Identification of the optimal charring temperature and the most suitable wood species for charcoal production in Benin

Charcoal is the main fuel used for domestic cooking in urban and peri-urban areas, with wood being used more often in rural areas in Benin. The quality of charcoal and the anhydrous weight yield of wood charcoal depends on several factors, including charcoal temperature and wood species. The lack of control of these data by charcoal makers in Benin causes socio-environmental and economic problems. The objective of this paper is therefore to determine the optimal charcoal temperature range and wood species best suited for optimal production of excellent quality charcoal in Benin. For this purpose, based on the physicochemical characteristics of about ten wood species, three tropical species, namely Bridelia ferruginea, Burkea africana and Prosopis africana, are selected and charred at different temperatures for a constant time. The physico-chemical characteristics of the coals obtained and the anhydrous weight yield of the carbonisation are determined in accordance with the standards in force. A Principal Component Analysis (PCA) between the calculated values allowed to potentially identify the Prosopis africana and Burkea africana species as the best for optimal coal production. The requirements of standard NF EN 1860-2 on the quality of a charcoal make it possible to identify the Prosopis africana species as the best adapted to the optimal production of quality charcoal. Prosopis africana produces charcoal with the maximum anhydrous weight yield (41.3%) at a charring temperature of approximately 400°C. The physico-chemical characteristics of the coal produced are: lower calorific value (26,82 MJ/kg), ash content (1,35 %), moisture content (6 %), fixed carbon content (78,84 %), volatile matter content (19,81 %).