Biogas – energy from waste

Opportunities in the biogas sector are developing fast as the world focuses increasingly on climate change and alternate energies. And there are now real opportunities for businesspeople in Africa.
The Biogas for Better Life ( ) convention in Nairobi in May 2007 was attended by representatives from 27 countries in Africa. This is an initiative aiming to source something like $1m/year over 10 years to build two million household digesters worldwide.
Biogas for Better Life has an impressive founding member list, including the African Development Bank; Biogas Sector Partnership, Nepal; the Netherlands Ministry of Foreign Affairs; The Netherlands Development Finance Company (FMO); the Eastern and Southern Africa Management Institute; German Technical Cooperation (GTZ); the International Institute of Tropical Agriculture (IITA); IT Power; Practical Action; Shell Foundation; West African Economic and Monetary Union; and Winrock Int.
Business people should approach the African Development Bank to identify particular opportunities for themselves in the initiative.
The biogas process
Biogas is an old process that is well established as a rural energy source in China, India and other Asian countries. It relies on a range of micro organisms which produce a methane-rich gas from organic materials when there is shortage of oxygen – so-called anaerobic fermentation.
Required is a mixture of biomass (traditionally manure in rural areas) and, if necessary, liquid to produce a slurry which flows and can be mixed, but which is thick enough to stop solids settling.
Any biomass can be fermented – for example, animal manure, human excreta, peanut shells, maize stalks, grass, brewery wastes, municipal effluent and hyacinth.
Different materials and moisture contents produce different quantities of gas and somewhat different gas compositions.
A fluid feed is an important component, which requires focus in areas where water is scarce. The water does not have to be clean – for instance, household waste water can be used. Other liquids, such as cattle urine and processing waste streams, can also be used.
A biogas digester consists, in principle, of a sealed vessel with a manhole to add material, a gas line (to remove the gas) and an outlet (to allow the digested material, which is a good, odour-free fertiliser, to be removed).
This functionality can be achieved with a number of different designs which suit particular needs and circumstances.
The gas produced can be burnt to produce heat or light, run a fridge or power a generator to produce electricity.
Industrial plants can sell excess gas into existing gas distribution systems or electricity to the electrical grid.
Industrial biogas is becoming important in Europe as governments encourage sustainable environmental policies.
Methane forms naturally in landfill sites where household garbage is piled and covered with soil, producing the necessary oxygen-free conditions.
Overseas, there are many projects where landfill sites are managed to allow the gas to be collected.
In sewage systems, for many years, and in many projects, the activated sludge from municipal sewage treatment has been anaerobically digested to produce gas which is used to heat or produce electricity to reduce the energy consumption of sewage treatment.
More recently, anerobic digestion has increasingly been seen as a means of reducing the waste leaving food processing factories while producing energy which can be used in the factory or converted to electricity.
Household-sized biogas systems have been set up in Africa over the years but have mainly failed for a range of reasons, including poor design, lack of training and lack of support – but mainly because of a lack of direct governmental involvement, which has been shown to be necessary and justified.
But this kind of support is increasingly forthcoming. Business people should now approach authorities to understand the possible developments and to establish themselves as possible suppliers for the programmes that will be established as governments move to implement energy plans.
The opportunity offered by the potential of integrating biogas with food processing, especially in areas where effluent treatment facilities and energy supply are not optimal, should also be investigated.
Businesspeople with skills in building can use the very detailed manuals on designing, building and operating family based biogas plants (such as the one at ) to supply biogas plants at household and farm level. These plants are for users in remote, unelectrified areas.
The Clean Development Mechanism (CDM) is a mechanism that encourages investment in renewable energy projects. Currently it includes very few African projects although there some in South Africa; it has included many successful biogas projects in India. Most countries have a Designated National Authority (DNA, see page 6), which  handles CDM issues locally – a list is available at .
AGAMA Energy of South Africa assists entrepreneurs in both the household and industrial biogas sectors while Talbot & Talbot of South Africa focuses on larger industrial installations, also using carbon credit financing (see page 6).
Note: biogas forms part of the rapidly growing biofuels sector (for more on ethanol and biodiesel technologies, search on )
Other contacts:
African Development Bank, Joachim Arrey: +216 71 10 27 59;
GAMA Energy, Neil Parker: Tel 021 7013364;
CDM Designated National Authority: 27 12 317-8227
Foundation for Sustainable Rural Development (SURUDE), Dr. Sebastian V. Sarwatt: Tel 255 – 744-411 968;
Mali-Folkecenter, Ibrahim Togola: Tel 223 20 06 17; ;
TALBOT & TALBOT (Pty) Ltd., Dr J-F. TALBOT: Tel 033 3461444 or 082 800 0667;