Experimental and numerical investigation of a solar-driven Air-Gap Membrane Distillation (AGMD) system for seawater desalination

Abstract This work focuses on the numerical and experimental optimization of a solar-powered air-gap membrane distillation (AGMD) system using a polytetrafluoroethylene (PTFE) membrane. The main objective is to evaluate and improve the thermal efficiency and freshwater production performance of this low-energy desalination configuration. A hybrid methodology combining numerical modeling (via thermal simulation software) and experimental validation under real solar conditions was employed. Influential parameters such as feed-water temperature (38–83 °C), flow rate (3–5 L/min), air-gap width, and membrane characteristics were systematically investigated. Results demonstrated excellent agreement between simulations and experiments, with less than 5% deviation, confirming the model reliability. The highest permeate flux reached 7.4 kg/m²·h at 83 °C feed temperature and 5 L/min flow rate. This study highlights the potential of solar–AGMD coupling as a sustainable and cost-effective desalination approach suitable for regions with high solar irradiance.