Who Needs Gasoline When You’ve Got Sodium?

YouTuber and serial debunker [Thunderf00t] was thinking about the use of sodium to counteract global warming. The theory is that sodium can be used as a fuel when combusted with air, producing a cloud of sodium hydroxide which apparently can have a cooling effect if enough of it is kicking around the upper atmosphere. The idea is to either use sodium directly as a fuel, or as a fuel additive, to increase the aerosol content of vehicle emissions and maybe reduce their impact a little.

One slight complication to using sodium as a fuel is that it’s solid at room temperature, so it would need to be either delivered as pellets or in liquid form. That’s not a major hurdle as the melting point is a smidge below 100 degrees Celsius and well within the operating region of an internal combustion engine, but you can imagine the impact of metal solidifying in your fuel system. Luckily, just like with solder eutectic mixes, sodium-potassium alloy happens to remain in liquid form at handleable temperatures and only has a slight tendency to spontaneously ignite. So that’s good.

Initial experiments using ultrasonic evaporators proved somewhat unsuccessful due to the alloy’s electrical conductivity and tendency to set everything on fire. The next attempt was using a standard automotive fuel injector from the petrol version of the Ford Fiesta. Using a suitable container, a three-way valve to allow the introduction of fuels, and an inert argon feed (preventing spontaneous combustion in the air), delivering the liquid metal fuel into the fuel injector seems straightforward enough.

[Thunderf00t] started with ethanol, then worked up to pentane before finally attempting to use the feisty sodium-potassium, once the bugs had been shaken out of the high-speed video setup. [Thunderf00t] does stress the importance of materials selection when handling this potential liquid metal fuel, since it apparently just bursts into flames in a violent manner on contact with incompatible materials. Heck, this stuff even reacts with PTFE, which is generally considered a very resistant material. We’re totally convinced we’d not like to see this stuff being pumped from a roadside gas station, at all, but it sure is a fun concept to think about.

Sodium-Potassium alloy doesn’t feature on these pages too often, but here’s a little fountain of the stuff, just because why not?

Thanks to [Stephen] for the tip!

58 thoughts on “Who Needs Gasoline When You’ve Got Sodium?

    1. id like to k ow where the assertion that a big cloud of lye, pH probably somewhere north of 12, kicking around in the upper atmosphere is going to cool anything.

      and then theres the ridiculous notion that the refining process for such a fuel additive might be a net negative in energy expenditure. the industrial production of sodium metal is by electrolysis of molten salt (mp like 700c)

      1. I saw this one before. It’s meant to be a way to get light-reflecting tiny particles suspended into the upper atmosphere, while also representing a storage of carbon since the carbonates of soda lye are washing and baking soda, which are also light colored and stick around reflecting light. Plus, it’s all alkaline, so the oceans would not be acidified by what eventually falls into them. But the carbonates are safer than other substances that hang around in our air, especially in low quantities.

        The real trouble is, the source of all that lye or sodium itself is almost surely NaCl, and if the Cl that was stripped off is just bonded to a hydrogen and left to go on its merry way, there comes the acid all over again. And, of course, it’s not a reasonable fuel. It might be a reasonable additive for geoengineering in desperation, on intercontinental jets.

      1. Solves the humanity pollutes the world problem nicely, nu humans no (unnatural) pollution ;). Still, there are carbon mine fires (1/3 of the greenhouse gasses come from this source if I remember correctly) and volcanoes are staunch polluters as well.

  1. Apart from clouds of lye — you have heard of acid rain, well this would be the other extreme.

    Anyway aside from that, you don’t have sodium. You have some sodium compound and it takes quite a bit of energy to produce metallic sodium, never mind how unstable it is. So at best it would be an odd and inconvenient energy storage mode.

    I find it hard to put a good spin on all of this (nor do I see the “hack”).

    1. The funny thing to me is back in 8th grade which was a very very long time ago I wanted to make a hybrid rocket using solid sodium as the fuel with an oxidizer of 50/50 H20 and H202. I balanced the equations and it would seem to work but when I presented it to the science fair adviser he looked at and said, “It might work but good grief it is a really bad idea.”
      Yes NaOH is nasty stuff really hot NaOH seems a lot worse to me. I have no idea what you could use to keep it from corroding everything in it’s path.
      BTW I am a software engineer working on an ECU for a rocket motor so I guess it wasn’t all a waste of time learning about rockets in my youth :)

  2. When I was a kid it was all about the “ozone layer” when I was a teenager it was all about “global warming” now it’s “climate change”. It’s a bunch of left wing tree hugging hippie crap. sodium hydroxide is Lye and you would be a fool to use that as a fuel.

    1. When I was student it was all about the ozone layer, and after banning the CFC worldwide, it mostly healed.
      It´s much more complex to tackle the global warming considering our dependency to oil, but your attitude, dismissing those as “left wing tree hugging hippie crap” clearly demonstrate the obstacle is more (i could say “stupid, stubborn, ignorant people” but i won´t get as low as you) and their beliefs. Unfortunately there are so much like you that it seems we´ll have to wait for them (and you) to die out to make any progress. It just might be a bit late: the more we wait to really handle the problem, the harder it will be.

      1. I bet youl love the 15 minute city while eating bugs. To save the planet.
        Climate change is a LIE! The sun has direct control over every weather system on earth, including earthquakes and volcanic eruptions.
        Soon youl see, with the waning magnetic field we are overdue for a big one.
        All those gadgets you all are so fond of will go POOF! I cant wait :D

        1. You may be right there, I compared the voltages induced by big solar storms with the breakdown voltage of silicon junctions and found that the next Carrington Style event will likely destroy every unprotected PV array in the larger solar installations that have long run lengths of conductors and so are more vulnerable.

        2. Funny, all my favourite travel has been to 15 minute cities, and I had a great quality of life when I was living in one (alas temporarily), with the lowest living expenses I’ve ever had.

          Not over concerned about climate change, but 15 minute cities and going slightly more sustainable would be good for quality of life.

          1. It was not CFCs or HCFCs that caused the no longer existent ozone hole. They’re both notably heavier than air and never made it more than a few feet above where they were released. The entire thing was either a scam, spouted by idiots, or a scam spouted by idiots.

        1. The Ozone Hole status is the perfect litmus test for incurable Everything-Doubters.

          On all issues, they first disavow the existence. Then the severity. Then then the abatement. They’ll spew their baseless theories, with nothing but the fact that there are others even more ignorant to agree with them. It’s the whole “Tuck.. Carls..” way of doubt spewing. “How do you know that’s true…..? … How do you know it’s not biased…..? … Who are these people ….? It’s PRETEND CRITICAL THINKING. But, it’s not thinking at all. There’s never any credentialed counter-study cited. No well thought out solution.

          Cures are generally not instantaneous, cheap, or perfect. Yes, there is still a shrinking hole in the ozone. I doubt anybody thought it would all of a sudden disappear, just because we reduce CFCs. Healing takes time, and compliance is imperfect.

          What if Ozone Hole, Climate Change, … are exaggerated, or the solution wrong? Even if 9 out of 10 issues were so, wouldn’t it be smart to take care of 10/10? That 1/10 we skip can be devastating. You think you can figure out what 1/10 you actually can support with 100% certainty? You’re wrong. Being a Rebel Without a Clue just isn’t that cool anymore.

          1. As far as the replacement of CFCs also being dangerous:

            What the h do you want? Everything has other impacts/costs. The idea is generally to improve situations, not cure them. It’s the same ignorance that goes with the initial resistance to seat belt mandates. “What if someone drives of a bridge, and they drown because they’re strapped in, or the car catches fire!” was commonly heard (facepalm). Do you want CFCs?

            Please do supply your ideal replacement refrigerant formulation to the rest of us.

          2. I wasn’t criticizing the ban of CFCs and other ozone depleting chemicals – just the idea that banning them was actually effective at closing the ozone hole, or actually banning these chemicals in the first place.

            It’s people congratulating themselves for a job well done, while ignoring the fact that the world keeps burning behind their backs.

          3. To put it more generally: the hype that goes around green tech and green politics is extremely damaging to the actual quest of solving environmental and climate issues.

            Policies that are lauded as great successes, technologies that are praised as great innovations, actually turn out to be ineffective or completely inadequate in the scale they’re implemented or can be implemented in the real world – yet people believe they’re doing the right thing and “doing their bit” without realizing that they have actually done jack s**t. They’re just wasting money and time going through the motions.

            The irony is that people like Greta Thunberg are correct – she’s just riding the environmental hobby horse for sociopolitical reasons (anti-capitalism), not environmentalism, because she thinks she’s killing two birds with one stone. This kind of idealism and thirst for power prevents her and her kind of actually coming up with any working solutions.

    2. There is no unambiguous correlation between the rate of CO2 rise in the atmosphere and human activity anyway, this was demonstrated very clearly when the drop in economic activity due to the lockdowns of recent years did not show up as a signal in the Keeling Curve data. At this stage it is best to just ignore climate zealots as they are entirely religious and not interested in applying the scientific method to their _beliefs._

      1. Freon is a brand name. You’re talking about CFC refrigerants that were replaced by HCFCs (and are marketed under the brand name Freon). Which are both heavier than air and could never have reached the ozone layer to cause any damage to begin with. Oh and HCFCs aren’t as efficient as CFCs as far as being good refrigerants goes, so more coal burned after the switch was made to keep the same level of comfort.

  3. Neal Stephenson talks about using liquid sulfur in high altitude vehicles as a fuel in his book Termination Shock. With the goal being to produce sulfur dioxide in order to reflect sunlight. Its a wild read.

  4. It’s amazing how easy it is for you, Americans, to access and destroy expensive technology just to make good fireworks. Most of the video is “look how good it burns”, which, in fact is useless for the goal that’s supposedly researched. Then one will cast a “safety first” by protecting his own face behind a PC helmet, but at the same time, put his arms under the “self igniting” chemical, to press the starter button.

    Lesson learned: No need to be super rich to earn a Darwin award.

    1. For me, mythbusters has made so much bad to science vulgarization. Going for the “cool” (in the amercian sense) and lifestyle. You don’t improve stuff by reaching for the bottom.

      I don’t want science to be keeewl, I want it to be correct.

      Or for the least, I don’t want the amercian burger style of “cool”.

  5. We use carbon nanoribbons to store hydrogen for energy storage, the resulting liquid has more hydrogen per volume than liquid hydrogen, and is much safer to use. We can source the nanoribbons from natural sources such that recycling the batteries is as simple as burning them along with the hydrogen. We call our invention diesel and it burns very cleanly when you add a magnetron to your exhaust so as to add a little plasma to it, thanks to some smart engineers over at MIT. 😏

  6. Came to see if the reasons I knew this to be a bad idea were mentioned…Left with a couple more reasons why this is a bad idea.

    Now – If you’re just doing this for the fun of blowing up some sodium, and trying to do something useful with it rather than just dumping it in water and watching the carnage, than I approve whole heartedly! How about trying some caesium instead :D (Not really serious, unless you happen to be very experienced with the stuff, and know all the less common knowledge problems of doing so! I mean, I have no idea what pressures would be generated…or if there are embrittlement problems, etc…so if you’re an expert, are bored, and can do it safely, then, I’m totally serious :D)

  7. I’d suggest everyone being critical of the idea watch all his videos on the subject. He is a strict scientist and very pragmatic about challenges. If you are mentioning something here, he has likely considered it and has an answer. It’s so easy to poo poo an idea in a 200 word comment that someone has spent years doing actual work on.

  8. If you just want to see if you can do it, sure do it. But suggesting this could potentially help with climate change is such a bullshit idea. I usually don’t like Thunderf00t, because he throws around more shit then needed. And this is the kind of video that he’d usually fling feces at.

  9. Re: all the face dissolving comments – do you realize that nitric and sulfuric acids are just as bad, and they’re what you already get from common fuels which contain some level of sulfur and emit some level of NOx? It’d be dumb to release lye from a car, yes. But maybe not a intercontinental jet, if our oceans are acid and our climate is fucked but we’re still flying around. And the wear may be bad, although rc car nitro fuel engines make acid in their exhaust, so it’s not like that will be a dealbreaker for someone. But making a lot of tiny particles of sodium near some co2 at high-ish temperatures sounds like a great way to convert it to washing soda instead, which is much less of a problem, so keep that in mind.

  10. Aside from the questionable effect of having sodium hydroxide in the air and the potential health risks, this would fail as a fuel in an IC engine. The heat from the engine would cause the fuel mixture to prematurely ignite.

    That being said, I like the outside the box thinking.

  11. The whole Sodium burning thing sounds a bit far fetched. However there was something mentioned that is far more interesting. The use of Ultrasoonic evaporators. Has anybody ever used Ultrasonics to enhance the evaporation of gasoline, and improve mixing before combustion? I have heard of heating the fule up to improve evaporation, but maybe Ultrasonics could be as good or better? We need 100 MPG gas engines.

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