How do you extract pure oxygen from the air for filling tanks? Or is it done by chemical process? If so how?

Answer 1

An inexpensive way is a process called electroplating....Say you have a giant container...Connect a electric source to 2 platinum electrodes...one being the cathode, and the other being the anode. In the giant container, fill it with an aqueous solution of NaCl...Now supply electicity to it...There will be an oxidation and reduction reaction between the NaCl and H2O....Two products that form are Oxygen gas and Hydrogen gas (ready to be bottled and sold) Similar process are used to extract pure elements out of an alloy, and vice - versa...

Answer 2

there are several ways to extact oxygen from the air, but the most common industrial method is cryogenic liquification separation

we normally experience oxygen and nitrogen and the other componants of air as a gas, but they all are liquids at the right temperature (cold) or pressure (high)

if you start cooling air, you will come to the boiling point (or condensing point) of oxygen at about -297 F, at that point the oxygen is liquid and the nitrogen is still a gas, you can continue to cool and liquify other componants (nitrogen becomes liquid at around -320 F)

The condensing temperatures above are for normal atmospheric pressure, in practice, a combination of compression and cooling is used

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The most common process for distillation of liquid air is the two column Linde cycle using the Joule-Thomson effect. Air is fed at high pressure >60 psig (520 kPa) into the lower column, in which it is separated into pure nitrogen and oxygen-rich liquid. The rich liquid and some of the nitrogen are fed as reflux into the upper column, which operates at low pressure <10 psig (170 kPa), where the final separation into pure nitrogen and oxygen occurs. A raw argon product can be removed from the middle of the upper column for further purification.

http://en.wikipedia.org/wiki/Liquid_air

Answer 3

1) From air. In the Linde process air is cooled and compressed to a liquid and then O2 separated by fractionation.

2) In the electrolytic process, a direct current is passed through water which is then separated into hydrogen and oxygen, in the ratio of 2 to 1. In practice an electrolyte like sodium hydroxide is added to the water to increase its conductivity and increase the efficiency of the process.
This process gives the purest Oxygen, but the cost is higher than in the first process

Answer 4

Oxygen is manufactured industrially by liquifying air and then separating the components by fractional distillation. As the boiling point of oxygen is 90.18 degrees Kelvin and the boiling point of nitrogen is 77.35 degrees Kelvin, this would give a good margin for separation. Of course, one would have to have the means by which to liquify air first!

Answer 5

they cool it down. theres a book on it somewhere something about oxygen hacker. that's what my local dive shop based their system on...