70 80 90 100 00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 Temperature of the die (°C) Time (min) Adaptation of pelletizing conditions to a set of agricultural waste from Senegal and Côte d’Ivoire This study has received funding from the European Union’s Horizon 2020 Framework Programme for Research and Innovation under Grant Agreement no 101000762 for the Bio 4 Africa project. B. RABDEAU1, M. CAMPARGUE1, L. G. NDIAYE2, B. K. YAO3, C. BROU3, O. BEDZO4, P. ROUSSET5, K. TYBIRK6, G. JANNOT1, J.M. COMMANDRE5, C. DUPONT7 ____________________________________________________________________________________________ 1RAGT Energie, 2UASZ Université Assane Seck de Ziguinchor, 3INP-HB Institut National Polytechnique Felix Houphouet-Biogny, 4Celignis Limited, 5CIRAD UR114 BioWooEB, 6Food & Bio Cluster Denmark A.S, 7IHE Delft Institute for Water Education Under-exploited agricultural by-product Palm seed shells (a) Cashew nut shells (b) Peanut shells (c) Millet stalks (d) Cocoa pods (e) Raw physical properties not adapted to their final use High moisture content Not stabilized Low bulk density Inadequate particle size Not homogenous Potential applications Clean energy production Clean cooking Animal feeding production Soil amendment production Need to densify/pelletize What are the best pelletizing conditions and adaptations ? Material and methods Feedstock selection Drying at 40°C Shredding at 10mm Grinding at 3mm Mixing during 20min Pelletizing at 6mm : Moisture content (12-16%) Compression ratio (5-14) Characterisation of biomasses Physical (moisture content, bulk density, particle size distribution) Thermochemical (ash content, heating value, volatile matter) Chemical (fixed carbon, C, H, O, N, S, Cl, metals and macromolecules) Characterisation of pellets Fines content (%) Mechanical durability (%) Bulk density (kg/m3) Pellet length & diameter (mm) 30 Pelletizing trials : iterative steps in order to optimize pellet quality Cooling Photos of different pellets produced with peanut shells 16% 14% 16% 12% Moisture content 8 9 5 5 Compression ratio 6% 10% 25% 40% Fines (lower is better) 95,5% 81,3% 83,7% 43% Mec. dura. (higher is better) 696 kg/m3 680 kg/m3 675 kg/m3 588 kg/m3 Bulk density (600-750 kg/m3) Purpose Biomasses tested during the study Flat-die pellet mill used for the trials (3kW-KAHL) Preliminary results Photos of the best pellets obtained for four biomasses Cocoa pods Millet stalks Peanut shells Palm seed shells Biomass 14% 13,5% 16% 12% Moisture content 10 6,5 8 12 Compression ratio 99,2% 98,8% 95,5% 88,1% Mec. dura. 741 kg/m3 703 kg/m3 696 kg/m3 733 kg/m3 Bulk density Findings about pelletizing trials Best pelletizing conditions can be determined through iterative pelletizing trials Adequate combinations of moisture content and compression ratio differ greatly between biomasses : the quantity of water to add and the pellet mill die have to be adapted for each biomass Cashew nut shells : pellets with poor physical quality due to its high oil content Palm seed shells and peanut shells : promising results but can be improved Millet stalks and cocoa pods : adequate pellet quality with different pelletizing conditions Conclusion Observations : Adequate pellet quality results have been achieved for millet stalks and cocoa pods but it can be improved for the others. Prospects : potential ways to improve pellet quality in future trials Use of different pelletizing binders Blending of different biomasses together Pelletizing trials on pyrolyzed biomasses Power curves and die temperature during pelletizing trials of 5kg Peanut shells Cocoa pods 0 1 2 3 4 00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 Power (kW) Time (min) Palm seed shells Millet stalks