They actually don't get that much precipitation... Plenty of places with far more sun get far more rain. The UK just gets clouds. Neither useful rain nor useful sun. Just clouds. I guess it means the rain they do get doesn't evaporate?
@@AntonOfTheWoodswell we get wind and that’s drying, and why I hang out my washing in it and have to water everything in pots and even in the ground during summer
It's far too sensible and un-clickbaity for the algorithms unfortunately. A very good channel and I particularly like how he goes back to look how new developments are progressing.
Most of the world's population is made up of dumb people, and dump people do not get interested in high-quality channels of information because it makes their heads hurt.
One challenge I see is biologic fouling. Doing this on a desktop is a big difference than running continuously. To move this to a usable technology will require preventing everything from seaweed to barnacles from growing. Even a tiny amount of fouling will cause turbulent flow completely defeating the separation mechanism.
The good thing is that by applying a charge across the feed, you can create Chlorine from the salt water. This keeps the system biologically clean and perhaps residual Cl (10ppm)in the outlet keeps it potable for longer storage. Have done this as standard with seawater cooling systems.
It's great to see recent innovations in desalination methods. As an Engineer who worked on power and desalination projects in Saudi, Qatar, Bahrain, and Libya, they were clearly relying on waste energy from power stations or industrial processes to provide thermal, multistage desalination. This is clearly better suited to lower technology areas the desperately need fresh water.
Denmark has, due to regulatory and political fuckups, quite a lot of surplus heat. And a set of new problems, handling water. Would you say that desalination is a consolidated industry one can draw inspiration from?
This video is a fine example of why channels like just have a think are BS merchants and not science channels. This is an unconfirmed lab experiment that almost certainly would not scale up to the scale of utility level water treatment. The idea that this could be powered by the sun is delusional.
The fact that they didn't build an actual working unit that achieved sufficient desalination but it was only theoretical should serve as a dose of enthusiasm dramping reality.
Exactly. It would be relatively easy to create their own ”theoretical” version and the obvious fact that they didn’t, speaks volumes. It’s the obvious next step. All that is missing is a cliche claim like “This changes everything, or revolutionizing desalination”…
@@seantiz Even if this does work as intended, it will likely be a component in multistage water treatment process. In fact, it seems like this process could be added to almost every existing water treatment plant to increase overall efficiency. The idea is absolutely worth grant money & engineering effort. The combined budget power of every municipal water system & privatized rentier system (that should be public) could easily afford to fund this research, were there some central system that could aggregate their resources.
@teadrinker7098, they built a system that would fit on a bench with the intention of proving that the idea is valid & could be measured. They succeeded. The next step is to hand it over to engineers to scale it up to a useful working system.
in science, if you want to build something, unless you pay from your own pocket, you need funding. Applying for funding takes time and energy. Ofthentimes up to a year. So I hope we'll hear from these people again
In reverse osmosis, the level of salinity is responsible for the necessary pressure. Means, with such a system upstream of an RO, the necessary pressure and related energy consumption of the RO could be reduced significantly! Sounds great!
I was not sure of that, but it makes sense. I have an home RO system to provide domestic drinking water and it does not use as much as energy as mentioned for desalinization.
@@Nosirrbro No, from the main running water distribution, but it is unclear that it is fit for human consumption. Supposedly it is, but no one drink tap water. There is also quite an amount of silt in the tap water. I am in Thailand.
This just got me thinking on the miracles this can do if applied to the lithium extraction pools in Atacama desert, just passing the water in such structures on the early stages to increase the lithium concentration and recover some fresh water to local agricultural use instead of simply evaporating it
I like how you focus on the incremental solutions that are being developed. We often forget about those initially, small, but significant solutions to problems like this...particularly as being a part of already existing technology. Yes, time is critical, but it'll be the low tech solutions that'll win the race...I'm convinced of that. Thank you for your commitment to finding and illuminating these technologies!
There's nothing I can add to this, since you've covered the topic quite completely. It does seem like the technology would work better as an add-on to existing desalination systems, improving their efficiency and reducing cost, rather than a complete system on its own. The 10% recovery rate makes this more of an in-development idea than a finished one that can help rural communities right away. Desalination is a really fascinating subject, though! There's such a complex interplay of economics with engineering and basic science.
Great video and I love the lower energy achievement. In our case here in mid Wales we opted to go for rain water harvesting to help reduce our dependence on main water. I found that the IBC tanks used in the drinks industry are very cheap and widely available. So we have 4 of these one thousand litre tanks mounted low in the ground so as to allow a work top above them used for beddings to bring seedlings. Another 2 are sited down the side of the our home. Combined with the 4 water butts we have a storage capacity of 7 thousand litres. This has reduced our water consumption to half, and also means no cleaning was necessary other than some simple inline metal filters. we use the water for flushing the loo, watering plants, and cleanign the cars. Total cost including a pump and pressure tank and pipework £700. We save about £80 a year, so payback should be 9 years. This would make quite a considerable difference to our national water system, and its effects on our environment, if all homes were made this way.
Oneka technologies have a working wave energy powered desalinization plant which is sustainable and affordable .It works without external inputs ,only the work of waves. It redistributes the excess salinity back to the ocean with no impacts to the surrounding sea. Fish and microscopic life are filtered at the input site. The osmosis membrane is cleansed by the process of the pump. This process is scalable in size to the project. I wish the Aussies the best of success in their endeavors.
Is their Californian demo site up and running yet. If it is I hope Dave does a video on them, or features them in a round-up vid of desalination technology that is currently in use or has a live demo system up and running.
Couple of things: 1. It "sounds" to me like the cold plate in this type of system would have to be mechanically cleaned of precipitated salt particles on a fairly regular basis, yes/no? 2. Since they haven't actually constructed or tested an actual working Burgers cascade device yet, I'll have to take their "theoretical" 10% recovery rate stat with a grain of salt (no pun intended).
If it isn't being boiled away, then I would think the salt and other things dissolved in the water would remain dissolved. If it was a system where water was continuously being recycled through with the goal of increasingly saltier water, then you would get to a point where the water is saturated and could precipitate salt out and gum things up. But if the saltier water is being cycled out of the system in attempts to get less salt flowing through, then the only potential issue is if the wall material reacted with the water, and that is a largely solved problem.
The mechanism is more akin to convection, where hot liquid floats to the surface and cold liquid sinks to the bottom. Saltier liquid sinks to the bottom/cold. It naturally happens in the oceans too.
Even if this method doesn't get the job done, 2-3 passes like this before using other methods can have significant savings! Less power needed, and much longer lasting filters could be a game changer even for existing systems. Very interesting tech!
More properly, this method reduces the amount of ELECTRICITY required to desalinate water, by trading some electrical energy for yet more heat energy. In terms of the ultimate thermodynamic efficiency, reverse osmosis is already achieving a separation efficiency of somewhere between 33% and 60%, meaning that it's using between 1/0.6 and 1/0.33 times as much energy as the thermodynamic minimum required to separate freshwater from seawater. That energy difference however is measured in joules, and there's no law of thermdodynamics that I'm aware of that requires the energy to be put into the system in the form of pure exergy (electricity) rather than in the form of some exergy and some heat. That's what this system does, and it might be useful- or not, depending on lots of things this video doesn't discuss, but which are very important to the at-scale feasibility of a desalination system. Finally, "yield" goes to how much seawater you need to pump, and how salty the water is that you reject to the sea again. While a low yield would mean that you perhaps pump 10 m3 of water from the sea to get 1 m3 of freshwater and 9 m3 of slightly saltier water would need to be pumped back to the sea, that means you have to pump a lot of water around, and that doesn't happen without electrical energy being expended. RO normally concentrates seawater about two to three-fold. However, that salty water needs to be carefully controlled so that it doesn't cause a locally high salt content in the ocean which is damaging to sea life.
How does one calculate the thermodynamic minimum energy required to separate fresh water from sea water? I do appreciate that separated water and salt in separate containers is lower entropy than the same salt dissolved in water.
A properly set up Siphon system should make your net pumping needs only scale with the fresh water yeild, not toal water moved. And returning larger volumes of lower salinity water would actually be better for most marine ecosstems, hyper saline brines just sink to the bottom and do not mix with the rest of the ocean, on the bottom they then damage marine life osmotically.
@@kennethferland5579 frictional loss in the pipe needs to be compensated for with energy input, either way. Moving matter around is not an energy-free deal.
@@zacriewright5258 frictional loss in pipe has to be compensated for either way. You don't get something for nothing by using a siphon. You need to lift water from the ocean to do anything to it, and then return the water to the ocean again. You lose energy in pipes in both directions. You can of course make it worse by not recovering the energy from the falling water that you input energy to raise, but you don't get something for nothing by digging a hole in the ground. That spent seawater needs to go back to the ocean regardless- it can't stay at the bottom of your hole, nor will it get back out of the bottom of your hole into the ocean of its own accord.
One thing I love about camping out long term is gathering my water. Most of the usa water infrastructure is old. The disinfecting agents react with organic solids in the water and make a host of potent chemicals new to science. Better desalination is great, but I'm gonna try and stay in places with forested hills with streams in them to gather the little I need, avoid using water infrastructure in general whenever possible. I use an electric kettle right now parked behind a house and town water coats it with mineral sediment very quickly, stream water boils off clean. Tastes soooooo much better too, town water usually tastes horrible by comparison. It's not that hard, I'm a poor hobo gardener living in a prius and I have gathered all my water this summer, including bathing. But not laundry, I take that to a laundromat. Using a wet rag makes it easy to wash up without using a lot of water. I could use the bathroom where I'm parked, but the forest is better, bathrooms are nasty. So funny, I work as a gardener and rich people buy up all this amazing land in VT and then barely experience it. I am poor but I have so much rich experience with the soil and water of these properties. So much stream water has flowed through my body, I've breathed so much fresh air and touched rich soil and eaten plants from it. People buy land as a wealth flex and then continue to get everything they need from the machine, so silly.
It is encouraging to see progress being made in this important area. Thanks for your work. One important observation: Distilled water is drinkable but it removes minerals making it unhealthy for human consumption over the long term.
Would love to see an update on Wave Energy Desalination. A Canadian company, Oneka Technologies, makes these desalination plants. It would be cool to see how many are now deployed and what further innovations and scale-up is taking place.
We used to make FW from SW at sea using an evaporator by creating a vacuum using pressured sea water pushed through a ventury nozzle. re-directed engine cooling water was pumped through the sea water at about 150 degrees whilst also using cold seawater through another coil at the top for condensing the resulting vapours.
Definitely something worth a degree of research into, but nothing to pin any hopes on. Kind of how it goes for a lot of these tech, realistic optimism.
It could. I have been doing this for around 10 years and every year I learn how to do it better. I manage to harvest around 1,000 litres of drinking quality water per winter - I live in drought stricken S. Europe - and this is sufficient for 2 people plus domestic animals. I also harvest 10,000 litres for irrigation, cleaning etc.
You have a talent for explaining systems which are not yet ready for prime time. The more we know, the more we can know... keep sharing these innovative methods that have promise for scaling up to industrial levels and the associated help to the involved communities.
Since the best yields are when the plates are close together, put this to use by using that method at the end of the line, Use the plates further apart at the beginning of the line. For the mass flux equation, I wonder if that could be overcome by simply lengthening the distance the water travels through the narrow plates at the end? I like this desalination idea because as you said the water stays in its liquid form, heating the top plate can be done using the best method available, and requires a fraction of the energy other methods use. This method seems very viable and promising. People that have no drinking water won't care much about yields and where the brine goes. They are dying of thirst.
ALL desalination produces an unpleasant byproduct- warm brine. It tends to cover the seabed in large areas next to desalination facilities and kill mostly everything. So while this new techique is as interesting as it is promising, desalination of seawater should be seen as a last resort when alternatives such as rainwater management, efficient irrigation, or wastewater recycling don't suffice.
ALMOST all desalination does that. One exception is where the brine is dumped into an evaporation lake, heated by the sun in a desert climate, so that the minerals can be skimmed off as they precipitate. As far as I know this scheme is still only theoretical at scale, so in terms of present day practice you are sadly correct
I absolutely have an idea that eradicates this issue. Though, its application would most likely only be effective in warm climates. However, I had no considered industrial waste heat until today.
@@trueriver1950 if we start needing more salt for sodium batteries that problem would solve by itself. Traditional salt production basically implies evaporating water from brine using the sun in open spaces
@@trueriver1950 ...minerals which contain, because of current industrialization, extreme concentrations of many, many, deadly & harmful substances. It’s human mechanical biomagnification of poisons.
Maybe we could somehow collect some of The rainwater that falls over the sea, and we should put solar panels over our waterways and reservoir to help the water we do have from evaporating.
What I’ve never understood is why humans don’t just cut a channel into the Sahara desert and others, into huge shallow pools, and just leave the water there for evaporation to increase rainfall. Natural and practically free.
Using this as a first stage that eliminates 5/6ths of the salt is big. If the heat is the back side of a solar cell that's being used to drive a reverse osmosis stage that could be a win. I wonder how this would perform in the Persian Gulf, where desalination is reaching a point of diminishing returns due to the increased salinity of the seawater. There has been promising membrane related work using graphene, but I've not kept up with that. Overall a very positive bit of good news.
"Using this as a first stage that eliminates 5/6ths of the salt is big. " - if only the first step did eliminate 5/6th, then it would be world-changing. Instead the first step, if by that you mean the first pass through the mechanism, removes a small percent of the dissolved salt.
Others have mentioned the energy needed to pump all of the water. Also there will be high pressure required to pump through a cascade of mm thin spaces. The narrower the pipe, the higher pressure needed to achieve a given output. Last, biofilms on the plates could be a problem.
If all nations built berms and swales on contour across their land, that would go far to address water issues. They collect and filter rainfall and allow it to be slowly absorbed. They make forests stronger while preventing flash-floods and flooding, and help prevent wildfires. They need to be build everywhere physically possible. That along with permaculture techniques is the answer. That and building bikeways and rail systems.
An amazing development - though have a more efficient and cleaner way to desalinate, with extra produce at the end, other than just drinking water. Thoigh the benfits of this system is astonishing. Especially when you consider the applications for industrail waste water. Super cool and keen to learn more on a later follow up video, as this progresses. Kudos and keep at em' 💪🤓
The moment I heard that the materials needs to made from nickel plated copper my heart dropped. Both are some of the most expensive metals out there...
The movement of salt to the cold plate I believe is due to seebeck effect. So in principle, the same movement can be achieved by moving the saline water between dissimilar electronegative plates. I also suspect that the setup you described will generate voltage difference between hot and cold plates. 15kwh energy requirement you mentioned for thermal heating, I presume can be reduced by concentrating Solar Energy onto a fine spray mist of saline water or use black ceramic balls to absorb the concentrated heat onto the salt solution. Anyway Kudos to the team on finding an innovative way to desaline which will reduce water stress of humanity
Perhaps it should be the first line of desalinization and use more conventional methods help? Another is using current fresh water efficiently instead of just over using it
People fight over water, and we need to consider how our future will be if we don't tackle the water problems that we have and which are emerging. Maybe this _thermodiffusive_ process will be a lifesaver in more than one way.
Perhaps for drinking water but consider the scale of water depletion in Iran or Iraq. These are water needs at the national scale and don’t come to terms with the loss of water to general environment and all the consequences to it.
Oh for sure. It's already happening in the area of the world where my parents are from (Kashmir) I really want this technology to succeed because it means that they can live peacefully (despite the sheer military presence, from the Pakistani side) It's not even the first time it's happened tbh. The very reason why I'm so mixed is due to it being invaded since time immemorial for water
All desalination methods produce mountains of salt that destroy life wherever they are dumped. Desalination is a horrible idea. The global population is ten times to large and even if it were to stop growing the biosphere will continue to degrade and while now six of the eight billion people on Earth live deprived lives, soon seven out of eight billion people will live deprived lives. In twenty years everyone on Earth will suffer great deprivations and have miserable lives.
Thanks. Appreciate the breakdown of processes. Another good, factual show in a long series of good shows that are reliably offering progress reports on a wide-ranging set of climate tools the world needs.
If integrated with other desalination plants or solar farms, it could be a game changer. Solar panels need cooling to remain efficient and reduce wear so that's one source of heat that could be reused and a lesser salt concentration would reduce power consumption and filter wear. This could make both the solar power plant and the desalination plant more efficient and financially profitable. Add a salt marsh next to it and you can get rid of the brine and produce salt and the thing is solved.
Awesome potential tech. Add in the newly discovered visible light contributing to evaporation (transverse magnetic polarization, 45 degree incident angle, and green wavelength maximized the effect), and for a bit more energy they might be able to then separate more water from both the low and high salinity flow, increasing their yield of usable water.
Dear David, thank you for your next great THINK. One of the solutions is resuse the grey water in households, industries and cities, currently most of the waster is used just once but charged by th water management companies like VEOLIA, two or event three times.
Removing 83% of the salt from 10% of the seawater yields a brine that's only 109% concentrated, so this process is fairly gentle in that regard as well. 🤓
It does seem like it might be useful for that opposite application of hyper-salinating brine solutions, concentrating them even further than they already are, so that you can more efficiently dry them out into an industrial salt product.
Ive long wondered why we can't use Ocean Thermal Energy facilities to run desalination facilities. Position the facilities off shore and use purpose built vessels to move the desalinated water to onshore pumping stations. A pilot Ocean Thermal facility was run off shore of Hawaii in the 70s.
interesting, but keeping things cool and hot enough may not be a 'free lunch' if an RO desalinator like I have installed on many pleasure craft were tied to a suitable off grid electrical supply, small villages could have good water. A 1hp/120vac motor hooked to a pressure washer pump will make up to 800 u.s.a gallons (almost 4 liters x 800) per day. Product usually 200 ppm or lower. Rendered sea water tastes sweet. These systems mostly self clean when running and back flush RO media filters upon shutdown. The wastewater could be put in covered ponds that create water vapor by day and the cooler night air chills the cover and distilled water gets harvested, as does salt and minerals. A pvc tarp stretched across a 1m round pit can make a liter of water at night and maybe attract a snake for breakfast.
Desalination with vacuum works too. Just get the seawater 10 meters above sea level. In a container that is able to hold vacuum. Sunlight evaporates water in vacuum quick. In sea water cold caves the water can be condensated. Pumping really cold water from the deep sea, helps condensation a lot. Sea water under plastic foil is able to produce water too. Just need a place to condense the wet air. Plant houses under salt water can grow vegetables. Just float a canal and put in air filled plastic foils to do agriculture. They float under the water surface.
@@mal2ksc With a hight difference of 10 meters, no 'vacuum pump' is needed all the time. The sea water evaporates at the hot spot. The fresh water condenses in the cold spot. If air is pumped out of the system, this works with really low pressure. How much vacuum depends on temperature and contact size of evaporation/dehydration. Just pump out the fresh water, if salt water comes in. Or use 10 meter height difference as fluid pump. No water vapor needs to be pumped.
Sad thing is expensive desalinated water will still be used to flush toilets, fill hot tubs, Jacuzzi's and not forgetting the obligatory swimming pools not to swim in, but just to sit by ! Gaz UK.
100M cu-m of water is 100B liters of water per day. Four liters a day is enough for a person to drink, so if we were really talking just about drinking water, that's 25B people. So we're really looking at that desalinated water being used for agriculture and maybe washing up by those who have access to it. But this seems to imply that it'd take a LOT less money/energy to provide drinking water for a few billion people than we've already expended on desalination for fewer people.
I saw a Palestinian woman using this method on You Tube the other day, I was wondering how the invention had come about, the water went through activated charcoal on it's way out, it's simple really, and brilliant.
I think I was “unsubscribed” since I was surprised to find I wasn’t. I see your videos in my feed all the time still though. I don’t know if that means anything or lot, still getting shown in my feed, but I’m resubscribed.
I find it hard to believe these greedy companies that sell bottled water for $4.99 per 16oz don't make enough money with that markup for desalination to be a feasible thing.
Yeah the trick is to be able to use heat that otherwise goes to waste. Solar heating is free once you've paid for the land area that the sun falls on. And the point about industrial waste heat may seem like a special case that would not be commonly available - but every industry really does produce a ton of it, and if you site your facility close enough to a factory or other industrial site (fixed sites, obviously not mobile industry like mining), you can potentially make use of it. The insight is that heat is energy, but _usable energy_ depends not on temperature but on a _temperature gradient._ That is, the more difference there is between your heat source and the surrounding environment, the more usable energy you can extract from that. Below a certain threshold, it becomes waste heat - the amount of usable energy you could theoretically extract is not worth the cost of the extraction mechanism. This is entropy at work. But _this partial desalination process_ appears to not need such a large heat gradient in order to do something useful with it. There could be other practical problems with this approach - this comments section is full of valid doubts and caveats - but I do think it's fair to count solar heat and industrial waste heat as essentially free.
Try reading about Electrodialysis reversal (EDR) I use it in my closed loop bioreactor to reduce sodium in the feed water. Membranes are good for 20-50 years. First developed in the 1950's. Easy to build, cheap to operate. I believe the city of Barcelona uses it for desal of public drinking water.
EDR is amazing from what I gathered from a short look on the internet. Reduced energy consumption compared to reverse osmosis and great potential for brine mineral collection for industrial use. May be a great way to gather magnesium and other needed devolved elements.
@@jasonneugebauer5310 There are two companies in Canada and one in Australia that use EDR at the core model of their lithium purification methods. Being that EDR cannot be capitalized as intellectual property being past the patent protection date, these outfits redress the EDR with other accessories without mentioning the EDR. Kinda like a trade secret. It is such a simple process. Cheers!
@@phizc As a proven technology, is has also been evolving in large steps. It's all about the membrane(s), the voltage and the amperage applied. In my system, I can pull down the sodium while leaving behind other components. There are many different membranes available through Fuji Film in Tokyo that can be dialed in for just about everything. It is not as thorough as RO as a one pass process, so you can stack various membranes in the same housing to achieve a desired output. The upside is the longevity and not needing any significant pressure. My membranes are over five years old and are as good as the day I put them in. But you are correct about some limitations. Frustrating thing about learning how to build one is that the companies that use the tech are very tight lipped and there is very little how to put there. Fuji has been my best source of how to.
As a farmer from Australia I am very aware of our salt water problem. A couple of points that a don't think the commentator understands. First, 10% recovery from inland scarce water resources is not enough. Second, 5000ppm of recovered water is not suitable for any livestock lactation or irrigation. Maybe he could do his own experiment and mix water and sea salt at 2000ppm and water some pot plants to see the result. Or maybe drink it himself for a week and see how a non lactating or dry mammal handles it. I understand its a theoretical concept at this stage and hopefully it can be improved.
Just a thought ... PVT+HeatPump ...instead of the described sun on hot / inlet cold arrangement: The described solar thermal setup would harness/put-to-use about ~80% of that solar input .. if the sunlight input is feed through a PVT panel .. you use the thermal harness part of the PVT to get ~60% of the incoming sunlight as heat to heat up that hot side water .. and you also get ~25% of the sunlight as electricity from the electric side of the PVT , feed that electricity to a high efficiency 4COP heat pump to create a larger dT between hot and cold desalination plates .. the combination would allow you create a roughly ~2x larger dT between the hot and cold plates , from the same amount of solar input.
Heat pump are expensive and wear out, making their use cost prohibited in low value applications like making water to flush toilets and agricultural use.
maybe have a think that it could be adapted too pre lower the PPM aspect of the feed water before entering a existing plant , thus lowering their maintenance cost ,by precipitating out the base feed stock prior to desalination , you get a pre clean of the feed too the plant ,producing more volume per membrane replacement , increasing efficient ,longevity ,lowering cost , thermo plant would benefit as well depending how they discharge brine
There are extreme rain bands in the ocean along the equator. It may be practical to simply collect the rain there with super-sized tanker ships equipped with collectors like giant upside-down umbrellas, or just vast plastic sheets with inflated plastic tubes around the edges floating on the ocean.
@@borisnicholson6508 I think the idea is that for the same surface area you could just desalinate way more seawater using this technique vs evaporation. Same with using waste heat from industrial processes.
I’ve also thought the same. Salt collectors along the coast of N.Africa do this but if done on a huge scale, it can generate huge rainfall. Also know of enviromission. Power tower to generate electricity from wind. Too bad nothing has come of it. The guy died too.
Enviromission used a concrete chimney which cost more than the projected energy produced- insane! You can make kite tubes.. I sent the idea to Gadaffi with drawings, in the late nineties, no response
I seem to remember when in the RN & MN we had desalination 'bubbles' in the liferafts, seemed to be a big plastic bubble using heat from the sun to desalinate sea water, dunno if they still have these things as that was back in the '70's
This feels like this is more suited to be "a step of the assembly line" in traditional desalination plants to bump up the power efficiency rather than be the whole system. At the end of the day I would guess a big tank of seawater mixed with charcoal powder as a black body absorber might be more efficient and reliable as a solar desalination system than having to fine tune these temperature gradients. Also with standard evaporation the heat exchange in the condenser could use the input seawater as a coolant to recover some heat that would otherwise be thrown away.
We have developed a similar system that achieves much higher rates. Natural Atlantic/Pacific Ocean salinity is circa 3.6% depending on the time of year. We can achieve nearer 99% desalination using a system that does not capture the moisture. We use waste products to generate the energy imput for a net zero cost.
The movement of salt to cooler plate is most probably due to seebeck effect. So in essence the same separation should be possible with dissimilar metal plates. 15kw energy that you mentioned for thermal desalination , I presume, can be reduced with concentrating Solar or other thermal sources onto salt water mist , or using black ceramics to absorb maximum heat and hence bring down energy requirements
Just had a quick read of the research paper. Seems like a Burgers Cascade wouldn't be that hard to model up and then 3d print, maybe utilizing metal sintering. It'd be pretty big though, so would probably have to be done in sections (the paper mentions a 490 cell bifurcation, so even at 2cm per cell, you're looking at a 10m long device). Although you could shorten the flow path by pumping the outlet from one cascade to another fairly easily.
You probably need to have an episode where desalination is explained. Many opponents of desalination believe that the process will lead to more saltier oceans and thus seriously harm the environment. This supposedly happens when the waste brine is pumped back into the ocean. These opponents do not understand the water cycle and implicitly think that water, once used by humans, disappears.
These don't use very much electricity for the actual desalination, but they do need a LOT of input water. They also need a lot of heat input even if it is low temperature because the desalination is driven by thermal conduction across the water stream. It does have some advantages for robustness and I assume it's better than straight-up solar distillation, but I suspect a solar panel hooked up to a reverse osmosis system is still more efficient. If you have an excess of industrial waste heat, multi-effect flash distillation with waste heat recovery is probably still going to be the most capital-efficient way to use it because it's so simple. If you really want to push efficiency with waste heat, there's already vacuum membrane distillation, which can also be staged and is a reasonably mature technology, though not very widespread. I think high-efficiency wastewater recycling (also usually using reverse osmosis), and the high-volume batch and semi-batch reverse osmosis systems being developed right now to further increase reverse osmosis efficiency are much more exciting. Combining reverse osmosis with hydrothermal processing seems like it would be extremely efficient for wastewater recycling, and potentially extracting high-quality fertilizer as a byproduct.
0:19 "plenty of precipitation" ah yes, the two things the UK is famous for: plenty of precipitation and understatements.
They actually don't get that much precipitation... Plenty of places with far more sun get far more rain. The UK just gets clouds. Neither useful rain nor useful sun. Just clouds. I guess it means the rain they do get doesn't evaporate?
@@AntonOfTheWoodswell we get wind and that’s drying, and why I hang out my washing in it and have to water everything in pots and even in the ground during summer
@unvergebeneid don't forget whinging about the weather!
Yet, we have hosepipe bans every few years.
I take it you're not particularly interests in facts, then. You just like slogans? And stereotypes?
It's so hard to find quality factual channels like this one that It baffles me that this channel doesn't have millions of subscribers.
its suppressed by Plutarchs
It's far too sensible and un-clickbaity for the algorithms unfortunately.
A very good channel and I particularly like how he goes back to look how new developments are progressing.
It panders to the narrative.
Most of the world's population is made up of dumb people, and dump people do not get interested in high-quality channels of information because it makes their heads hurt.
Many of his facts are just politically motivated opinions. 🧐
One challenge I see is biologic fouling. Doing this on a desktop is a big difference than running continuously. To move this to a usable technology will require preventing everything from seaweed to barnacles from growing. Even a tiny amount of fouling will cause turbulent flow completely defeating the separation mechanism.
The good thing is that by applying a charge across the feed, you can create Chlorine from the salt water. This keeps the system biologically clean and perhaps residual Cl (10ppm)in the outlet keeps it potable for longer storage.
Have done this as standard with seawater cooling systems.
It's great to see recent innovations in desalination methods. As an Engineer who worked on power and desalination projects in Saudi, Qatar, Bahrain, and Libya, they were clearly relying on waste energy from power stations or industrial processes to provide thermal, multistage desalination. This is clearly better suited to lower technology areas the desperately need fresh water.
Denmark has, due to regulatory and political fuckups, quite a lot of surplus heat. And a set of new problems, handling water. Would you say that desalination is a consolidated industry one can draw inspiration from?
What will the effect be if you put this system in front of traditional desalination plants?
@@user-pt1ow8hx5lcouldn't you use the surplus heat for municipal heating?
@@TheFabledSCP7000 You have a point. Yet not all of it can, or need be, used for municipal heating.
This video is a fine example of why channels like just have a think are BS merchants and not science channels.
This is an unconfirmed lab experiment that almost certainly would not scale up to the scale of utility level water treatment. The idea that this could be powered by the sun is delusional.
The fact that they didn't build an actual working unit that achieved sufficient desalination but it was only theoretical should serve as a dose of enthusiasm dramping reality.
Exactly. It would be relatively easy to create their own ”theoretical” version and the obvious fact that they didn’t, speaks volumes. It’s the obvious next step. All that is missing is a cliche claim like “This changes everything, or revolutionizing desalination”…
@@seantiz Even if this does work as intended, it will likely be a component in multistage water treatment process. In fact, it seems like this process could be added to almost every existing water treatment plant to increase overall efficiency. The idea is absolutely worth grant money & engineering effort. The combined budget power of every municipal water system & privatized rentier system (that should be public) could easily afford to fund this research, were there some central system that could aggregate their resources.
@teadrinker7098, they built a system that would fit on a bench with the intention of proving that the idea is valid & could be measured.
They succeeded.
The next step is to hand it over to engineers to scale it up to a useful working system.
ikr
in science, if you want to build something, unless you pay from your own pocket, you need funding. Applying for funding takes time and energy. Ofthentimes up to a year. So I hope we'll hear from these people again
In reverse osmosis, the level of salinity is responsible for the necessary pressure. Means, with such a system upstream of an RO, the necessary pressure and related energy consumption of the RO could be reduced significantly! Sounds great!
Yes, good point there
I was not sure of that, but it makes sense. I have an home RO system to provide domestic drinking water and it does not use as much as energy as mentioned for desalinization.
@@olivier2553You get the water from a well yeah?
@@Nosirrbro No, from the main running water distribution, but it is unclear that it is fit for human consumption. Supposedly it is, but no one drink tap water. There is also quite an amount of silt in the tap water.
I am in Thailand.
@@olivier2553 That makes sense, but yeah that probably doesn’t have much salt in it so it makes sense it’s not as power consuming
This just got me thinking on the miracles this can do if applied to the lithium extraction pools in Atacama desert, just passing the water in such structures on the early stages to increase the lithium concentration and recover some fresh water to local agricultural use instead of simply evaporating it
The Atacama is a desert, there isn't much local agriculture.
I like how you focus on the incremental solutions that are being developed. We often forget about those initially, small, but significant solutions to problems like this...particularly as being a part of already existing technology. Yes, time is critical, but it'll be the low tech solutions that'll win the race...I'm convinced of that. Thank you for your commitment to finding and illuminating these technologies!
Thanks for your support. Much appreciated.
Note this is not a solution, it's a possible solution. Mr. Think says "could" a dozen times. It's more R&D than development.
‘Just have a drink’ eh? Nice.
This technology along with recent discovery that light itself creates evaporation in water sounds like big progress, and huge savings in desalination.
good comment ... suggest that most are not aware that just green photons will cause evaporation
I was, just yesterday, wondering about the developments on this subject. I knew you'd have something to say about it. Thanks for reading my mind.
Glad it was helpful!
There's nothing I can add to this, since you've covered the topic quite completely. It does seem like the technology would work better as an add-on to existing desalination systems, improving their efficiency and reducing cost, rather than a complete system on its own. The 10% recovery rate makes this more of an in-development idea than a finished one that can help rural communities right away.
Desalination is a really fascinating subject, though! There's such a complex interplay of economics with engineering and basic science.
Great video and I love the lower energy achievement. In our case here in mid Wales we opted to go for rain water harvesting to help reduce our dependence on main water. I found that the IBC tanks used in the drinks industry are very cheap and widely available. So we have 4 of these one thousand litre tanks mounted low in the ground so as to allow a work top above them used for beddings to bring seedlings. Another 2 are sited down the side of the our home. Combined with the 4 water butts we have a storage capacity of 7 thousand litres. This has reduced our water consumption to half, and also means no cleaning was necessary other than some simple inline metal filters. we use the water for flushing the loo, watering plants, and cleanign the cars. Total cost including a pump and pressure tank and pipework £700. We save about £80 a year, so payback should be 9 years. This would make quite a considerable difference to our national water system, and its effects on our environment, if all homes were made this way.
Oneka technologies have a working wave energy powered desalinization plant which is sustainable and affordable .It works without external inputs ,only the work of waves. It redistributes the excess salinity back to the ocean with no impacts to the surrounding sea. Fish and microscopic life are filtered at the input site. The osmosis membrane is cleansed by the process of the pump. This process is scalable in size to the project.
I wish the Aussies the best of success in their endeavors.
Is their Californian demo site up and running yet. If it is I hope Dave does a video on them, or features them in a round-up vid of desalination technology that is currently in use or has a live demo system up and running.
That sounds too good to be true
@@feynstein1004 what does?
@@MrMichiel1983 Working without external input
@@feynstein1004 That's because it likely is.
Couple of things:
1. It "sounds" to me like the cold plate in this type of system would have to be mechanically cleaned of precipitated salt particles on a fairly regular basis, yes/no?
2. Since they haven't actually constructed or tested an actual working Burgers cascade device yet, I'll have to take their "theoretical" 10% recovery rate stat with a grain of salt (no pun intended).
I say it depends on if the salt deposits or not. If the flow rate is fast enough it should stay clear.
If it isn't being boiled away, then I would think the salt and other things dissolved in the water would remain dissolved. If it was a system where water was continuously being recycled through with the goal of increasingly saltier water, then you would get to a point where the water is saturated and could precipitate salt out and gum things up. But if the saltier water is being cycled out of the system in attempts to get less salt flowing through, then the only potential issue is if the wall material reacted with the water, and that is a largely solved problem.
Not to mention biofilms...
The mechanism is more akin to convection, where hot liquid floats to the surface and cold liquid sinks to the bottom. Saltier liquid sinks to the bottom/cold. It naturally happens in the oceans too.
At the concentration change being discussed, I doubt precipitation is a problem. Various other forms of fouling would be, though.
Even if this method doesn't get the job done, 2-3 passes like this before using other methods can have significant savings! Less power needed, and much longer lasting filters could be a game changer even for existing systems. Very interesting tech!
More properly, this method reduces the amount of ELECTRICITY required to desalinate water, by trading some electrical energy for yet more heat energy. In terms of the ultimate thermodynamic efficiency, reverse osmosis is already achieving a separation efficiency of somewhere between 33% and 60%, meaning that it's using between 1/0.6 and 1/0.33 times as much energy as the thermodynamic minimum required to separate freshwater from seawater. That energy difference however is measured in joules, and there's no law of thermdodynamics that I'm aware of that requires the energy to be put into the system in the form of pure exergy (electricity) rather than in the form of some exergy and some heat. That's what this system does, and it might be useful- or not, depending on lots of things this video doesn't discuss, but which are very important to the at-scale feasibility of a desalination system.
Finally, "yield" goes to how much seawater you need to pump, and how salty the water is that you reject to the sea again. While a low yield would mean that you perhaps pump 10 m3 of water from the sea to get 1 m3 of freshwater and 9 m3 of slightly saltier water would need to be pumped back to the sea, that means you have to pump a lot of water around, and that doesn't happen without electrical energy being expended. RO normally concentrates seawater about two to three-fold. However, that salty water needs to be carefully controlled so that it doesn't cause a locally high salt content in the ocean which is damaging to sea life.
How does one calculate the thermodynamic minimum energy required to separate fresh water from sea water? I do appreciate that separated water and salt in separate containers is lower entropy than the same salt dissolved in water.
A properly set up Siphon system should make your net pumping needs only scale with the fresh water yeild, not toal water moved. And returning larger volumes of lower salinity water would actually be better for most marine ecosstems, hyper saline brines just sink to the bottom and do not mix with the rest of the ocean, on the bottom they then damage marine life osmotically.
@@kennethferland5579 frictional loss in the pipe needs to be compensated for with energy input, either way. Moving matter around is not an energy-free deal.
you can just dig and put the device below sea level and let gravity force it through the system so you dont have to pump it mechanically
@@zacriewright5258 frictional loss in pipe has to be compensated for either way. You don't get something for nothing by using a siphon. You need to lift water from the ocean to do anything to it, and then return the water to the ocean again. You lose energy in pipes in both directions. You can of course make it worse by not recovering the energy from the falling water that you input energy to raise, but you don't get something for nothing by digging a hole in the ground. That spent seawater needs to go back to the ocean regardless- it can't stay at the bottom of your hole, nor will it get back out of the bottom of your hole into the ocean of its own accord.
One thing I love about camping out long term is gathering my water. Most of the usa water infrastructure is old. The disinfecting agents react with organic solids in the water and make a host of potent chemicals new to science. Better desalination is great, but I'm gonna try and stay in places with forested hills with streams in them to gather the little I need, avoid using water infrastructure in general whenever possible. I use an electric kettle right now parked behind a house and town water coats it with mineral sediment very quickly, stream water boils off clean. Tastes soooooo much better too, town water usually tastes horrible by comparison.
It's not that hard, I'm a poor hobo gardener living in a prius and I have gathered all my water this summer, including bathing. But not laundry, I take that to a laundromat. Using a wet rag makes it easy to wash up without using a lot of water. I could use the bathroom where I'm parked, but the forest is better, bathrooms are nasty.
So funny, I work as a gardener and rich people buy up all this amazing land in VT and then barely experience it. I am poor but I have so much rich experience with the soil and water of these properties. So much stream water has flowed through my body, I've breathed so much fresh air and touched rich soil and eaten plants from it. People buy land as a wealth flex and then continue to get everything they need from the machine, so silly.
It is encouraging to see progress being made in this important area. Thanks for your work.
One important observation: Distilled water is drinkable but it removes minerals making it unhealthy for human consumption over the long term.
The device in this video doesn't remove all the minerals from the water. A lot of them are left in.
Would love to see an update on Wave Energy Desalination. A Canadian company, Oneka Technologies, makes these desalination plants. It would be cool to see how many are now deployed and what further innovations and scale-up is taking place.
We used to make FW from SW at sea using an evaporator by creating a vacuum using pressured sea water pushed through a ventury nozzle.
re-directed engine cooling water was pumped through the sea water at about 150 degrees whilst also using cold seawater through another coil at the top for condensing the resulting vapours.
I really like the conclusion of this being a step forward to lead to perhaps a better method down the line. Good way to think of something like this.
It seems like a really low volume system that would require a lot of material to function for any usable quantities of water.
Definitely something worth a degree of research into, but nothing to pin any hopes on. Kind of how it goes for a lot of these tech, realistic optimism.
If storm runoff was captured, cleaned and stored, I'm guessing many of the water scarcity issues could be solved.
It could. I have been doing this for around 10 years and every year I learn how to do it better. I manage to harvest around 1,000 litres of drinking quality water per winter - I live in drought stricken S. Europe - and this is sufficient for 2 people plus domestic animals. I also harvest 10,000 litres for irrigation, cleaning etc.
@@chichestermaritime8174 wow sounds awesome. You do it with rain barrels?
You have a talent for explaining systems which are not yet ready for prime time. The more we know, the more we can know... keep sharing these innovative methods that have promise for scaling up to industrial levels and the associated help to the involved communities.
The "algorithm" is incorrectly unsubscribing people? What the hell is going on at Google?
Such an important topic, thanks for bringing this invention to our attention!
Our pleasure!
Since the best yields are when the plates are close together, put this to use by using that method at the end of the line, Use the plates further apart at the beginning of the line.
For the mass flux equation, I wonder if that could be overcome by simply lengthening the distance the water travels through the narrow plates at the end?
I like this desalination idea because as you said the water stays in its liquid form, heating the top plate can be done using the best method available, and requires a fraction of the energy other methods use. This method seems very viable and promising. People that have no drinking water won't care much about yields and where the brine goes. They are dying of thirst.
Great! didn't understand most of it but sounds good. Live in Arizona with lots of sun and could stand more water. Bring it on!
ALL desalination produces an unpleasant byproduct- warm brine. It tends to cover the seabed in large areas next to desalination facilities and kill mostly everything. So while this new techique is as interesting as it is promising, desalination of seawater should be seen as a last resort when alternatives such as rainwater management, efficient irrigation, or wastewater recycling don't suffice.
ALMOST all desalination does that. One exception is where the brine is dumped into an evaporation lake, heated by the sun in a desert climate, so that the minerals can be skimmed off as they precipitate.
As far as I know this scheme is still only theoretical at scale, so in terms of present day practice you are sadly correct
The lower recovery fraction (10%) would mean less concentrated brine (but also means moving more water from a living ocean). Fascinating physics...
I absolutely have an idea that eradicates this issue. Though, its application would most likely only be effective in warm climates.
However, I had no considered industrial waste heat until today.
@@trueriver1950 if we start needing more salt for sodium batteries that problem would solve by itself. Traditional salt production basically implies evaporating water from brine using the sun in open spaces
@@trueriver1950 ...minerals which contain, because of current industrialization, extreme concentrations of many, many, deadly & harmful substances. It’s human mechanical biomagnification of poisons.
Bottoms up, Dave! 🎉😊
Brilliant out the box thinking. 👍🇬🇧🙏♥️
Which is what 'Just Have a Think' loves.
Maybe we could somehow collect some of The rainwater that falls over the sea, and we should put solar panels over our waterways and reservoir to help the water we do have from evaporating.
What I’ve never understood is why humans don’t just cut a channel into the Sahara desert and others, into huge shallow pools, and just leave the water there for evaporation to increase rainfall. Natural and practically free.
@@TheBooban Cost, thats why.
@@AlvinnVanAert cost of digging a shallow trench? What? I don’t think your calculations are correct.
Rainwater is polluted, and also undrinkable on the long term without being treated. But sure, it's easier than with salt.
@@rutufn0596 eh? Only in some dirty countries. Most places is clean and you can drink it right out of the lake or stream.
Turn it up ! !
Some of us served in the artillery...
Using this as a first stage that eliminates 5/6ths of the salt is big. If the heat is the back side of a solar cell that's being used to drive a reverse osmosis stage that could be a win. I wonder how this would perform in the Persian Gulf, where desalination is reaching a point of diminishing returns due to the increased salinity of the seawater. There has been promising membrane related work using graphene, but I've not kept up with that.
Overall a very positive bit of good news.
"Using this as a first stage that eliminates 5/6ths of the salt is big. " - if only the first step did eliminate 5/6th, then it would be world-changing. Instead the first step, if by that you mean the first pass through the mechanism, removes a small percent of the dissolved salt.
Others have mentioned the energy needed to pump all of the water. Also there will be high pressure required to pump through a cascade of mm thin spaces. The narrower the pipe, the higher pressure needed to achieve a given output. Last, biofilms on the plates could be a problem.
I'm still subscribed and it still takes around a day to be notified of a new post!
Thanks for not much, yt!
Thanks for sharing this discovery from ANU. Great stuff.
😊 good stuff as always!
Really encouraging developments. Thank you Dave 😊
Dear Australian Government,
Having a great time, wish you were here. Send funds!
If all nations built berms and swales on contour across their land, that would go far to address water issues. They collect and filter rainfall and allow it to be slowly absorbed. They make forests stronger while preventing flash-floods and flooding, and help prevent wildfires. They need to be build everywhere physically possible. That along with permaculture techniques is the answer. That and building bikeways and rail systems.
Very true, but the solution being researched is about places where rainfall is extremely low to non-existent.
Thank you for your encouraging video. I hope everyone is having a great day. Sheila Mink in New Mexico
An amazing development - though have a more efficient and cleaner way to desalinate, with extra produce at the end, other than just drinking water.
Thoigh the benfits of this system is astonishing.
Especially when you consider the applications for industrail waste water.
Super cool and keen to learn more on a later follow up video, as this progresses.
Kudos and keep at em' 💪🤓
The moment I heard that the materials needs to made from nickel plated copper my heart dropped. Both are some of the most expensive metals out there...
Since it is a thermal effect, probably isn't a requirement to use those materials. Probably convenient for working with in the lab.
The movement of salt to the cold plate I believe is due to seebeck effect. So in principle, the same movement can be achieved by moving the saline water between dissimilar electronegative plates. I also suspect that the setup you described will generate voltage difference between hot and cold plates.
15kwh energy requirement you mentioned for thermal heating, I presume can be reduced by concentrating Solar Energy onto a fine spray mist of saline water or use black ceramic balls to absorb the concentrated heat onto the salt solution. Anyway Kudos to the team on finding an innovative way to desaline which will reduce water stress of humanity
Great news, can't wait to see this further tested. Would be a big future for this. 😮
Perhaps it should be the first line of desalinization and use more conventional methods help?
Another is using current fresh water efficiently instead of just over using it
People fight over water, and we need to consider how our future will be if we don't tackle the water problems that we have and which are emerging. Maybe this _thermodiffusive_ process will be a lifesaver in more than one way.
Perhaps for drinking water but consider the scale of water depletion in Iran or Iraq. These are water needs at the national scale and don’t come to terms with the loss of water to general environment and all the consequences to it.
@@TheDanEdwards "Whiskey is for drinking, water is for fighting" heard it somewhere.
Oh for sure. It's already happening in the area of the world where my parents are from (Kashmir)
I really want this technology to succeed because it means that they can live peacefully (despite the sheer military presence, from the Pakistani side)
It's not even the first time it's happened tbh. The very reason why I'm so mixed is due to it being invaded since time immemorial for water
All desalination methods produce mountains of salt that destroy life wherever they are dumped. Desalination is a horrible idea. The global population is ten times to large and even if it were to stop growing the biosphere will continue to degrade and while now six of the eight billion people on Earth live deprived lives, soon seven out of eight billion people will live deprived lives. In twenty years everyone on Earth will suffer great deprivations and have miserable lives.
Besides desalination, sometimes water diversion can help with "regional water problems". Take Chinese moving of almost complete rivers vast distances.
Wow that's next level. What a clever idea.
Thanks. Appreciate the breakdown of processes. Another good, factual show in a long series of good shows that are reliably offering progress reports on a wide-ranging set of climate tools the world needs.
Thanks from Sao Paulo
If integrated with other desalination plants or solar farms, it could be a game changer.
Solar panels need cooling to remain efficient and reduce wear so that's one source of heat that could be reused and a lesser salt concentration would reduce power consumption and filter wear.
This could make both the solar power plant and the desalination plant more efficient and financially profitable.
Add a salt marsh next to it and you can get rid of the brine and produce salt and the thing is solved.
Awesome potential tech.
Add in the newly discovered visible light contributing to evaporation
(transverse magnetic polarization, 45 degree incident angle, and green wavelength maximized the effect),
and for a bit more energy
they might be able to then separate more water from both the low and high salinity flow,
increasing their yield of usable water.
Dear David, thank you for your next great THINK. One of the solutions is resuse the grey water in households, industries and cities, currently most of the waster is used just once but charged by th water management companies like VEOLIA, two or event three times.
Very good point Michael.
thank you
Removing 83% of the salt from 10% of the seawater yields a brine that's only 109% concentrated, so this process is fairly gentle in that regard as well. 🤓
It does seem like it might be useful for that opposite application of hyper-salinating brine solutions, concentrating them even further than they already are, so that you can more efficiently dry them out into an industrial salt product.
Diffusion is so cool
Build a nuclear reactor
Use sea water as coolant
Distill steam into water
Add water to aquaphor
Now you have cheap energy and fresh water.
Awesome news ❤
Ive long wondered why we can't use Ocean Thermal Energy facilities to run desalination facilities. Position the facilities off shore and use purpose built vessels to move the desalinated water to onshore pumping stations. A pilot Ocean Thermal facility was run off shore of Hawaii in the 70s.
interesting, but keeping things cool and hot enough may not be a 'free lunch'
if an RO desalinator like I have installed on many pleasure craft were tied to a suitable off grid electrical supply, small villages could have good water. A 1hp/120vac motor hooked to a pressure washer pump will make up to 800 u.s.a gallons (almost 4 liters x 800) per day. Product usually 200 ppm or lower. Rendered sea water tastes sweet. These systems mostly self clean when running and back flush RO media filters upon shutdown.
The wastewater could be put in covered ponds that create water vapor by day and the cooler night air chills the cover and distilled water gets harvested, as does salt and minerals.
A pvc tarp stretched across a 1m round pit can make a liter of water at night and maybe attract a snake for breakfast.
Desalination with vacuum works too.
Just get the seawater 10 meters above sea level.
In a container that is able to hold vacuum.
Sunlight evaporates water in vacuum quick.
In sea water cold caves the water can be condensated.
Pumping really cold water from the deep sea, helps condensation a lot.
Sea water under plastic foil is able to produce water too.
Just need a place to condense the wet air.
Plant houses under salt water can grow vegetables.
Just float a canal and put in air filled plastic foils to do agriculture. They float under the water surface.
Water vapor is really hard on vacuum pumps. This is why it's not a good idea to use a vacuum chamber to dehydrate food, the water fouls up the pump.
@@mal2ksc
With a hight difference of 10 meters, no 'vacuum pump' is needed all the time.
The sea water evaporates at the hot spot.
The fresh water condenses in the cold spot.
If air is pumped out of the system, this works with really low pressure.
How much vacuum depends on temperature and contact size of evaporation/dehydration.
Just pump out the fresh water, if salt water comes in. Or use 10 meter height difference as fluid pump.
No water vapor needs to be pumped.
Sad thing is expensive desalinated water will still be used to flush toilets, fill hot tubs, Jacuzzi's and not forgetting the obligatory swimming pools not to swim in, but just to sit by !
Gaz UK.
Leaving a comment for the algorithmatorical boost.
Reducing the energy cost for an industrial desalination plant is quite hard to believe
100M cu-m of water is 100B liters of water per day. Four liters a day is enough for a person to drink, so if we were really talking just about drinking water, that's 25B people.
So we're really looking at that desalinated water being used for agriculture and maybe washing up by those who have access to it.
But this seems to imply that it'd take a LOT less money/energy to provide drinking water for a few billion people than we've already expended on desalination for fewer people.
I saw a Palestinian woman using this method on You Tube the other day, I was wondering how the invention had come about, the water went through activated charcoal on it's way out, it's simple really, and brilliant.
Thanks
I think I was “unsubscribed” since I was surprised to find I wasn’t. I see your videos in my feed all the time still though. I don’t know if that means anything or lot, still getting shown in my feed, but I’m resubscribed.
Hope you are right,I'll certainly drink to that dave.
I find it hard to believe these greedy companies that sell bottled water for $4.99 per 16oz don't make enough money with that markup for desalination to be a feasible thing.
Great video as usual.
Small correction: 5:14 I'm pretty sure the phenomenon is called 'thermophoretic transport', also known as the Soret effect.
It's amazing how energy efficient a system can be when you don't count the energy from heating!
It's efficient in the energy you "pay" for.
@@unoriginalname4321 so no water on cloudy days because the sun is free?
@@unoriginalname4321 Like the free waste heat of thermal power plants, they usually use for thermal desalination?
Yeah the trick is to be able to use heat that otherwise goes to waste. Solar heating is free once you've paid for the land area that the sun falls on. And the point about industrial waste heat may seem like a special case that would not be commonly available - but every industry really does produce a ton of it, and if you site your facility close enough to a factory or other industrial site (fixed sites, obviously not mobile industry like mining), you can potentially make use of it.
The insight is that heat is energy, but _usable energy_ depends not on temperature but on a _temperature gradient._ That is, the more difference there is between your heat source and the surrounding environment, the more usable energy you can extract from that. Below a certain threshold, it becomes waste heat - the amount of usable energy you could theoretically extract is not worth the cost of the extraction mechanism. This is entropy at work.
But _this partial desalination process_ appears to not need such a large heat gradient in order to do something useful with it. There could be other practical problems with this approach - this comments section is full of valid doubts and caveats - but I do think it's fair to count solar heat and industrial waste heat as essentially free.
Try reading about Electrodialysis reversal (EDR)
I use it in my closed loop bioreactor to reduce sodium in the feed water. Membranes are good for 20-50 years. First developed in the 1950's. Easy to build, cheap to operate. I believe the city of Barcelona uses it for desal of public drinking water.
EDR is amazing from what I gathered from a short look on the internet. Reduced energy consumption compared to reverse osmosis and great potential for brine mineral collection for industrial use. May be a great way to gather magnesium and other needed devolved elements.
@@jasonneugebauer5310 There are two companies in Canada and one in Australia that use EDR at the core model of their lithium purification methods. Being that EDR cannot be capitalized as intellectual property being past the patent protection date, these outfits redress the EDR with other accessories without mentioning the EDR. Kinda like a trade secret. It is such a simple process. Cheers!
Electrodialisys looks promising, but RO beats it unless the concentration is less tha 5000 ppm from what I read.
@@phizc As a proven technology, is has also been evolving in large steps. It's all about the membrane(s), the voltage and the amperage applied. In my system, I can pull down the sodium while leaving behind other components. There are many different membranes available through Fuji Film in Tokyo that can be dialed in for just about everything. It is not as thorough as RO as a one pass process, so you can stack various membranes in the same housing to achieve a desired output. The upside is the longevity and not needing any significant pressure. My membranes are over five years old and are as good as the day I put them in. But you are correct about some limitations. Frustrating thing about learning how to build one is that the companies that use the tech are very tight lipped and there is very little how to put there. Fuji has been my best source of how to.
As a farmer from Australia I am very aware of our salt water problem.
A couple of points that a don't think the commentator understands.
First, 10% recovery from inland scarce water resources is not enough.
Second, 5000ppm of recovered water is not suitable for any livestock lactation or irrigation.
Maybe he could do his own experiment and mix water and sea salt at 2000ppm and water some pot plants to see the result. Or maybe drink it himself for a week and see how a non lactating or dry mammal handles it.
I understand its a theoretical concept at this stage and hopefully it can be improved.
Stick to farming I reckon.
I think Dave understands both of those issues.
Just as you said I was unsubscribed by TH-cam wondered why I hadn’t see you pop up in my feed.
Was watch for years. I’m back woohoo
Just a thought ... PVT+HeatPump ...instead of the described sun on hot / inlet cold arrangement:
The described solar thermal setup would harness/put-to-use about ~80% of that solar input .. if the sunlight input is feed through a PVT panel .. you use the thermal harness part of the PVT to get ~60% of the incoming sunlight as heat to heat up that hot side water .. and you also get ~25% of the sunlight as electricity from the electric side of the PVT , feed that electricity to a high efficiency 4COP heat pump to create a larger dT between hot and cold desalination plates .. the combination would allow you create a roughly ~2x larger dT between the hot and cold plates , from the same amount of solar input.
Heat pump are expensive and wear out, making their use cost prohibited in low value applications like making water to flush toilets and agricultural use.
Always have appreciated your channel. Good stuff ~ Thanks
TY for the commentary sir!
maybe have a think that it could be adapted too pre lower the PPM aspect of the feed water before entering a existing plant , thus lowering their maintenance cost ,by precipitating out the base feed stock prior to desalination , you get a pre clean of the feed too the plant ,producing more volume per membrane replacement , increasing efficient ,longevity ,lowering cost , thermo plant would benefit as well depending how they discharge brine
There are extreme rain bands in the ocean along the equator. It may be practical to simply collect the rain there with super-sized tanker ships equipped with collectors like giant upside-down umbrellas, or just vast plastic sheets with inflated plastic tubes around the edges floating on the ocean.
That sounds bat-shit crazy, but it just might make economic sense.
Just mount a chimney over a saltwater pond and harvest the evaporate. You can also get power out of the updraught. See Enviromission (Australia)
@@borisnicholson6508 I think the idea is that for the same surface area you could just desalinate way more seawater using this technique vs evaporation. Same with using waste heat from industrial processes.
I’ve also thought the same. Salt collectors along the coast of N.Africa do this but if done on a huge scale, it can generate huge rainfall.
Also know of enviromission. Power tower to generate electricity from wind. Too bad nothing has come of it. The guy died too.
The size of the facility would be impractically large. It's only ever made it to prototype, and the prototypes are already hard enough to construct.
@@truhartwood3170 who cares about surface area when it’s all desert?
Enviromission used a concrete chimney which cost more than the projected energy produced- insane! You can make kite tubes..
I sent the idea to Gadaffi with drawings, in the late nineties, no response
I seem to remember when in the RN & MN we had desalination 'bubbles' in the liferafts, seemed to be a big plastic bubble using heat from the sun to desalinate sea water, dunno if they still have these things as that was back in the '70's
They provide very little water. But very little is a lot better than none in a survival situation.
This feels like this is more suited to be "a step of the assembly line" in traditional desalination plants to bump up the power efficiency rather than be the whole system. At the end of the day I would guess a big tank of seawater mixed with charcoal powder as a black body absorber might be more efficient and reliable as a solar desalination system than having to fine tune these temperature gradients. Also with standard evaporation the heat exchange in the condenser could use the input seawater as a coolant to recover some heat that would otherwise be thrown away.
That's so smart. Love the channel!
We have developed a similar system that achieves much higher rates. Natural Atlantic/Pacific Ocean salinity is circa 3.6% depending on the time of year. We can achieve nearer 99% desalination using a system that does not capture the moisture. We use waste products to generate the energy imput for a net zero cost.
This is a company you work at?
Water in a vacuum boil at temperatures below 60⁰ Celsius, temperature lower than the condenser of a air conditioner or any solar hot water heater.
So it seems we are looking for a "thermo-diffusive flux capacitor" next. Calling Dr. Brown.
Even if this can only get us half way it makes a great precursors i love that you thought it was worth mentioning as such
The movement of salt to cooler plate is most probably due to seebeck effect. So in essence the same separation should be possible with dissimilar metal plates.
15kw energy that you mentioned for thermal desalination , I presume, can be reduced with concentrating Solar or other thermal sources onto salt water mist , or using black ceramics to absorb maximum heat and hence bring down energy requirements
Just had a quick read of the research paper. Seems like a Burgers Cascade wouldn't be that hard to model up and then 3d print, maybe utilizing metal sintering. It'd be pretty big though, so would probably have to be done in sections (the paper mentions a 490 cell bifurcation, so even at 2cm per cell, you're looking at a 10m long device). Although you could shorten the flow path by pumping the outlet from one cascade to another fairly easily.
Thanks!
WOW. Thanks for your support. Much appreciated :-)
You probably need to have an episode where desalination is explained. Many opponents of desalination believe that the process will lead to more saltier oceans and thus seriously harm the environment. This supposedly happens when the waste brine is pumped back into the ocean. These opponents do not understand the water cycle and implicitly think that water, once used by humans, disappears.
Another excellent infiormative video I am thankfully receiving.
Interesting stuff
Always worth a watch. Thanks
beautiful! next time they need to actually build the cascade desal prototype and not just simulate it.
These don't use very much electricity for the actual desalination, but they do need a LOT of input water. They also need a lot of heat input even if it is low temperature because the desalination is driven by thermal conduction across the water stream.
It does have some advantages for robustness and I assume it's better than straight-up solar distillation, but I suspect a solar panel hooked up to a reverse osmosis system is still more efficient.
If you have an excess of industrial waste heat, multi-effect flash distillation with waste heat recovery is probably still going to be the most capital-efficient way to use it because it's so simple. If you really want to push efficiency with waste heat, there's already vacuum membrane distillation, which can also be staged and is a reasonably mature technology, though not very widespread.
I think high-efficiency wastewater recycling (also usually using reverse osmosis), and the high-volume batch and semi-batch reverse osmosis systems being developed right now to further increase reverse osmosis efficiency are much more exciting.
Combining reverse osmosis with hydrothermal processing seems like it would be extremely efficient for wastewater recycling, and potentially extracting high-quality fertilizer as a byproduct.