Thermal Performance and Heat Transfer Characteristics of Sustainable Banana Peel Biochar Briquettes for Small-Scale Fish Smoking

This study presents an experimental investigation of the thermal performance and heat transfer characteristics of sustainable banana peel biochar briquettes for small-scale fish smoking under real production conditions. Experiments were conducted using a portable biomass-fueled smoking chamber and benchmarked against coconut shell briquettes and wood sawdust briquettes. Key parameters evaluated included temperature–time profiles, inter-rack temperature gradients (ΔT) as indicators of thermal uniformity, conductive and natural convective heat fluxes, and water evaporation rates representing drying performance. The results demonstrate that banana peel biochar briquettes exhibit the most stable thermal behavior, characterized by an inter-rack temperature gradient as low as 3 °C, compared with 5 °C for wood sawdust briquettes and 6 °C for coconut shell briquettes. Heat transfer analysis shows that banana peel biochar briquettes generate the highest natural convective heat flux, reaching 96 W m−2, exceeding wood sawdust briquettes (80 W m−2) and coconut shell briquettes (64 W m−2). The enhanced convective heat transfer promotes improved moisture removal, resulting in a maximum evaporation rate of approximately 0.038 kg h−1 and more uniform drying during the smoking process. From a thermal engineering perspective, these findings demonstrate that the combustion characteristics of banana peel biochar briquettes significantly influence heat distribution, natural convection intensity, and thermal uniformity in biomass-based smoking applications. The study highlights the potential of agricultural waste-derived biochar briquettes as sustainable and high-performance fuels for improving thermal efficiency in small-scale fish smoking.