The proposed project activity consists in the installation of a biomass pyrolyzer "Pyro-6F" which produces green charcoal, a high-quality household fuel obtained from unused renewable biomass such as agricultural wastes or invasive weeds. The use of green charcoal instead of traditional wood charcoal obtained from unsustainable deforestation leads, with the project activity, to a reduction in carbon emissions.

Currently, the wood charcoal used by Senegalese households is produced very inefficiently with traditional methods such as earth-mound kilns. With this method, 5,5 kg of dry wood is necessary in average to produce 1 kg of charcoal (standard carbonization ratio used by the FAO in Senegal). Since fuel wood and wood charcoal are the primary sources of energy for the households, the resulting demand on fuel wood is very high, and is currently the main incentive for the uncontrolled deforestation of the surrounding forests.

The proposed project activity intends to replace the wood charcoal and fuel wood used as domestic fuel by green charcoal, an alternative household fuel obtained from the clean carbonization of renewable biomass such as agricultural residues or invasive weeds (typha). Savannah weeds, reeds and various types of straw (wheat, rice or maize), rice husk, or more generally all plants with a sufficient lignin content can be used to produce green charcoal.

This production is achieved by a new biomass pyrolyzer, the "Pyro-6F", which has a production capacity of 120 kg of green charcoal per hour. Full capacity leads to an annual production of 700 tons of green charcoal, obtained from about 2,100 tons of renewable biomass. With a traditional carbonization and wood charcoal, generating an equivalent thermal energy would require over 3,800 tons of dry wood, a value which shows the potential of green charcoal to alleviate deforestation.

The biomass pyrolyzer Pyro-6F performs a continuous carbonization of vegetative material into green charcoal fines. A subsequent agglomeration transforms the fines into charcoal briquettes ready for the end-users consumption. Other attempts made to carbonize biomass on a batch-processing instead of a continuous basis to date have all failed due to mechanical reasons or low energy yields. The process proposed by Pro-Natura has resolved these problems. The technology is now well-proven; it has won the 2001 Altran Foundation International First Prize for the best technological innovation regarding developing countries. The corresponding R&D program has been funded by the ADEME (Agence de l’Environnement et de la Maîtrise de l’Energie), the French Ministry of Industry, the Ile de France Region, the European Commission and the Nicolas Hulot Foundation.

The technology developed by Pro-Natura is based on the utilisation of a chamber heated to 500°C through which the biomass flows continually, the temperature being maintained at a constant level by the combustion of pyrolysis gases that are recycled and burnt in a second chamber. One of the unique features of the process is that once the machine has been pre-heated, the process produces almost all the energy it needs to continue, thus functionning in a quasi-autonomous manner.

The only external supply of energy which is still needed for the continuous process of the Pyro-6F is 10 kWh currently provided by a connection to the local electrical grid. However, since the Pyro-6F is already thermically autonomous and even produces heat in excess, an optimized version is currently in development, which would use the exceeding heat as complementary source of energy, thus achieving 100% autonomy as soon as the initial pre-heating has been completed.