Water scarcity is among the most serious long-term risks facing society worldwide. Climate impacts are worsening drought conditions, causing billions of dollars in economic losses and fresh water supplies are dwindling. To make matters worse, 97 percent of the planet’s water is salt water, 2 percent is glacier ice, and just 1 percent is usable fresh water. It seems inevitable that we will need to desalinate some of the planet’s salt water to survive, and the technology will need to use a lot less energy and require a lot less capital than it does now.
Startups (like Okeanos Technologies) and large corporations alike are working on this problem. This month, General Electric (GE) and Veolia announced they expect new techniques to reduce the operating costs of their desalination technologies.
GE Global Research and US Department of Energy (DOE) scientists are developing a small, extremely efficient desalination machine. The technology freezes saline water at a cost up to 20 percent lower than conventional thermal evaporation approaches, and with a much smaller product.
Douglas Hofer, a GE senior principal engineer and steam turbine specialist, and Vitali Lissianski, a GE chemical engineer, used the same miniaturized, 3D-printed turbo-machinery used in the steam turbines developed with the DOE for the new product.
Hofer explained, “In traditional steam turbines, steam condenses and turns to water. We thought maybe the same principle could be applied to water desalination.”
The water desalination technology compresses and streams a mixture of air, salt and water through a hyper-cooling loop. The mixture freezes, naturally separating the salt in a solid crystal form and the water as ice.
“97.5 percent of the earth’s water supply is virtually inaccessible because water desalination is still too expensive and difficult to deploy at a large scale. By putting desalination ‘on ice,’ we hope to change that dynamic,” said Lissianski.
Meanwhile, Veolia’s technology is currently being used in a pilot program at Masdar’s renewable energy-powered desalination plant in Abu Dhabi. It has already lowered energy costs by 7 percent compared to the contractual target set by Masdar, and Veolia says electricity consumption is improving daily. The desalination technology is capable of processing very harsh seawater with salinity up to 52 grams per litre, temperature over 42 degrees Celsius, and harmful algal blooms.
Veolia also expects its new pre-treatment design to save up to 25 percent on civil engineering costs and reduce the footprint of the plant. The design combines air floatation and filtration, as well as a new osmosis membrane feed configuration able to deal with high treatment fluxes.
Xavier Joseph, CEO of Veolia Gulf Countries, said in the press release, “As a major player in water desalination for the past several decades, Veolia now aims to develop the next generation of sustainable desalination technologies, helping populations and industries in water-scarce regions access this precious resource in an environmentally sound and energy-efficient way. We are very proud to be partnering with Masdar on this ambitious project.”