Biogasdoneright®

Problem statement

It is used for a sustainable agriculture to address the simultaneous demands of food, energy, and environmental security. Biomasses are converted to biogas and thence to electricity, heat and / or biomethane; stable carbon and plant nutrients are recycled to the fields by applying effluent digestate avoiding the greenhouse gases (GHG) emissions and other environmental impacts associated with fossil-based fertilisers.

Executive summary

Biogas production in rethinking innovative agricultural systems to produce food and bioenergy achieving large environmental benefits.

Technology description

Biogas is produced from the anaerobic decomposition of organic feedstock such as manure, agricultural residues, agro-industrial by products, energy crops, food waste. These residues are placed into anaerobic digesters (biogas plant) in which specific microorganisms at controlled conditions break down the organic materials producing biogas and digestate. Pre-treatment technology (i.e.: mechanical devices, trace elements supplementation, enzymes) can be used to optimize the process. The effluent from anaerobic digestion is called digestate and it is a natural fertiliser. It is returned to the land by irrigation (“fertigation”) recycling a large fraction of the mineral nutrients and increasing soil carbon levels with soil fertility benefits (organic farming).

Market deployment considerations

Anaerobic digestion is a very scalable technology in terms of plants size and feedstock/biomasses exploiting. To implement anaerobic digestion widespread in Africa, capital and operational costs reduction and small-scale technology development are key aspects for the market deployment.

Environmental considerations

No, negative relevant environmental impact. On the contrary, a primary cause of illness and reduced life expectancy in sub-Saharan Africa is open-fire cooking and heating with wood. Using anaerobic digestion at the African village level to process animal wastes, crop residues, and energy crops could improve soils providing some electricity and biogas for heating and cooking.