Assessment of the Valorization Potential of Agricultural Residues in Agroecological Zone 5 in Bénin

Abstract

The study assessed the exploitable potential of agricultural residues in Agroecological Zone 5 (ZAE5) of Benin, a region with intensive agricultural activities and increasing pressure on forest resources due to the predominant use of wood energy. The main objective was to estimate the quantities of agricultural residues from major crops and livestock production available for potential energy valorization. The methodology combined agricultural production data from 2018 to 2021 with residue-to-product ratios derived from literature and adjusted locally. A survey of 207 farmers was conducted to evaluate the current utilization rates of residues. Results indicated that more than 2 million tons of dry matter of agricultural residues are produced annually, with approximately 71 % available for potential valorization. Corn stalks were the most abundant residue, accounting for 28 % of the total. Methane production potential was estimated at 248 million Nm³, equivalent to 210 kilotonnes of oil equivalent (ktoe) that is more than 25 % of overall energy demand of the area. The communes of Kétou, Tchaourou, and Djidja had the highest potential. The study concludes that valorizing agricultural residues through anaerobic digestion can significantly reduce dependence on wood energy and support local energy transition efforts. However, further research is needed to optimize the anaerobic digestion conditions for the various identified residues.