Valorization of Pangium edule shell waste into high-performance charcoal briquettes using cassava waste starch and pine resin as renewable bio-based binders
Abstract
The valorization of underutilized forestry residues into renewable solid biofuels offers an opportunity to reduce waste while supporting low-carbon energy transitions. This study investigated Pangium edule shell waste as a feedstock for charcoal briquette production using cassava waste starch and pine resin as a dual renewable binder system. A completely randomized factorial design was employed to examine the effects of cassava waste starch (8, 12, and 16 wt%) and pine resin (0 and 5 wt%) on proximate composition, physical properties, ignition behavior, and higher heating value (HHV). Moisture, volatile matter, ash, and fixed carbon contents ranged from 3.45–7.15%, 20.67–29.15%, 2.01–2.71%, and 61.00–73.86%, respectively, while density, compressive strength, ignition time, and HHV ranged from 0.60–0.66 g cm -3 , 3.45–7.02 kg cm -2 , 41–128 s, and 6.620–7.080 kcal kg -1 , respectively. Increasing starch concentration significantly increased moisture, volatile matter, density, and com - pressive strength, but reduced fixed carbon. Pine resin markedly shortened ignition time, while its effect on ash content was comparatively limited. Among the tested formulations, 12 wt% cassava waste starch + 5 wt% pine resin (A2B2) provided the most favorable performance profile, with the highest density (0.66 g cm-3 ), compressive strength (7.02 kg cm -2 ), and HHV (7.080 kcal kg -1 ), together with the shortest ignition time (41 s), while maintaining 5.35% moisture, 2.18% ash, and 72.97% fixed carbon. Although volatile matter exceeded the corresponding SNI 01-6235-2000 limit, all formulations complied with the specified moisture and ash limits. The findings dem - onstrate that integrating P. edule shell waste with cassava waste starch and pine resin can produce a structurally robust and energy-rich solid biofuel. The study provides experimental evidence for a dual-binder strategy that balances mechanical integrity,