30 MWH per Year From 1 Square Meter of Membrane

Apparently, boron nitride nanotubes have a lot of other uses too...

https://www.thestar.com/news/insight/2016/02/01/boron-nitride-nanotubes-are-the-next-big-really-really-tiny-thing.html

After looking at your link, I'm wondering if these could be the next mesothelioma cases?

boron nitride nanotubes ↓

blue asbestos ↓

It's a little too soon to get excited over, but does look promising...

https://en.wikipedia.org/wiki/Osmotic_power

https://webberenergyblog.wordpress.com/2012/04/01/osmotic-power-generation/

Researchers have concluded that pressure-retarded osmosis (PRO) was commercially "dead" primarily due to biofouling ...."Our research shows that commercial PRO is currently dead in the water," said Zuckerberg's Dr. Edo Bar-Zeev. "Biofouling is detrimental to the process and can't be mitigated since there are no membranes today that are specifically designed for PRO."

The main drawback to boron nitride nanotubes is the cost. In 2014-2015 the cost approaches about one thousand dollars per gram.

Even with boron nitride nanotubes, I think biofouling is still going to be a problem and if they can get pass the tree huggers that will bitch about "our rivers are being choked off". It sounds promising

Clog attractor.

I'm not sure what gets "consumed" in this process. Does electric power come from forward osmosis thus making less fresh water? If so then aren't we just trading a precious commodity (clean water) for energy desires.

Dilution will occur when the two are mixed anyway,but the energy is not harnessed,merely absorbed by the constituents.

The net result on the total water mixture should be zero.

Sort of like harnessing the energy from a waterfall.

Look at the process as a battery,with the anode/cathode ends separated by the membrane.

The potential problem I see in the future is using mined salt and fresh water to create the generator.

That would put extra demand on limited fresh water supplies.

The Colorado is already drained before it reaches the ocean.

The Great Lakes are next,after they install the cross-country pipeline to send the water west.

There will be osmotic generators along the entire length,to power the pumps,salt provided by mined salt.

Yes,I realize the magnitude and scale of the project.

Cost does not matter,it is ROI that counts.

Sure there will be protests,as with the oil pipeline,but big money always wins,and tramples resistance with persistence and their total control of the press.

You want a drink of water,or a crispy head of lettuce,or power to your home?

Eventually,there will be a water pipeline.

Russia is sitting on a future gold mine with Lake Baika.

Lake Baikal is the largest freshwater lake by volume (23,600km³), containing 20% of the world's fresh water.More than all of the great lakes combined.

The next cartel will be a water cartel.

Insofar as biofouling goes:Let the zebra mussels do the heavy lifting of the filtering process.

They have already cleaned up the great lakes.

Sure,they displaced native species,but the native species were not doing the job.

Nature has always replaced species with more efficient ones.

The main complaint is from the fouling of the cooling water piping at generating plants.

This is an engineering problem for which a known solution exists,but it is expensive.

"I bring the news from D street,and the news is not good."

Ref:http://www.sfwriter.com/northern.htm

"sfwriter" sounds about right, "sf" standing for science fiction.

Here's my understanding. The Na⁺ ions are smaller than the Cl^- ions, and the nanopores allow passage only of the smaller Na⁺. So as the Na⁺ ions diffuse through the membrane, the fresh water side becomes charged positive and the saltwater side becomes charged negative, thus creating a battery.

So yes, the fresh water becomes less fresh, but if it's a river dumping into the ocean, it was going to happen anyway.

Perhaps some of the chemical engineers or physicists can help with this:

How much energy can be extracted from 1 gallon of saturated salt water vs 1 gallon of distilled water,using the membrane ion method?

I realize the concentration will decrease as energy is used,and it will have to be dumped and restored by adding more salt,or fresh salt solution.

Picture this scenario:

Near the Great Lakes,a osmotic generator,powered by fresh water from the lake,and charged with salt from nearby salt mines.

The waste,diluted saline solution is dumped onto solar drying beds,where the salt is recovered.

The water would not have to be totally removed,just concentrated.

This would be using solar energy to improve the efficiency of the process.

Now,if a way could be found to recover the evaporated water, the loop could be closed and you would have a near self sustaining process, with the condensate needing no filtering before reuse.

Perhaps a plastic cover,with a cone shape in the center to concentrate the condensate water to a central collection point.

If the system was 100% (which nothing is) it would even be viable in the desert.

1 square meter is small enough to back-pack ,depending on weight.

But who needs a portable 4 kw generator while camping? Downsize it.

Maybe like a 6" square?

The quantity of water is another matter.

So how much energy is in 1 gallon of water and one gallon of saturated brine?

What you have is basically a salt water battery and an inefficient way to recharge or reclaim the raw materials from solar energy. I can't see it as being any serious source of energy except as an energy harvester where river runoff into the ocean provides the raw materials for free.

I'm all for this technology if they can get it out of the lab and into production. I rather live off grid than pay a utility company any day. And to have a power supply that I could backpack, life couldn't get much better

I'm waiting for hydrogen fuel cells to come down in price, then I'll convert everything I own to hydrogen.

Here is a shot at your question, "How much can you get from a gallon of brine?"

Energy = pressure x volume

The osmotic pressure of seawater is about 25 atm =375 psi

1 gallon = 231 cu in (231 inches long x 1 sq in)

375 lb/in² x 231 in³ x 1/12 ft/in = 7219 ft lb = 2.718 WH = 9788 Joules

You can calculate osmotic pressure from concentration here