Résumé
This study presents the characterization of an innovative simple and low-cost staged combustion reactor designed for cashew nut shells (CNS), with the aim of optimizing their energy recovery for productive applications. A comprehensive experimental campaign was conducted to evaluate the performance of the pilot unit installed at the BioWooEB platform of CIRAD. Additional tests were carried out on a less instrumented prototype operating under industrial conditions in Bobo-Dioulasso. The pilot tests revealed moderate thermal efficiency, below 50 %, due to operational constraints. The presence of flow meters introduced pressure drops and disrupted airflow distribution—particularly between Air 1 and Air 2—leading to a misinterpretation of the reaction regime. This caused a reduction in the calorific value of the produced gases and decreased the overall system efficiency. Despite these limitations, the pilot exhibited satisfactory environmental performance, with minimal pollutant emissions. In contrast, the prototype achieved higher thermal efficiency (≥60 %), attributed to improved airflow management and the absence of flow meters, which allowed for a more homogeneous distribution of air. This resulted in slower solid bed movement, higher reactor temperatures (up to 800 °C), and enhanced conversion of CNS into high-energy syngas. However, challenges such as localized overheating and insufficient pressure persist, requiring further optimization. Addressing these technical barriers could substantially improve CNS combustion performance, positioning this technology as a viable and cleaner alternative to fossil fuels for energy generation in small and medium-sized agro-industrial enterprises in West Africa.