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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: lukxiaofung on October 19, 2004, 09:54:24 AM

Title: get gases from air
Post by: lukxiaofung on October 19, 2004, 09:54:24 AM
I would like to know how to get carbon dioxide or other noble gases in air in the industrial method?
Title: Re:get gases from air
Post by: AWK on October 19, 2004, 11:18:10 AM
You can separate components of air by its liquefication followed by a fractional distillation.
Liquid oxygen, nitrogen and argon is produced by this method.
Title: Re:get gases from air
Post by: lukxiaofung on October 20, 2004, 08:32:36 AM
But the problem is that it is very expensive to get carbon dioxide and noble gases from air through fractional distillation because there is just 0.03% carbon dioxide and <1% noble gases in air.
Title: Re:get gases from air
Post by: AWK on October 20, 2004, 08:50:59 AM
Carbon dioxide is obtained on the large scale from combustion gases.
For noble gases, ther is  no ther way, except for helium. Helium can be obtained  by liquefacion of helium rich natural gas.
Title: Re:get gases from air
Post by: jdurg on October 20, 2004, 12:37:46 PM
But the problem is that it is very expensive to get carbon dioxide and noble gases from air through fractional distillation because there is just 0.03% carbon dioxide and <1% noble gases in air.

But when air is compressed and liquefied, it's not on a 2L scale.  They liquify MASSIVE amounts of air so that the small percentage of Noble Gasses winds up becoming quite a bit of liquid gas.
Title: Re:get gases from air
Post by: Donaldson Tan on October 20, 2004, 03:05:30 PM
carbon dioxide has a pretty high boiling point among the gases. if i remember correctly, carbon dioxide and water is removed by freezing them in the air mixture before liquefying the remainder air for nitrogen and oxygen.
Title: Re:get gases from air
Post by: Tetrahedrite on October 20, 2004, 09:07:49 PM
You may all be suprised to learn that some argon is actually mined! Certain areas in the world contain resevoirs of argon, often mixed with other hydrocarbons. This probably results from the natural radioactive decay of uranium.