Agri-Eco Energy: Evaluating Non-Edible Binders in Coconut Shell Biochar and Cinnamon Sawdust Briquettes for Sustainable Fuel Production
Lasitha Madhusanka, Helitha Nilmalgoda, Isuru Wijethunga, A. D. Ampitiyawatta, Kaveenga Rasika Koswattage
Abstract
This study investigates the production of biomass briquettes using waste coconut shell charcoal and cinnamon sawdust, bound by eco-friendly, non-edible binders: cassava peel starch, giant taro starch, and pine resin. The production process involved carbonization of coconut shells, followed by crushing, blending with sawdust, pressing, and a 12-day sun-drying period. The briquettes were tested for calorific value, density, compressive strength, and shatter resistance. The calorific values ranged from 26.07–31.60 MJ/kg, meeting the industrial standards, while densities varied between 0.83 g/cm3 and 1.14 g/cm3, ensuring compactness and efficient combustion. Among the binders, cassava peel starch provided the best bonding strength, resulting in high-density briquettes with superior durability and energy release, showing a calorific value and compressive strength of 2.11 MPa. Giant taro starch also improved durability, though with slightly lower calorific values but better bonding than pine resin. Pine resin, while contributing to high calorific values, reduced compressive strength with increased resin content, making it less suitable for high mechanical strength applications. Proximate analysis revealed that cassava peel starch-based briquettes had moisture content from 6.5% to 8.6%, volatile matter from 15.2% to 23.5%, ash content from 2.1% to 3.2%, and fixed carbon between 69% and 76.2%. Giant taro starch-based briquettes exhibited 63.2% to 75% fixed carbon, while pine resin-based briquettes had the highest fixed carbon content (66.4% to 78.3%), demonstrating the potential of non-edible adhesives for sustainable, high-performance fuel production.