Production of Briquette from Sawdust Using Cellulose Starch as Binder

This study investigates the potential of agro-waste components—specifically sawdust, starch tapioca, and cassava peel—for the production of fuel briquettes, with a detailed characterization of the raw materials and evaluation of various briquette formulations. Proximate analysis of the samples revealed promising fuel properties: the moisture contents of sawdust, starch tapioca, and cassava peel were 9.91%, 9.47%, and 9.58% respectively, ensuring long-term storage stability by mitigating mold growth and reducing moisture-dependent biochemical reactions. The samples exhibited volatile matter ranging from 26.07% to 33.52%, suggesting a high ignition rate during combustion, while the low ash content (2.61%–3.32%) indicates minimal residual inorganic matter that could lead to environmental pollution. Additionally, the fixed carbon values—60.70% for sawdust, 54.18% for starch tapioca, and 58.85% for cassava peel—demonstrate that sawdust, in particular, possesses a higher calorific potential and better thermal properties. Four briquette formulations were prepared by varying the proportions of the agro-waste constituents: Briquette A (100 g sawdust + 100 g starch tapioca), Briquette B (100 g sawdust + 50 g starch tapioca + 50 g cassava peel), Briquette C (100 g sawdust + 70 g starch tapioca + 30 g cassava peel), and Briquette D (100 g sawdust + 30 g starch tapioca + 70 g cassava peel). Fourier Transform Infrared (FTIR) analysis of the sawdust revealed the presence of key functional groups—such as symmetric and asymmetric C–O–C stretches, C=C stretches, O–H, and C=O stretches—that confirm a high content of oxygen, hydrogen, and carbon, which are essential for efficient combustion. These molecular features enhance the binding and energy release characteristics of the briquettes, making them suitable for fuel applications. The performance evaluation of the briquettes indicated that Briquette D had the highest density, which correlates with a longer burning rate and improved thermal fuel efficiency (20.08%), as compared to the other formulations (Briquette A: 18.80%, Briquette B: 19.36%, and Briquette C: 18.94%). The energy value of Briquette D was determined to be 1830.02 kJ/100 g, implying its superior potential as a household cooking fuel. The enhanced thermal efficiency observed in Briquette D can be attributed to the optimal interaction of molecular forces among the sawdust, starch tapioca, and cassava peel. Overall, the study confirms that with the appropriate formulation and processing, agro-waste can be effectively transformed into high-quality fuel briquettes that offer a sustainable alternative for household energy needs.