Biogas Technology in the Ivory Coast (Region of Korhogo)
History
The biogas project began at the slaughterhouse in Ferkessedougou. For this, 2 large balloon plants were developed and constructed. The gas from these was used to produce electricity for the slaughterhouse in a generator. In 1982, the first six household plants with balloon-type gas-holders were built for the cattle herdsmen and their families in the slaughterhouse pen. The objective of this measure was mainly to save on wood as a fuel. In the course of further dissemination it turned out that light produced by biogas played a great role in the demand for small biogas plants. For this reason, gas was promoted as providing light gas for cooking during the subsequent programme.
Problems
By March 1991, a total of 80 family biogas plants had been built. This number includes all plants, as well as the first demonstration plants and those which have been put out of operation as well as those still operating. In 1991 there were still 10 of the 80 plants in operation. Of the 70 plants out of operation, 7 could be repaired, rehabilitation for 24 is likely, the rest must be written off. The following main causes for taking the plants out of operation were determined:
1) Technical Defects:
After a certain time, the foil becomes brittle and holes appear which have occurred due to damage by animals, children or other effects. The wooden frame to which the foil is attached quickly becomes weather-worn and is eaten by termites. The stoves produced from iron sheets by craftsmen rust quickly due to the high sulphur content and become blocked or completely break down. The flexible gas pipes become porous and leak because of the effect of sunshine.
2) Social Causes:
A lot of biogas plants were individual demonstration plants which were not really wanted by the users, but were more tolerated. Traditional sources of energy continued to receive preference. In polygamous households clear lines of responsibility were missing. The chief of the household traditionally does not get involved in disputes of the wives, and also in this case, had no direct right to issue instructions to the children. This is particularly the case in non-Islamic families where each wife cooks every day for her own children and in turn for the husband. Each wife's household should then be connected to the biogas plant, and service and daily management would have to be carried out by the husband (which would mean a completely new division of labour), or by the wives in turn. Apart from this there is also a conflict of interests between the source of energy for cooking wished for by the wives and lighting, which is the responsibility of the man.
In the demonstration phase when a large number of plants were built in many different places, there was a lack of liaison staff. Their own input at first was under 10%, later it rose to around 20%. After German participation ended, the biogas programme was integrated into the structures of the SODEPRA and put in the charge of the livestock extension officers. In line with structures of hierarchy, information flowed through 3 or 4 levels on the way from user to the biogas service. Furthermore, competence for the selection of sites was no longer with trained biogas staff, but with the livestock extension officers who did not have the necessary detailed knowledge to guarantee selection of an optimum site. Intensive training of the agricultural extension officers like, e.g. in Thailand, by the Biogas Dissemination Programme did not take place.
Slurry
The slurry was never used in a liquid state. When needed, the dried slurry was scratched from the ground and taken to the fields. This was never seen as an additional asset and can also not be plausibly imparted to the farmers. Even a possible reduction of weed seeds in the fertiliser is unrealistic with this method of utilisation. To make biogas technology attractive and economically feasible there will have to be far more extensive measures towards restructuring within farms which e.g. introduce controlled composting of the slurry.
external links + further readings:
