How Do Nuclear Submarines Make Oxygen?- Smarter Every Day 251
SmarterEveryDay5 HN recommenders · recommended in 5 months, 2021–2026
explainer · general · evergreen · 2021–2026 on HN
A Smarter Every Day episode from aboard a nuclear submarine on how the crew makes breathable air. It covers oxygen generation from seawater, oxygen candles and CO2 scrubbing with amine.
Go-to link when oxygen candles, CO2 capture or submarine air quality come up.
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10 comments from Hacker News
The SmarterEveryDay YouTube channel did a slightly more indepth series of videos aboard a nuclear sub, obviously still censored, but educational. link The video on producing oxygen was particularly enlightening: ▶ this video
Yes, but the context of this post was emergency systems which are purely chemical. For routine operations on e.g. a submarine, link As other people have mentioned, this is a great introduction to the topic: ▶ this video
I really enjoyed this Smarter Every Day episode that talks about maintaining air quality on a submarine: ▶ this video
You might find this series from Smarter Every Day interesting. ▶ this video I didn't find a bit about how they make drinking water, but here's an episode about how they regenerate their oxygen on a nuclear sub.
Not sure if it's the same stuff exactly or if the cost includes reprocessing but there's an amine cycle that seems to be mostly closed that's used for CO2 removal on submarines. So it's just used to separate CO2 from the rest of the output. I think that's what this sentence is talking about: > Notably, it is projected that this solvent can operate at a regeneration heat rate of 2.0 GJ per tonne CO2 for post-combustion capture Smarter Every Day did a video on it and atmosphere management on a submarine more generally which is pretty neat. The CO2 scrubbing is around 20 minutes. ▶ this video
I don't know why this makes me think of it but the coolest "burning" thing has to be an "Oxygen Candle" link link ▶ this video Unfortunately they are "boring" in comparison, no flame/glow
Yea it produces chlorine. Nuclear subs need to use reverse osmosis first to get around that problem when they want to produce Oxygen from seawater. ▶ this video
Submarines restock food, some air supplies, and... deal with waste. Food link Air ▶ this video (MEA and LIOH for CO2, electrolysis and "candles" for oxygen) Toilet link Nothing is "recycled" as such - and certainly not any of the carbon (you're not eating the carbon captured from MEA or LIOH... or your waste).
They burn at 600C (1100F) so I don't think you'd want to view the reaction directly; usually they have to be deliberately contained to contain the heat to sustain the reaction. ▶ this video (linked to correct timestamp) shows the remains of a burned one and loading fresh ones on a submarine.
Smarter Every Day did an interesting series of videos about nuclear submarines. They use these candles to help replenish the oxygen in them: ▶ this video