207. URANIUM FROM SEAWATER (PART 1)
Lately, we've been hearing a lot of the "peak uranium" soundbite: "if we turn to uranium, it too will peak in 30 years." This isn't true, and to see why, I'm going to walk you through the most elegant and beautiful mining technique ever invented: recovering uranium from seawater.
This feat has actually been accomplished by Takanobu Sugo and his colleagues at the Japan Atomic Energy Research Institute (JAERI).
To begin, the group fabricates a material called the "adsorbent" which can selectively soak up uranium. This material begins as a nonwoven fabric made primarily of polyethylene. Molecules called amidoxime groups are attached to this fabric by a process called "graft polymerization" (which apparently involves irradiating the polyethylene with a high energy electron beam). Each pair of attached amidoxime groups can "grab" a single heavy metal ion.
This material has an amazing capacity to soak up uranium (as well as other valuable metals like vanadium, cobalt and titanium). Bench tests show it can hold an amazing 500g of heavy metals per kg of absorbent. It can also be washed with alkali, and reused. Here's an abstract of the JAERI group's most recent experiment (2003):
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m3 in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m2 in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.SourceThis is what one of these adsorption cages looks like:
So if you want to collect tons of yellow cake, instead of just kilograms, you just need to string 300 of the cages together and hang them in the ocean. Sugo illustrates three possibilities (from the top): suspension from a floating platform, dangling under a bridge, or stringing with buoys (like a trot line):
The technique reminds me of Asian seaweed farms:
It's a beautiful low-tech approach... almost agricultural. And it's hard to imagine any cleaner method of "mining". No tailings, no scarring of the landscape. In fact, it would clean the ocean rather than pollute it.
You can even take it a step further. The following shows an idea for synergetic wind farming and aquaculture, but we could just as well imagine hanging adsorbent cages, and hoisting them with wind power (click to enlarge):
*Part 2 of this article is located here: 208. URANIUM FROM SEAWATER (PART 2)
-- by JD
posted by JD @ 3:00 AM
35 comments
35 Comments:
can you plz open a disussion forum, for non doomers ...
i have enough of discussions with doomers without technical knowledge
or anyone knows a good forum ?
Yes, but what will you do in a million years after peak uranium?
:+)
The problem with debunking doomer scenarios, is that they may start to believe you and take matters into their own hands, as in "The Twelfth Monkey." These people badly want to see widespread doom and gloom.
JD:
You need to understand that most of the uraniums are not useful nuclear fuels. There are U238 and U235. You need U235, which is one part of 137 part of total Uranium.
They harvested 1 kg of Uranium in terms of yellow cake. Of these, there is maybe 7 gram of the useful U235. That, at the cost of 350 kg of specially made material and one years of operation of the facility. You have got to wonder whether that 7 gram of U235 would give you back enough energy to pay back the energy cost of manufacturing the special material and the operation of the facility. So, ah ha, EROEI gets in your way again.
The earth does not lack Uranium, which is more abundant than even the lead. But the earth lacks economically mineable uranium. Uranium from the sea water may not be economical, in terms of EROEI.
Quantoken
Another way of considering it is consider how much uranium, the U235 kind, the world currently consumes per year in nuclear power plants. My estimate is above ten thousand tons per year.
But let's be very conservative. Let say we only use one thousand ton. Which is way too conservative. To harvest 100 ton of U235 per year, use the Japanese device which harvests 7 grams per 350 kilogram speciality material. A simple calculation shows you need 5x10^10 kilogram of those materials, averaging 8 kilogram per person. Which does not seem to be something you can ramp up in scale.
I quote from this article:
http://www.world-nuclear.org/sym/1997/bourd.htm
This would seem to be one of nuclear power's strong points. Conventional thermal reactors consume relatively small amounts of fuel, and known global reserves of uranium are widespread. Yet, at current rates of use of about 70 000 t per year in world nuclear reactors, known resources of 3.851 million tonnes (Ref 5) amount to only 55 years of supply. If 11 million tonnes of additional speculative (undiscovered) resources are included, some 200 years of resource can be identified.
This is not greatly different than the horizon for fossil fuels. Coal alone is thought to be present in sufficient quantities to represent 300 to 400 years of supply at present rates of use. Like any other non-renewable energy source, reserves of fissile material for nuclear energy are limited.
Uranium is distributed throughout the world in reserves having various costs of exploitation. The above figures for known resources include those of less than US$130/kg. Even though large amounts of uranium may be available beyond known or speculative reserves, this does not mean that the potential supply of energy from nuclear power is simply proportional to whatever quantities can be identified. For example, seawater is often cited as a source of natural uranium without reference to the cost of extracting it. Uranium dispersed throughout the earth's crust or in seawater may be a large energy resource, but is not necessarily an economic energy source in comparison with other options.
The article goes on to say really breeder reactors, which are much more expensive and have technical problems are the only real option.
Without Fusion, nuclear seems more of a stop-gap and we should try to get on truly renewable energy or suffer long term pain.
Not the figures above express *current* rate of use, a little more food for thought here:
China’s consumption of steel, a basic indicator of industrial development, is now nearly two and a half times that of the United States: 258 million tons to 104 million tons in 2003. As China has moved into the construction phase of development, building hundreds of thousands of factories and high-rise apartment and office buildings, steel consumption has climbed to levels never seen in any country.
With consumer goods, China leads in the number of cell phones, television sets, and refrigerators. The United States still leads in the number of personal computers, though likely not for much longer, and in automobiles.
That China has overtaken the United States in consumption of basic resources gives us license to ask the next question. What if China catches up with the United States in consumption per person? If the Chinese economy continues to grow at 8 percent a year, by 2031 income per person will equal that in the United States in 2004. If we further assume that consumption patterns of China’s affluent population in 2031, by then 1.45 billion, will be roughly similar to those of Americans in 2004, we have a startling answer to our question.
At the current annual U.S. grain consumption of 900 kilograms per person, including industrial use, China’s grain consumption in 2031 would equal roughly two- thirds of the current world grain harvest. If paper use per person in China in 2031 reaches the current U.S. level, this translates into 305 million tons of paper—double existing world production of 161 million tons. There go the world’s forests. And if oil consumption per person reaches the U.S. level by 2031, China will use 99 million barrels of oil a day. The world is currently producing 84 million barrels a day and may never produce much more. This helps explain why China’s fast-expanding use of oil is already helping to create a politics of scarcity.
The inevitable conclusion is that there are not enough resources for China to reach U.S. consumption levels. The western economic model — the fossil-fuel-based, automobile-centered, throwaway economy — will not work for China’s 1.45 billion in 2031. If it does not work for China, it will not work for India either, which by 2031 is projected to have even more people than China. Nor will it work for the other 3 billion people in developing countries who are also dreaming the “American dream.” And in an increasingly integrated world economy, where countries everywhere are competing for the same resources — the same oil, grain, and iron ore — the existing economic model will not work for industrial countries either.
http://www.vermontguardian.com/local/012006/PlanB.shtml
schinkenpilze wrote:
can you plz open a disussion forum, for non doomers ...
i have enough of discussions with doomers without technical knowledge
or anyone knows a good forum ?
We already got one. It's very nice.
http://groups.google.com/group/Peak-Oil-Debunked
Wildwell: Thanks for the information source. My original estimate used 1000 ton uranium. Now it looks the world currently use 70,000 ton per year. 70 time more than my conservative estimate. And if nuclear electric power should replace all fossil fuel electric power, you need 5 times more uranium. That's 350 times my original estimate. So each person on the earth needs to have 8 kg * 350 = 2.8 ton of that special material that absorbs uranium. An impossible goal to reach.
Does uranium really peak in the same way as oil?
Also, has anyone seen this flying windmill? Or this one?
By having the wind farms high up you can harvest high air currents where the wind never stops, avoid killing birds and not interfere with the landscape. Very clever.
Does uranium really peak in the same way as oil?
In that it's a finite resource with an initial extraction rate of zero and a final extraction rate of zero when it's all gone with a peak extraction rate in in-between, yeah uranium peaks in the same way oil does.
Roland:
Keep day dreaming with the Flying Windmill, but they can not be built.
Those floating units, tethered to the ground and generating 20 megawatts each, are just some huge kites. There is indeed strong constant air flow high up in the air. Let's borrow Einstein's idea and change our reference frame so we move at the same speed as the air flow at 30000 feet high. What we see?
What we see is the air is not flowing, it is at rest. The ground is moving at a very fast speed, almost like highway speed. Let's say 30 meters per second, relative to the air. And a tether, tied to the ground, drags the huge kite so it moves forward with the ground. The dragging force of the tether provides a Newton mechanical work per meter of distance moved. And part of that energy provided by the dragging force is converted into electricity energy and sent down the tether.
Let's assume 100% efficiency. The horizental dragging force on the tether would then need to provide enough power to generate 20 megawatts. Since the moving speed is 30 meter per second. Divide 20 megawatts by 30 m/s. The horizental component of the dragging force would have to be 0.667 mega newton, or 68 metric ton of weight.
The tether itself will have height, too! A tether capable of supporting 68 ton is quite thick. The weigh of the tether would probably be much more than the kite can support without falling down.
Regarding the energy required to "harvest uranium from seawater"
The objective trash (sorry study) of Strawman & Van Der Luddite quotes various studies done in the 70s.
These studies estimated an energy cost anywhere from 100GJ to 9000GJ/kgr (the average is < 500GJ/kgr). Even though these studies assumed an active extraction process (e.g. pumping an obscene volume of sea water in an installation, subsequent concentration of water in brine and then extraction via chemicals), let's assume that this energy cost is representative of the amidoximine adsorption process.
Assuming the uranium is utilized in a breader reactor set-up, 1 mg of uranium (consisting of both U235/U238) will yield 80-90MJ of energy => 1kgr of uranium yields 80-90 TJ i.e. the return rate is 10-90.
The procedure is energetically positive and the margin of error for the calculations is huge.
90TJ/100GJ = 90
90TJ/9000GJ = 10.
Since a passive adsorption is going to have a much lower energy cost than an active process, the 10-90 margin might have to be scaled upwards by a factor of 2-10 (this is my estimate though so feel free to reject it and stick with the 10-90 figure).
By the way the Strawman , Van Der Luddite paper is a joke among nuclear engineers. They make no reference to passive extraction (which is the only method regarded as practical) and instead develop a straw-man argument based on pumping large volumes of seawater or building large tidal barrages.
energyspin:
Information source URL, please. I am skeptical to the accuracy of your data, but not knowing your source I can not comment.
As for the new method that the Japanese invented, you forget to count in the energy required to manufacture the speciality material used to absorb uranium from sea water. If you count that in the net EROEI is less than one. Since this method is claimed to be the most economical of all that retrieve uranium from sea water, it means other method must have an even lower EROEI.
Einstein's refrigerator
No moving parts. Low energy(?)
Invented by Einstein and Szilard 70 years ago.
http://en.wikipedia.org/wiki/Einstein_refrigerator
Quantoken, fantastic debunking of the 20MW kite... what the maximum tensile strength of a 30,000 feet conducting cable, that would tell us the maximum available power... I suspect it's extremely low.
Quantoken,
The data regarding the energy inputs needed to harvest uranium from the seawater are from the Storm article which is an anti-nuclear source :-D.
The energy inputs include emboddied energy to construct plants that rely on active extraction processes i.e. pumping ridiculous amounts of sewatater which is at least an order of magnitude more expensive (financially and energetically) than passive adsorption and yet even these numbers (which refer to processes that are extremely more complicated) than passive adsorption demonstrate the viability of the idea if breeder reactors are used. fabrication.
I think I provided the source of my information regarding the energy yield of a breeder reactor (the article by Cohen in the American Journal of Physics).
And your statement : " If you count that in the net EROEI is less than one." is in fact erroneous in the light of the material science of amidoximine (pick up any decent mat sci textbook to see why).
By the way ... it will be a long time before we even have to consider going to the oceans for uranium (there is plenty of uranium out there).
Since "doomers" are so keen of the idea that oil was/is the best fuel/energy source we ever found, you might want to run the numbers again. Of course this will require that you educate yourself about nuclear engineering (i.e. the statement : "You need U235, which is one part of 137 part of total Uranium." is correct ONLY for LWR, not for breeder reactors). Unless of course you are being deliberately disingenuous about the whole issue.
Since my motivation behind nuclear energy relates to both climate change and PO, I will provide another reference for you to chew on.
The following:
http://www.aps-pub.com/proceedings/1452/Perry.pdf
is a paper that was read in the American Philosophical Society a few years ago. Go to page 2 and you will get the data that interest you regarding breeder reactors. The breeder reactor they used is the Phaenix/SuperPhaenix/Monju variety. I am assuming a MSBR model, which should push the Ef close to 100%. And MS(B)Rs are in the GenIV roadmap.
The anti-nuclear rant by S&VDL may be found in the opendemocracy.net website.
Keep day dreaming with the Flying Windmill, but they can not be built ... The weigh of the tether would probably be much more than the kite can support without falling down.
Hence the idea of floating the windmills using helium. Please refer to the second link in my original post.
Chris Vernon asked:
what's the maximum tensile strength of a 30,000 feet conducting cable
A 30,000-foot cable could be made using carbon nano-tubes, far lighter then traditional materials and hundreds of times stronger then steel. The conducting material inside the cable would not need to support any weight (assuming that the nano-fibres themselves can’t be used as conductors).
Ultra lightweight and exceedingly strong nano-tube materials, which are in mass production right now, greatly alter many calculations previously used to debunk solutions.
Apologies for not finding a way to relate this to uranium.
I'm being sarcastic with the following remark.
When are we going to reach peak salt?
It's finite,
It has a production curve..
It is neccessary for life, human and otherwise.....
peak water maybe?
Thorium Fission............see pebble bed.....
Also have a look at this windmill from Al Fin's webpage.
Roland:
I wish you had not talked about flying a huge Helium ballon 30000 feet above in the air, and tethered to the ground. The wind there blows at near Hurricane Katrina speed. A helium ballon of that size does not stand a chance to survive a single second under that condition!!!
Also keep in mind the earth do not have a natural source of helium, other than the minuscule few helium atoms generated by natural radioactive decay, and trapped in underground natural gas fields, and mined out together with natural gas.
And so as the world natural gas production peaks, which is happening now, so does the helium production!!! Even if helium production does not peak. The current production rate barely provided enough helium ballons to children in American shopping malls. You do not have nearly enough helium to float that many huge wind mill kites. Remember each one needs to support nearly a hundred ton of weight of the kite and the tether!!! What volume of a helium ballon is needed to provide enough air buoyant force to support 100 ton? At 30000 feet, one cubic meter of helium ballon volume provides less than 10 ounces of buoyant force.
And of course, with the wind blowing at more than 30 meters per second, the ballon will result in several hundred time more horizental dragging force, than the vertical buoyant force. Which of course means you need many times stronger and many times heavier tether cable to tie the ballon down, and even bigger ballon to support the heavier tether.
Roland:
I wish you had not talked about flying a huge Helium ballon 30000 feet above in the air, and tethered to the ground. The wind there blows at near Hurricane Katrina speed. A helium ballon of that size does not stand a chance to survive a single second under that condition!!!
Also keep in mind the earth do not have a natural source of helium, other than the minuscule few helium atoms generated by natural radioactive decay, and trapped in underground natural gas fields, and mined out together with natural gas.
And so as the world natural gas production peaks, which is happening now, so does the helium production!!! Even if helium production does not peak. The current production rate barely provided enough helium ballons to children in American shopping malls. You do not have nearly enough helium to float that many huge wind mill kites. Remember each one needs to support nearly a hundred ton of weight of the kite and the tether!!! What volume of a helium ballon is needed to provide enough air buoyant force to support 100 ton? At 30000 feet, one cubic meter of helium ballon volume provides less than 10 ounces of buoyant force.
And of course, with the wind blowing at more than 30 meters per second, the ballon will result in several hundred time more horizental dragging force, than the vertical buoyant force. Which of course means you need many times stronger and many times heavier tether cable to tie the ballon down, and even bigger ballon to support the heavier tether.
"And so as the world natural gas production peaks, which is happening now"
No it's not....
"so does the helium production!!!"
No it doesn't......
Would this process work for gold?? I calculate a cost of $100 per troy ounce, if so...
”And so as the world natural gas production peaks, which is happening now”
Local U.S. natural gas peak does not equate to world natural gas peak.
Massive amounts of natural gas are still flared off around the world as a waste product. The only issue is that countries that need it aren’t equipped to import it. It’s not a resource supply issue; it’s a logistical issue.
It’s amazing how many people are perpetuating the rumour that NG is imminently peaking along with oil. It’s simply not true.
We may not be looking at a global natural gas peak as soon as oil... but that's not to say the gas situation is okay. The issue with gas is the regional peaks due to the logistical issues.
aren't a lot of US supply problems still related to damage in the Gulf of Mexico??
"Would this process work for gold?? I calculate a cost of $100 per troy ounce, if so... "
I'm serious. If this really works, why isn't it being used for gold, which is also dissolved in seawater?
As for the new method that the Japanese invented, you forget to count in the energy required to manufacture the speciality material used to absorb uranium from sea water. If you count that in the net EROEI is less than one.
This is simply false. The polyamidoxime material soaks up about 1% by mass uranium. If burned in a conventional thermal reactor, a kilogram of uranium yields about 700 gigajoules of thermal energy. This more than 100x the heat of combustion of 100 kilograms of plastic. Moreover, the plastic adsorber can be reused many times.
Economic studies show that the cost of the adsorber (and its extraction/regeneration treatment) is a small fraction of the cost of the seawater uranium process. The dominant cost is the cost of the support structure that suspends the cages. Even this is tolerable, if uranium rises to a few times the current spot market price.
If this really works, why isn't it being used for gold, which is also dissolved in seawater?
The concentration of gold in seawater is much lower than that of uranium. Uranyl ions are rather soluble when complexed with bicarbonate ions.
the world will always have energy, it can just get a bit more expensive than it is now, even though right now it is overpriced due to speculation.
There isn't going to be a doomsday without energy.
With breeder reactors and uranium and thorium from the earth's crust and then from seawater, there is enough electricity to last a billion years.
When oil runs out our transport needs will be supplied by battery vehicles powered by nuclear.
Airplanes are a bit tougher to replace with batteries.. but they are irrelevant in the grand scheme.
dommsdayers eat shit. you will not run out of juice anyday soon. but it might get a bit more expensive. but since we live in a post industrial society, not even that little extra cost matters.
hold on ... we'll use batteries in place of oil.
What are batteries made out of?
Quantokens mass computation were interesting but false.
They used 350kg polymeric for 240 days to extract 1 kg uranium.
In 365 days they would get 1.5kg.
Current uranium comsumption is approx. 70 million kg. Then you need
70e6/1.5*350kg = 16.3e9 kg device material, approx. 2.5kg/man on earth.
If uranium power generation would be increased by factor 5, these are 17.5kg/man on earth.
If additionally uranium breeding technology would be applied, the weight will be reduced by (theoretically) a factor of 100.
Anyway you cut it, there will not be enough resources to match the growth of world population. When will population control become a reality? If not you better get with renewable energy and recycling. And for all the advocates of big families with religous justification, God only made the planet so big and made you smart enough to know it.
The calculations of the previous anonymous user are incorrect.
The process was improved and now yields 1gU3O8/kg adsobent in ~10days. The adsorbent can be reused ~20times.
1 atom of U235 yields ~250MeV in a typical lightwater reactor, so the EROI is easily in the green because the adsorbent consist mainly of polyethylene.
Hey Ren,
Sorry to inform you, but unlike many other websites, this one is not a beachhead for doomer spam. You've been censored, asswipe. Have a nice day.
JD
Using electron beam to irradiate the absorption material, and then arranging cages in extensive sea areas, waiting a year, recovering few kg Uranium, out of which 8% U235 will be used in powerplants? Economically viable alternative to current 20 USD per barrel instantaneous oil production???
This makes no financial sense and no EROEI sense.
Sure, as some people commented, there are always alternatives to oil such as breeder and thorium fission, but messing up practical approaches with fairytales like this post helps to ensure that what needs to get done will not get done before a crisis!
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