Traditional salt production in coastal Indonesia still relies heavily on firewood, contributing to deforestation pressure, unstable fuel supply, and local air-pollution exposure. This study evaluates multi-feedstock biomass briquettes made from cow manure, rice husk, and sawdust as potential firewood substitutes by assessing their proximate properties and controlled-combustion emissions. Briquettes were prepared using a mixture of 74% cow manure, 5% rice husk, 9% sawdust, 1% tapioca starch, and 11% water, then dried to approximately 12% moisture. Proximate analysis (moisture, ash, volatile matter, and fixed carbon by difference) was conducted following standardized wood/biomass fuel test methods. Flue-gas emissions (SO₂, NO₂, CO, opacity, and O₂) were measured in a controlled combustion chamber (garden incinerator) by an accredited laboratory with triplicate measurements, and results were benchmarked against commonly used local firewood (petai, sentang, rambutan) and published pellet data. The briquettes exhibited 12% moisture (as received) and, on a dry basis, 29% ash, 60% volatile matter, and 11% fixed carbon. Emissions showed very low SO₂ (1.2 mg/Nm³) and moderate NO₂ (7.4 mg/Nm³), but comparatively high CO (1,857.6 mg/Nm³), indicating incomplete combustion under the tested airflow and mixing conditions. Overall, the briquettes offer a clear sulfur-emission advantage over firewood, while combustion-system optimization (air supply and fuel–air mixing) is required to reduce CO and improve combustion completeness for salt-processing applications.
