A comprehensive review on atmospheric water harvesting technologies: From thermodynamic concepts to mechanism and process development

Water scarcity is one of the most challenging problems that the world has ever faced. There are numerous methods to remedy the water crises. One is using atmospheric water harvesting (AWH) to provide water. So far, there is much research on the subject of AWH. However, there is still a lack of establishing an extensive com-parison between different technologies and methods used to harvest atmospheric water. In this review, we provide details on the thermodynamic performance of the AWH system. The systems are categorized into both active and passive systems. Heat pumps, membranes, thermoelectric solar systems, and adsorption systems are some atmospheric harvesting technologies that will be thoroughly discussed. Based on the comparison that had been made, it was found that TEC systems are the best for small applications. In contrast, systems such as vapour recompression can meet great demands as they can be integrated with different types of energy, such as natural gas and biogas. Solar systems as passive systems can also be coupled with active systems to boost the efficiency of vapour recompression systems and reduce energy consumption. Furthermore, this review will focus on recent development for each category, the utilization of different advanced materials, and the prospect and challenges associated with AWH.