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MIT team invents efficient shockwave-based process for desalination of water
- matthewmcg 11y agoProbably the first time "efficient" and "shockwave-based" have appeared together in a Hacker News headline ;)
- mattkevan 11y agoThey had a flash of inspiration
- deleted 11y ago[deleted]
- Rexxar 11y agoIndeed: https://hn.algolia.com/?query=efficient%20shockwave-based&sort=byPopularity&prefix&page=0&dateRange=all&type=story https://hn.algolia.com/?query=efficient%20shockwave-based&so... And your comment is the first one with this two words: https://hn.algolia.com/?query=efficient%20shockwave-based&sort=byPopularity&prefix&page=0&dateRange=all&type=comment https://hn.algolia.com/?query=efficient%20shockwave-based&so...
- eveningcoffee 11y agoUnfortunately Initially at least, this process would not be competitive with methods such as reverse osmosis for large-scale seawater desalination. But it could find other uses in the cleanup of contaminated water, Schlumpberger says. But it could help to make portable desalination modules: Unlike some other approaches to desalination, he adds, this one requires little infrastructure, so it might be useful for portable systems for use in remote locations, or for emergencies where water supplies are disrupted by storms or earthquakes.
- nlh 11y agoOther than that statement, TFA didn't really go into why it wouldn't be competitive with reverse osmosis. Any thoughts or ideas? Edit: New comment basically explained it. Very very low flow rates.
- Animats 11y agoHe patented this five years ago.[1] Here's the 2015 paper.[2] Flow rates are very, very low. Note the reference to the fluid source being a "Harvard Apparatus Syringe Pump".[3] That's just a motorized device for very slowly pressing the plunger on a syringe, for very low flow rates. If they're using that after five years of work, the process is still limited to very low flow rates. This is not necessarily a killer limitation. Reverse osmosis started that way, but has been scaled up to industrial scale. But the technology is not here yet. [1] http://www.google.com/patents/US8801910 http://www.google.com/patents/US8801910 [2] http://web.mit.edu/bazant/www/papers/pdf/Schlumberger_2015_shock_ED_justaccepted.pdf http://web.mit.edu/bazant/www/papers/pdf/Schlumberger_2015_s... [3] https://www.harvardapparatus.com/webapp/wcs/stores/servlet/haisku3_10001_11051_68275_-1_HAI_ProductDetail_N_37295_37313_44353 https://www.harvardapparatus.com/webapp/wcs/stores/servlet/h...
- Animats 11y agoMIT Technology Review announced this last year, too.[1] [1] http://www.technologyreview.com/view/524606/new-desalination-technique-also-cleans-and-disinfects-water/ http://www.technologyreview.com/view/524606/new-desalination...
- chris_va 11y agoIn this 170 first SED prototype, the impressive salt removal and water recovery come with significant energy costs, in the range of 10−1 to 103 kWh/m3 171 (hydraulic pumping makes up about 0.5 kWh/m3 172 ) That is quite the energy range...
- godgod 11y agoHumanity can really benefit from this. I am waiting to see what becomes of this breakthrough.
- leot 11y agoDoes anyone know why forward osmosis (e.g. https://www.youtube.com/watch?v=R63zYZZuRvQ https://www.youtube.com/watch?v=R63zYZZuRvQ) hasn't taken off yet? It seems like it has the biggest potential to do desalination at an extremely low cost energy-wise.
- jjoonathan 11y agoSure, if you don't account for the energy needed to form the high-energy carbon and nitrogen compounds ("special salts") in the first place. In practice the "special salts" are either a very low efficiency fossil fuel (if you dig them out of the ground) or a really roundabout and inefficient way to spend other forms of energy. The Haber process reduces N2 and plants reduce CO2, giving you the "special salts" (energy inputs: H2 and pump pressure for Haber, sunlight for plants). Then you burn the high-energy nitrogen+carbon compounds back into N2, H2O, and CO2 to remove them from the "forward-osmosis" solution. The sunlight, H2, and mechanical work used to create the special salts could almost certainly be used more effectively to generate electricity for reverse osmosis or distillation.
- leot 11y agoBut in the video I shared, it's claimed that the fancy salts can be entirely reused, and that extracting them takes relatively little energy. Thus their ongoing energy impact, and the longer-term impact of their initial cost should be relatively low, no?
- zbgxyz 11y agoSee, this is an obvious win.
- hackuser 11y agoMIT's PR is more amazing than their research. How many science and technology programs are there in U.S. universities, all of them producing new discoveries? How about universities outside the U.S.? The rate and impact of discoveries vary by school, yet it seems like half the discoveries I read about come from MIT, and often via links directly to MIT press releases (i.e., not to coverage in the news). MIT is a great school, but they can't be that great.
- x1798DE 11y agoWhenever I see one of these MIT press releases, I know to take it with a giant grain of salt. I wonder if HN will eventually start penalizing links from them as low quality.
- dannypgh 11y agoIf you run out of grains of salt, I know how you can get some more with shockwaves...
- dredmorbius 11y agoSadly, it's many University PR offices. I know Stanford's is absolutely abysmal as well for overhyping stories.