Theoretical investigation of a humidification-dehumidification/reverse osmosis hybrid desalination unit driven by concentrated photovoltaic/ thermal solar collector: On both energy and mass recovery

Hybrid humidification-dehumidification reverse osmosis desalination unit driven by concentrated photovoltaic/ thermal is considered a potentially viable option for global water scarcity, especially in remote islands or coastal areas. The presented model embraces the following novelty points: concentrated photovoltaic/thermal stand-alone driving system, humidification dehumidification optimization, and considering the cascade use of thermal energy and mass recovery during desalination. The study involves theoretical modeling of a small-scale hybrid desalination system comprising three subsystems: concentrated photovoltaic/thermal as the energy source, closed air open water humidification dehumidification, and three series of reverse osmosis membrane elements. The investigation focused on key system/subsystem performance parameters, such as freshwater productivity, recovery ratio, freshwater salinity, gain output ratio, and photovoltaic system efficiencies. Results showed that, inlet water temperature and solar radiation have a significant impact, while heat transfer fluid volume flow rate has a minor effect. The humidification dehumidification optimized unit achieves better productivity and performance at inlet water temperatures less than 35 degrees C. At solar radiation of 800 W/m2, inlet feedwater temperature of 25 degrees C, optimal system products 287.6 L/h freshwater with a recovery ratio of 20.6% and salinity of 220 ppm.

Automated summary

This study presents a novel hybrid humidification-dehumidification reverse osmosis desalination unit driven by concentrated photovoltaic/thermal. The results show that inlet water temperature and solar radiation have a significant impact on the performance of the system, and the humidification dehumidification optimized unit achieves better productivity and performance at lower temperatures.