Kinetic and structural changes during gasification of cashew nut shell char particles

摘要

Cashew Nut Shell (CNS), an abundant waste from the cashew nut production, could become a promising material for gasification. Nevertheless, engineering data regarding this technology is still small and fragmented. In this study, the evolution of the char textural properties during gasification, as well as the effect of operating conditions on char gasification kinetics were extensively investigated and quantified. The textural properties of cashew nut shell char changed significantly following different pathways between CO_2 and H_2O gasification. Micropores and mesopores were well developed along with the conversion in the case of H_2O gasification instead of only micropores in the case of CO_2 gasification. Regarding char gasification kinetics, an increase of the temperature from 800 to 1000°C enhanced five times the conversion rate under an H_2O atmosphere and 15 times under a CO_2 atmosphere. The conversion rate increased two times when the concentration of reacting gases changed from 20 to 60 vol % for both atmospheres. Similarities in terms of gasification kinetics between CNS chars and wood chip chars were found in this range of operating conditions.