An article in yesterday’s Austin American-Statesman – “How gas flare-offs could bring water” – caught my attention. It was written by Vaibhav Bahadur, an Assistant Professor of Mechanical Engineering at UT Austin. He posits that natural gas could be used to harvest water from the atmosphere (“atmospheric water harvesting”), enough to supply a significant part of the water needed for hydraulic fracturing.
I remember reading about atmospheric water harvesting using solar power, for drinking water. Scientists have developed crystalline powders called metal organic frameworks, or MOFs, that suck water from the air. Omar Yaghi, a chemist at the University of California, and Evelyn Wang, a mechanical engineer at MIT, designed a system using an MOF that uses solar energy to condense 2.8 liters of water per day from the air, even in the desert.
Bahadur’s proposal is to use conventional gas-powered engines to run compressors that condense water from the air. He says that a cubic meter of gas would capture up to 2.3 gallons of water. He estimates that 2 billion gallons of water could be harvested annually from gas flared in the Eagle Ford, which would meet 11% of the annual water consumption in the Eagle Ford. In the Bakken, he estimates that 4 billion gallons of water could be harvested in a year, supplying 65% of the annual water consumption there.