Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/1019735
evaporates water from brine. As hot air interacts with the brine it evaporates it, becomes humid and leaves solid salt particles behind. A recuperator recycles the heat. The solid salt can be sold at a profit. DIRECT SOLAR-THERMAL FORWARD OSMOSIS DESALINATION OF PRODUCED WATERS • Team: Lawrence Berkeley National Laboratory • Location: Berkeley, CA • DOE Award Amount: $800,000 • Awardee Cost Share: $200,000 • Principal Investigator: Robert Kostecki High-salinity and/or high TDS cannot be efficiently treated by reverse osmosis. As a result, investigators have looked at the benefits of draw solutions in forward osmosis. Robert Kostecki is leading a team at Berkeley Lab, developing an integrated ionic liquid-based forward osmosis water treatment system. Making use of low-level solar heat, Kostecki and colleagues aim to drive the separation and regeneration processes at a small capacity, creating integrated desalination systems at a lower capital cost. HIGH-EFFICIENCY, ZERO LIQUID DISCHARGE, MULTIPLE-EFFECT ADSORPTION DISTILLATION • Team: Greenblu • Project Name: Location: Hamilton, NJ • DOE Award Amount: $1,600,000 • Awardee Cost Share: $400,000 • Principal Investigator: Dr Howard Yuh With its dual innovation of energy recycling and patented adsorbent materials, Dr Howard Yuh's technique resembles a combination of multi-effect dis - tillation (MED) and adsorption distillation (AD). But where MED recycles the latent heat through succes- sive chambers with decreasing pressure to recover the optimum amount of water, vapour adsorp- tion distillation with energy recycling (VADER) vaporises brine through a sequence of na- nocomposite adsorbent material in beds. The low-cost nanocom- posite adsorbent uses graphite nanosheets to boost thermal conductivity. The material effectually low- ers the vaporisation temperature of the seawater, increasing cycle efficiency by starting at 120 to180 degrees Celsius. Vapour is ad- sorbed and desorbed depending on the temperature of the solar- thermal-powered heat exchanger connected to the beds. The beds of oscillating tem- perature acts as a vapour pump, moving steam through the system. Because the adsorbent is the highest temperature com- ponent rather than the seawater, this helps eliminate the scaling that dogs MED systems. And the beds do not come into contact with the brine, leaving only distilled water as the evaporate. The system can overcome the top brine limit that impedes desalination efficiency for other thermal techniques. VADER is the only adsorption technology that repeatedly recy - cles all available thermal energy (adsorption, latent vaporisation, and sensible heat) and GreenBlu estimates that it will achieve a performance ratio of around 28, tripling the thermal energy efficiency of current methods, and reducing electricity usage to near zero. GreenBlu's grant will help advance development of the new technology, culminating with a scaled demonstration prototype of a commercial product. The concept is for an easy-to-deploy, shipping container module, each producing 60 m3/d, at $0.60 to $1 per cube. The capacity can be scaled up as needed. Production is set to commence following pilot testing to validate that the prototype works as expected. "We will build a water-pro - ducing demonstration prototype that will prove the efficacy of our new distillation method, show- ing that desalination can be free from drawbacks," says Yuh, add- ing that his product could help factories and refineries to reduce demand on freshwater and to cut their waste streams. "There are lots of industries waiting for an affordable, sustainable zero liquid discharge process to reduce waste and the water they take from community, including fracking and electrical genera - tion," he says. In fact, GreenBlu's zero liquid discharge solution might better be described as a separation process. Beyond the scope of the DoE programme, the company has its eye on selling the mineral extracts of brine, such as mag - nesium chloride and table salt, along with the water. Magnesium extraction might potentially be a boon for owner or third-party system opera - tors trying to make zero liquid discharge desalination economi- cally viable. The metal is the lightest structural material, used for the chassis of Microsoœ's Surface Pro laptops, and increas- ingly in transportation. Despite being one of the most common elements, there are no terrestrial deposits in the US, and seawa - ter and saltwater is the only source. Seawater contains about 1,300mg per litre of magnesium and at current costs, each cube of seawater contains about $48 of the metal if extracted and refined. Yuh developed his solution following a career researching fusion energy as a plasma physi - cist at Princeton, with degrees in nuclear engineering and materials science. He founded GreenBlu in 2016 aœer realising the urgent need for sustainable, non-electric water technology that can be deployed with mini- mal infrastructure as the world rapidly ramps up desalination to alleviate the water crisis. September 2018 Water. desalination + reuse Far Site 31 The project aims to build a demonstration prototype of vapour adsorption distillation with energy recycling (VADER), which vapourises brine through a sequence of beds of nanocomposite adsorbent material. There are lots of industries waiting for an affordable, sustainable zero liquid discharge process to reduce waste