Menghan Huang, Qin Chen, Daad Phool
This study presents a comprehensive thermodynamic and economic assessment of a newly designed integrated drying system that combines solar thermal energy with biomass combustion and is enhanced through copper-based heat transfer components. The experimental investigation was conducted to evaluate thermal efficiency, exergetic sustainability, environmental benefits, and economic feasibility under humid tropical operating conditions. Field experiments showed that the integrated hybrid drying system reduced the drying duration to 12–18 hours for 5 mm thick agricultural samples, achieving a final moisture content of 18% from an initial level of 68%. In comparison, traditional open sun-drying required 28–36 hours to achieve a similar drying outcome. The system thermal efficiency was measured between 19.5% and 23.2% under different operating scenarios. The exergetic assessment considered four major energy pathways: solar irradiation input, convective airflow through the thermal collector, latent heat associated with moisture removal, and biomass combustion products. The system exergy efficiency varied from 8.2% to 92.7% during operational periods, while the development potential ranged from 0.045 to 18.8 W. Environmental sustainability indicators showed waste exergy fractions of 0.42–0.61 and sustainability coefficients of 2.8–5.9. Complete drying operations required a total energy input of 6.1–38.2 MJ, corresponding to a specific energy consumption of 4.8–28.5 kWh per kilogram of moisture extracted. Carbon footprint analysis indicated that the proposed system could mitigate 52–2,850 tonnes of CO 2 annually compared with conventional diesel-fueled drying systems, depending on operational capacity factors ranging from 15% to 100%. The financial assessment further revealed annual economic savings of $3.20–$189.50 across different utilization scenarios. These findings demonstrate that copper-enhanced hybrid solar–biomass drying technology offers a practical and sustainable solution for rural agricultural processing, supporting energy conservation, emission reduction, and low-carbon development in China’s rural regions.