Atmospheric water harvesting from low humid regions using tubular solar still powered by a parabolic concentrator system

Abstract

The present study proposed a new system of atmospheric water harvesting from extreme low humid regions under climatic conditions of Hail city (27.64 oN, 41.75 oE), Saudi Arabia. The concept of the proposed system was to activate the tubular solar still by a parabolic solar concentrator. This concept would increase TSS ability to evaporate water from strong desiccant of calcium chloride under extreme low humid conditions. The TSS was opened and exposed to atmospheric air during night hours starting the absorption process. At the beginning of the sunrise, the TSS was closed and placed at the focal line of the parabolic concentrator starting the regeneration process. The proposed system was able to produce 0.51 L/kg of calcium chloride. The system thermal efficiency and water production cost were 24.61% and $0.15 respectively. The proposed device increased the productivity and the efficiency of the TSS by 292.4% and 82.3%, while reduced the water production cost by 25%. The proposed system was compact, small and portable that could be operated easily in a desert, remote and isolated areas without any need for water resource or infrastructure. The proposed new system could be lifesaving in urgent situations especially in the desert areas.