Improved freshwater generation via hemispherical solar desalination unit using paraffin wax as phase change material encapsulated in waste aluminium cans

Abstract

The present work aims to increase the amount of water generated by the hemispherical solar still (HSS) using paraffin wax as phase change material (PCM) encapsulated in waste aluminium-cans in two different shape of square pattern (4 PCM cans) and triangular pattern (3 PCM cans). Furthermore, a comparative analysis for the conventional HSS over the modified HSS with PCM two different arrangements was carried out to optimize the most suitable mass of PCM. Results showed that PCM encapsulated in aluminium cans in square and triangular patterns placed in HSS basin augmented the clean water production by 92.80 % (full day water generation of 5.63 kg/m2) and 67.12 % (full day water generation of 4.88 kg/m2) respectively, as compared to the bare HSS without any PCM (full day water generation of 2.92 kg/m2). The effective utilization of the heat from the aluminium cans filled with paraffin wax augmented the potable water production with increased evaporation of water. The economic analysis revealed that with the use of PCM encapsulated cans in square and triangular pattern, the cost per liter of water produced reduced to 67.65 % and 45.31 % respectively than HSS without any PCM. It was concluded that the low-cost encapsulating material with excellent conductivity and maximum mass of PCM (4 PCM cans in present case) could be beneficial in generating higher amount of freshwater from brackish water.