State of the art on energy recovery from shea residue

Africa has enormous potential for untapped energy resources from agro-processing residues. Ideas for valuing these residues have been developed by several governments, projects and programs, but in Benin the effects seem to be in vain. This work deals with the energy recovery of shea nut residues such as shea shells and cakes, which respectively represent 0.28 tonnes, 0.43 tonnes per tonne of processed dry shea nuts. These residues have a high energy potential which is justified by their calorific value which is 18.7 MJ / kg for the shells and 22.42 MJ / kg for the shea cake. Compared to other residues such as peanut shells, cashew shells, palm shells, shea residues present very interesting physicochemical properties. The shea sector is a booming sector with an annual production of 15,000t and an estimated contribution of 1.3 billion CFA francs, hence the importance of developing processes and technologies for the efficient recovery of residues and especially for the energy supply for Small Medium Firms (SMF). This work brought out the physicochemical properties of shea residue, differents recovery methods such as the design of briquettes for combustion, use in powder form for gasification and direct combustion or pyrolysis for the hulls. Wood energy can thus replace the recovery of shea residue for the production of electricity and heat.