Evaluation and Modeling the Effect of Clay Soil Binding Ratio and Compaction Pressure Level on the Thermal Properties of Carbonized Rice Husk Briquetting Charcoal

In developing countries, the mismanagement of agricultural residues such as rice husks not only exacerbates environmental pollution but also poses serious health risks. As a byproduct of the rice milling process, rice husks are abundant and largely underutilized, presenting a significant opportunity for renewable energy generation. This study evaluates and models the thermal properties of carbonized rice husk charcoal briquettes by analyzing the effects of varying clay soil binder ratios at five levels (0%, 5%, 10%, 15%, and 20%) and applied compaction pressures at three levels (6mm, 12mm, and 18mm) on burning temperature and duration. It involves a total of 15 treatments arranged using a 5×3 factorial experiment in a completely randomized design, with three replications for each treatment. The regression polynomial equation and modeling graph were developed to predict the outcomes of each treatment combination, enabling the identification of the optimal burning temperature and duration based on experimental findings and the modeling equation. The results showed that the treatment combination of 0% clay soil binder with a 6mm compaction pressure level resulted in a burning temperature below 110°C, with the low burning temperature lasting less than 5 minutes, the peak burning temperature of above 965°C was achieved with 12 mm compaction pressure and a 5% clay soil binder ratio, while the longest burning duration, exceeding two hours, occurred with 18 mm compaction pressure and a 20% clay soil binder ratio. In general a lower clay soil binder ratio reduces ash content, increasing burning temperature, while medium compaction pressure optimizes airflow for peak combustion. Future research could explore alternative binders, compaction pressures, agricultural residues, moisture levels, and particle sizes to enhance burning temperature and duration.