Experimental investigation on tubular solar desalination using phase change material enhanced with nano-Co3O4 and aluminum shavings

Abstract

This experimental study aims to improve the performance of a tubular solar still using enhanced thermal management methods. Paraffin wax with a melting point of 44 °C is used as a phase change material (PCM). Three main methods of improving solar still desalination performance were analyzed including pure PCM, nano-enhanced PCM with Co3O4, and the combination of nano-enhanced PCM with aluminum shavings, and compared to a conventional tubular solar still. In order to improve the thermal performance of the portable desalination design, copper tubes containing industrial metal waste, as the porous media, and baffles coated with micro Al2O3-black paint were utilized in the solar still basin. The addition of 0.3 % Co3O4 nanoparticles along with aluminum shavings led to improve the thermal properties of paraffin wax by reducing >50 min in the melting time. Based on the obtained results, the enhancement in cumulative productivity reached 5.69 %, 15.30 %, and 24.56 % for these three scenarios compared to the conventional solar still with a cuboid basin, respectively. Also, the average efficiency improved from 41 % to about 46.7 %, 51.2 %, and 64.3 %, respectively. Furthermore, the measured total dissolved solids (TDS) of the distilled water in all scenarios was within an acceptable range.