Natural / Fantasy Methods of Procuring Hydrogen / Helium

Hello, writing friends!

I'm in the process of justifying airships! Ye-olde-medieval-country has access to magic, and also a Mordor-esque region rife with volcanoes, metals, and other such craft-worthy goods. Now, I'm no scientist, but I was hoping having access to this region might provide them with the resources necessary to find and harvest Hydrogen / Helium as the primary way to create big'ole floating balloons to carry their airships. That said, I have no real idea as to how human beings procure such gasses. Does anyone happen to have a mastery of such a subject, and a willingness to teach me the subtle ways of capturing gas? Does hydrogen/helium even occur in nature? I realize I might sound ignorant of basic chemistry facts, but that's a risk I'm willing to take for fantasy airships.

Thanks so much for any insight!

 

Did you reject hot-air balloons for any particular reason?

Edited to add: It appears that "coal gas", whatever that is, was once used for balloons.

 

@ChickenFreak ...to be honest I completely forgot that you can just heat up normal air to accomplish relatively the same function... thank goodness for you guys!!

@big soft moose I thought about that a little, but I worried that, since I'm going for relative-realism in the first place, the addition of a strange new type of gas into the atmosphere might have crazy unintended side effects that I'm not smart enough to foresee! That said, I'll have to take a look into both electrolysis and coal gas: i imagine having a crew of wizards zapping water until the molecules separate isn't that far-fetched of an idea, as long as I can justify how they figured out it was a thing.

...all of that said, I do really like the idea of an entire career where you sneak around collecting pixie farts. Can you imagine an country next to a pixie forest where that's their major export? That's a short story at least.

 

Here's a thing for you,
In the 1914-18 war, the Germans used airships filled with hydrogen, Zeppelins, to drop bombs on wimin and children in the lush green fields of Old England.
An interesting feature is that they used the intestines of several million cattle to make the bags to put the hydrogen in.
(Don't worry though, the cattle didn't need them anymore).
The tricky bit was gluing the intestines together satisfactorily and quickly enough, they managed it ok but apparently the smell was 'interesting' for miles around the factory where they did it.
There you go; another fun fact from the bottomless cesspool of my mind.
Have fun.

 

Just make up a substance and pick your own preferred method of harvesting it. If it’s a fantasy setting then you have the freedom to be more creative - maybe have the gas harvested from huge land whales that are only able to ‘walk’ due to internal pockets of some given gas. Have the stuff appear in certain species of trees and/or have ‘floating forests’ (I’ve used this idea myself in part of my world building and I’m sure many others have before too).

 

In a short I wrote, the Dragons had Hydrogen gas pockets (to justify them flying) which they could vent to make flames. So after they breathed fire they were less and less able to fly.
A number of jelly fish use carbon monoxide as a lifting gas. Perhaps harvest them and "farm" them in a vat of high value food, with the tops open so they vent gas into your storage container.
Hydrogen is very very hard to contain, so the material for the gasbag would need an unusual source (see stomach lining above)
I agree that hot air is probably the easiest answer. In Dungeons and dragons online, they have fire elementals into airships to provide hot air - which can make for a fun sabotage.

 

Hydrogen is also the byproduct of some basic acid-base reactions. Think vinegar and baking soda. Old alchemists could be doing this without fully understanding what they are making in gas with the reaction.

 

But not exactly the same

• Hot air is perfectly safe and extremely easy to make (you take air, and you make it hot), but it's not very powerful
• Hydrogen is very powerful, and it's very easy to make if you know what you're doing, but it can also be very dangerous
• Helium is almost as powerful as hydrogen and a lot safer, but you need to know exactly where to find it (decaying uranium/thorium deposits)

Maybe there's a raging academic debate in the military establishment about whether hot air or hydrogen is better, but some new radical has discovered helium, told the establishment that this new "wonder gas" is better than either of the popular options, and is trying to get permission to search for natural deposits and keeps getting denied, but somehow finds out that enemy spies infiltrating his side believed him, and that their superiors on the other side have started looking for deposits with a massive headstart over the protagonist's own side?

Perhaps a hundred years ago, they were trying to develop thunderbolt-weapons for a war against the merfolk, and they were initially surprised by all the explosions they were creating in the air shortly after firing their weapons into the water (accidentally splitting water into hydrogen and oxygen, which then ignited back into water vapor and fire)?

 

IMO, Stick to hot air unless you go the magical production route.

My father worked for the US Bureau of Mines, Helium Activity. Helium is extracted from natural gas deposits by using compression and expansion. It will be the last gas left after everything else has frozen/liquified out.

 

Or you could use a vacuum. A cylinder with nothing in it would theoretically be lighter than regular atmosphere of the same volume, as long as the mass of the container didn't negate the difference.

 

The problem being that a container would need to be heavy in order to avoid being crushed by the atmospheric pressure (as opposed to hot air and lighter-than-air gases, which reduce mass while still providing internal pressure to protect structural integrity).

There would be ways for mages to work around that too, but it would need to be mentioned that they’re doing it (and the risk of crashing if they can’t sustain it)

 

Which would work well with their version of chess. In order to win, you need to capture your opponents mage, and the airship will implode and crash to the earth.