Potential Analysis of Atmospheric Water Harvesting Technologies from the Perspective of “Trading-in Energy for Water”

Abstract

An applicable, high-volume, and sustainable water uptake technology can alleviate freshwater shortages, improve the energy utilization rate and promote the development of energy technology. Traditional seawater desalination, fog water, and dew collection are limited by the geographical environment, and the water resource transportation cost is high, or the water uptake volume is limited, so they cannot be used on a large scale. There are potential safety problems with wastewater reuse and recycled water. Atmospheric water harvesting technology uses energy for direct condensation or uses adsorbent to absorb water, which is characterized by strong sustainability, high applicability, decentralization, and stable water uptake. This study summarizes the working principle of mainstream atmospheric water harvesting technologies, mainly including condensation, absorption, and desorption water harvesting, and some active dew and fog collection technologies. It also theoretically analyzes the energy consumption of condensation and adsorption and desorption water harvesting technologies. Aiming at the problems of difficult condensing for direct condensation and long adsorption/desorption cycle of adsorption and desorption water harvesting, it summarizes the countermeasures of multi-stage condensation and multi-cycle adsorption and desorption. The development prospect of atmospheric water harvesting technologies is also discussed