Atmospheric water harvesting using metal organic framework (MOF) materials
Our lab is developing systems for continuously cycled sorption/desorption water harvesting from atmospheric air. As an absorbent, we use a new class of materials metal-organic framework (MOF). These exceedingly hygroscopic materials are able to draw water out of the air even at 25% relative humidity (the typical humidity in the Sahara desert). The most cost-efficient manner to use such materials is to achieve the highest productivity rate of water which scales as product of the sorption frequency and the capacity of the MOFs. To maximize this frequency, we use fluidized bed devices filled with MOF in powder form. Fluidized beds are a scale-able technology which offers maximal surface-to-volume ratio but has complex coupling between fluid flow, particle dynamics, mass transfer, and heat transfer.
Alexandros Terzis, Ashwin Ramachandran, Kecheng Wang, Mehdi Asheghi, Kenneth E. Goodson, and Juan G. Santiago. "High-frequency water vapor sorption cycling using fluidization of metal-organic frameworks" Cell Reports Physical Science 1, no. 5 (2020): 100057.
Water absorption isotherms adapted from Kim et al., Science, 2017, 356, 6336, 430-434