Technical improvements and perspectives on humidification-dehumidification desalination — A review

Seawater desalination based on humidification-dehumidification (HDH) process is a competitive method to obtain fresh water from sea and brackish water that can be naturally coupled with renewable energy. Compared with the traditional seawater desalination technologies, such as reverse osmosis (RO), multi-stage flash (MSF), low-temperature multi-effect distillation (LT-MED) and mechanical vapor compression (MVC), HDH process shows the benefits of simpler configuration, relatively lower working temperature, milder evaporation, easier control and atmospheric operation. This paper presents an elaborate review on the progress of HDH desalination technology. From an implemented perspective, prompting the HDH desalination system produce fresh water efficiently, stably and continuously is a major concern. Efforts to improve the system performance and stability as well as reducing the energy consumption are reviewed and evaluated on the basis of the introduced system configurations and state variations of process air during HDH process. The paper also provides an overview on the concerned issues, which indicate that new types of humidifying and dehumidifying process to improve the heat recovery efficiency and thermally balanced cycles are the methods with great potential for system performance improvement. Furthermore, some possibilities for further improving HDH desalination system, to promote the development of this technology are also proposed and discussed.