Site dédié à la fin de l'âge du pétrole
http://www.oleocene.org/phpBB3/
Par exemple, il y a pas mal de fer... pas sûr qu'on arrive à le vendre pour autantToTheEnd a écrit : parce que l'air de rien, vu qu'il y a quand même pas mal de trucs dans l'eau de mer, ça serait une bonne diversification si c'est rentable.
http://www.enerzine.com/2/18970+une-nou ... -mer+.htmlUne nouvelle voie pour extraire l'uranium de l'eau de mer
06 janv 2016 enerzine
Pour la première fois, un procédé en ultra-haute résolution a été utilisé dans l'objectif d'étudier des fibres polymères capables de pièger l'uranium contenu dans l'eau de mer.
...............
http://nextbigfuture.com/2016/07/uraniu ... makes.htmlUranium Seawater Extraction Makes Nuclear Power Completely Renewable
July 03, 2016 nextbigfuture.com
New technological breakthroughs from DOE’s Pacific Northwest (PNNL) and Oak Ridge (ORNL) national laboratories have made removing uranium from seawater within economic reach and the only question is – when will the source of uranium for our nuclear power plants change from mined ore to seawater extraction?
...........
The latest technology builds on work by researchers in Japan and uses polyethylene fibers coated with amidoxime to pull in and bind uranium dioxide from seawater (see figure above). In seawater, amidoxime attracts and binds uranium dioxide to the surface of the fiber braids, which can be on the order of 15 centimeters in diameter and run multiple meters in length depending on where they are deployed
Advances by PNNL and ORNL have reduced the cost by a factor of four in just five years. But it’s still over $200/lb of U3O8, twice as much as it needs to be to replace mining uranium ore.
Over the last twenty years, uranium spot prices have varied between $10 and $120/lb of U3O8, mainly from changes in the availability of weapons-grade uranium to blend down to make reactor fuel.
So as the cost of extracting U from seawater falls to below $100/lb, it will become a commercially viable alternative to mining new uranium ore. But even at $200/lb of U3O8, it doesn’t add more than a small fraction of a cent per kWh to the cost of nuclear power.
Marine testing at PNNL showed an ORNL adsorbent material had the capacity to hold 5.2 grams of uranium per kilogram of adsorbent in 49 days of natural seawater exposure — the crowning result presented in the special issue. The Uranium from Seawater program continues to make significant advancements, producing adsorbents with even higher capacities for grabbing uranium. Recent testing exceeded 6 grams of uranium per kilogram of adsorbent after 56 days in natural seawater — an adsorbent capacity that is 15 percent higher than the results highlighted in the special edition.
Uranium is dissolved in seawater at very low concentrations, only about 3 parts per billion (3 micrograms/liter or 0.00000045 ounces per gallon). But there is a lot of ocean water – 300 million cubic miles or about 350 million trillion gallons (350 quintillion gallons). So there’s about 4 billion tons of uranium in the ocean at any one time.
However, seawater concentrations of uranium are controlled by steady-state, or pseudo-equilibrium, chemical reactions between waters and rocks on the Earth, both in the ocean and on land. And those rocks contain 100 trillion tons of uranium. So whenever uranium is extracted from seawater, more is leached from rocks to replace it, to the same concentration
..............
Scientists from two DOE labs, Oak Ridge National Laboratory in Tennessee and Pacific Northwest National Laboratory in Washington, led more than half of the 30 papers in the special issue. ORNL contributions concentrated on synthesizing and characterizing uranium adsorbents, whereas PNNL papers focused on marine testing of adsorbents synthesized at national labs and universities.
....................
That teamwork culminated in the creation of braids of polyethylene fibers containing a chemical species called amidoxime that attracts uranium. So far, testing has been conducted in the laboratory with real seawater; but the braids are deployable in oceans, where nature would do the mixing, avoiding the expense of pumping large quantities of seawater through the fibers. After several weeks, uranium oxide-laden fibers are collected and subjected to an acidic treatment that releases, or desorbs, uranyl ions, regenerating the adsorbent for reuse. Further processing and enriching of the uranium produces a material to fuel nuclear power plants.
http://www.nextbigfuture.com/2017/02/st ... ction.htmlStanford researchers improve extraction of uranium from seawater
February 20, 2017
In the recent work, Stanford researchers improved on all three variables related to extracting uranium from seawater: capacity, rate and reuse. Their key advance was to create a conductive hybrid fiber incorporating carbon and amidoxime. By sending pulses of electricity down the fiber, they altered the properties of the hybrid fiber so that more uranyl ions could be collected.
..................
L'uranium n'est pas un élément rare, tout le monde en a dans son jardin, en quantités infimes. Les éléments rares on en trouve bien plus beaucoup plus près de nous que l'eau de mer ou le fond des océans, dans les égouts et les boues d'épuration. Le problème est toujours celui de la concentration et de la séparation des éléments, avec son coût financier et énergétique.Glycogène a écrit :Par exemple, il y a pas mal de fer... pas sûr qu'on arrive à le vendre pour autantToTheEnd a écrit : parce que l'air de rien, vu qu'il y a quand même pas mal de trucs dans l'eau de mer, ça serait une bonne diversification si c'est rentable.
A ce prix là, vaut mieux ramasser le nodules au fond des océans...
Lire l' analyse : http://lenergeek.com/2017/08/23/luraniu ... nucleaire/L’URANIUM MARIN : UNE ALTERNATIVE VIABLE POUR LE NUCLÉAIRE ?
23 août 2017 l' Energeek
Alors que la question de l’approvisionnement en uranium de la filière nucléaire se pose de manière pressante, des scientifiques américains travaillent à mettre au point un nouveau procédé : l’extraction de l’uranium marin. La mer, qui représente une ressource quasiment infinie en uranium, pourrait bien devenir la principale ressource pour la production d’énergie nucléaire. Mais de nombreuses interrogations demeurent : peut-on réellement extraire de l’uranium marin à grande échelle ? A-t-il les mêmes propriétés énergétiques que l’uranium qu’on trouve sur Terre ? Pour l’équipe de recherche américaine, la réponse est évidente : l’uranium marin représente une opportunité à ne pas laisser passer.
........................
https://www.nextbigfuture.com/2018/06/o ... water.htmlOn track to commercial extraction of uranium from seawater
brian wang | June 16, 2018
Researchers at Pacific Northwest National Laboratory and LCW Supercritical Technologies have created five grams of yellowcake — a powdered form of uranium used to produce fuel for nuclear power production — using acrylic fibers to extract it from seawater.
LCW, a Moscow, Idaho clean energy company with early support from PNNL through DOE’s Office of Nuclear Energy, developed an acrylic fiber which attracts and holds on to dissolved uranium naturally present in ocean water.
LCW is applying for further SBIR funding for a uranium extraction field demonstration, to be led by PNNL, in the Gulf of Mexico, where the water is much warmer. The material performs much better in warmer water and extraction rates in the Gulf are expected to be three to five times higher, therefore making it more economical to obtain uranium from seawater.
.........
Un litre d'eau de mer contient en moyenne 35 grammes de sels (à 30 €/tonne) soit 10 000 000 000 fois plusIl est couramment admis comme teneur en uranium des océans, une valeur moyenne de 3,3 microgrammes d’uranium par litre avec une dispersion de valeurs allant de 1 à 5 micro-grammes par litre
Et non, ça fait 10 000 000 de fois plus (3 zéros d'erreur ! ça mérite au moins le bûcher).
Bien sur. en 2016 la production mondiale est de 73 500 tonnes (équivalent U3O8).