The mango is a very common product in Burkina Faso. 300,000 tons of mangoes are produced each year, and a significant portion goes to the agro-food industries. According to Issiaka Bougoum, president of the Professional Association of Mango Exporters and Traders of Burkina Faso (APROMAB), the sector generates more than 14 billion CFA Francs [24 million USD] per year. The production of dried mangoes was 2,774,257 tons in 2018, according to the data from the APROMAB. However, the waste from processing is abandoned in nature and contributes to heavy landfill pollution.
A new process has been developed to transform this waste into energy. Dieudonné Ouédraogo, PhD in exact and applied sciences at the Joseph Ki-Zerbo university, specialist in renewable energies, is at the origin of this technology which converts waste into biogas.
For a kilogram of mango waste, the daily amount of biogas produced is 0.061 m3, according to the inventor. His technology would be an alternative to butane gas, which is costly for mango drying units. “Butane gas is widely used in dried mango processing units [...] while they produce a lot of humid waste including ripe or rotten mangoes and the skins that can be used to produce a lot of energy without any cost,” explains the researcher.
Thanks to the methanization technique, the waste from mangoes is placed in an anaerobic (oxygen-free) environment, mainly in digesters. This helps microorganisms develop, which will transform this waste into biogas within 3 to 5 days inside the digesters until the 20th day.
“The mango processing units will not need to buy butane gas anymore. The waste from mangoes, freely available around them, will allow them to produce the amount of biogas necessary to run their industrial unit. A well-maintained digester can produce biogas for twenty years,” reveals Dieudonné Ouédraogo.
Managing waste: a real puzzle
The introduction of tunnel drying, a technology from South Africa, has brought a true revolution for mango drying companies. Attesta, another type of drying tool, produces 44 lbs of dried mangoes per day while the tunnel produces 550 lbs per day.
But with this high performance comes an equally high amount of waste (84 tons per season for the company Tansyla in Toussiana, in western Burkina Faso, 260 miles from Ouagadougou). The energy source represents a significant financial weight for corporate resources. Most of these dryers work on butane gas.
“Managing the waste and its evacuation requires a lot of resources. Flies were a nuisance for the surrounding area. At first, mango waste was buried in pits dug in the factory. With the heat, they dry in the pit, and they are then transported and burned about 5 miles away from the factory,” explains Roland Nikiéma, production manager at Roseeclat. In his company, besides electricity, the dryers run on 29 bottles of gas per day during the three months of the season. “Electricity is very costly. Without butane gas, we cannot run the factory. Using biogas could be a blessing for waste management and it could allow us to get energy without any cost and reduce our energy bill.”
Recycling waste: the future of production
Issaka Ouédraogo, head of the energy department at the research institute for applied sciences and technologies (IRSAT), is convinced that this technology will allow the units at the national level to obtain an energy source at a lower cost. Treating waste helps create a cleaner living environment and offers many advantages such as the access to a clean energy for cooking and lighting, as well as the access to an organic fertilizer to enhance food safety, explains Gwladys Sandwidi of the National Biodigester Program of Burkina Faso (PNB-BF).
Managing waste will allow Burkina Faso to increase its contribution to renewable energies within the country’s energy record.
Source: 24haubenin.info
