When: Wednesday morning, 10:00 am
Where: an undisclosed location behind two levels of security fences somewhere in Ashkelon (supposedly)
Who: Oshik, an affable chap who served as our tour guide
Israel’s available freshwater supply is very shaky. It comes mainly from the Sea of Galilee which has been shrinking in recent years, also causing the Dead Sea to shrink. Israel’s water needs have only risen lately as the innovation and commerce that we spent a week touring use resources at an increasing rate.
Oshik treated us to a fascinatingly detailed description of the desalination process:
- Seawater is pumped in to the facility from a little less than a kilometer offshore to ensure the freshest possible seawater.
- The seawater goes through a pre-treatment process to filter and clean it. Debris trying to squeeze through the sensitive desalination equipment would ruin it.
- A high pressure booster brings the seawater up to a pressure of 70 bar (1,015 psi for those familiar with air pressure in tires)!
- SWRO (seawater reverse osmosis): the seawater passes through special filters which remove the brine from the (now fresh) water.
- Traces of limestone are added to prevent the water from corroding the metal pipes which would cause specks of metal to enter the water.
The brine exiting SWRO is still at an insanely high pressure, but instead of being innovative and putting a turbine at the exit to take advantage of the kinetic energy and generate electricity, the company has been doubly innovative and channeled the high power brine back into the system to directly energize the high pressure pumps. This ensures the highest level of potential energy usage.
The amazing thing about that is that typically when someone innovates something they are quite self-satisfied by their accomplishment, but the engineers at the desalination plant weren’t satisfied with putting a turbine at the exit to catch the brine, they achieved an even better end result. And this is not even part of their core business!
Class photo (photo credit: Prof. Bachenheimer)