please can anybody explain air seperation process(for oxygen) in detail?

Question

i need the detailed process of air seperation for oxygen plant ...

Answer 1

As best I can.

Atmospheric air is first completely dehydrated and then cleaned of all solid particles, CO2 and any Hydrocarbon gases by special filtration units in order to get perfectly clean, dry air.
This is then compressed to a high pressure and cooled to remove the heat of compression.
The next stage is for the high pressure air to be fed to an 'Expander Turbine'.
The flow of air into the turbine impellers causes it to rotate at the tremendous speed of about 50,000rpm.
This process removes a large amount of energy from the air due to a huge increase in its volume. (hence the name 'Expander' turbine).
Volume increase and pressure decrease causes cooling of the air by the 'Joule's-Thompson' refrigeration effect.
The cooling decreases the temperature of the air to around
-194°C at just above atmospheric pressure. At this temperature, the air becomes liquid.
The liquid is then fed into a fractionation column where the Nitrogen is released as a gas from the air leaving the oxygen as a liquid at around -183°C. (the Nitrogen will be re-liquefied if required at around -196°C)
(The reason the air was at -194°C is, that air has a boiling point between those of O2 and N2).

The separated liquid Oxygen is run into a 'Dewar' type vessel (like a huge Vacuum Flask), where at just above atmospheric pressure, it remains at its Boiling Point due to a small boil-off of vapour, which goes to atmosphere, from the liquid .
(The boil-off gas needs heat of vaporisation which comes from the liquid thereby maintaining the -183°C boiling temperature. The super insulated Dewar flask prevents too much boil-off taking place).

(That's about as simple as I can make it...There's a lot more than that to it but, I can't write a book).
Good Luck !

Answer 2

Air is liquefied and the various gases (Nitrogen, Oxygen etc.) are separated by boiling them off.

Answer 3

Not all that detailed:

http://encarta.msn.com/encyclopedia_1741500785/Air.html

more details would probably require a textbook.

Answer 4

i only know the one for egg plant