Performance evaluation of nano-enhanced phase change materials in a two-stage solar still with parabolic dish collector

Among the most pressing global concerns are those related to sustainable energy supply, effective water recycling, and comprehensive water management. Scarcity of clean water is often exacerbated by inadequate saline water management, highlighting the need for innovative solutions. The current study explores an advanced thermal energy storage system based on a parabolic dish solar collector, which is integrated with a desalination unit. This system utilizes pure paraffin wax and various nano-enhanced phase change materials, including mono, binary, and ternary configurations. The setup features two water tanks coupled with the parabolic dish solar collector and phase change material section, where the phase change materials are implemented in different phases: mono (Al₂O₃, CuO, MWNCNT), binary (Al₂O₃-CuO, CuO-MWCNT), and ternary (Al₂O₃-CuO-MWCNT) nanocomposites. Key performance indicators analyzed in this research include temperature behavior, thermal efficiency, water yield, and economic feasibility. The results demonstrate accumulated water yields of 4.82, 6.95, 7.61, 8.36, 8.88, 9.28, and 9.81 L/m² for each respective phase change materials module. Among the selected PCMs, the ternary Al₂O₃-CuO-MWCNT nanocomposite possess higher energy efficiency of 82.46 % with the cost per litre of $0.02213. Notably, binary nano-enhanced phase change materials outperforms pure paraffin wax and mono nano-enhanced phase change materials, while ternary nano-enhanced phase change materials exhibits superior performance over binary nano-enhanced phase change materials. This innovative approach offers significant potential for reducing the cost and energy requirements of water purification systems, providing an economically viable alternative for facilities looking to optimize their reverse osmosis purification processes.