<![CDATA[This study aims to evaluate and compare the physicochemical quality of charcoal briquettes produced from pure coconut shells and from a mixture of coconut shells and corn cobs as alternative solid biofuels. The research is motivated by the need to optimize underutilized agricultural residues to support renewable energy development and waste valorization. Charcoal was produced through carbonization at 400 °C, followed by grinding to 60-mesh particle size and mixing with tapioca binder (10% w/w). Two formulations were prepared: (1) 100% coconut shell briquettes (TK) and (2) a 50:50 mixture of coconut shell and corn cob briquettes (TT). Briquettes were molded under 400 psi pressure and oven-dried prior to testing. The experiment employed a completely randomized design (CRD) with two treatments and three replications. The evaluated parameters included moisture content, ash content, volatile matter, fixed carbon, and calorific value, in accordance with SNI 01-6235-2000 standard testing procedures. Results showed that pure coconut shell briquettes exhibited moisture content of 0.41%, ash content of 7.10%, volatile matter of 10.35%, fixed carbon of 70.24%, and calorific value of 5,975 cal/g. In contrast, mixed briquettes showed moisture content of 0.63%, ash content of 22.77%, volatile matter of 25.68%, fixed carbon of 50.94%, and calorific value of 4,228 cal/g. Analysis of variance (ANOVA) indicated significant differences (p < 0.05) between treatments for ash content, volatile matter, fixed carbon, and calorific value, while moisture content did not differ significantly. Based on SNI 01-6235-2000 criteria, pure coconut shell briquettes met most quality requirements, particularly in terms of moisture, fixed carbon, and calorific value. However, mixed briquettes exceeded the allowable ash content limit, indicating the need for optimization of carbonization parameters and raw material pre-treatment. Overall, coconut shell charcoal demonstrates superior energy performance and is recommended as the primary raw material for high-quality briquette production. Nevertheless, mixed biomass formulations remain promising for circular bioenergy systems if further process refinement is implemented.]]>
Copyrights © 2026
