Thermo-economic and environmental evaluation of thin film evaporation using novel metal-organic frameworks to enhance solar desalination performance

The growing shortage of freshwater resources has spurred the development of innovative and sustainable desalination technologies. This study presents a thermo-economic analysis of an innovative hemispherical solar still (HSS) enhanced with a novel Metal-Organic Framework (MOF), specifically Iron-Aluminum Benzene Tricarboxylate. The MOF was characterized through structural, morphological, and optical investigations and integrated into the HSS using two enhancement methods: (I) as a nanofluid (MOF-NF) at a 1 wt% concentration in the feedwater, and (II) as a heat localization material (MOF-HL) by dispersing it on a black cotton wick that spans the basin surface. An external condenser (EC) was added to further enhance condensation in a subsequent configuration. Three identical HSS systems were used for comparative performance evaluation: a baseline unit (CHSS) and two modified systems, one with a condenser and one without. The results indicated that both MOF-based approaches significantly improved the thermal performance and freshwater yield of the HSS. Notably, the MOF-HL configuration outperformed the MOF-NF configuration across all performance metrics. The configuration designated as MOF-HL-EC achieved the highest rate of freshwater production, with a 96.16 % increase in distillate productivity compared to the CHSS. Additionally, this configuration exhibited exergy and energy efficiencies of 3.18 % and 61.1 %, respectively—improvements of 80.85 % and 95.72 % over the traditional system. Economically, the MOF-HL-EC configuration reduced the production cost of distilled water to 0.0115$ per liter, marking a reduction of 25.29 %.