Air Humidification-Dehumidification Process for Desalination: A review

Abstract

The humidification-dehumidification desalination system is known as an appealing process for small and medium scales, and high-salinity water desalination. These systems consist of humidifier and dehumidifier as the main components, energy sources for heating and electrical energy generation, accessories used for the fluid transfer or efficiency improvement, and measurement/control devices. Different system designs are reported and categorized based on enhancement in productivity, energy consumption and effective parameters such as gained output ratio, specific electrical energy consumption and production cost. According to input energy types and used components, these systems react differently, and the performance parameters change. This literature reviews past/current status and future ideas about humidification-dehumidification systems to pave the way for the researchers to improve this technology. All technologies that improve the humidification-dehumidification system performance via using efficient constitutes, renewable energy, heat recovery via multi-effect and multi-stage processes, accelerating the humidification and dehumidification processes by pressure variation or using heat pump as well as exergy and cost analyses are clarified. It is concluded that despite improving humidification-dehumidification system as a promising process for decentralized small-scale freshwater production applications, it requires further development to improve the system performance based on gained output ratio and economy. © 2020 Elsevier Ltd