Pineapple waste at Promo Fruits Benin is bulky and difficult to manage. In addition, the company is dependent on electrical and thermal energy. With the aim of reducing waste and the energy bill, a technical-economic and environmental study was carried out. The methodology used is based on the analysis of energy needs, the study of recovery processes, economic and environmental analysis. The results showed that the company's annual energy consumption in electricity and diesel is 600 MWh and 307,695 liters respectively. The annual waste potential available is 11,607 T while that necessary to meet the company's energy needs is 14,904 T. The study of the choice of process retained biomethanation. The Functional Specifications of the reactor allowing said recovery has been defined and the digester has been sized. The economic study for a period of 25 years revealed that the investment cost is 2,101,196,208 FCFA and that the operating cost is 19,385,128 FCFA per year. In addition, the study made it possible to reduce from 96,434,691.12 FCFA to 0 FCFA the annual bill for electrical energy and from 123,078,750 FCFA to 71,898,186 FCFA for thermal energy of the company. From an environmental point of view, a reduction of 472.76 tonnes CO_2/year is obtained from emissions produced by non-recovered waste.
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.