Sun-Assisted Desalination  

Posted by Big Gav in

Technology Review has an article on solar powered desalination in Canada - Sun-Assisted Desalination.

A Canadian startup has built a pilot desalination plant in Vancouver that uses a quarter of the energy of conventional plants to remove salt from seawater. The process relies on concentration gradients, and the natural tendency of sodium and chloride ions--the key components of salt--to flow from higher to lower salinity concentrations. If the system can be scaled up it could offer a cheaper way to bring drinking water to the planet's most parched regions while leaving behind a much lower carbon footprint than other desalination methods.

"We've taken it from a benchtop prototype to a fully functional seawater pilot plant," says inventor Ben Sparrow, a mechanical engineer who established Saltworks Technologies in 2008 to commercialize the process. "The plant is currently running on real seawater, and we're in the final stage of expanding it to a capacity of 1,000 liters a day."

Today most desalination plants are based on one of two approaches. One is distillation through an evaporation-condensation cycle, and the other is membrane filtration through reverse osmosis. But both options are energy-intensive and costly.

Saltworks takes a completely different approach based on the principles of ionic exchange. The process begins with the creation of a reservoir of seawater that is evaporated until its salt concentration rises from 3.5 percent to 18 percent or higher.

The evaporation is done in one of two ways: either the seawater is sprayed into a shallow pond exposed to sunlight and dry ambient air, or seawater is kept in a large tower that's exposed to waste heat from a neighboring industrial facility. The second approach is used in the commercial-scale plant. The concentrated water is then pumped at low pressure into the company's desalting unit along with three separated streams of regular seawater. At this point the most energy-intensive part of the process is already over.

0 comments

Post a Comment

Statistics

Locations of visitors to this page

blogspot visitor
Stat Counter

Total Pageviews

Ads

Books

Followers

Blog Archive

Labels

australia (607) global warming (393) solar power (376) peak oil (343) renewable energy (253) electric vehicles (221) wind power (184) ocean energy (163) csp (156) geothermal energy (144) solar thermal power (143) smart grids (139) tidal power (137) coal seam gas (130) oil (129) solar pv (127) nuclear power (126) energy storage (125) lng (116) china (113) geothermal power (112) iraq (112) green buildings (109) natural gas (108) agriculture (88) oil price (79) biofuel (78) smart meters (72) wave power (71) uk (68) electricity grid (67) energy efficiency (63) coal (61) google (57) bicycle (51) internet (51) shale gas (49) surveillance (49) food prices (48) big brother (47) thin film solar (42) canada (40) biomimicry (39) scotland (38) ocean power (37) politics (37) tesla (37) shale oil (36) new zealand (35) air transport (34) algae (34) water (34) concentrating solar power (32) queensland (32) saudi arabia (32) california (31) credit crunch (31) bioplastic (30) offshore wind power (30) arctic ice (29) population (29) cogeneration (28) geoengineering (28) batteries (26) drought (26) resource wars (26) woodside (26) bruce sterling (25) censorship (25) cleantech (25) ctl (23) economics (22) limits to growth (22) carbon tax (20) coal to liquids (20) distributed manufacturing (20) indonesia (20) iraq oil law (20) lithium (20) origin energy (20) brightsource (19) buckminster fuller (19) rail transport (19) ultracapacitor (19) exxon (18) santos (18) ausra (17) michael klare (17) atlantis (16) cellulosic ethanol (16) collapse (16) electric bikes (16) iceland (16) mapping (16) ucg (16) bees (15) concentrating solar thermal power (15) ethanol (15) geodynamics (15) psychology (15) brazil (14) fertiliser (14) lithium ion batteries (14) al gore (13) ambient energy (13) biodiesel (13) bucky fuller (13) carbon emissions (13) cities (13) investment (13) kenya (13) matthew simmons (13) public transport (13) biochar (12) chile (12) desertec (12) internet of things (12) otec (12) texas (12) victoria (12) cradle to cradle (11) energy policy (11) hybrid car (11) terra preta (11) toyota (11) amory lovins (10) fabber (10) gazprom (10) goldman sachs (10) gtl (10) severn estuary (10) tinfoil (10) volt (10) afghanistan (9) alaska (9) antarctica (9) biomass (9) carbon trading (9) distributed generation (9) esolar (9) four day week (9) fuel cells (9) jeremy leggett (9) pge (9) sweden (9) arrow energy (8) big oil (8) eroei (8) fish (8) floating offshore wind power (8) guerilla gardening (8) linc energy (8) methane (8) methane hydrates (8) nanosolar (8) natural gas pipelines (8) pentland firth (8) relocalisation (8) saul griffith (8) stirling engine (8) us elections (8) western australia (8) airborne wind turbines (7) bloom energy (7) boeing (7) bolivia (7) chp (7) climategate (7) copenhagen (7) vinod khosla (7) apocaphilia (6) ceramic fuel cells (6) cigs (6) futurism (6) jatropha (6) local currencies (6) nigeria (6) ocean acidification (6) scenario planning (6) somalia (6) t boone pickens (6) space based solar power (5) varanus island (5) garbage (4) global energy grid (4) kevin kelly (4) low temperature geothermal power (4) oled (4) tim flannery (4) v2g (4) club of rome (3) norman borlaug (2) peak oil portfolio (1)