One of the biggest challenges facing society is access to clean freshwater. Saltwater might be in our veins and the canvas on which we surf, but you can't drink it. It will kill most plants, and can ruin land for agriculture. 97% of Earth's water is salty. Half of the freshwater is trapped in ice. The remaining 1.5% must meet the needs of 7 billion people, their industries and agriculture. A further strain on water supplies occurs anytime natural sources are polluted or by shifting global weather patterns which bring draught.
So the obvious way out of this Malthusian Trap is to tap into that big supply of saltwater. The process of distillation has been around forever. Ships used to rely on low pressure flash distillation to meet their freshwater needs on the open ocean. This process involves heating the water and then rapidly lowering the pressure to cause it to flash to steam which is then condensed into freshwater. Effective but very energy intensive and output is limited. The current state of the art in desalination is Reverse Osmosis. Reverse Osmosis which is now used on ships and for large land based desal plants in places like the Middle East uses massive, high pressure pumps to force saltwater through a special membrane through which the salt can not pass. R.O. works well and can provide large quantities of freshwater. However, it uses a massive amount of electricity to get the job done. This makes the water produced expensive and adds a large carbon footprint. Also, the highly concentrated brine which is normally dumped back into the sea can kill sea life in the area.
Saltworks Technologies founded by Ben Sparrow and Joshua Zoshi out of Vancouver, British Columbia have hit upon a revolutionary new process for desalination of seawater. Their process uses passive heat from the sun or waste heat to concentrate a brine solution. Then low pressure pumps flow the water through a desalination process. Saltworks Technologies desalination process takes advantage of the differences in chemical energy between the highly concentrated brine and normal seawater. The result is a low cost, low carbon footprint method of producing freshwater. It should be completely scalable and could be added to existing desalination plants to boost efficiency. Here is an excellent explanation in The Economist. This could be a major step towards solving one of mankind's biggest challenges.
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