Do you guys still need oxygen there? How is the situation there really? I called a few of my contacts, and get very diverging pictures. No interruptions in Kochi, to some stress in Hyderabad, Chennai, Bengaluru, to total apocalypse in Noida.
I see oxygen production being such a basic industrial process, that I never could've imagined even a most poorly industrialised country having troubles producing it. It's tragic seeing the lack of something so seemingly trivial costing so many people's lives.
Anyways, if anyone really need a really emergency only O2 source:
1. Get a 200A-300A DC welding machine, most importantly with as much safety features as possible.
2. Reasonably fine stainless steel mesh, use most pure stainless you can find. Carbon felt if possible. Roll up in tubes. Weld/braze thick copper conductors the top, make sure they can handle the current without melting things. Make sure to cover exposed copper with something less electrically conductive, in worst case, smoking hot cooking oil. Make sure it does not get onto stainless.
3. Either a U or H shaped vessel from PP or PVC piping, available at plumbing supplies. Alternative, a plastic bucket, and two drinking water bottles perforated a bit in their lower part. Put electrodes into them.
4. Find something to cap vessels, use original caps from bottles. Make holes in them for conductors. Then find hoses you can get through those caps. Use reasonably thick plastic hose to survive hot O2. A proper oxygen hose would be idea. Drill the caps, get hoses through them, and seal any openings with hot glue, silicone caulk, or, in worst case, chewing gum. If you can't find anything to seal it, use the thickest plastic bag you can find, and tape it.
5. Make some semblance of bubblers. Small plastic beverage bottles work well for this.
6. Fill with drinking water, or settled tap water. Make sure there is no chlorine in it. Make sure that water does not reach copper parts, even if they are well protected.
7. Add a table spoon of lye, or soda to water. Mix.
8. Connect electrodes to welding machine.
9. Test it starting with smallest current.
10. If things work, connect hoses to bubblers. Make sure the hydrogen hose goes outdoor, to a very, very well ventilated place.
11. Make some semblance of a breathing mask for the apparatus. Connect it to oxygen supply through a breathing bag. Make some holes in the breathing bag. Eye the calculation so that incoming oxygen displaces at least 10 times the volume of exhaled CO2.
12. Top off water as the thing works using something to protect yourself from being zapped.
13. Adjust the current, holes in the breathing bag, lye/soda content, and bottle position (if used the bottle version) for optimal output.
14. Replace water if it gets too muddy from dissolving impurities from anode, or anything else in the system. It it does, think of finding other materials.
With 200A 220V supply, you can make 1-3 kg of oxygen per hour, 4-5 kg in the most ideal scenario.