As the world transitions towards green energy sources solar drying has become a vital technology for sustainable agricultural production, offering a cleaner, more efficient alternative to traditional drying methods. Solar drying has been demonstrated to be a sustainable and eco-friendly drying process for drying and preserving agricultural products, offering advantages over traditional methods that include faster drying rates, improved product quality, and reduced energy costs. This review examines the mechanisms and methods applicable to solar drying, including indirect and direct solar drying, hybrid systems combining solar drying with other heating sources, and thermal storage materials to address challenges such as intermittent solar radiation. The designs of solar drying systems include various solar collector configurations, drying chamber geometries, and air conveyance mechanisms crucial for efficient drying. This review therefore explores different design approaches and their effects on drying performance, highlighting the importance of understanding the complex interactions between system components. Additionally, the approach for Energy and exergy analysis of solar drying systems was explored, providing insights into energy utilization and efficiency. Finally, this review elucidates the complex transport phenomena governing solar drying, including moisture diffusion, heat and mass transfer, and airflow patterns. It identifies knowledge gaps in existing models and future research directions in transport modelling phenomena to advance sustainable, efficient, and scalable solar drying techniques.

Hydrogen, as a green energy resource, presents a crucial opportunity to reduce emissions and facilitate the transition to sustainable energy, particularly in the shipping industry. The storage pressure for hydrogen gas (like 35 MPa for metal-composite Type III vessels and 70 MPa for polymer-composite Type IV vessels) is prone to leakage or even rupture, and hydrogen could be spontaneously ignited during pressurized leakage; thus, investigating the dynamics of spontaneous hydrogen combustion is essential for safely advancing hydrogen energy in marine applications. This study numerically examined the development of shockwaves and the spontaneous combustion process during pressurized leakage within tubes featuring various configurations (L-shaped and Tshaped, which are commonly found in actual pipelines) at pressures of 35 and 70 MPa. The results indicated that, upon release from the tested pressures, hydrogen would spontaneously ignite within the upstream sections of the tubes beyond the leakage port, with the flame propagating downstream along with the shockwave development. Notably, shockwave and spontaneous combustion characteristics variations differed across the two tube configurations. Velocity measurements showed that values would be lowest near the corner of the L-shaped tube, whereas they would consistently decline downstream in the T-shaped tube. This suggested that measures to mitigate shockwave effects (thus reducing the likelihood of spontaneous combustion) should be implemented in the upstream section of the tubes, regardless of the configuration. Additionally, pressure readings were highest near the corner of the L-shaped tube and showed a consistent decline downstream in the T-shaped tube. Therefore, protective measures addressing stress intensity should focus on the L-shaped tube's corner and the Tshaped tube's upstream section.