Innovative Insights into Solar Drying of Kola Fish: Mechanisms, Modeling, and Optimization

Solar drying is a method employed to expedite moisture reduction and enhance preservation capacity, characterized by intricate heat and mass transfer processes, challenging the micro-level description of drying kinetics. This study aims to optimize solar drying conditions for kola fish using a double slope solar dryer. An empirical investigation was conducted in three modes viz: open sun drying, natural convection solar dryer and forced convection solar drying. The research underscores the advantages of forced convection drying, showcasing a notable reduction of 4 h in drying time in comparison to natural convection. Furthermore, natural convection surpassed open sun drying, yielding an impressive 18-hour time-saving. An empirical model was formulated to establish the relationship between surface temperature and influential parameters, including insolation, air temperature, and ambient temperature. This model exhibited a high degree of reliability, featuring a correlation coefficient of 0.982 and a narrow standard deviation of 0.028, enabling precise surface temperature predictions under various conditions. The study delved into the effective moisture diffusivity range of kola fish, pinpointing it within the range of 5.16 × 10^–9 to 5.29 ×10^–8 m²/s. This understanding of intrinsic moisture migration during drying contributes to process optimization. Furthermore, the determination of the activation energy for kola fish drying, which ranged from 28.34 to 38.83 kJ/mol, elucidates the temperature-dependent nature of drying kinetics and underlying energy-driven mechanisms. These revelations significantly enhance the comprehension and advancement of controlled solar drying techniques for kola fish.