Risks and Opportunities of Sustainable Biomass and Biogas Production for the African Market

Abstract

Almost all important natural resources – e.g. oil, diamonds, gold, platinum, coal, copper, ore, phosphate etc. – including rare earth metals for industries functioning in the international arena, are available on the African continent. Roughly 15% of the total world market of resources is in Africa. International interest in Africa is via the relatively political and economic stable countries of the ‘Africa 7’ – South Africa, Botswana, Morocco, Ghana, Nigeria, Egypt and Kenya. According to Doing Business Report and the World Bank, statistically, about 60% of the resources from agriculture in Africa are still reserves. Based on the international trends to support developing countries by establishing a market for biomass production, with the aim of advanced energy production, resource efficiency, emission reduction, it has to be balanced with the internationally supervised and important sector of food security. As markets in Africa show, the agricultural sector, including cattle production, to be a very strong market, biomass residues such as cow manure and other organic substances are available as a cheap or free by-product. To turn these natural resources into a valuable commodity, it simply has to be converted by fermentation into biogas usable for cooking or electricity and fertiliser usable for private gardening. Current knowledge has proved how effective and simple biomass and biogas production can be. The output of one ton of silage can produce up to 200 m³ of biogas with a productivity of 5.0–7.5 kWh electricity per m³ of biogas. Cow manure as a source of waste product is available at an annual amount of 7.5–21.0 m³ per animal with a productivity of about 30 m³ of biogas including 56% of methane (CH₄). A micro-biogas production facility is viable with a capacity of about 1 kWh – this is equivalent to the digestion of cow manure from seven milk cows. Using biomass additionally supports the reduction of greenhouse gases (GHG) particularly CO₂, NH₄, N₂O. Compared to CO₂, NH₄ has got 25-times higher and N₂O 298-times higher Global Warming Potential (GWP). The reduction of these greenhouse gases as a side benefit of biomass production provides an indication of how positive this strategy could be for both the agricultural sector as well and general public.