Abstract
Increasing water scarcity in the face of climate change has driven significant interest in finding low-carbon-intensity ways of generating fresh water from saline sources. Conventional membrane and thermal desalination techniques require large energy inputs that can become prohibitive as salinity increases. Alternatively, solar desalination is a well-developed passive evaporative approach but is limited seasonally and geographically by solar insolation. Here, we propose and demonstrate a passive approach to a more thermodynamically attractive phase change that can also enable desalination: freezing. We develop a system that uses passive radiative cooling to the ultimate heat sink, outer space, to freeze and desalinate salt water. We experimentally demonstrate the passive desalination of 37.3 g/L salt water to 1.88 g/L after two radiative cooling-driven freezing desalination stages with 50% recovery and 17.5 g/L salt water to 0.7 g/L with 65% recovery. Our results highlight the potential of harnessing untapped thermodynamic resources for water technologies.
Original language | English (US) |
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Pages (from-to) | 2762-2775 |
Number of pages | 14 |
Journal | Joule |
Volume | 6 |
Issue number | 12 |
DOIs | |
State | Published - Dec 21 2022 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Energy
Keywords
- decarbonization
- desalination
- energy-water nexus
- freezing desalination
- radiative cooling
- renewable energy
- thermal desalination
- water treatment