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A molten salt storage solution using sodium hydroxide
- s0rce 5y agoInteresting, doesn't say much about the patented corrosion prevention that would enable the storage of the molten sodium hydroxide.
- pfdietz 5y agoMolten NaOH will oxidize many metals, including nickel and iron, so maybe cathodic protection? Yes, that's what it looks like: https://www.freepatentsonline.com/y2020/0105424.html https://www.freepatentsonline.com/y2020/0105424.html
- oconnore 5y agoIt seems unfortunate that it's possible to patent something so well documented: https://en.wikipedia.org/wiki/Cathodic_protection https://en.wikipedia.org/wiki/Cathodic_protection https://en.wikipedia.org/wiki/Galvanic_anode https://en.wikipedia.org/wiki/Galvanic_anode
- CameronNemo 5y agoIsn't the point that a patented process is documented as part of the patent application? Industrial processes and materials seem like a great use of patents from my POV. Psychology and biology I'm more concerned with.
- mensetmanusman 5y agoIt’s a well documented problem that many groups have tried various technical approaches to mitigate over 100,000 hour operating windows. It’s not too surprising that a particular implementation that has various benefits compared to the existing state of the art would be patentable.
- mcdonje 5y agoWell it says that's the company's core IP, so...
- s0rce 5y agoPresumably the fundamentals are patented and not a trade secret. I could see parts of the manufacturing process being a trade secret.
- ortusdux 5y agoSounds promising. I work in metal cladding, and there is significant interest in molten salt resistant coatings. It doesn't sound like this solution would work for molten salt nuclear reactors, which is a shame because they could be revolutionary if perfected.
- djrogers 5y ago> It doesn't sound like this solution would work for molten salt nuclear reactors That's actually what the company is researching - this is a side-track. Their patent specifically calls out reactors...
- jabl 5y agoIIRC the seaborg reactor design uses a "traditional" flouride based salt for the fuel salt. The NaOH is a separate circuit used as the moderator, instead of a graphite block like other thermal spectrum molten salt reactors. Being a liquid, this sidesteps the problem of radiation damage to the graphite with associated swelling, cracking etc. etc.
- kangnkodos 5y agoA US company, Ambri, is also working on a molten salt battery. "The liquid metal battery is comprised of a liquid calcium alloy anode, a molten salt electrolyte and a cathode comprised of solid particles of antimony"
- davidhyde 5y ago“If we filled up a building the size of the Colosseum in Rome with the salt and heated it to 700 degrees, we would actually” … have a whole lot of pissed off Italians on our hands
- ISL 5y agoIt seems to be an unfortunate property of nature that some of the most-useful chemical and physical systems are also some of the least-friendly. NaOH, in large quantities, is an unforgiving material. As I've read my way into carbon-capture technology, I was saddened to find it there, too. HF also comes to mind in this direction (but is in another league). There's a correlation between those properties that make them useful and those that make them dangerous. The most powerful counterexample to this notion that comes to mind, though, is water. What a spectacular chemical, one that is so useful we have built ourselves from it, yet we can also swim in it for hours without concern for any adverse effect beyond temporarily-wrinkly skin. (While it's less-relevant for thermal solar, it's darn good at heat-capacity, too! :) )
- saulrh 5y agoI mean, water is also aggressively hostile. We're just really well adapted to it. Even pure water will turn metal into rust unless you're using special alloys. Salt water is so bad that even alloys won't save you, you have to depend on sacrificial anodes and exotic surface coatings. Steam takes everything bad about water and jams the fast-forward button until the tape catches fire. There's a reason the first hundred years of steam power is basically just a timeline of scientific metallurgy and gasket technology.
- lapetitejort 5y agoLet's not forget about how dangerous oxygen can be. The oxygen we enjoy now first caused an extinction event: https://en.wikipedia.org/wiki/Great_Oxidation_Event https://en.wikipedia.org/wiki/Great_Oxidation_Event
- dvh 5y agoIsn't NaOH part of the soap?
- moralestapia 5y agoIt's a precursor but there's barely any left of it in the final product.
- Manuel_D 5y agoWhat does this add over existing [1] solar thermal plants? The approach seems to be roughly the same: heat a material with solar power and then operate a heat engine with it. Is storing heat generated by photovoltaics better than using solar energy to heat material directly? 1. https://en.wikipedia.org/wiki/Solar_power_tower https://en.wikipedia.org/wiki/Solar_power_tower
- cdeonier 5y agoWhen you're dealing with solar (or any renewable really), you have to think about the generation of electricity and storage of that electricity. Solar thermal plants can be used to generate energy, but they're not great at storing it for dispatch at later times. Even the link you provided has thermal storage as a component of the system-- you need to figure out how to dispatch electricity at night. What's proposed is a cheaper storage solution, and they state it can still provide power after 10 hours.
- Manuel_D 5y agoSolar thermal inherently has built in storage: the molten salt heated during the day continues to provide energy through the night. > Even the link you provided has thermal storage as a component of the system-- you need to figure out how to dispatch electricity at night. This is referring to the thermal storage of the molten salt tower. What I'm getting at is why is solar PV -> electricity -> thermal storage preferable to solar mirrors -> thermal storage. Is solar PV less expensive than mirrors?
- philipkglass 5y agoSolar PV performs better under imperfect illumination conditions. Concentrating solar thermal power can't make use of diffuse light on partly cloudy days, whereas solar PV can. Solar thermal also has to reach a minimum operating temperature before it starts generating steam/electricity. PV actually works better on bright, cold days and will generate full power the instant an array reaches full illumination. These factors, plus the greater mechanical complexity and maintenance requirements for thermal solar, make it very hard for new thermal solar plants to deliver a lower levelized cost of energy than new PV plants.
- adrianmonk 5y ago> we cannot let it defocus Seaborg’s current mission to power regions with poor or no access to renewable energy sources through our compact molten salt reactor Are there a lot of regions where neither solar nor wind is viable but (their new version of) nuclear is?
- danuker 5y agoSolar and wind need very expensive storage to be reliable. I would say these technologies and nuclear complement each other.
- pfdietz 5y agoSolar and wind do need storage, but if their levelized cost of energy is low enough they still beat nuclear. Remember not to use batteries for annual load leveling, which some dishonest analysts try to do.
- cinntaile 5y agoWhat are the main alternatives? Pumping water is probably the biggest?
- markvdb 5y agoHigh voltage dc interconnects? Importing Danish wind energy is one of the projects supposed to keep the lights on after an exit from nuclear in Belgium.
- cinntaile 5y agoYeah... I'm not too sure about those Danish winds blowing when the Belgian ones aren't. This last week would have been a major issue for example.
- pfdietz 5y agoFor seasonal storage and rare event backup: hydrogen burned in a combined cycle plant. Hydrogen can be stored underground for maybe $1/kWh of storage capacity.
- otrahuevada 5y agoThis link here https://aris.iaea.org/PDF/MSTW.pdf https://aris.iaea.org/PDF/MSTW.pdf seems to provide a little bit more info on how they manage to keep the corrosion within acceptable parameters. It involves the addition of an unnamed chemical compound functioning as a reducing anode straight into the fuel, which is a fairly awesome thing I wasn't aware was possible.
- chris_va 5y ago(I do some research in this space) There are lots of cheap ways of storing heat... The capacity cost of thermal storage has not been the bottleneck for commercialization, but rather the round trip efficiency. This seems academically interesting, but I doubt it will be much more than that. To a first order approximation, the cost of power from a storage system is going to be $/kWh_source_power/efficiency+ammortized cost of capital. No matter how cheap the second term is (and it can't be that cheap unless someone invents a 10x cheaper turbine), the first term tends to make storage uneconomical unless your RTE is above ~80%. This will get ~60% at best. (of course, I could always be wrong)
- new_realist 5y agoDoes this hold true for spilled wind and solar? Does the efficiency matter at all if it would otherwise be wasted?
- chris_va 5y agoCurtailed renewables might make this economical in the short term, but also provides the same benefit for competitive storage technologies (e.g. LiFePO4 batteries). You'd have to compare the LCOE for each over the lifetime of the installation, and I don't think thermal would stack up well.
- KennyBlanken 5y agoThoughts about the iron flow batteries from ESS? They're using an iron flow chemistry that doesn't require exotic stuff. Looks like they've been testing for a while at a bunch of sites, and brought their first 'real' non-test customer online this fall. On paper to a layman, they look perfect for at least some applications. Very cheap and easy to build the "stacks", almost completely nontoxic/safe, and relatively easy to scale (I think they don't scale indefinitely with liquid tank size...that the plate surface area also matters?)
- pjc50 5y ago
- pfdietz 5y agoI wonder if direct contact heat transfer to a gas is feasible with NaOH. Avoiding a heat exchanger would be a great cost savings.
- tosser0001 5y agoI always hate the freaking Thunder Sentence: ... blah blah blah blah blah. UNTIL NOW. It's everywhere nowadays and it makes me wince every time I run into it. And for whatever reason it's especially annoying when I can feel it building up to it, like here which is basically the text book example. Okay, with that off my chest, this technology seems on the surface pretty cool and I certainly hope it works out.
- lovemenot 5y agoI too had always hated it ...
- PaulDavisThe1st 5y agoFor years, people wrote sentences designed to build tension, create interest and promote the general welfare. Nobody could see a way out of this wince-inducing methodology and scientists estimate that 389 million person-hours of useful waking time are destroyed every year by this irritating "thunder sentence" structure. UNTIL NOW.
- kragen 5y agoA tank containing thousands of tons of red-hot lye makes a steel mill sound relaxing and safe.
- KSteffensen 5y agoMaybe not keep all of it in one tank?
- kragen 5y agoWell, then the question is, what do you have in between the tanks? Is it red hot too or not? If it's not red hot, you're losing a bunch of heat through the extra surface area. But if it is, now you have a bunch more material that's annoyingly reactive (because it's red hot) and may decide to melt down into a pool of red-hot material on the ground, letting the lye tanks cool down and possibly spill. That's my understanding of the problem, anyway.
- ineedasername 5y ago>Lithium-ion batteries are too expensive... Molten salt is a more efficient solution Well, I just spent an hour bringing a pound of salt to a nice boil. The I tossed in my phone, which was at 10% battery. It did not recharge.
- lebuffon 5y agoIf you want to use heat for storage liquid metal batteries might be better. (?)(Ambri) From what I understand they have ~80% round-trip efficiency, functionally unlimited lifespan and no moving parts required. Electrons in/Electrons out.
- JackPoach 5y agoThis is nothing new. Molten salt ideas have been around 30+ years and there are projects in Spain and other countries that tested them on small scale. The economics is still poor.
- rob_c 5y agoNot really seeing much here in the way of details, which always makes me worry; Are they using rare-earth based catalysts to control some chemical reaction? It's corrosive so will always break down parts, so have they extended the life by 10x or 1,000,000x ? Storing heat in this medium leads to thermal losses I'm not seeing a mock-up of how it's proposed that this is minimised. Surely trying to store high-energy corrosive materials at high-temp is dangerous even at this modular scale? Naively this sounds like their solution to "saving the world" is "boiling acid" which is at least novel...
- 8bitsrule 5y agoNaOH is lye ... relatively nasty stuff (for metal and skin). (MP 323°C) I've read that 'Glauber's salt' (Na2SO4.10H2O<->Na2SO4) (MP 32.4°C) is good for heat storage. Sounds like a better idea for residential applications.
- Protostome 5y agoIf you have a renewable energy source in the form of heat, storing it in chemical bonds could be a better alternative in terms of long term energy storage. molten salt loses approx. 50% of it's energy after 14 days, while hexametaphosphate for example, when kept as salt, can be stored probably for decades. Hexametaphosphate can be produced from cheap monophosphate salt by heating it in solution to 700c and can be kept in room temperature until it is utilized. The energy density of hexametaphosphate is around ~ 80kWh , which higher or the same as most molten salt heat storages available. Disclaimer: My company (Enzymit) develops enzymes that use polyphosphates, rather than ATP as an energy source to catalyze many types of reactions.