<10% of natural gas plants recover helium. All of them extract it. The remaining >90% vent it into the atmosphere. This is an engineering / money problem, not a physics problem.
I'm not a chemist but are there really no alternatives? Running fusion plants to make helium seems very unlikely to become cost effective, but it would be quite the sci-fi future if we filled party balloons by bombarding hydrogen with free protons.
I guess there aren't any easy molecules to break apart to get helium either since its a noble gas. No hydrolyses type solutions because there aren't any molecules that incorporate helium. I guess radioactive decay, but even that is ultimately limited over long enough timescales.
How dangerous are party balloons filled with hydrogen? Not a whole balloon arch obviously.
I would.
Things can always go wrong. We probably shouldn't strive for 100% safety because they we'd spend our lives in a padded cell. But we also shouldn't assume things are safe because they're common or routine.
That's because the starting density of the hydrogen air mixes at near atmospheric pressure (such as in a balloon) is pretty low. Also, the balloon does not significantly contain the explosion, which reduces the danger a lot. I would not want to do it in a glass container.
How does that bang compare to the bang from an equally-inflated balloon full of ordinary air?
ETA: I may be misremembering, the more I think about it, the more I recall that we did not use air, we did use pure oxygen. Not like it was hard to get (and we had lots more interesting stuff than that in the lab, this was the 80s...). But the outcome I do remember. The entire point of the experiment was to examine the difference between the individual pure elements and the mix. We expected the pure hydrogen to be far more interesting than it turned out.
The instructors would bring out a helium balloon and a candle on a meter stick. The balloon goes pop, huzzah.
Then the twist. "Hey, wanna do it again?" All the kids would be like "meh, I guess?" They would then bring out a balloon full of hydrogen (maybe some oxygen too?). It would look identical to the first one, floating there tethered to the lab bench.
When the candle hit the second one, it made a white flash and a really sharp BANG. It was an order of magnitude louder, and you could hear the transient bouncing off the walls and echoing in the halls. It made an impression.
https://www.youtube.com/watch?v=Rwbyl7ywfhk&list=PLLnAFJxOjz...
Hydrogen mixed with air or with oxygen produces an ear piercing supersonic detonation, exceedingly loud and unpleasant. Not recommended for demonstrations.
One of the larger episodes was in 2012 in Armenia, where thousands of balloons exploded during a meeting, injuring 154 people, of which 4 seriously (the video is of poor quality): https://www.youtube.com/watch?v=jWEm2sS7Dw8
A smaller, more recent episode in India: https://www.youtube.com/watch?v=FH5JwHeKnZo
I actually remember a similar problem from some compound that was mainly formed as a byproduct of some old Canadian nuclear reactor design. As the tech gets phased out, the material is no longer available in significant quantities, with consequences for a projects that need it (like Iter).
Some things can be cheap if they are produced as a byproduct, but very expensive if they have to be obtained directly.
All these "we're going to run out" stories pretend that engineering cannot adapt to changing cost structures, which is just total nonsense.
Sure, there is nothing that can be directly substituted for how we use Helium today, but clearly we're using Helium inefficiently today and the answer is that once markets force us to change, we will find more efficient ways.
We use a lot in our MR scanners.
The tech is changing and magnets are using far far less.
Super-conduction at higher temperatures has made progress too.
So while you are right that nothing else stays liquid at those temps, we won’t be needing nearly as much helium in radiology in the next few years.
The new generation use something like 700ml of helium, where the standard was hundreds of litres. https://magneticsmag.com/siemens-healthineers-gets-fda-clear...
How many loans for MRI machines that require helium haven't been paid back yet?
They use a lot when installed, but rarely need top-ups.
They are shipped full of helium and chilled, but aren’t ramped up (so aren’t superconducting magnets until after commissioning).