Helium Recovery System Saves Costs

Helium is the most common element in the universe besides hydrogen, but despite this universal abundance it is surprisingly difficult to come across on Earth. Part of the problem is that it is non-renewable, so unless it is specifically captured during mining its low density means that it simply escapes the atmosphere. For that reason [Meow] maintains a helium recovery system for a lab which is detailed in this build.

The purpose of the system is to supply a refrigerant to other projects in the lab. Liquid helium is around 4 Kelvin and is useful across a wide variety of lab tests, but it is extremely expensive to come across. [Meow]’s recovery system is given gaseous helium recovered from these tests, and the equipment turns it back into extremely cold liquid helium in a closed-cycle process. The post outlines the system as a whole plus goes over some troubleshooting that they recently had to do, and shows off a lot of the specialized tools needed as well.

Low-weight gasses like these can be particularly difficult to deal with as well because their small atomic size means they can escape fittings, plumbing, and equipment quite easily compared to other gasses. As a result, this equipment is very specialized and worth a look. For a less lab-based helium project, though, head on over to this helium-filled guitar instead.

31 thoughts on “Helium Recovery System Saves Costs

    1. Apparently the helium industry (of course) takes care to distinguish “balloon gas” from (more pure) helium to dodge these concerns. I guess the balloon stuff isn’t very pure helium. Seems a shallow defense, though, since I assume there is a purification technique…

  1. Good to see someone is trying to conserve helium, being how it’s both a limited resource and essentially unrecoverable once it’s released.

    I confidently predict that in 100 years our descendants will be scavenging helium wherever they can find it, looking back at us and mumbling “Those *idiots*! They had all this cheap helium and they just threw it away in party balloons! – If they even bothered to separate it from the natural gas in the first place!”

  2. If helium becomes expensive enough, collecting and shipping it to Earth from one of our Solar System’s outer planets could become practical. I imagine satellites in a very low orbit scooping up rarified gas and using some of it as propellent in an atomic powered thruster to maintain the orbit. Any lower, and our upcoming technology couldn’t compensate for the drag. Also, orbital velocity is closer to escape velocity, making shipping easier.

  3. Liquid helium costs about the same as decent wine. (Liquid nitrogen, about the same cost as beer. )
    But don’t drink either.

    Hard to handle stuff: it likes to just boil away if you so happen to look at it crossways. Literally: it’s almost impossible to actually see liquid helium in an open container. Its latent heat of vaporization is astoundingly low: Litre for litre, about 800 times less than water. Every three months we’d order in 250 litre dewars just to have 100 litres of liquid delivered to the instruments. You boil off a significant fraction of the shipment just cooling down a couple of meters of the transfer line. We’d order about 10% extra though, so I always had a few litres to play with. For a few minutes anyway.

    That 100 litres provided a few dozen milliwatts of cooling for three months. Crazy.

    Capturing is good. We were backwater heathens though, and just let it go.

    1. I inflated a 150,000 cubic foot helium filled airship in Istanbul years ago using liquid helium from a truckload of large dewars. It had to pass through a truck sized radiator to gasify and the fittings leaked liquid He profusely. Fun to play with in small quantities in your hand, it would skitter around like mercury in your palm while vaporizing. Made great 2 liter pop bottle bombs too!

    2. A friend of mine had a moonlighting gig refilling NMR superconducting magnets with liquid helium. The transfer line got cold enough that oxygen would precipitate out of the air and condense into gorgeous crystal blue droplets.

      1. Well plutonium can be breed at roughly 1mw*yr/kg. Not sure what the cross section is for capture and or the effect on the neutron budget if you were making he instead…

        1. Not quite, it gives off alpha particles, which are helium nuclei

          A ton of highly-active, alpha-emitting waste gives off helium at a rate of ten or twenty grams per year, so you would need quite a bit to extract helium at appreciable quantities, although it does suggest a solution to the nuclear waste issue. Stick all the waste in a big pit and rename it Helium production facility.

          What could go wrong?

  4. Helium is relatively scarce on Earth, even though it is the second-most common element in the universe. It is a non-toxic, colorless, odorless, tasteless, inert, monoatomic gas. It is the first noble gas in the periodic table of elements, and its boiling point is the lowest among all of the elements. These properties make helium absolutely unique – there is no substitute, and no natural or manufactured replacement for it.

    Helium leaves the atmosphere once it is used, making it impossible to recover from a landfill in the future, as can be done with other vital materials. While there is a large amount of helium in the atmosphere, it is prohibitively expensive to extract it from this source because its concentration is so low. It is estimated that distilling helium from the atmosphere would cost over US$1,500.00 per Mcf (1000 cubic feet [1]) of helium, so all commercial helium supply on earth comes from underground reservoirs, in which helium produced by the radioactive decay of uranium and thorium is concentrated and trapped over hundreds of millions of years.[2]

    There’s much more to read at [2] below, enjoy…

    * References:

    1. Mcf – Wikipedia


    2. Helium Production – North American Helium


  5. If helium was non-renewable, we wouldn’t have any at all, since it would long since have floated to the top of Earth’s atmosphere, to be blown away by solar wind. Helium contains two protons and two neutrons in its nucleus, which lucky for us is the same as an alpha particle. This means that any radioactive decay that produces alpha particles is generating helium. Also lucky for us, thorium and uranium have decay mechanisms that produce alpha particles. The very low partial pressure of helium in our atmosphere is the result of the equilibrium between the loss from the atmosphere and the replenishment by natural decay of uranium, for the most part, so it is not accurate to say it is non-renewable.

  6. I would have thought helium would float to the top of the atmosphere and just stay there until affected by the solar wind which may be helium also. Might be wrong about that, orbital mechanics isn’t my specialty

    1. I could be wrong but it’s my understanding that because it’s non-reactive it exists as single atoms, and because they’re so light they can occasionally gain enough thermal energy to drift far from Earth where they’re subject to getting swept away in the solar wind

    2. SteveS is pretty much correct.

      Helium is dissolved in the atmosphere, like any other gas. It won’t selectively “float to the top of the atmosphere” Helium leaking out of the earth’s surface will eventually diffuse to the upper atmosphere, where it can escape.

      Helium will leak away from earth faster than oxygen or nitrogen because, for a given temperature (=energy of the atom), its atoms are moving faster (E=0.5mV^2…), so a greater fraction is in that very high end of the velocity distribution, and escapes earth. Or (more likely), just get up high enough that solar wind strips it.

      Oxygen molecules might have a speed normally (actually Maxwell-Boltzmann) distributed around 500 m/s, where helium atoms would be around 1400 m/s. A few sigmas away from 7700 m/s escape velocity, but a few can make it.

      I have no idea which mechanism is more significant (stripping or simple escape), but I’m sure google will provide if you’re interested.

  7. As luck would have it, just a few days ago I bought an only slightly broken but otherwise complete Gifford-McMahon cryocooler setup including a helium compressor, control circuitry etc. on a famous online platform for auctions.

    I plan on running a by-pass of the compressed (2.2 MPa) He gas through the cold head at 10…15 K and feeding it through an expansion nozzle inside a dewar, returning the non-liquid excess fraction of the expanded gas back to the compressor inlet.

    Is this feasible on a low budget?

    If so, it would be nice to play around with a Nb-Sn3 superconductor coils, where I still have no idea how to connect thick copper normal conductors to the low-temperature superconducting terminals without boiling off all the liquid He due to conducted heat through the copper wires… How is this handled in the professional world?

    1. If you are connecting some copper wires from room temp. You would need heat shields. And some terminal blocks at strategic positions to act as a heat block. Look up cryostat wiring you can get some ideas from there.

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