Optimizing the performance of solar still with Al₂O₃ nanofluid: an experimental study

This paper presents a comparative analysis of the performance of a single-slope passive solar still using regular water and a water-based nanofluid containing aluminium oxide. The Al₂O₃ nanoparticles were characterized through X-ray diffraction, transmission electron microscopy, and X-ray energy dispersive spectroscopy. Two identical experimental solar stills with the same basin area were constructed and evaluated for identical thermal performance. The study involved concurrent experiments conducted at the same location and time, with one solar still using water and the other employing a water-based nanofluid with varying concentrations of aluminium oxide. The objective of this study is to assess the impact of using Al₂O₃ nanofluids on the performance of a passive solar still in comparison to using regular water. The concentrations of Al₂O₃ nanofluid tested started at 0.05% by volume, with an increment of 0.05% until an optimum distillate output is reached. The results show that the solar still incorporating water-based Al₂O₃ nanofluid, particularly at a concentration of 0.15%, enhances the water distillate output by 24.11%, indicating an optimal enhancement level. Furthermore, the study observes that Al₂O₃ nanofluids promote a more significant evaporative heat transfer compared to convective heat transfer.