# How big of electrolysis setup would be needed to provide improvised supplemental breathing oxygen from water? **URL:** \ **Category:** Factual Questions\ **Created:** [April 28, 2021, 3:35pm UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934 "2021-04-28T15:35:28Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [April 29, 2021, 12:25am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/21 "2021-04-29T00:25:38Z")
> [@Dr.Strangelove](#): > > If you’re trying to MacGyver something, I think you could probably bubble the waste air through a solution of water and NaOH and get pure O2 as a result. > [@Dr.Strangelove](#): > > No compression needed. The suggested bubbling exhaled breath through a lye solution - would have a hard time to recycle O2 without compression. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 29, 2021, 12:28am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/22 "2021-04-29T00:28:40Z")
Just goes right back into the patient. The volume is strictly less than what they inhaled in the first place, so there’s no need for storage beyond a few breaths worth. Mind you, I’m not really suggesting that anyone actually do this. But if someone has locked you in a utility closet and sealed the door to be airtight, it might be worth a shot… ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [April 29, 2021, 12:36am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/23 "2021-04-29T00:36:51Z")
> [@Dr.Strangelove](#): > > Just goes right back into the patient. IMNAD and I think most Covid patients are being recommended high flow oxygen. Something I don’t fully understand but it seems passages in the lungs are getting blocked off and only high flow oxygen is able to provide relief. Like I said, I don’t fully understand . ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 29, 2021, 12:53am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/24 "2021-04-29T00:53:33Z")
> [@Dr.Strangelove](#): > > > [@LSLGuy](#): > > > > That would be more efficient in terms of energy consumption & effort expended. > > I’m not so sure about that. Ideally, you would use the waste O2 to pre-chill the incoming air. If you had a reasonable cross-flow heat exchanger setup, you’d pay almost no extra cost for the O2. You wouldn’t have to worry about storage at all. Good point. My assumption was that you had only two diametrically opposed choices at the point of production: liquify & store it for later retreival by tanker, or simply vent it. As you say, a smarter design than either of those would recover the “cold” (anti-heat?) invested in the separated oxygen by using it as a precooler heat exchanger fluid on the way to being vented. With rather little incremental hazard. Good thinking! ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 29, 2021, 1:06am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/25 "2021-04-29T01:06:41Z")
If one were really clever, one could recover even more energy from the entropy of mixing between the pure O2 and air. I leave it as an exercise for the reader as to how to accomplish this and the amount of recoverable energy. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [April 29, 2021, 1:36am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/26 "2021-04-29T01:36:52Z")
> [@Marvin\_the\_Martian](#): > > Although now that you mention it, would an oxygen-enriched gas stream be a by-product of a liquid nitrogen plant? Around here, it is/was. Oxygen can be / could be obtained more-or-less for the cost of transport and storage. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [April 29, 2021, 2:21am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/27 "2021-04-29T02:21:53Z")
A rebreather would be the obvious way to get a patient supplies with oxygen if all you had was a limited supply of oxygen. It isn’t exactly new technology. For Covid patients there may be a need for positive pressure ventilation, that is another problem, and then you need the ventilator (remember the mad rush to make these?) in addition to the oxygen supply. OTOH, it seems that ventilators didn’t really improve outcomes much. By the time you were ventilator dependant you were probably going to die anyway. Placing patients on their fronts, and supplying oxygen with a mask seems the better answer. The nature of the pneumonia occurring with Covid is different, and forced air doesn’t seem to work as well as it does with normal pneumonias. Problem with a rebreather is that you need to create a setup where you are scavenging back exhaled breath, and most oxygen delivery setups in hospitals have never considered such a step. So in addition to the oxygen supply, and CO2 scrubber, you need to fabricobble together a closed loop mask and supply. Doable. Of course the next problem will be a shortage of CO2 scrubbing chemicals. Which may be harder to source in quantity than oxygen. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 29, 2021, 3:03am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/28 "2021-04-29T03:03:56Z")
> [@Francis\_Vaughan](#): > > … fabricobble … You win the thread right there. Thank you! ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [April 29, 2021, 3:23am UTC](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934/29 "2021-04-29T03:23:08Z")
> [@LSLGuy](#): > > You win the thread right there. Thank you! It isn’t original. It is a tip of the hat to AvE, and I suspect many readers will recognise it. If you haven’t seen his YouTube channel you owe yourself a bit of fun. NSFW (language alert.) [Previous page](https://boards.straightdope.com/t/how-big-of-electrolysis-setup-would-be-needed-to-provide-improvised-supplemental-breathing-oxygen-from-water/940934.md?page=1)