Abstract Summary
The increasing global water scarcity - exacerbated by climate change - requires innovative and sustainable solutions. This study presents a novel adsorption-based water harvesting device designed to capture water from atmospheric air. The device utilizes sorption materials, operating in two different ways: water adsorption at night and water desorption during the day, the latter driven by solar heat. A theoretical model is presented for the device using the linear driving force (LDF) approach. The model incorporates assumptions on sorption kinetics, material geometries, and air flow characteristics to balance computational effort and physical accuracy. Initial modelling results are presented and validated using experimental data recorded for two different sorption materials, silica gel and zeolite. Prototype operation in Berlin/Germany during 2024 demonstrated an average water extraction from atmosphere of 180 ml/kg sorption material per day using an average amount of electrical energy of 0.28 kWh/litre of water. Initial results are promising, however further experimental campaigns are planned to refine both device and model and to improve overall system performance. The research presented in this paper underscores the potential of adsorption-based technologies as sustainable alternative to traditional water supply methods, particularly in resource-constrained environments.
