Improving the freshwater productivity of hemispherical solar distillers using waste aluminum as store materials

Large amounts of aluminum waste are present in factories and workshops that produce aluminum. And the latter is constantly seeking the most efficient means of getting rid of them. Additionally, due to the higher thermal conductivity of aluminum, aluminum waste is a good solar energy absorber. Whereas, the present experimental study aims to achieve the highest performance of hemispherical solar stills, which are characterized by a large condensing surface area. It requires increasing evaporation rates within the hemispherical distillers using aluminum waste in the hemispherical distillation basin. As this waste helps to increase the rates of absorption of solar radiation and improve the rates of heat transfer to the basin water. In addition, aluminum waste represents the thermal storage materials that store part of the solar thermal energy in periods of higher intensity of solar rays and retrieve it again in the period of low intensity of the solar rays. To achieve this goal, two hemispherical solar stills (HSS) were tested for this purpose; the first served as a Reference HSS-R and the second held Aluminum Waste (HSS-AlW). The results indicate that combining aluminum waste with hemispherical solar still (HSS-AlW) produces distilled water at a rate of 6.15 kg/m2/day, while the reference distiller (HSS-R) produces 4.15 kg/m2/day. These results concluded that the utilization of waste aluminum causes an improvement in productivity by a rate of 48.19 %. Also, the use of waste aluminum causes improved thermal efficiency from 35.36 % (RHSS) to 52.18 % (HSS-AlW), with an improvement of 47.56 % compared to RHSS. As a result, it is recommended to use waste aluminum because it has high thermal conductivity and is free to use.