Enhancing water desalination efficiency through integrated photovoltaic thermal systems with phase change materials

This study investigates the effectiveness of chemically modified composite phase change materials in photovoltaic thermal solar energy systems and hybrid desalination systems in two municipalities, comparing their efficacy using different draw solutions for thorough comparison. The effect of non-composite Paraffin PCMs, Paraffin/CNTs Composite PCMs, and Nitrogen-doped graphene Composite PCMs on system efficiency over 96 h is investigated. The simulation under natural conditions looks at two scenarios: brackish water desalination in Irbid with tetraethylammonium bromide and seawater desalination in Aqaba with sodium chloride as a draw solution. When evaluated after 96 h of operation, non-composite Paraffin PCMs produced the most desalinated water compared to the two chemically modified materials, with 909.45 L and 760.43 L in the Irbid and Aqaba scenarios, respectively. In contrast, using Nitrogen-doped graphene Composite PCMs material produced the most desalinated water during night hours when compared to non-composite Paraffin PCMs; the difference was 37.36 L and 37.77 L in the Irbid and Aqaba scenarios, respectively. Electrically, using Nitrogen-doped graphene Composite PCMs material resulted in a significant improvement; the difference between using non-composite Paraffin PCMs and Nitrogen-doped graphene Composite PCMs material was 119.17 W/the first day of operation in Irbid and 107.16 W/the first day of operation in Aqaba. In the Irbid scenario, the difference in evaporation efficiency and specific thermal energy consumption at 4 a.m. between Nitrogen-doped graphene Composite PCMs and non-composite Paraffin PCMs was 6.26% and 334.47 kWh/m³, respectively. In contrast, it was 7.12% and 439.57 kWh/m³ in the Aqaba scenario, with Nitrogen-doped graphene Composite PCMs being the best option.