For a long time, water sources determined the places of settlement of people, since it is prerequisite for the live. Currently, the development of the human society has led to a scarcity of fresh water resources around the world. By 2025, about 1.8 billion people will suffer from extreme water shortages (<500 m3 per year per capita), and two-thirds of the population will meet “high stress” conditions (between 500 and 1000 m3 per capita) . However, the Earth's atmosphere is a huge reservoir of moisture (~13000 km3). The Adsorption method for Water Extraction from the Atmosphere (AWEA) involves the vapor adsorption on a solid adsorbent at night, when the relative humidity is high, and thermal desorption in the daytime, followed by vapor condensation on the cold surface of the condenser . The employed adsorbent and the harmonization of its properties with the climatic conditions of the area where AWEA is realized are key-factors affecting the performance of AWEA. This research is focused on the study of novel composite sorbents based on inorganic hygroscopic salt – CaCl2 - inside pores of MIL-101(Cr) developed for AWEA in arid climatic regions. The composites were characterised by XRD, low temperature nitrogen adsorption, FTIR and SEM methods. Water adsorption equilibrium was explored by TG method, isosteric heat of adsorption was calculated. The effects of the salt content on the adsorption equilibrium were studied. CaCl2/MIL-101(Cr) demonstrated high specific water productivity of 0.82 gH2O/gcomposite per cycle under conditions of the arid climate typical of the Sahara Desert and Saudi Arabia regions, which exceeds the appropriate values for other adsorbents. It was shown that the water adsorption on the composite cannot be presented as a combination of the adsorption on the components; a synergistic effect was revealed. The performance of AWEA employing CaCl2/MIL-101(Cr) composite was evaluated in terms of the fractions of water extracted collected, and the specific energy consumption, demonstrating its high potential for AWEA.
Acknowledges. This work was supported by Russian Foundation for Basic Research (project no. 18-29-04033).
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|Affiliation of speaker||Novosibirsk State University, Russia, Novosibirsk, Pirogova str. 2, 630090|
|Publication||Impact Factor journals|