Densification and analysis of the physical properties of bio-coal produced from the pyrolysis cashew nut shells in Benin

To overcome the problem of access to energy in Benin, some researches have been carried out on the production of energy from cashew shells. Thus, two pyrolysis plants on the basis of a reactor designed by CEFREPADE and RONGEAD have been constructed in Benin. Those reactors have been used in Benin for energy recovery from cashew nut shells. Although the pyrolysis products reduce the waste deposit and provide the energy needed for combustion, the exploitation of biochars remains incomplete: they are bulky and difficult to transport because of their low density. To help operators to better manage and facilitate the transport of biocharbons, new research was conducted to densify these biochars. A manual lever press with at lower pressure of 1.80 bar has been developed. Analysis of physical and mechanical properties showed that degree of densification, impact resistance of briquettes and resistance to water penetration were respectively 81%, 90% and 0.94. Also, the effect pressure on density of briquettes and the influence of the drying time on the masses of briquettes were determined. The high rate of densification make that the biocharbons of cashew shells were less bulky and more portable.