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Practical water production from desert air

Authors:
  • Baxter Hechingen

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Energy-efficient production of water from desert air has not been developed. A proof-of-concept device for harvesting water at low relative humidity was reported; however, it used external cooling and was not desert-tested. We report a laboratory-to-desert experiment where a prototype using up to 1.2 kg of metal-organic framework (MOF)–801 was tested in the laboratory and later in the desert of Arizona, USA. It produced 100 g of water per kilogram of MOF-801 per day-and-night cycle, using only natural cooling and ambient sunlight as a source of energy. We also report an aluminum-based MOF-303, which delivers more than twice the amount of water. The desert experiment uncovered key parameters pertaining to the energy, material, and air requirements for efficient production of water from desert air, even at a subzero dew point.
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... (E) In just 5 years, the adsorbent-assisted AWH device has evolved from a gram-level technology validation device and the first on-site water production device to a multi-cycle device that is improving energy consumption [16,[31][32][33][34][35][36]. MOF-801 [31], MOF-801/G [37], MOF-303 [38], Al-fumarate [39], and MOF-801 [40]. MOF-801/G is mixed with porous graphite in MOF-801 to enhance its solar energy adsorption performance and thermal physical properties. ...
... Subsequent MOFs, including MIL-101 [58], UiO-66 [59], Co2Cl2(BTDD) [12], and Ni2Br2BTDD [17], managed to adsorb water at 20~60%RH, but this still falls short of the requirements for arid climate conditions (15~40%RH). It was not until the development of CAU-10 [60], DUT-67 [61], MOF-801 [62], MOF-303 [37], and MOF-LA2-1 [20] that water adsorption at 20%RH became feasible. For practical applications, factors such as the water adsorption rate, capacity, and cycling stability must be taken into account. ...
... For practical applications, factors such as the water adsorption rate, capacity, and cycling stability must be taken into account. To date, MOF-801 and MOF-303 have been the subjects of extensive research as they have excellent water adsorption characteristics at lower humidity and have large water adsorption capacity ( Figure 1C,D) [29,31,37,38,40,[63][64][65][66]. Recently, novel MOFs like MOF-333 [29], CAU-23 [67], and MOF-LA2-1 [68] have also been explored for their potential in assisted AWH. ...
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