Low-cost biodigesters are more than biogas producers – they hold tremendous untapped potential for wastewater treatment. Jaime Martí Herrero reflects on a project that took him from a metropolitan slaughterhouse in Ecuador to Indigenous communities in the Amazon.
Cashew Processing on a Sustainable Basis in Dakoró, Burkina Faso
In the south west corner of Burkina Faso a cashew nut processing unit is converting to using renewable energies. The processing of cashew nuts is very energy intensive. The cashew nut shells have to be steamed open and the steam is traditionally produced by heating water using fuel wood, which is scarce.
In a later stage of the process, the kernel is dried using butane gas to neutralise its poisonous and corrosive oil. With support from SEPS in a project conducted by SNV, the heat produced by fuel wood and butane gas will in future be replaced by the gasification of cashew shells and the combustion of the resultant gas. For that purpose a gasifier and new driers, constructed by the Burkinan enterprise ISOMET, were installed. Once the unit has been fully modified, the process will use 100% renewable energies.
During the visit to the project by a WISIONS team member in November 2012, it was clear that the modification of the process was already in development. At the same time it became evident that some adjustments to the original design had to be made e.g. installing fans to increase the efficiency of the gasifier. However, it is possible to generate the electricity required to power these fans using photovoltaic panels.
These adjustments to the original project concept illustrate the importance of carrying out real experiments on a local level.
