An innovative air saturator for humidification-dehumidification desalination application

In this work, an innovative and novel integrated Maisotsenko cycle-based air saturator is proposed as a humidifier in humidification-dehumidification type desalination system. The proposed system has unique flow characteristic within the heat and mass exchanger to maximize air saturation at the exit of humidifier; thus, maximizing the potential for desalination. The process of air saturation in the wet channel is altered by including an infiltration flow from the dry passes on to the wet passes of the air saturator. A detailed mathematical model is developed and solved through an iterative procedure, and the performance of the system is deduced based on fresh water production rate, recovery ratio, and gain-output-ratio. It is reported that in the proposed design an infiltration rate of 0.6 corresponds to maximum water evaporation rate and justified pump and blower work. Comparative analysis has shown that the proposed novel system configuration offers 30% higher fresh water productivity, 46% higher recovery ratio, and 11% higher gain-output-ratio as compared to conventional direct contact humidifier-based desalination plant. Performance investigation analysis is carried out for 31 different cities of the world to determine the applicability of the proposed system under different climatic conditions. Economic estimation has shown that the cost of desalinated water using proposed system is 0.030 USD/liter which is 14% lower than the conventional humidification-dehumidification desalination system. Furthermore, environmental analysis has shown that the proposed system has 7% lower carbon footprints. It is concluded that the proposed system offers energy-efficient, cost-effective and environmental friendly method of desalination and can be used in most parts of the world.