Clean water is all around us, and more literally than you might think – it’s floating around in the air most of the time. Of course, it’s not particularly drinkable in that form, but now researchers at the Johns Hopkins Applied Physics Lab (APL) have found materials that can collect huge amounts of water from the air.

As is the case with similar systems we’ve covered previously, the key lies with a material called a metal-organic framework (MOF). These structures have the highest surface area of any known material – in fact, if you were able to unfold just one gram of an MOF, it would be enough to cover a football field. And all that internal space makes them perfect for capturing and storing water.

“We identified a MOF that could produce 8.66 liters (2.3 gall) of water per day per kilogram of MOF under ideal conditions, an extraordinary finding,” says Zhiyong Xia, co-lead author of the study. “This will help us deepen our understanding of these materials and guide the discovery of next-generation water-harvesting methods.”

https://newatlas.com/materials/harvester-drinking-water-thin-air/

what did i ‘king say, when they finally save the world, it’s all going to be solar and moisture farming and solar powered moisture farming

SCIENCE said:

what did i ‘king say, when they finally save the world, it’s all going to be solar and moisture farming and solar powered moisture farming

How will that save the world? Maybe his world but not the whole earth.

I suspect that this suffers from the same issue that bugs all these forms of systems; it takes a shitload of energy to get water to phase transition from a vapour state to a liquid state. Way too much energy to make this a viable proposition.

sibeen said:

I suspect that this suffers from the same issue that bugs all these forms of systems; it takes a shitload of energy to get water to phase transition from a vapour state to a liquid state. Way too much energy to make this a viable proposition.

eh maybe, it’s an exothermic process so imagine all the energy you could get from condensing water, you could almost use it to boil some other water and drive a turbine, wait

sibeen said:

I suspect that this suffers from the same issue that bugs all these forms of systems; it takes a shitload of energy to get water to phase transition from a vapour state to a liquid state. Way too much energy to make this a viable proposition.

Is that the latent heat of vapourisation? If so it’s 2256 kJ/kg

If you do it with self contained units powered by solar it would be great

Cymek said:

If you do it with self contained units powered by solar it would be great

Designed well enough it may be possible as a byproduct of solar.

maybe read the linked to paper

https://www.nature.com/articles/s41598-020-58405-9

… Direct water harvesting from air has been demonstrated through cooling water vapor below its saturation pressure is not practical in dry climates due to its high energy demands3.

Metal-organic frameworks (MOFs) due to their unique micro-structure, intrinsic porosity, and unprecedented functional and chemical control have a high potential to be used for harvesting water from air5,6. Recently, the use of MOFs to leverage the earth’s natural thermal swing process to efficiently sequester clean water with little to no additional energy input has been demonstrated…

ChrispenEvan said:

maybe read the linked to paper

https://www.nature.com/articles/s41598-020-58405-9

… Direct water harvesting from air has been demonstrated through cooling water vapor below its saturation pressure is not practical in dry climates due to its high energy demands3.

Metal-organic frameworks (MOFs) due to their unique micro-structure, intrinsic porosity, and unprecedented functional and chemical control have a high potential to be used for harvesting water from air5,6. Recently, the use of MOFs to leverage the earth’s natural thermal swing process to efficiently sequester clean water with little to no additional energy input has been demonstrated…

Yes.

ChrispenEvan said:

maybe read the linked to paper

I refuse, i very much respect scientific opinion, but every day across my desk comes enough information for me to say that there are other opinions. I’m not relying on evidence, i am saying, but this is why my mind is open.

SCIENCE said:

ChrispenEvan said:

maybe read the linked to paper

I refuse, i very much respect scientific opinion, but every day across my desk comes enough information for me to say that there are other opinions. I’m not relying on evidence, i am saying, but this is why my mind is open.

:-)

SCIENCE said:

ChrispenEvan said:

maybe read the linked to paper

I refuse, i very much respect scientific opinion, but every day across my desk comes enough information for me to say that there are other opinions. I’m not relying on evidence, i am saying, but this is why my mind is open.

open, I can see through to your other ear?

SCIENCE said:

ChrispenEvan said:

maybe read the linked to paper

I refuse, i very much respect scientific opinion, but every day across my desk comes enough information for me to say that there are other opinions. I’m not relying on evidence, i am saying, but this is why my mind is open.

I hope not too open minded that your brains fall out.

;)

Michael V said:

SCIENCE said:

ChrispenEvan said:

maybe read the linked to paper

I refuse, i very much respect scientific opinion, but every day across my desk comes enough information for me to say that there are other opinions. I’m not relying on evidence, i am saying, but this is why my mind is open.

I hope not too open minded that your brains fall out.

;)

Senny Jim, did ‘e have any to begin with

ChrispenEvan said:

maybe read the linked to paper

https://www.nature.com/articles/s41598-020-58405-9

… Direct water harvesting from air has been demonstrated through cooling water vapor below its saturation pressure is not practical in dry climates due to its high energy demands3.

Metal-organic frameworks (MOFs) due to their unique micro-structure, intrinsic porosity, and unprecedented functional and chemical control have a high potential to be used for harvesting water from air5,6. Recently, the use of MOFs to leverage the earth’s natural thermal swing process to efficiently sequester clean water with little to no additional energy input has been demonstrated…

Ok, I’ve read the Nature paper. The gist of it is that they placed the prepared sample into a test chamber at 22° and 70% relative humidity, left it for 24 hours to soak up the atmospheric water and then raised the temperature to 60° and lowered the relative humidity to 30% and extracted the water. The test was performed with varying thickness of the layer of material between 1 and 10 mm. The headline figure of 8.66 liters of water per day per kilogram was their best result.

Outside the laboratory I suspect it’d be quite a bust and I doubt there would ever be a commercial version manufactured. It may even work OKish in a place like Darwin or Singapore, but they’re not exactly crying out for water. In a place where they are crying out for water something like this would be next to useless.

sibeen said:

ChrispenEvan said:

maybe read the linked to paper

https://www.nature.com/articles/s41598-020-58405-9

… Direct water harvesting from air has been demonstrated through cooling water vapor below its saturation pressure is not practical in dry climates due to its high energy demands3.

Metal-organic frameworks (MOFs) due to their unique micro-structure, intrinsic porosity, and unprecedented functional and chemical control have a high potential to be used for harvesting water from air5,6. Recently, the use of MOFs to leverage the earth’s natural thermal swing process to efficiently sequester clean water with little to no additional energy input has been demonstrated…

Ok, I’ve read the Nature paper. The gist of it is that they placed the prepared sample into a test chamber at 22° and 70% relative humidity, left it for 24 hours to soak up the atmospheric water and then raised the temperature to 60° and lowered the relative humidity to 30% and extracted the water. The test was performed with varying thickness of the layer of material between 1 and 10 mm. The headline figure of 8.66 liters of water per day per kilogram was their best result.

Outside the laboratory I suspect it’d be quite a bust and I doubt there would ever be a commercial version manufactured. It may even work OKish in a place like Darwin or Singapore, but they’re not exactly crying out for water. In a place where they are crying out for water something like this would be next to useless.

“This will help us deepen our understanding of these materials and guide the discovery of next-generation water-harvesting methods.”

sibeen said:

ChrispenEvan said:

maybe read the linked to paper

https://www.nature.com/articles/s41598-020-58405-9

… Direct water harvesting from air has been demonstrated through cooling water vapor below its saturation pressure is not practical in dry climates due to its high energy demands3.

Metal-organic frameworks (MOFs) due to their unique micro-structure, intrinsic porosity, and unprecedented functional and chemical control have a high potential to be used for harvesting water from air5,6. Recently, the use of MOFs to leverage the earth’s natural thermal swing process to efficiently sequester clean water with little to no additional energy input has been demonstrated…

Ok, I’ve read the Nature paper. The gist of it is that they placed the prepared sample into a test chamber at 22° and 70% relative humidity, left it for 24 hours to soak up the atmospheric water and then raised the temperature to 60° and lowered the relative humidity to 30% and extracted the water. The test was performed with varying thickness of the layer of material between 1 and 10 mm. The headline figure of 8.66 liters of water per day per kilogram was their best result.

Outside the laboratory I suspect it’d be quite a bust and I doubt there would ever be a commercial version manufactured. It may even work OKish in a place like Darwin or Singapore, but they’re not exactly crying out for water. In a place where they are crying out for water something like this would be next to useless.

Probably work here. It’s 25.6°C and 85% RH currently.

Michael V said:

sibeen said:

ChrispenEvan said:

maybe read the linked to paper

https://www.nature.com/articles/s41598-020-58405-9

… Direct water harvesting from air has been demonstrated through cooling water vapor below its saturation pressure is not practical in dry climates due to its high energy demands3.

Metal-organic frameworks (MOFs) due to their unique micro-structure, intrinsic porosity, and unprecedented functional and chemical control have a high potential to be used for harvesting water from air5,6. Recently, the use of MOFs to leverage the earth’s natural thermal swing process to efficiently sequester clean water with little to no additional energy input has been demonstrated…

Ok, I’ve read the Nature paper. The gist of it is that they placed the prepared sample into a test chamber at 22° and 70% relative humidity, left it for 24 hours to soak up the atmospheric water and then raised the temperature to 60° and lowered the relative humidity to 30% and extracted the water. The test was performed with varying thickness of the layer of material between 1 and 10 mm. The headline figure of 8.66 liters of water per day per kilogram was their best result.

Outside the laboratory I suspect it’d be quite a bust and I doubt there would ever be a commercial version manufactured. It may even work OKish in a place like Darwin or Singapore, but they’re not exactly crying out for water. In a place where they are crying out for water something like this would be next to useless.

Probably work here. It’s 25.6°C and 85% RH currently.

Yeah, now all you need to do is get up to 60°, OK we could do that with mirrors, and get your RH down to 30% before you can begin extracting all that lovel water :)

sibeen said:

Michael V said:

sibeen said:

Ok, I’ve read the Nature paper. The gist of it is that they placed the prepared sample into a test chamber at 22° and 70% relative humidity, left it for 24 hours to soak up the atmospheric water and then raised the temperature to 60° and lowered the relative humidity to 30% and extracted the water. The test was performed with varying thickness of the layer of material between 1 and 10 mm. The headline figure of 8.66 liters of water per day per kilogram was their best result.

Outside the laboratory I suspect it’d be quite a bust and I doubt there would ever be a commercial version manufactured. It may even work OKish in a place like Darwin or Singapore, but they’re not exactly crying out for water. In a place where they are crying out for water something like this would be next to useless.

Probably work here. It’s 25.6°C and 85% RH currently.

Yeah, now all you need to do is get up to 60°, OK we could do that with mirrors, and get your RH down to 30% before you can begin extracting all that lovel water :)

And a good few kilos of MOFs, too.

The 60°C is doable on a sunny day (my solar hot water gets hotter than that). I’d bet that the RH would be lower than 30% at that temp.

> a metal-organic framework (MOF). These structures have the highest surface area of any known material.

Then I’d say they have much more useful applications than collecting water. They’d be the ultimate catalyst for starters.

> absorb water vapour from the air

Absorbing water is not the issue – releasing it is the issue.

> Reversible Atmospheric Water Harvesting. “the maximum amount of harvested water is not determined by the uptake equilibrium, but rather by the amount of the water that can be desorbed after saturation.” Capture at low temperatures, release at high temperatures.

That’s a good start.

> We identified a MOF that could produce 8.66 liters of water per day per kilogram of MOF under ideal conditions

At what relative humidity? eg. MgCl2 will deliquesce at a much lower relative humidity than NaCl.

> how different environmental conditions, such as temperature and humidity, affected their ability to absorb water vapour. The adsorption cycle was performed over 24 h at 70% RH and 22 °C. In comparison, the desorption was performed at 30% RH and 60 °C

Very Good. I once did a study which showed that 70% RH was the average RH of Adelaide.

> Zr-MOF-808

How fast does it rust?

This looks good, I note that it’s Cr not Zr. Absorption time of 200 minutes is a bit over 3 hours. Desorption time 1 1/2 hours. Cr MOF has a much slower uptake rate than Zr MOF but greater capacity per kg. Zr MOF absorbs in 1 hour and has the second largest total capacity.

> Loose-grain powder bed reactors are simple but can suffer from limited diffusivity as bed thickness increases.

Using a slow fan to force air through the bed would be faster?

This looks really good to me, both the Cr and Zr based MOFs. But they need to see how performance degrades over a period of about a year, at present they’ve only tested it for ten days.