Evaluation of algae drying process using a solar air dryer built from recycled materials

This article presents a preliminary evaluation of a low-cost solar drying system, built entirely from recycled materials and tested for marine biomass applications. The experiment was set up using an air solar collector constructed from a reused window frame and a drying chamber housed inside a repurposed refrigerator. Tests were conducted on commercial wakame (Undaria pinnatifida) under forced convection, using a solar simulator with 2.0 kW halogen lamps. After 3.75 hours of system operation, a 47.2% reduction in mass was observed, from 477.7 g to 252.3 g. The recycled collector raised the drying air temperature by about 14...15°C above ambient, with a peak of 33.9°C and an air velocity of 0.5...0.6 m/s. The results show that the system is promising, but insulation and airflow need improvement to increase even further the drying air temperature.