The first article on Saltworks
News page is about a breakthrough Energy Efficient Desalination Technology.
And I'm familiar enough with desal plants having worked on the engineering/procurement/construction/commissioning of a couple of plants that this term got me interested : innovative thermo-ionic energy conversion system.
What is it? As my day was spent trying to get a handle on ALL of Saltworks history I didn't have time to go digging through patents, but I did read this article & it is pretty amazing if this works as described.
Salt-lution: Vancouver's Saltworks Technologies has captured the attention of the desalination industry and a petroleum sector thirsty for solutions to water quality problems.
Here are the highlights - my comments look like this
There are nearly 15,000 desalination plants in operation around the world today and two technologies currently dominate the market.
One is multi-stage flash distillation, which involves the rapid vaporization of seawater followed by condensation to produce fresh water.
This process is energy-intensive, as it requires huge amounts of heat.
The other leading and increasingly popular approach is reverse-osmosis, by which salt water is forced through special membranes that selectively prevent salt ions from passing through.
Reverse-osmosis uses less energy than flash distillation, but because of the high pressures needed to reverse the osmotic flow of water a considerable amount of electricity is required to operate the pumps.
Saltworks boasts a more efficient technology that can cut energy costs by at least half compared to a reverse-osmosis system.
It also works under low pressure--as low as five pounds per square inch versus 1,000 psi for reverse-osmosis--meaning expensive stainless steel and titanium pipes aren't required.
All of it can run on low-cost plastic piping of the sort found at Home Depot.1000 psi is 6900 kpa. 5psi is 34 kpa.
Standard Atmospheric pressure is 101.3 kpa
Sparrow explains that a Saltworks desalination plant would begin by taking in an initial batch of seawater, which contains about 3.5 per cent salt and further concentrating it to 18 per cent or higher.
This would be accomplished through evaporation, using low-grade waste heat from a nearby industrial process or by way of a shallow-pond system exposed to the heat of the sun.
That salt-concentrated ocean water would then be pumped into a tank, called tank A.
Next to it are three other tanks: B, C and D, which contain seawater with normal concentrations.
When A is connected to B and C, the ions in the more concentrated tank A are naturally drawn to the two tanks with lower concentrations.
Separating this flow, however, are chemically treated filters called ion exchange membrane stacks.
These stacks are manufactured by Saltworks and together with process arrangement represent the company's core innovation.
The membrane stack between tanks A and B only lets negative ions pass through.
The stack between tanks A and C only lets positive ions pass through.
The result is that tank B ends up with a higher concentration of negative ions, such as chloride, and tank C ends up with a higher concentration of positive ions, such as sodium.
As a result, tanks B and C are out of balance.
Regular seawater is still sitting in tank D.
When tank B with the surplus negative ions is connected to D, it desperately wants to be in balance again, so it strips out all of the positive ions (such as sodium, magnesium, calcium) from D.
Likewise, when C is connected to D it pulls the negative ions (such as chloride, sulphate, bromine) out of D in an effort to rebalance itself.
This leaves tank D completely salt free.
IOW - Evaporation concentrated salt is in tank A. Because of ion exchange membranes - Tank B Ends up with surplus negatively charged ions. Tank C ends up with surplus positively charged ions. When tank D is connected to B & then C it strips out the positiively charged ions then negatively charged ions leaving tank D with No salt.
But don't call yet, there is more :
This is where Saltworks enters the picture. Its process can turn about 60 per cent of that leftover brine water into pure water, boosting total recovery from 75 to 90 per cent and leaving behind a much smaller volume of brine waste. But it can go a step further. The company has developed a new evaporator tower technology that can retrieve the remaining water from the brine and leave behind an easy-to-handle solid salt.
The system works best in the dry regions that need water. Saltworks President Joshua Zoshi said.
This is a pretty amazing application of IX membrane technology as part of a process solution - pretty much exactly what has just been through it's paces at Kachi in the demo plant.
