Vietnam, India, China and Nepal. Their recent success in South and Central America is due mostly to the fact that development agencies have switched from marketing them as an affordable energy source to marketing them as an affordable and effective fertilizer source.

Every biodigester produces both biol and methane. Another possible cause of the increase in interest is the fact that the materials to build a biodigester are now very inexpensive and available in almost every town. Their simplicity means farmers can build and install their own biodigesters relatively easily.

Hopefully this trend toward green energy and fertilizer will only increase as the international community turns its attention to the Sustainable Development Goals, where environmentally friendly technology like biodigesters are primed to play a central role.

– Marina Middleton

Sources: Sustainable Development, World Bank, Clay for Earth, Agricultures Network, FAO
Photo: Flickr