Adsorption-based atmospheric water harvesting device for arid climates

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Water scarcity is a critical global challenge, especially in arid regions.
• Conventional dewing technologies are energy-intensive and inefficient at low relative humidity (RH).
• Sorbent-based atmospheric water generators offer a promising alternative for efficient water capture from air, even at low RH levels.

Purpose of the Study:

• To demonstrate a novel air-cooled, sorbent-based atmospheric water harvesting device.
• To evaluate the device's performance in an exceptionally arid climate with low RH and sub-zero dew points.
• To assess the thermal efficiency of solar-thermal energy conversion for water production.

Main Methods:

• Utilized the metal-organic framework (MOF)-801 [Zr 6 O 4 (OH) 4 (fumarate) 6 ] as the sorbent material.
• Operated the device in an arid climate (Tempe, Arizona) with 10-40% RH and sub-zero dew points.
• Measured the solar thermal input and water output to determine thermal efficiency.

Main Results:

• The device successfully harvested water vapor in an arid environment with low RH.
• Achieved a thermal efficiency of approximately 14% for solar input to water conversion.
• Predicted water delivery of over 0.25 L per kg of MOF per daily cycle.

Conclusions:

• The demonstrated sorbent-based atmospheric water generator is effective in extremely arid conditions.
• This technology offers a potentially sustainable and efficient method for water production using solar energy.
• The MOF-801 based system shows promise for addressing water scarcity in challenging climates.