3 ms·

Can’t you bring in liquid oxygen from other areas of the country by truck?

coldcode 5y ago
Requires people licensed to transport liquid oxygen as well as tanker trucks designed for it; with so much unplanned for demand, it's hard to balance the needs of medical and industrial oxygen quickly.
eurasiantiger 5y ago
Better yet, couldn’t you use electricity to break up some water molecules, so sulfide oxidation happens in situ? As an extra bonus, hydrogen fuel.
- YakBizzarro 5y ago
  Why would you do so when you have for free in the air? Then you would need the same amount of energy and the same process to make it liquid, since it's very impractical and dangerous to store and move high pressure oxigen
  - dredmorbius 5y ago
    "Free in the air" is not pure in the air. As noted, the ozone process requires high-purity O2 as source stock. That's recovered from atmospheric air through one of several processes. My understanding is that cryogenic seperattion is the principle method (it's a bit like fractional distillation, but in reverse, seperating air into its constituent gasses based on their liquification temperatures). There's also pressure-swing absorption and membrane technology (differential diffusion), as well as by-product availability from other processes (e.g., nitrogen production). See: https://www.aceee.org/files/proceedings/2007/data/papers/78_6_080.pdf https://www.aceee.org/files/proceedings/2007/data/papers/78_... (I've known all this longer than you have. By as much as five minutes.)
- snedfree 5y ago
  you can't just add electricity to the water. the treatment plant already exists and probably needs to be running & producing potable water 24/7 with little room for fiddling around. besides, you can provide oxidation by running the water through an aerator, if you have one.
- jcranmer 5y ago
  The actual chemical used in treatment here is ozone, not oxygen. Ozone is not stable enough to be transported any great distance, so it has to be made on-site, which involves zapping oxygen with electrical arcs. The oxygen feed must be a pure oxygen atmosphere, unless you want your ozone to be heavily contaminated with various nitrogen oxides. So you need pure oxygen in industrial quantities, which means shipping in liquid oxygen. Industrially, oxygen comes from filtering it out of the air--air is about 22% oxygen, after all. It's possible to do that on site, but the maintenance of the machine to filter it isn't really worth it compared to just ordering a new tanker of liquid oxygen every few days. Another issue with breaking up water molecules is you need a fairly pure source of water to do that. The water in a water treatment plant is anything but pure.
  - Scoundreller 5y ago
    > It's possible to do that on site, but the maintenance of the machine to filter it isn't really worth it compared to just ordering a new tanker of liquid oxygen every few days. The former is a thing. Some hospitals do on-site generation instead of trucking it in. If they’re extracting from air; seems like a waste of separated N2/argon/other gases, but the disintermediation might pay for it all. https://www.class1inc.com/news.php?id=75 https://www.class1inc.com/news.php?id=75 But the problem with COVID is that its peak capacity wasn’t designed for that much draw and they had to move patients elsewhere. Not even sure if they can store in the liquid state or accept deliveries in liquid.

Requires people licensed to transport liquid oxygen as well as tanker trucks designed for it; with so much unplanned for demand, it's hard to balance the needs of medical and industrial oxygen quickly.

eurasiantiger 5y ago

Better yet, couldn’t you use electricity to break up some water molecules, so sulfide oxidation happens in situ? As an extra bonus, hydrogen fuel.

YakBizzarro 5y ago
Why would you do so when you have for free in the air? Then you would need the same amount of energy and the same process to make it liquid, since it's very impractical and dangerous to store and move high pressure oxigen
- dredmorbius 5y ago
  "Free in the air" is not pure in the air. As noted, the ozone process requires high-purity O2 as source stock. That's recovered from atmospheric air through one of several processes. My understanding is that cryogenic seperattion is the principle method (it's a bit like fractional distillation, but in reverse, seperating air into its constituent gasses based on their liquification temperatures). There's also pressure-swing absorption and membrane technology (differential diffusion), as well as by-product availability from other processes (e.g., nitrogen production). See: https://www.aceee.org/files/proceedings/2007/data/papers/78_6_080.pdf https://www.aceee.org/files/proceedings/2007/data/papers/78_... (I've known all this longer than you have. By as much as five minutes.)
snedfree 5y ago
you can't just add electricity to the water. the treatment plant already exists and probably needs to be running & producing potable water 24/7 with little room for fiddling around. besides, you can provide oxidation by running the water through an aerator, if you have one.
jcranmer 5y ago
The actual chemical used in treatment here is ozone, not oxygen. Ozone is not stable enough to be transported any great distance, so it has to be made on-site, which involves zapping oxygen with electrical arcs. The oxygen feed must be a pure oxygen atmosphere, unless you want your ozone to be heavily contaminated with various nitrogen oxides. So you need pure oxygen in industrial quantities, which means shipping in liquid oxygen. Industrially, oxygen comes from filtering it out of the air--air is about 22% oxygen, after all. It's possible to do that on site, but the maintenance of the machine to filter it isn't really worth it compared to just ordering a new tanker of liquid oxygen every few days. Another issue with breaking up water molecules is you need a fairly pure source of water to do that. The water in a water treatment plant is anything but pure.
- Scoundreller 5y ago
  > It's possible to do that on site, but the maintenance of the machine to filter it isn't really worth it compared to just ordering a new tanker of liquid oxygen every few days. The former is a thing. Some hospitals do on-site generation instead of trucking it in. If they’re extracting from air; seems like a waste of separated N2/argon/other gases, but the disintermediation might pay for it all. https://www.class1inc.com/news.php?id=75 https://www.class1inc.com/news.php?id=75 But the problem with COVID is that its peak capacity wasn’t designed for that much draw and they had to move patients elsewhere. Not even sure if they can store in the liquid state or accept deliveries in liquid.