An Interfacial Solar Heating Assisted Liquid Sorbent Atmospheric Water Generator

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Atmospheric water harvesting is crucial for freshwater production, especially in water-scarce regions.
• High-concentration liquid sorbents offer excellent water absorption but face challenges in efficient water release (desorption).
• Existing atmospheric water generators often struggle with low efficiency or high energy requirements for desorption.

Purpose of the Study:

• To develop and demonstrate an effective atmospheric water generator utilizing a high-concentration liquid sorbent.
• To overcome the desorption limitations of liquid sorbents using interfacial solar heating.
• To assess the performance and efficiency of the proposed water harvesting system.

Main Methods:

• Fabrication of a salt-resistant graphene oxide (GO)-based aerogel for interfacial solar heating.
• Integration of the aerogel with a high-concentration calcium chloride (CaCl2) solution (50 wt%).
• Experimental testing of the atmospheric water generator under simulated solar irradiation and controlled humidity (approx. 70% relative humidity).

Main Results:

• The system achieved a freshwater production rate of 2.89 kg m⁻² day⁻¹.
• Efficient water desorption was achieved using only solar energy input.
• The energy efficiency of the desorption process reached as high as 66.9%.

Conclusions:

• Interfacial solar heating with a GO-based aerogel enables efficient atmospheric water generation using a high-concentration liquid sorbent.
• This low-cost, solar-driven approach offers a promising solution for freshwater scarcity in arid and land-locked areas.
• The developed technology presents an attractive pathway for sustainable water extraction from air.